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Al-Rubaee, Rasha Hassan. "A conceptual model to effectively prioritise recovery of roads damaged by natural/man-made disasters." Thesis, University of Birmingham, 2012. http://etheses.bham.ac.uk//id/eprint/3699/.
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After natural/man-made disasters, a major challenge faced by governments is to ensure a speedy recovery of roads and transportation networks. In order to achieve this, a new road recovery priority (RRP) model has been developed to identify key issues and their inter-relationships giving a better understanding of factors that govern prioritisation across the affected regions. Interviews are conducted with experts in road reconstruction and maintenance organisations to investigate respondents’ evaluation and understanding of the RRP model in terms of its ease of use, usefulness, comprehensiveness, applicability, feasibility and structure. A questionnaire survey is conducted to investigate the impact of the important proposed affecting factors that can be critical for successful implementation and application of the RRP model in the road rehabilitation sector. A field survey is carried out to collect data which are essential to determine parameters in the model’s application. Four case studies are carried out to investigate the RRP model’s application in a variety of road conditions. The application of this model may solve the problem of decision making in road recovery priority determination in a hierarchical manner so that the recovery process can be accomplished from an urgent repair need to a lower recovery priority.
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Karagania, Richard M. "Road roughness and infrastructure damage." Thesis, Queensland University of Technology, 1997. https://eprints.qut.edu.au/36011/1/36011_Karagania_1997.pdf.
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Scientific research has identified road roughness as a significant factor that
contributes to increased vehicle dynamic wheel loads and therefore damage to
pavements and bridges. The other factors include vehicle speed and vehicle
suspension type. More specifically and regarding road roughness, research has
shown that damaging effects are caused by certain wavelengths and features in road
profiles and not the overall road roughness. Various methods of classifying road
roughness based on the ride quality are available. These methods, though important,
are limited in identifying the location of features along road profiles that cause
exceptionally high dynamic wheel loads hence damage. It is the development of a
methodology for identifying the location of these abnormally high dynamic wheel
forces that this thesis addresses.
A vehicle-road interaction model was developed for this research. This computer
model uses a quarter vehicle model and recorded road profile elevation data to
simulate the response of half a vehicle axle (quarter vehicle) driving along a road. 47
road profiles over 17 bridges were measured to run the model.
Signal processing techniques developed by electrical and mechanical engineers have
been used as an additional tool to road profile analysis. These techniques are very
powerful and their application to road profile investigations is significant. Using
computer simulation and by combining ride and damage criteria analysis, a
methodology of identifying segments of road that induce high dynamic wheel forces
and the location of abnormally high dynamic wheel forces has been established.
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Gopallawa, Praveen. "Fatigue Failure Model for Local Roads in Ohio that Use Road User Maintenance Agreements Due to the Increase in Truck Traffic." Ohio University / OhioLINK, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1566389151107255.
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Zhang, Jizhe. "Moisture damage of aggregate-bitumen bonds." Thesis, University of Nottingham, 2016. http://eprints.nottingham.ac.uk/32725/.
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Moisture damage of the asphalt mixture is defined as the loss of strength, stiffness and durability due to the presence of moisture (in a liquid or vapour state) leading to adhesive failure at the aggregate-bitumen interface and/or the cohesive failure within the bitumen or bitumen-filler mastic. The presence of moisture can accelerate the distress of asphalt pavement in several different modes, such as rutting, fatigue cracking, thermal cracking and the formation of potholes. In the field, the moisture damage normally happens first at the interface of two pavement layers or at the bottom of pavement layers and develops gradually upward. Once moisture has come into contact and interacted with the asphalt mixture, moisture damage could be developed by the following mechanisms: detachment, displacement, spontaneous emulsification, pore pressure, and hydraulic scour. It should be mentioned that moisture damage is not limited to only one mechanism but is the result of a combination of several mechanisms. As mentioned previously, the common modes of moisture damage of asphalt mixtures are a loss of adhesion between the aggregate and bitumen and/or a loss of cohesion in the mixture. Among these two failures, the adhesive failure is recognised as the main mode of moisture damage. Hence, the physico-chemical interactions between aggregates and bitumen in the presence of moisture are believed to partially govern the moisture sensitivity of asphalt mixtures, which can also affect the serviceability, performance and durability of the asphalt pavement. This thesis describes the work that was carried out with regard to the moisture damage evaluation of aggregate-bitumen bonds through different procedures. The fundamental properties of the individual material such as the chemical composition and rheological properties of bitumen, moisture absorption, surface morphology and mineralogical composition of aggregates were first characterised. Two types of equipment, namely the dynamic contact angle (DCA) analyser and dynamic vapour sorption (DVS) system were used for determining the surface energy of the bitumen and aggregates, respectively. The obtained surface energy results were then combined thermodynamically to determine the work of adhesion between aggregate and bitumen, and the reduction in the adhesive properties if water is introduced into the system. Three established mechanical tests consisting of the standard peel test, Pneumatic Adhesion Tensile Testing Instrument (PATTI) test and a pull off test were developed and redesigned to make sure that these tests are practical, reliable and feasible to measure the bonding strength of aggregate-bitumen combined specimens. The composite substrate peel test (CSPT) was developed to prepare composite substrates using crushed coarse aggregates as a more practical replacement for the aggregate substrates prepared from aggregate boulders. Finally, the moisture damage results from mechanical tests and thermodynamic results were compared and correlated with the basic physico-chemical properties of the original materials. The results showed that in the dry condition, all techniques used in this research, including the mechanical tests and the surface energy tests led to similar results, with bitumen rather than aggregates dominating the bonding properties of aggregate-bitumen systems. After moisture conditioning, the four mechanical tests, including standard peel test, CSPT, PATTI test and pull-off test showed similar moisture sensitivity ranking and failure surface results demonstrating the good correlation between these four tests. In addition, based on the comparison conducted, the four mechanical tests are all considered to be reliable to evaluate the moisture sensitivity of different aggregate-bitumen systems. However, based on the aggregates considered in this research, the moisture sensitivity parameters obtained from the surface energy tests are suggested unreliable to evaluate the moisture sensitivity of aggregate-bitumen systems.
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Alzubaidi, Hossein. "On rating of gravel roads." Doctoral thesis, KTH, Infrastructure and Planning, 2001. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-3252.
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Cahoon, Lindsey Charlene. "Micro-CT Inspection of Impact Damage in Carbon/Epoxy Rods." BYU ScholarsArchive, 2016. https://scholarsarchive.byu.edu/etd/6350.
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Various configurations of unidirectional carbon/epoxy composite rods were impacted radially, inspected using micro-CT scanning equipment, and tested in axial compression to measure the residual strength after impact. This data was used to correlate the relationship between impact energy, residual strength, and the peak crack area and total crack volume along the length of the specimens. These specimens represent local members of open three-dimensional composite lattice structures (e.g., based on isogrid or IsoTruss® geometries) that are continuously fabricated using advanced three-dimensional braiding techniques. The specimens were radially impacted with 2.5 J (1.9 ft-lbs), 5.0 J (3.7 ft-lbs), 7.5 J (5.6 ft-lbs), 10 J (7.4 ft-lb), 15 J (11 ft-lbs), and 20 J (15 ft-lbs) of energy, and compared to undamaged control specimens. The unidirectional core specimens were 8 mm (5/16") in diameter and were consolidated with various sleeve configurations and materials. Sleeves differed in types (bi-directional braided sleeves or unidirectional spiral wraps), nominal sleeve coverage of the core fibers (full or half), and sleeve material (Nomex Thread or Dunstone Hi-Shrink Tape). The unsupported length of the specimens used in this research was 50.8 mm (2") to ensure a strength-controlled compression failure rather than a failure due to buckling. After impact, the specimens were scanned using a micro-CT scanner at resolutions of 50 and 35 microns and subsequently tested in axial compression. The micro-CT scan images were analyzed to measure the crack areas along the specimen. From this analysis, the peak crack area and total crack volume along the length of the specimen was calculated. Similar to past research, as the impact energy increases, the residual compression-strength-after-impact decreases. As the impact energy increases, specimens with shrink tape sleeves had the largest increase in peak crack area and overall crack volume while specimens with full spiral sleeves had the lowest increase in peak crack area and overall crack volume. A bimodal increase is evident in the peak crack area and total crack volume over the length of the specimen where specimens impacted at 15 J (11 ft-lbs) showed the highest peak crack area across all sleeve types. There is a slight correlation between the increase in peak crack area and overall crack volume and the decrease in residual compression strength after impact. Shrink Tape, while yielding a higher quality specimen with greater compression strength prior to impact, did not protect the specimens against damage due to impact as well as other sleeve types. This was shown by the large decrease in residual compression strength after impact and increase in peak crack area and overall crack volume as the impact energy increased.
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Hardy, Michael Stuart Anthony. "The response of flexible pavements to dynamic tyre forces." Thesis, University of Cambridge, 1990. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.385406.
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Cole, David James. "Measurement and analysis of dynamic tyre forces generated by lorries." Thesis, University of Cambridge, 1990. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.334095.
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Gonzales, Elkin, and Kevin Lundberg. "Vägskador av tung trafik : Upplåtande av vägnätet för 74-tons lastbilar." Thesis, KTH, Byggteknik och design, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-189558.
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Näringslivet efterfrågar ett införande av 74 tons lastbilar på det statliga vägnätet. Det finns ett flertal fördelar med att höja maximala bruttovikten från nuvarande 64 till 74 ton. Däremot är höga bruttovikter direkt kopplade till bärighetsrelaterade skador. Syftet med denna studie är att ligga till grund för vidare arbete av Trafikverket. Detta för att uppnå bättre kontroll på hela det statliga vägnätet och den tunga trafikens inverkan. Studien har utgått från observationer i PMSv3, ett webbaserat system med grafiska tvärprofiler baserade på vägytemätning samt information om det statliga belagda vägnätet. Observationerna innefattar mönsteridentifiering av återkommande tvärprofilstyper tillskrivna skador av den tunga trafiken. Resultatet av tvärprofilstyperna har sedan analyserats och beskrivits som representativa spårtyper för det statliga vägnätet. Slutsatsen är att det finns indikation på mönster av spårtyper. Utifrån observationerna i PMSv3 har spårtyperna formulerats som hypoteser för vidare forskning.The wood industry asks for an imposition of 74-ton trucks on the national road system. There are several advantages of increasing the maximum gross weight from 64 to 74 tons. On the other hand, high gross weights are directly connected to structural road damage. The purpose of this study is to serve as foundation for further research by the Swedish transport administration. The ulterior goal is to reach better control on the national road system. The basis of the study is a web-based system - PMSv3, which contain road information and transverse road profiles. The observations in PMSv3 have led to rut-types ascribed due to heavy gross weights. The conclusion is that rut-patterns indications exist. Based on the observations in PMSv3, the rut-types have been formulated as hypothesis for further research.
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Tsampardoukas, Georgios. "Semi-active control algorithms to reduce road damage caused by heavy articulated vehicles." Thesis, University of Bath, 2007. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.443124.
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Kitching, Kevin John. "Semi-active damping of heavy vehicles." Thesis, University of Cambridge, 1997. https://www.repository.cam.ac.uk/handle/1810/265419.
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This thesis is concerned with the use of semi-active suspensions in heavy vehicles to improve ride and reduce road damage. An introduction into the subject is given in chapter 1 and a review of the relevant literature is presented at the beginning of each main chapter. The development and modelling of a prototype, continuously variable semi-active damper for heavy vehicles is described in chapter 2. A proportional valve is used to generate the variable damping coefficient and the detrimental effects of the oil flow forces acting on the valve spool are studied. The force tracking performance of the damper is then examined for simple input conditions and the compliance of the hydraulic fluid is found to have a strong influence upon the response of the damper. The different vehicle and road models used in the thesis are described in chapter 3. In chapter 4, the performance of the prototype damper is investigated under realistic operating condition using a Hardware-in-the-Loop (HiL) test rig, with a single wheel station vehicle model. The prototype damper displays a phase lag of approximately 20ms between the demanded and achieved damping force. The semi-active suspension is found to be most effective in reducing the body accelerations relative to an optimum non-linear passive suspension. A theoretical investigation into the reduction of road damage through the use of active and semi-active suspensions is described in chapter 5. The relative performance of four linear state feedback control strategies is examined. The potential for reducing road damage by using a controller which directly regulates various measures of road damage is also studied. Significant improvements are predicted for the three controllers which assume the road inputs to the vehicle are correlated. However, these benefits are shown to diminish as the vehicle speed is reduced. It is concluded that the control of the dynamic tyre forces is an effective means by which to regulate road damage. Theoretical predictions of the benefits from wheelbase preview control are measured experimentally in chapter 6, using the prototype semi-active damper in a half-car HiL rig with a planar two axled heavy vehicle model. The benefits of preview control using the prototype semi-active damper are found to be less than theoretically possible due to the phase lag between the demanded and achieved damping force of the prototype damper. The final section of chapter 6 shows that the performance of the prototype damper can be improved further by having a theoretical simulation running ahead of the HiL vehicle. The theoretical simulation is used to predict the demanded damper force for the HiL vehicle and thereby compensate for the phase lag in the prototype damper. Conclusions and recommendations for further work are presented in chapter 7.
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Altmann, Craig Tyler. "Identification and Characterization of Damaging Road Events." Diss., Virginia Tech, 2020. http://hdl.handle.net/10919/98844.
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In the field of vehicle durability, many individuals are focusing on methods for better replicating the durability a user will experience throughout the typical design lifespan of a vehicle (e.g., 100,000 miles). To estimate user durability a means of understand the types of damaging events and driving styles of uses must be understood. The difficulty with accurately estimating customer usage is, firstly, there is a large pool of possible roads for a user to drive along, for example, there are over 4 million miles of public roads in the United States, alone [1]. In addition, while measurements of these surfaces could be collected it would be impractical for two reasons, the first is the financial and extreme time burden this would take. Second, when collecting measurements of a road surface only the current state of a road surface can be measured, thus as a road deteriorates or is repaved the measurements collected would no longer be an accurate representation of the road. It should be mentioned that even, if all of the road surfaces were measured performing simulation and analysis of all of these road surfaces would be computationally intensive. Instead, it would be beneficial if select events that account for a significant portion of the damage a vehicle experiences can be identified. These damaging events could then be used in more complex vehicle simulation models and as input and validation of proving ground and laboratory durability testing. The objective of this research is to provide a means for improved estimation of vehicle durability, specifically a means for identifying, characterizing, and grouping unique separable damaging events from a road profile measurement.
In order to achieve this objective a measure that can be used to identify separate damaging events from a road profile is developed. This measure is defined as Localized Pseudo Damage (LPD), which identifies the amount of damage each individual road excitation makes to the total accumulated damage for a single load path in a vehicle system. LPD is defined as a damage density to minimize the effect of measurement spacing on the resulting metric. The developed LPD measure is causal in that the value of LPD at a location is not affected by any future locations. In addition, for a singular event (e.g., impulse or step) in the absences of other excitations, the LPD value at the singular event location is equivalent to the total pseudo damage divided by the step size at the location.
Once a measure of pseudo damage density is known at multiple locations along a road profile for multiple load paths of interest, then separable damaging events can be identified. To identify separable damaging events the activity of the vehicle system must be considered because separate damaging events can only occur when a region of inactivity is present across all load paths. Subsequently, an optimization problem is formed to determine the optimal active regions to maintain. The cost function associated with the optimization problem is defined to minimize the cost (number of locations maintained in damaging events) and maximize the benefit (the amount of pseudo damage maintained).
Lastly, a statistical test is developed to assess if separate damaging events can be considered to be from the same general class of events based on their damage characteristics. The developed assessment methods establish the similarity between two more separable damaging events based on application specific user defined inputs. In the development, two example similarity metrics are defined. The first similarity metric is in terms of distance and the second is in terms of likelihood (probability). The developed statistical analysis uses the current state-of-the-art in clustering algorithms to allow for multiple damaging events to be identified and grouped together.Doctor of Philosophy
In the automotive field determining the level of damage a typical production vehicle experiences over its lifetime has always been a desirable criterion to identify. This criterion is commonly referred to as customer usage. By understanding the typical customer usage of a vehicle over the lifetime of a vehicle, automotive engineers are able to improve the design of vehicle components. The issue with defining customer usage is that there are millions of miles of roads that a customer can travel on and millions of customers that all have unique driving characteristics. While it is possible to collect measurements of these road surfaces to use in further vehicle simulations, it is not feasible both from a financial and time perspective. In addition, the simulation and analysis of all road surfaces would be computationally intensive. However, if select damaging events (regions of the road surface that excessively contribute to accumulated damage) are identified, then they can be used in more complex vehicle durability analyses with lower computational efforts. In conventional damage analysis a total amount of accumulated damage is established for a known road surface. The issue with defining damage this way is that unique events which likely contributed a large amount of the accumulated damage cannot be identified. The first objective of this research is to define damage as a function of the vehicle's location along a road surface. Then, unique and separable damaging events can be identified and separated from sections of the road that do not significantly contribute to the accumulated damage. After defining this measure, an optimization problem is developed to identify damaging events based on maximizing the benefit (amount of damage accounted for in damaging events) and minimizing the cost (amount of road surface retained). Unique and separable damaging events are identified by solving this optimization problem. While the optimization problem identifies unique, separable damaging events, it is likely that some damaging events contain similar characteristics to each other. When performing additional durability analysis, it would be beneficial to form connections between similar damaging events to allow for analysis to be performed based on groups of events. To identify damaging events with similar characteristics, a statistical analysis is developed as the last contribution of this work. By combining this analysis with current state-of-the-art clustering algorithms and user provided definitions based on applications, similar damaging events are able to be grouped together.
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Karim, Hawzheen. "Improved Road Design for Future Maintenance - Analysis of Road Barrier Repair Costs." Licentiate thesis, Stockholm : Division of Highway Engineering, Royal Institute of Technology, 2008. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-9260.
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West, Patience J. "Land rehabilitation of construction damaged parcel at Santa Fe Road and Hoover Avenue in San Luis Obispo, California." Click here to view, 2009. http://digitalcommons.calpoly.edu/erscsp/4/.
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Thesis (B.S.)--California Polytechnic State University, 2009.Project advisor: Lynn E. Moody. Title from PDF title page; viewed on Feb. 2, 2010. Includes bibliographical references. Also available on microfiche.
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Dodoo, Nii Amoo. "A new approach for allocating pavement damage between heavy goods vehicles for road-user charging." Thesis, University of Newcastle Upon Tyne, 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.430344.
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Suntharavadivel, Thuraichamy Guganesan. "Behaviour of shear damaged reinforced concrete beams strengthened with external post-tensioning and clamping." University of Southern Queensland, Faculty of Engineering and Surveying, 2008. http://eprints.usq.edu.au/archive/00006254/.
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[Abstract]Over the last few decades, there has been a rapid increase in the volume and weight of heavy vehicles using national road networks. More than half of the bridges around the world are over forty years old. The deterioration of these existing bridges due to increased traffic loading, progressive structural aging, and reinforcement corrosion from severe environmental conditions has become a major problem in most countries. Several techniques have been used to strengthen these structures around the world. External post-tensioning is one of the widely used strengthening techniques in many countries due to its advantages over other methods. Furthermore, flexural strengthening using external post-tensioning has become a well established technique over the past few decades. However, when external post-tensioning is used to strengthen shear damaged reinforced concrete members, unlike flexural damage, the efficiency is significantly reduced by existing shear cracks.This research study was carried out to investigate the behaviour of reinforced concrete beams with existing shear cracks when strengthened by external means. The study consists of two parts: experimental investigations of reinforced concrete beams with different parameters and numerical analysis of reinforced concrete beams usingsimplified theoretical formulation and finite element modelling.To study the behaviour of shear damaged concrete beams, two different strengthening techniques, namely external post-tensioning and external clamping, were used. In addition to the strengthening, the effect of cracks on the behaviour of reinforced concrete beams was investigated by repairing such cracks using epoxy resin injection. Experimental results showed that existing shear cracks have a substantial effect on the member capacity when strengthened by external posttensioning. Although there are concerns about the practical applications of externalclamping, the experimental results suggest that external clamping could be a more effective technique than external post-tensioning to reduce the effect of existing shear cracks on the behaviour of concrete beams. Furthermore, proper repair of the shear cracks could significantly reduce their impact.In the numerical analysis, a simplified mathematical approach was developed to estimate the capacity of shear damaged reinforced concrete beam by expanding themodified compression field theory (MCFT). In addition to the simplified theoretical formulation, a finite element model was developed using the commercial finite element package, Abaqus. Comparison between the predicted behaviour using finite element analysis (FEA) and the experimental data illustrated that the developed finite element model could be used as a reliable tool to estimate the capacity of shear damaged reinforced concrete beams. A parametric study was conducted to investigate the effect of different parameters such as concrete strength, amount of shear reinforcement and crack width, using the developed finite element model. From the numerical study, it was concluded that the simplified approach developedin this study can be used as a reliable and conservative technique to predict the member capacity of a cracked reinforced concrete beam strengthened by external means. Furthermore, the parametric study showed that crack width is the most sensitive parameter that affects the capacity of a cracked beam strengthened by external post-tensioning.Based on this research study it can be concluded that existing shear cracks have a substantial effect on the behaviour of reinforced concrete beams strengthened byexternal post-tensioning. The simplified mathematical approach developed in this study can be used to estimate the capacity of such beams.
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Chan, Ying Chuen (Maple). "Truck overloading study in developing countries and strategies to minimize its impact." Thesis, Queensland University of Technology, 2008. https://eprints.qut.edu.au/28561/1/Ying_Chan_Thesis.pdf.
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Overloading truck traffic is an untenable problem around the world. The occurrence of overloaded truck traffic can be evidence of rapid development of an economy. Most of the developing countries emphasize the development of economy, thus supporting reform of infrastructure is limited. This research investigates the relationship between truck overloading and the condition of road damage. The objective of this research is to determine the amount of economic loss due to overloaded truck traffic is. Axle load will be used to calculate the total ESAL to pavement. This study intends to provide perspective on the relationship between change in axle load due to overloading and the resultant service life of pavement. It can then be used in the estimation of pavement damage in other developing countries facing the problem of truck overloading. In conclusion, economical loss was found, which include reduction of pavement life and increase in maintenance and rehabilitation (M&R) cost. As a result, net present value (NPV) of pavement investment with overloading truck traffic is higher than normal truck traffic.
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Chan, Ying Chuen (Maple). "Truck overloading study in developing countries and strategies to minimize its impact." Queensland University of Technology, 2008. http://eprints.qut.edu.au/28561/.
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Overloading truck traffic is an untenable problem around the world. The occurrence of overloaded truck traffic can be evidence of rapid development of an economy. Most of the developing countries emphasize the development of economy, thus supporting reform of infrastructure is limited. This research investigates the relationship between truck overloading and the condition of road damage. The objective of this research is to determine the amount of economic loss due to overloaded truck traffic is. Axle load will be used to calculate the total ESAL to pavement. This study intends to provide perspective on the relationship between change in axle load due to overloading and the resultant service life of pavement. It can then be used in the estimation of pavement damage in other developing countries facing the problem of truck overloading. In conclusion, economical loss was found, which include reduction of pavement life and increase in maintenance and rehabilitation (M&R) cost. As a result, net present value (NPV) of pavement investment with overloading truck traffic is higher than normal truck traffic.
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Ballew, Wesley D. "Taylor Impact Test and Penetration of Reinforced Concrete Targets by Cylindrical Composite Rods." Thesis, Virginia Tech, 2004. http://hdl.handle.net/10919/34098.
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We use the three-dimensional finite element code DYNA3D to analyze two problems: (a) the normal impact of a cylindrical monolithic or composite rod against a smooth flat rigid target, (commonly known as the Taylor impact test), and (b) the penetration of composite and monolithic steel cylindrical rods into reinforced concrete targets. The composite rod is made of either a steel or copper shell enclosing a ceramic. The ceramic and the steel are assumed to fail at a critical value of the effective plastic strain, whereas no failure is considered in the copper. The thermoviscoplastic response of steel and copper is modeled by the Johnson-Cook relation and the ceramic and concrete are assumed to be elastic-plastic. Values of material parameters in the constitutive relation for the reinforced concrete (RC) are derived by the rule of mixtures. Failure of a material is simulated by the element erosion technique for ceramic and steel, and element erosion along with stiffness reduction for the RC. The effect of the angle of obliquity of impact on the damage induced in the target is ascertained.
For the solid cylindrical copper rod impacting a smooth flat rigid target, the time history of the deformed length and the axial variation of the final diameter are found to match well with the experimental findings. For the composite rod, the diameter of the deformed impacted surface, the shape and size of the mushroomed region and the volume fraction of the failed ceramic material strongly depend upon the impact speed, the shell wall thickness and the thickness of the solid copper rod at the front end.
Some composite cylindrical rods impacting at normal incidence RC targets were found to buckle during the penetration process in the sense that their outer diameter at a cross-section close to the impacted end increased by at least 20%. For steel penetrators, the damage experienced increased as the nose shape got blunter and the angle of obliquity became larger whereas the damage induced to the target only increased with penetrator bluntness.
Master of Science
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Crosby, Charles L. "Energy Dissipation Caused by Asphalt Roadway Gouges for Use in Accident Reconstruction." BYU ScholarsArchive, 2009. https://scholarsarchive.byu.edu/etd/1983.
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In reconstruction of on-roadway vehicle accidents, roadway surface gouges and the forces and energy attributed to the related vehicle components become important keys to resolving an accurate accident reconstruction. These roadway gouge forces vary depending upon such factors as surface temperature and the velocity and geometry of the gouging mechanism. Accounting for the forces applied to vehicle components and the energy dissipated from such forces can be helpful in accident reconstruction where supporting data exists. This research documents the force necessary to create a given roadway gouge geometry. Controlled pavement gouging tests were performed using roadway surface temperature and gouging velocity as main factors. The results of this testing and analysis are useful in quantifying gouge forces and energies for use in accident reconstruction. The findings show that the temperature of the roadway surface that is being damaged significantly affects the amount of force required to cause the damage. A summary of experiments and techniques as applied to accident reconstruction are presented.
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Barzngy, Ahmad, and Majid Zangana. "Beläggningsskadors typ, omfattning och orsaker på statliga vägnätet." Thesis, KTH, Byggteknik och design, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-215216.
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Trafikverket genomför i dagsläget ett större projekt där undersökningar och analyser utav vägskador på statliga vägar utförs. Syftet med projektet är att långsiktigt förbättra möjligheterna att mäta vägnätet, försöka ta fram mätvärden som kopplar orsaken till skadornas uppkomst och varför vald underhållsåtgärd genomförs. Målet med denna studie är att med hjälp av en omfattande insamlingsfas i PMSv3, som lagrar data utifrån vägytemätningar, att kunna analysera olika typer av vägskador och dess olika egenskaper. Indata har sedan jämförts med Trafikverkets krav på underhållsstandard. Resultatet av datainsamlingen har sedan analyserats och samband mellan visuell skada och mätdata från PMSv3 har observerats. Nyttan med sambanden som har iakttagits leder till bättre förståelse om vilka huvudfaktorer som påverkar vägens nedbrytning och var dem vanligen förekommer. Totalt har 19 av 67 vägsträckor valts ut från datainsamlingen att redovisa och analysera. Det finns indikationer på sambanden utifrån resultatet som är redovisade i analysen och slutsatsen. Med hänsyn till observationerna i PMSv3 ligger denna studie för vidare fördjupning och forskning.The transport administration currently performs a research project where they conduct investigations and analysis of road damage on state road. The purpose of the project is to in the long-term improve the possibilities to measure the road network, try to find the readings that connect the cause for the accidents and why the chosen maintenance is conducted. The aim of this study is to, with the help of an extensive collection phase in PMSv3, that stores data by road surface measurement, to be able to analyse different type of road damages and ther characteristics. Input has then been compared to the transport administrations requirement on maintenance standard. The results of the data collection has then been analysed and conection between visual damage and data from PMSv3 has been observed. The usefulness of the connections that have been observed lead to better understandnings on what main factors that affect the roads breaking down and where they frequently occur. There are indications of connections from the results that have been demostrated in the analysis and the conclusion. With consideration to the observations in PMSv3 lies this study for further depth and research.
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Berka, Jan. "Analýza poškození vozidel při střetech se silničními svodidly." Master's thesis, Vysoké učení technické v Brně. Ústav soudního inženýrství, 2016. http://www.nusl.cz/ntk/nusl-241251.
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The theme of this thesis is the analysis of vehicle damage, which was caused by a collision with road safety barriers. The theoretical part describes the guardrail, their classification, structure, process design and methods of their testing, including criteria that must be met. Furthermore, the theoretical part describes the safety of vehicles in relation to the body structure and its material composition. The last chapter in this section is focused on the process of insurance companies in solving their clients' loss events. The second (practical) part is focused on defining the criteria that are important for the determination of certain facts in question accident. These criteria were drawn up based on the requirements of insurance companies while they were processed catalog. This catalog is the result of the work, which describes the happening of insured events, their assessment according to predefined criteria and estimate, if it is a plot manipulated insured or not. It can also be beneficial to insurance companies, which can be used as an aid in dealing with loss events.
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Blomqvist, Göran. "De-icing salt and the roadside environment : Air-borne exposure, damage to Norway spruce and system monitoring." Doctoral thesis, KTH, Civil and Environmental Engineering, 2001. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-3140.
Full textAbstract:
After decades of investigation, we still have to deal withthe problem of environmental effects of the use of de-icingsalt on roads. Lacking useful indicators of the system, westill do not know the environmental utility of ameliorativemeasures taken. The thesis aims at
i) describing the system of de-icing practices and theirenvironmental effects with special reference to the exposure ofthe roadside environment to air-borne salt and damage to Norwayspruce seedlings and ii) at proposing indicators for afollow-up system. By collecting bulk deposition and relatingthe deposition pattern to factors concerning wind androad-maintenance characteristics, the influence of thesefactors on air-borne exposure is investigated. By exposingNorway spruce (Picea abies(L.) Karst.) seedlings to roadsideconditions the influence ofsalt exposure on the degree ofdamage is investigated. Based on a comparison of severalsystems of monitoring, improvements are suggested by proposingnew indicators for salt use and its environmental effects.
A large part of the salt that is applied on the road surfacewill be transported by air and deposited on the ground in theroadside. While the vast majority of the salt will be depositedwithin some tens of metres of the road, some may still be windtransported several hundred metres away. The wind directionplays an important role for the deposition already at adistance of some ten metres from the road. Wind speedinfluences the distance to which the salt is transported.Chloride concentration in unwashed needles collected after thesalting season is positively related to the bulk deposition ofCl during the exposure. The degree of damage can be describedby a sigmoid curve of response to the Cl concentration inneedles. Improvements to the follow-up system are suggested byproposing indicators of the driving forces, pressures, states,impacts and possible responses as regards the undesired impactson water resources, vegetation and the roadside scenery as asocietal asset.
Keywords:road, de-icing salt, air-borne, environmentalimpact, vegetation damage, Norway spruce, seedling, follow-up,monitoring, indicator
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Oxborrow, Ian Michael. "Axial Compression Behavior of Unidirectional Carbon/Epoxy Tubes and Rods Before and After Impact." BYU ScholarsArchive, 2014. https://scholarsarchive.byu.edu/etd/5549.
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Compression tests were performed on damaged and undamaged rods and tubes made from unidirectional carbon/epoxy composite and lightweight core materials. Tested samples represent local members in an open, three-dimensional, composite lattice structure. Testing was performed in order to establish effective core materials to use in order to increase the buckling length of local IsoTruss® members while maintaining low weight. Members were formed from T700SC-12K-50C carbon fiber with UF6639-100 resin. Core materials consisted of 3/8-inch (0.953 cm) outside diameter Teflon® rods, Teflon® tubes, nylon rods, nylon tubes, Ertalyte® rods, and Duratron® rods. All 3/8-inch (0.953-cm) cores were each surrounded by 50 tows of carbon/epoxy prepreg. Control samples were also created with 50 carbon/epoxy prepreg tows. Half-inch (1.27 cm) outside diameter copper tubes were used as core materials for tubes consisting of 100 carbon/epoxy prepreg tows. Control samples to compare against samples with copper cores were also created with 100 tows of carbon/epoxy prepreg. Impact damage was inflicted using a cylindrical tup with 20 ft-lb impact energy.In undamaged specimens, nylon tube showed the highest structural efficiency. Nylon showed structural efficiencies much higher than other materials when comparing undamaged samples. In damaged specimens Ertalyte® rods showed the highest structural efficiency. Core stiffness appeared to control the level of absorbed impact energy with stiffer cores absorbing and dissipating more energy than softer equivalents during impact.
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De, Villiers Jonathan Izak. "Reducing the potential for accidents and the associated environmental impacts arising from road tankers transporting petro-chemical substances / J.I. de Villiers." Thesis, North-West University, 2003. http://hdl.handle.net/10394/293.
Full textAbstract:
Petroleum products, which are required to keep the 'wheels' of industry and
commerce turning, are distributed from the various refineries to their destinations
throughout the country on a daily basis and the mode and extent of
transportation or conveyance of these products is varied. This distribution activity
predominantly takes place by means of road tanker, pipeline as well as rail
tanker and quantities during transit could vary from a few hundred litres to many
thousands of litres per trip.
Road tanker transportation is considered to be the most vulnerable form of
distribution means and this poses a high risk in terms of the potential for being
involved in an accident.
The risk potential associated with the road transportation of these fuels, from an
environmental point of view, is aggravated due to:
*The conveyance of bulk loads,
*non-roadworthiness of many vehicles,
*inconsistency in vehicle condition checking systems and in the application of
*safety systems,
*poor road conditions,
*driver fatigue,
*hi-jacking threats,
*the level of incompetence or unsuitability of drivers,
*the inconsistency in driver training programs,
*the vulnerability of the tankers being subject to collision and accidents.
The potential exists for road tankers involved in accidents to leak or spill large
quantities of petroleum products which in turn could result in catastrophic
environmental consequences (such as leaking large quantities of fuel into
sewers, plantations, rivers and streams thus causing much ground and water
pollution). Also, during an accident the fuel leaking from a road tanker may ignite
causing it to burn for several hours before it is finally brought under control and
extinguished. This may result in much air pollution as well as damage to the
surrounding ecological systems. Subsequent explosions could further result in
severe loss of life and associated fires which in turn could cause more
environmental degradation and damage.
For the purpose of this dissertation, focus was specifically placed on the
introduction of internal company control measures that a "supplier” company
(such as Natref (Pty) Ltd) could implement to check whether petroleum product
distributors are complying with predetermined criteria aimed at reducing the
potential for accidents involving road tankers. The measuring of how these
controls have an effect in the bigger scheme of things in terms of reducing
accidents and environmental degradation was very difficult to determine because
it was not possible to extract from the distributors how many of their vehicles
were actually involved in incidents during the study period. As a result it was not
possible to determine whether the improved control measures had an effect on
the number of accidents incurred by the vehicles that were effected by the
improved application of the standards.
The study thus focused primarily on the effect that the implementation of an
inspection system could have in progressively reducing the number of defects
found on road tankers wanting to gain access to Natrefs site as well as
measuring whether an improvement in compliance to standards actually took
place. This study was conducted over a period of 22 months and involved the
development and implementation of a new procedure and training course,
implementation of an inspection checklist, improved reporting methods as well as
improved the overall environmental awareness of the employees involved in the
checking and inspection process. It is however assumed that the implementation
and ongoing enforcement of the company standards has assisted in contributing
towards minimising the potential for pollution exposures arising from accidents
and in so doing minimising environmental degradation to a larger or lesser
extent.Thesis (M. Environmental Management)--North-West University, Potchefstroom Campus, 2004.
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VECCHIETTI, MARIA VITTORIA. "Static and dynamic response of RC beams strengthened with NSM C/GFRP rods." Doctoral thesis, Università Politecnica delle Marche, 2022. http://hdl.handle.net/11566/295509.
Full textAbstract:
Negli ultimi anni è stato dimostrato che la tecnica di rinforzo Near Surface Mounted (NSM) rappresenta una valida alternativa ai metodi di rinforzo convenzionali, come le fasciature esterne (metodo Externally Bonded). Potenzialità, vantaggi ed applicazioni sono stati studiati negli ultimi 20 anni cercando di ottimizzare il sistema ed i parametri che lo influenzano. È interessante approfondire il tema sia dal punto di vista statico, evidenziando la non validità dell’ipotesi di conservazione delle sezioni piane, che si manifesta a causa dello scorrimento tra FRP e resina, che per semplicità non viene mai preso in considerazione dai modelli analitici proposti in letteratura, che dal punto di vista dinamico, che consente di analizzare l’andamento delle frequenze proprie di vibrazione, per monitorare l’efficacia del rinforzo e come agisce il grado di danneggiamento.
Durante questo lavoro di ricerca sono state effettuate prove statiche e dinamiche su campioni di travi in cemento armato rinforzati con barre in CFRP e GFRP mediante tecnica NSM. Lo scopo del progetto è proprio quello di analizzare gli effetti delle differenti tipologie di rinforzo applicate.
Le prove statiche a flessione sono consistite nell’applicazione di cicli di carico e scarico, questi test hanno consentito di definire il comportamento dei campioni di trave anche in presenza di fessurazione del calcestruzzo e di individuare diversi livelli di danno. Dopo ogni step di carico sono state effettuate le prove dinamiche in vibrazione libera che hanno consentito di osservare come agisce il rinforzo. Sono stati osservati anche i modi di rottura delle travi.
Le risposte del campione non rinforzato sono quindi state confrontate con quelle dei campioni rinforzati, il comportamento è stato analizzato anche attraverso dei modelli teorici.
Infine, è stato sviluppato un modello agli elementi finiti dei campioni di trave in modo da validare i risultati ottenuti sperimentalmente.The Near-Surface Mounted (NSM) strengthening technique has proven, in recent years, as a valid alternative to the conventional strengthening methods, like the externally bonded (EB) technique. In the last two decades its potential and its advantages, as well as its applications, has been studied, trying to optimize the construction system and the parameters that influence it. However, it is interesting to deepen the topic both in static, highlighting the non-conservation of the flat section, due to the bond-slip effect between FRP rod and resin, which, for simplification has never been taken into consideration by analytical models proposed in literature, both in dynamic key, which allows, by studying the trend of proper frequencies of vibration, to understand the effectiveness of the reinforcement and how different types of damage affect it. Therefore, in this research work, static and dynamic tests were performed on RC beams strengthened with NSM CFRP and GFRP rods, which still need to be investigated. The aim of the research is to analyze the effects of different types of strengthening. Bending tests with cycles of loading until failure are carried out, these tests allowed to define the behavior of beam specimens, even in presence of damage, and to generate different damage degrees, due to cracking of concrete. At each step of load, dynamic analysis, by free vibration test, allows monitoring the effectiveness of the reinforcement at different damage degrees. Failure modes of beam models are also analyzed. A comparison between the responses of the unreinforced and reinforced models is presented; the behavior of beam specimens was also analyzed by theoretical models. In the end, a finite element analysis of beam models has been developed, in order to validate the results obtained by the experimental research.
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Siripun, Komsun. "Characterisations of base course materials in Western Australia pavements." Thesis, Curtin University, 2010. http://hdl.handle.net/20.500.11937/960.
Full textAbstract:
Western Australia (WA) has a road network of approximately 177,700 km, including a 17,800 km stage highway system (Main Roads Western Australia 2009). This infrastructure supports a population of only about two million, and road funds always have to be carefully considered when allocated to highway authorities or other organisations. Pavement design is a process intended to find the most economical combination of suitable materials and layer thicknesses for construction. The pavement must have a carefully-specified unbound granular base to further reduce construction costs, and must be surfaced with an approximately 30 mm asphalt surface in WA. High quality aggregates are therefore required for the base course layer of a pavement because of its proximity to the road surface. Traffic loads on the road surface result in high stress levels on the base course layer. Consequently, Hydrated Cement Treated Crushed Rock Base (HCTCRB) was developed.Current pavement analysis and design in WA is thought to be sub-standard. A number of highways and roads in WA are exhibiting extensive surface damage as a result of the increasing numbers of vehicles in use. Since pavement analysis and design in WA relies predominantly on empirical design, experience and basic experimentation, explanations for the damage occurring under present conditions are difficult to determine and assess.In most areas of the USA and Europe, pavement design and analysis has entered a new era with mechanistic design replacing empirical design. Unlike the empirical approach, a mechanistic approach seeks to explain pavement characteristics under real operational pavement conditions (loads, material properties of the pavement structure, and environments), and is based on design parameters derived from sophisticated tests which can simulate real pavement conditions in the test protocol (WSDOT 2008). The mechanistic approach to pavement design produces more relevant and useful results and these procedures, along with linear elastic analysis, were introduced into Australia by the 1987 NAASRA Guide (NAASRA 1987), of which the revised version became the AUSTROADS Guide (Austroads 2004) to the Structural Design of Road Pavements. AUSTROADS published a National Pavement Research Strategy which has been the keystone for the national co-ordination of pavement research, both within government and industry.Adaptation of the Cement Modified Crushed Rock Base concept has brought about an excellent road base material for Western Australia (WA) by the addition of a small amount of cement (1-2% by mass) to a fresh crushed rock material. The mix is stockpiled for a hydration period, and after that retreated before construction, unlike the traditional concept for cement modified/stabilised materials. This material is usually called Hydrated Cement Treated Crushed Rock Base (HCTCRB), a name established by Western Australia Mainroads (MRWA). More than 250,000 tonnes of HCTCRB has been used at a cost in excess of $10 million over the last eight years.Recently, as a result of early damage on new highways and roads in WA, MRWA and its contractors and organisations have attempted to identify the cause of this damage. HCTCRB, which is currently the best option for base course materials in WA, and Crushed Road Base (CRB), the original road base material, need to be re-examined to overcome the shortcomings in terms of analysis, design, and application. All of the factors involved in HCTCRB and CRB for today’s pavement conditions have been extrapolated far beyond the bounds of the original data, and current experience shows these require detailed re-investigation.This research aimed to study on the characteristics of CRB and HCTCRB and to determine reliable mathematical material models for the improvement in the current pavement design criteria. This study also investigated both elastic and plastic behaviour of CRB and HCTCRB. In this study, there were two relevant factors of both pavement materials which are considered in order to fulfil a lack of understanding in realistic conditions in pavements of the current pavement design. 1) The material strength which indicates the limitation and stability of pavement materials under traffic loads. This study employed the Mohr-Coulomb failure envelope to define the limitation of material implementation and also brought in the resilient modulus of materials to be the significant input parameter for multilayer finite element analysis to characterise the stress distribution in pavements. 2) The pavement failure of long term road performance relating to the design life of pavements. The permanent deformation behaviour and the shakedown concept under various stress conditions, simulated from repeated load triaxial (RLT) tests, therefore, were taken into account to investigate such long-term performance of HCTCRB and CRB and then the implementation of the findings was made to the current pavement analysis and design. Furthermore, more reliable mathematic models of base course materials for short and long term performance during their service life were established based on the laboratory test results of this study.
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Cintra, Roberta Hehl de Sylos. "Análise qualitativa e quantitativa dos danos ambientais do Município de São Carlos (SP) com base em instrumentos jurídicos." Universidade Federal de São Carlos, 2002. https://repositorio.ufscar.br/handle/ufscar/1982.
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Previous issue date: 2002-08-19Universidade Federal de Sao Carlos
The public instauration and registration of environmental damages in the local landscape became a fundamental tool to collect information with easiness and reliability. Qualitative and quantitative analysis of the environmental damages was accomplished in the municipal district of São Carlos, SP, based on the organization and analysis of a database contemplating the juridical instruments established to the State public prosecution service, in the perspective of a diagnosis and of the environmental quality of the local landscape in terms of the relationship among the environmental damages and the current development trajectories. It was organized in a database 326 Administrative Procedures and 22 Public Civil Actions, totaling 348 prosecution registrations of environmental damages, in the period regarding 1991-2000. The environmental damages were classified in nine types, being deforestation the one of larger occurrence in every year and along the study period. Of the total number of deforestation 82,9% is related with areas smaller than five hectares, with prevalence of the performance of natural persons in relation to legal entities. It corresponds to 9,8% of the deforested total area, being equal to 110,35 hectares. The remaining 17,1% are associated with areas larger than five hectares embracing 90,2% of the deforested total area, being equal to 1013,27 hectares. The 217 registrations of environmental damages in the period from 1991 to 2000 determined a total loss of 1121,62 hectares of the vegetation component of the local landscape. In a rude estimate this total corresponds to the medium losses of 5,91 ±4,14 ha/occurrence and of 112,36 ± 91,73 ha/year of deforested area. The occurrence of environmental damages in Permanent Protection Areas, in number and in extension of deforested area, it is basically associated to the net road and to the riparian vegetation of the local watersheds. This process evidences the compromising of the environmental quality of the water resource, and landscape areas of hills and hillsides, in terms of the habitat loss and of the associated biodiversity. These results doesn t correspond to the real scenery of the local landscape conditions, once the environmental damages were not registered in your totality. It is fundamental the interaction among the information registered by the fiscal organs and those responsible ones by the elaboration and application of the guidelines for local development.
A instauração e o registro público dos danos ambientais na paisagem local tornou-se uma ferramenta fundamental quanto à facilidade de acesso e confiabilidade das informações coletadas. Neste contexto, foi realizada a análise qualitativa e quantitativa dos danos ambientais ocorridos na Comarca de São Carlos, SP, com base na organização e análise de um banco de dados contemplando os instrumentos jurídicos instaurados para autuação junto ao Ministério Público Estadual, na perspectiva de um diagnóstico e compreensão das modificações na qualidade ambiental em termos da relação entre os problemas ambientais e as ações desenvolvimentistas no âmbito da paisagem local. Foram organizados em um banco de dados e analisados 326 Procedimentos Administrativos e 22 Ações Civis Públicas, totalizando 348 registros de autuações de danos ambientais no período referente a 1991-2000. Os danos ambientais foram agrupados em nove classes, sendo desmatamento o de maior ocorrência em cada ano e ao longo do período de estudo. Do número total de ocorrências de desmatamento 82,9% está relacionada com áreas menores que cinco hectares, com predomínio da atuação de Pessoas Físicas em relação a Pessoas Jurídicas. Corresponde a 9,8% da área total desmatada no período de estudo, equivalendo a 110,35 ha. Os 17,1% restantes estão associados com áreas superiores a cinco hectares abrangendo 90,2% da área total desmatada, equivalendo a 1013,27 ha. Os 215 registros de danos ambientais no período de 1991 a 2000 determinaram uma perda total de 1121,62 ha da vegetação da paisagem em questão. Em uma estimativa grosseira este total corresponde às perdas médias de 5,91± 4,14 ha/ocorrência e de 112,36 ± 91,73 ha/ano de área desmatada. A ocorrência de danos ambientais em áreas de APP, tanto em número quanto em extensão de área desmatada, está basicamente associada ao entorno da malha viária e da vegetação ripária das bacias hidrográficas locais. Evidencia o comprometimento da qualidade ambiental dos recursos hídricos, das áreas de morros e encostas e da paisagem, em termos da perda de habitat e da biodiversidade associada.Estes resultados não refletem o cenário real das condições da paisagem local, uma vez que os danos ambientais não foram registrados em sua totalidade. É fundamental a interação efetiva entre as informações registradas pelos órgãos de fiscalização e aqueles responsáveis pela elaboração e aplicação das diretrizes para o desenvolvimento municipal.
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Špaček, Petr. "Stanovení výše škody v případě výskytu vad a poruch krytových vrstev netuhých vozovek pozemních komunikací." Doctoral thesis, Vysoké učení technické v Brně. Ústav soudního inženýrství, 2017. http://www.nusl.cz/ntk/nusl-255816.
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This thesis is focused on possibilities of financial valuation of flexible pavements surface layers conditions, in connection with whole life cycle of the pavement and certain possibilities of their maintenance and repairs, in cases of defects and failures from forensic engineering point of view. There were carried out analysis of the topics connected with judging of flexible pavements surface layers defects and failures related to forensic investigation in the Czech Republic, as well as abroad. In this thesis there were created pricing models of the certain construction works which are related to repairs and maintenance of flexible pavements. Within the possibilities of the author, there were compared market prices of the particular construction works in selected regions with the prices according to generally used pricing systems in the Czech Republic. The goal of this thesis is to create unified methodology for amount of damage financial valuation in cases of defects and failures of flexible road pavements surface layers for forensic engineering practice in the Czech Republic.
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Brzovic, Andres. "Characterisation of primary copper ore for block caving at the El Teniente mine, Chile." Thesis, Curtin University, 2010. http://hdl.handle.net/20.500.11937/1807.
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This thesis investigated the rock mass geotechnical behaviour of primary copper ore at the El Teniente mine in Chile, which has been described as a massive and competent rock mass. The rock mass was characterised considering different structural data collection techniques and mapping scales. Modifications were made to the traditional sampling methodologies to better determine the observed geological discontinuities within primary copper ore. It was found that few open geological discontinuities, mainly the widely spaced large scale sub-vertical faults, are observed within primary ore, and this could be in agreement with the observed “competent” and “massive” rock mass behaviour at the mine site. The study also found a high frequency of small scale stockwork veins (cemented joints), which define at least three semi-orthogonal set orientations mine wide.The faces of caved rock blocks found in the production level draw points were also characterised and an empirical criterion to define weak discontinuities that define caved blocks was established. From these observations, it can be concluded that the geological discontinuities (veins) having less than 1/3 of hard minerals as infill (hard mineral means Mohs scale of hardness ≥ 4) and thickness greater than or equal to 2mm may also be the weaker path where a competent rock mass fail under caveinduced stress conditions. This empirical definition was applied for the structural data collected from different geological units and mine sectors of the El Teniente mine. The results allowed a differentiation of several geotechnical units where traditional rock mass classifications schemes failed.The observed rock mass behaviour during caving operations was back analysed to correlate with the new geotechnical units defined using that empirical definition. The back analysis studies included the rock damage as mine overbrake in mine drive at the undercut level, fragmentation performance, and mine seismicity recorded within a rock volume completely caved. A mine scale finite element numerical model was also built to assess the stress state around excavations during caving propagation. Damage orientation determination by seismic focal solutions was used to correlate against collected structural data to investigate the influence of weak discontinuities during block caving performance.
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Novák, Jan. "Analýza návrhových prvků okružních křižovatek v závislosti na nehodovost." Doctoral thesis, Vysoké učení technické v Brně. Fakulta stavební, 2018. http://www.nusl.cz/ntk/nusl-390280.
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The dissertation deals with the analysis of roundabout design elements and their impact on accidents. The analysis objective was to identify the important elements of roundabouts that have impact on accidents. In order to achieve this goal, the multifactorial statistical safety assessment method was used on the basis of a representative sample of data, by developing several safety performance functions, verifying them and interpreting the result. Several design elements, which from the point of view of the traffic accident mechanism belong to the infrastructure factor, have been identified: AADT, average diameter, entrance width, entry angle, direct passage angle, location and many others. The original sample contained about 1200 roundabouts, which were reduced to 200 based on data availability. Accident frequencies were monitored between 2009 and 2016, i.e. for eight years, resulting in total 2674 roundabouts accidents. The result is an accident prediction model, developer based on roundabout approach design elements, and map of critical roundabouts, identified based on empirical Bayes estimate of accident frequency. Following approach parameters were identified: AADT, entry angle, distance between collision points, deviation of angles between approaches, presence of apron, presence of bypass, entry type, presence of pedestrian crossing and surrounding area type.
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Parak, Mohamed. "Flood estimation for roads, bridges and dams." Thesis, 2010. http://hdl.handle.net/10413/1460.
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Flood estimation can be classified into two categories, i.e. flood prediction and flood forecasting. Flood prediction is used for the estimation of design floods, which are floods associated with a degree of risk of being equalled or exceeded. Predictions are needed for the design and construction of infrastructure that are at risk to flowing water. Flood forecasting is used for the estimation of flood flows from an impending and/or occurring rainfall event (i.e. the estimation of the magnitude of future flood flows with reference to a specific time in the future). These are needed by catchment and disaster managers for the mitigation of flood damage. The estimation of flood magnitudes for flood forecasting requires the specific knowledge of prevailing surface conditions which are associated with the processes of rainfall conversion into flood runoff. In order to best achieve this, a distributed model (in order to exploit remotely sensed data and capture the spatial scale of the phenomenon) is used to continuously update the surface conditions that are important in this conversion process. This dissertation focuses on both flood estimation categories. In the first part of the dissertation, attention is given to the improvement of two simple event-based design flood prediction methods currently in use by design practitioners, namely the regional maximum flood (RMF) and the rational formula (RF) by comparison with statistically modelled historical flood data. The second part of the dissertation lays the theoretical and practical foundation for the implementation of a fully distributed physically-based rainfall-runoff model for real-time flood forecasting in South Africa. The TOPKAPI model was chosen for this purpose. This aspect of the research involved assimilating the literature on the model, testing the model and gathering and preparing of the input data required by the model for its eventual application in the Liebenbergsvlei catchment. The practical application of the model is left for a follow-up study.Thesis (M.Sc.Eng.)-University of KwaZulu-Natal, 2007.
Thesis (M.Sc.Eng.)-University of KwaZulu-Natal, 2007
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Hsu, Jhao-Bo, and 許兆博. "A Study of Landslide Damage Risk Evaluation Model for Mountain Roads." Thesis, 2006. http://ndltd.ncl.edu.tw/handle/5tr95s.
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碩士國立臺灣科技大學
營建工程系
94
Landslides, large or small, along the mountain roads of Taiwan often occurred during or after strong earthquake or typhoon induced heavy rainfall. Landslides not only cause interruption of road traffic but also cause damage to passing by vehicles and injure people. Due to the resource limitation of government, the overall assessments and maintenance of all road slops can not be fulfilled. Priority of road for maintenance is a crucial task for road maintenance department to identify. The purposes of this research are to develop an assessment method for the landslide risk and to make strategies to maintain or repair the slopes along mountain roads. To aim Both needs to take into account the environmental conditions of the slopes, the engineering measures for stabilizing road slopes, the transportation issues, and the human concerns when dealing with the slopes maintenance along the mountain roads. This study firstly establishes the estimation model to caculate the risk of slope failure, considering the probability of Landslides, temporal probability, spatial impact probability, the value of human life, transportation time increased, and travel cost due to detour etc., and then the loss of life and transportation can be caculated. Secondly, based on the value of risk, the risk evaluation, considering the risk acceptance criteria for loss of life, that could provides assistance for road maintenance department to determine the priority of mountain roads for maintenance.
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LIU, HUNG-KUAN, and 劉鴻寬. "The Study of Rehabilitation Design And Its Control Effect for the Damage of Mountain Roads in Remote Regions the Case of Li-Shing Mountain Road." Thesis, 2008. http://ndltd.ncl.edu.tw/handle/92008427952089338782.
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碩士逢甲大學
土木工程所
96
Parts of Central Cross-Island Highway were damaged and closed by Earthquake 921. Therefore, Li-Shing path was become main traffic way of Li-Shan district residents, along tribes and farm products. AERE typhoon was stormed on August 1994 and continuity cloudburst on 1995, they caused multiple landsliding and roadbed flowed away. Due to Li-Shing path geology was weakness and shatter, numbers of damaged locations were increased from 70 to 108. Frequent hillside disaster caused traffic obstruction. This research purpose is based on short-middle-term restoration and rebuilding. Improvement of existing conditions repaired damaged locations of Li-Shing path in order to increase safety and maintain basic traffic demands. Effectively realize with geology, hydrology, environment and existing conditions of Li-Shing path. Analyze design principles of short-middle-term restoration and discuss occurrence reasons of numerous damages to be the theorizing base of restoration. Depending on restoration method’s functions and suitabilities evaluate restoration’s results and compare whole effects after previous typhoons, cloudbursts, landsliding attacked. Analyzing and evaluating the restoration methods after particularizing the damage reasons. In accordance with experience of short-middle-term restoration provides long-term restoration methods, suggestions and budget estimation. And expect long-term emergent hillside restorations will be combined short-middle-term restoration methods to achieve performance by exercising effective.
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Lin, Chun-Yen, and 林俊延. "The Road-dike Effect on The Inundation Damage." Thesis, 2001. http://ndltd.ncl.edu.tw/handle/39448488778415817990.
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碩士國立成功大學
水利及海洋工程學系
89
Looking back to the history of damages or casualties caused by disasters in recent years, floods are the most often to be seen. To view the whole situation, the reasons of how deluges occur are nothing more than improperly artificial developments. One of the improper developments is the road expansion. It could be said that the more street network increases, the more river flows are changed. To prevent the flowage of the varied rivers, the authorities or the publicity normally choose to build dikes to control the flood. However, this method makes the water currents limit within the confines between street network and dikes. Therefore, the flow cannot circulate properly. The seriousness of this problem is shown in many cases of the inundated calamities in recent years. The main purpose of this research is to study on the Inundation Effect, what is called Road-dike Effect, which was caused by the situation mentioned above. The districts of this study, Xin-shi, Yong-Kang in Tainan County and Gang-shan, Jia-xing in Kaohsiung County, had floods all the time in the past decades. To begin this program, the first step is to collect the information of the road and water system and the history of disasters in the two research regions. Then, utilizing the numerical simulation to reappear the historical incidents and discussing the possibilities of road-dike effect that may happen in all the situations and the mutuality between Drainage System and Road-dike Effect. Finally, there is a deeply hope that from the investigations and analyses in this research, people could have a further understanding of the Road-dike Effect and it is able to be for reference to plan and design the road systems and drainage engineering projects in the near future.
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Wu, Ming Huei, and 吳明惠. "Research on the Damage Potential of Secondary Roads from Gully Development in Mountainous Region." Thesis, 2008. http://ndltd.ncl.edu.tw/handle/38928747044448020550.
Full textAbstract:
碩士國立宜蘭大學
土木工程學系碩士班
96
Abstract For the steep mountainous region in Taiwan, the annual precipitation is relatively high due to the humid and warm climate as well as the heavy rainfalls brought in by typhoon. Secondary roads in this steep-sloped area showed characteristics of meandering routes with profound gully development along the roadside slopes. Damages along roadway and its uphill and downhill slopes, such as pavement subsidence, subgrade losses, slope scouring and instabilities, are believed to attributed to the nearby gully development. In this research, scenery routes in the Tai-pin-shan National Forest Recreation Area were studied to clarify the damage potential of roadways from local gully developments. The Tai-pin-shan National Forest Recreation Area is located at the northern part of the central mountain ridge of Taiwan with slope averaging about 30~40 degree. Rainy season of the region starts from October till February the following year. Along with typhoons coming up during summer, the annual rainfall is considerably high in the area. Combining the effects of abundant precipitation and steep slope, the traffic in the region was seriously affected by the instability of roadway foundations which were induced by the developing gullies nearby. In order to set up the priority for roadway maintenance plan, the gully development on the uphill and downhill slopes along the scenery routes in the region were studied and a inference scheme based on neural network analysis was proposed. A series of analyses were involved in developing the inference scheme. Firstly, the gully locations were positioned through terrain analysis over digital terrain model (DTM) of the region. Secondly, hydrological analyses were preformed using the HEC-HMS software and the peak flows for 25-year recurrence period of each gully were calculated. In the mean time, gully profiles were extracted and the positions where headward erosion may occur were determined manually. Other factors such as the gully length, basin area, basin average slope, and the roadway mileage within each gully catchment were also determined using the ArcGIS software. Thirdly, statistical tests were conducted over the collected factors to determine the correlation among them. Following the statistical test, factors with better independency were selected as the input factors in the neural network inference scheme. Finally, four factors including the basin average slope, gully length, distance from headward erosion point to roadway, and the roadway mileage within each gully catchment were selected for neural network training. In addition, according to the from site survey along the route, the degree of roadway damage were determined and used as the output factor in the neural network training. The resulting fuzzy backpropagation neural network inference scheme was then tested using another set of roadway data and 78% accuracy was obtained from the test. Therefore, it is fairly justified to conclude that the four gully development related factors are indeed directly influencing the damage potential along roadway route. The inference scheme should be confidently used in evaluating the damage potential for roadways within similar geology and hydrological region. Result from the analysis can also be displayed using GIS program as the reference data for the planning, rerouting, and maintenance plan of the roadways.
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Hsiao, Ching-Chen, and 蕭清鎮. "A Study on the Compensation for the Damage of Installing Pipelines under the Existing Roads." Thesis, 2006. http://ndltd.ncl.edu.tw/handle/97283269430046610170.
Full textAbstract:
碩士長榮大學
土地管理與開發研究所
94
The public facilities such as tap water, electricity, telephone, gas and petroleum must install underground pipelines in public and private land. In the past, the public benefits transcend the private benefits, which acquisition without consideration. Those merely give compensations while cause damages. The relevant regulation also only stipulate , “if damages should compensate according to the extent of damage” .Public enterprises should make compensation regulations for installing underground pipelines. They should set up the rules of payment, methods, and how to do. There are no any formal regulations in our legislations Therefore, this legislation should be legislated immediately. According to the result of questionnaire of research analysis, it discovers the general public, the private land of ownerships, public employees, specialists, and scholars and so on. Most of them agree to set up “The right of opposite underground” regarding methods and the amount of money to compensate ownerships. They consider Mass Rapid Transit (MRT) system, bullet trains, and sewers which are all present the form of lines and utilize merely parts of spaces. Moreover they think the sum of compensation should be more preference and acceptability to those ownerships. Meanwhile, the sum of compensation should equal or over the current price which would improve the living quality, to increase the income of ownerships. That would be good for these land ownerships. According to the result of statistic analysis, it compares the methods of compensation and the sum of money of compensation. There is without any difference in the sum of money of compensation for “Lands utilize expense”. That is also meaning the general public, the private land of ownerships, public employees, specialists, and scholars and so on who have the similar opinions for “Lands utilize expense”. Otherwise, there are obviously differences in compensation of “Levy”, “Accord price”, “Rent”, “Public land exchange” , “government securities compensation”, and “ The right of opposite underground”. To sum up, most of interview objects all hope public enterprises can set up the regulation of compensation for methods and sum of money to protect the right of ownerships. Finally, this research puts forward the suggestions on the result of study, for our public enterprise and government to set up some formal legislations.
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HUNG, I.-WEI, and 洪藝瑋. "Investigation of Large-scale Collapse Roads, Damages to Buildings and Discussion of Causes in Luchang Area." Thesis, 2018. http://ndltd.ncl.edu.tw/handle/ctze5g.
Full textAbstract:
碩士國立聯合大學
土木與防災工程學系碩士班
106
This study investigated the landslide area with suspected large-scale deep-seated gravitational slope deformation in Luchang. Miao 21 County Road and the connection road to Luhu are vulnerable to disasters such as typhoons, extremely heavy rain, and earthquakes, thereby posing considerable risks to residents’ safety. In this study, monitoring results of the Luchang area since 2007 were combined with continual on-site investigations of retaining walls on both sides of Miao 21 County Road, cracks on guardrails, and damages on buildings in Luchang. Seven measurements were performed on 20 sites using the global positioning system (GPS). The measurement results were used to analyze the overall displacement of the Luchang area. Geological parameters determined from cores obtained from core drilling were input in FLAC3D slope stability analysis software to analyze the displacement of the Luchang area. Unmanned aerial vehicles (UAVs) were employed to map the morphology of the area to facilitate the comparison of the GPS measurements, on-site investigations, and FLAC3D analysis results. The four approaches were used for cross comparison and verification to identify causes of disasters in the area. The on-site investigation results of the retaining walls, cracks on guardrails, and building damages were compared with historical monitoring data since 2007. The results revealed that at 12K+300 from Fengmei Bridge to Miao 21 County Road, a crack of larger than 50 cm was observed, whereas no observable crack was found in the Luchang Tribe. The GPS measurement results revealed that most sites moved northeasterly, with the highest displacement reaching 16 cm over 2 years . The FLAC3D analysis results revealed that displacement of 10 cm or longer was expected to be found in the research area. Cross comparison of on-site damage investigations, GPS, and FLAC3D results demonstrated consistent displacement tendencies. Comparisons of the UAV-constructed morphology with the investigated site with the on-site damage investigation, GPS measurements, and FLAC3D results further revealed that the landslide phenomenon was more observable in sites with larger displacement levels. A summary of the aforementioned results indicated that the stratum on which the Luchang Tribe is located is stable. However, the severe retaining wall damages, guardrail cracks, and road pavement settlement were possibly caused by the cutting of the toe of slope underneath the road by the river. In addition, the fact that the research area features steep slopes and is located on an old colluvium might have contributed to the aforementioned damages through slipping and creeping.
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Lin, Qi-Jun, and 林啟鈞. "Investigation on pavement damage - a case study of Zhong-Shan Road." Thesis, 2016. http://ndltd.ncl.edu.tw/handle/853b88.
Full textAbstract:
碩士義守大學
土木與生態工程學系
104
Zhong-Shan road is a main road connecting city and harbor with heavy traffic volume and heavy vehicles including container trucks. With such a heavy traffic volume and heavy vehicles driven on it, uneven pavement surface, potholes, and deformation of pavement are seen on this road. The correlations between pavement damage types and surface layer as well as the base or subbase layer are investigated. Information including traffic volume and damage locations and tests such as flatness, GPR, FWD, DCP and cored samples are applied to study the causes of the pavement damage. Then, the improvement strategies are proposed. The GPR is applied to detect on the material changes of pavement surface and the base or subbase layer and assess the thickness of each layer. Then, these thicknesses of each layer are applied to the FWD for the in-site measurement of thickness of each layer and the back-calculation of resilient modulus. To be more accurate to detect the pavement status, the DCP is used to evaluate the strength, layer number, and thickness of the subgrade soil and the base or subbase layer. Then, the DCPI values are obtained and analyzed. From the results obtained from DCPI values and limits, the bearing capacity of the asphalt layer and the base or subbase layer are evaluated for the pavement status of the Zhong-Shan road. The standard deviation of roughness of the Zhong-Shan road is 6.5mm in which is much higher than the requirements set by the standard. Result obtained from the FWD for part of pavement is higher than 25mils. Moreover, the penetration depth obtained from DCP is 100mm/blow. It implies that the structure of the base or subbase layer may cause the pavement damage. Furthermore, the cored samples are broken quickly during the test. It indicates that no strength is left in part of the pavement surface layer. The study shows that positive correlation between pavement damage and the soft layer of the base or subbase is observed. Because the soft layer of the base or subbase resulting in an insufficient bearing capacity of the pavement, as a result, the asphalt layer is deformed after rolling by vehicles. Therefore, before the asphalt layer is rehabilitated, the strength of the base or subbase layer needs to be considered and evaluated to avoid the insufficient bearing capacity of the pavement leading to constant pavement damage.
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Shateri, Mohammadhadi. "Acoustic emission monitoring of damage progression in fiber reinforced polymer rods." 2017. http://hdl.handle.net/1993/32148.
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The fiber reinforced polymer (FRP) bars have been widely used in pre-stressing applications and reinforcing of the civil structures. High strength-to-weight ratio and high resistance to the corrosion make the FRP bars a good replacement for steel reinforcing bars in civil engineering applications. According to the CAN/CSA-S806-12 standard, the maximum recommended stress in FRP bars under service loads should not exceed 25% and 65% of the ultimate strength for glass FRP (GFRP) and carbon FRP (CFRP), respectively. These stress values are set to prevent creep failure in FRP bars. However, for in-service applications, there are few physical indicators that these values have been reached or exceeded. In this work analysis of acoustic emission (AE) signals is used. Two new techniques based on pattern recognition and frequency entropy of the isolated acoustic emission (AE) signal are presented for monitoring damage progression and prediction of failure in FRPs.May 2017
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Hsu, Ya-Ting, and 許雅婷. "The study on relations between typhoon rainfall and road damages in Taiwan." Thesis, 2010. http://ndltd.ncl.edu.tw/handle/12103843365641791288.
Full textAbstract:
碩士清雲科技大學
空間資訊與防災研究所
98
Natural hazards, such as earthquake, typhoon, torrential rain, flood and drought, frequently cause a great deal of casualties and property damages in Taiwan. The governmental agencies have established many disaster-related data banks open to the public in order to educate people to understand the causes of disasters and how to response to the disasters occurred in the surroundings. These data banks would be more valuable only if they were fully and wisely used by the public. The highway disaster prevention and rescue information system by the Ministry of Communications Transportation Research Institute and the Typhoon data bank by the Central Weather Bureau are good examples to demonstrate how these data could be analyzed to produce some useful information through data mining. This research correlated data of road damages during certain typhoons with typhoon rainfalls and tried to define a threshold rainfall causing the road damage. The data of road damages were registered in the ArcGIS overlaid by the typhoon rainfalls to evaluate their inter-relationship. Data from three typhoons were used. They are the KALMAEGI typhoon, the JANGMI typhoon, 2008,and the MORAKOT typhoon, 2009. The typhoon rainfall distribution were interpolated and gridded by the Kriging method. The result shows that although some minor road damages occur in the accumulated rainfall of 100mm, the major road damages occur in the accumulated rainfall of 300mm. The MORAKOT typhoon has set the record on the road damages. The main types of road damage were caused by the debris flows, the side-slope failures, and the subgrade washed-off. Nevertheless, road damages caused by the typhoon rainfall are measured in moderate degree.
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Li, Pei-Chan, and 李珮甄. "The study of Urban Seismic Building Damage Evaluation and Road Block Analysis." Thesis, 2005. http://ndltd.ncl.edu.tw/handle/16801778228181195586.
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碩士逢甲大學
土地管理所
93
On September 21th, 1999, a violent earthquake stroke Chi-Chi located in Nan-tou County. It caused unprecedented damage to the buildings and nearly twenty thousands houses totally or partially collapsed. In consideration of the extensive destruction this time, the anti-seismic ability of the house has becomes the most critical issue among the recent earthquake engineering. The study is basically divided into three parts; Firstly, it builds the Earthquake Damage Data Base for major buildings from Chi-Chi Earthquake record data. Second, we used this database and fragility curve of building to evaluate the building seismic damage evaluation model. A couple of major topics will be discussed for all kinds of building, they are Strong Motion Attenuation and distance with a fault. When the construction of these relations building up behind, we can evaluated the major building collapsed status and road block problem. The resultant model can be immediately applied to assessing buildings in the test area, as well as to verify the current near fault building’s national design criteria or using the simulation data to anti-seismic disaster.
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Liu, Shi-Kun, and 劉錫崑. "Effects of Road Race for Elite Cyclists on Antioxidant Capacity and Muscle Damage." Thesis, 2006. http://ndltd.ncl.edu.tw/handle/86844577171704332564.
Full textAbstract:
碩士國立彰化師範大學
應用運動科學研究所
94
Purpose: To investigate the effects of road race for elite cyclists on antioxidant capacity and muscle damage. Methods: Ten elite cyclists (age =21.4 ± 1.9 years、height =164.4 ± 2.1 cm、body mass =57.6 ± 2.9 kg、body mass index (BMI) =21.2 ± 0.6 kg/m2 ) were recruited during the 2005 National Cycling Road Race Championship. They spent 175.7 ± 4.5 min (7-Km time trial：11.8 ± 0.3 min and 100-Km road race：163.4 ± 4.3 min) to finish the race. The blood samples were collected 2 hours before the race (pre), immediately after the race(0 h), 3, 7, 24, 72, and 120 hours after the race to determine superoxide dismutase (SOD), total glutathione (TGSH), oxidized glutathione (GSSG), creatine kinase (CK), lactate dehydrogenase (LDH), malondialdehyde (MDA), protein carbonyls (PC), uric acid (UA), and nitric oxide (NO). Results: The plasma CK increased 93.66% and 91.08% significantly at 3 and 7 hours after race and the plasma LDH was significantly increased 82.72% and 66.29% at 7 and 24 hours after race as compared to pre. Meanwhile, the TGSH of erythrocyte was significantly elevated 202.92%, 185.71%, and 185.50% at 7, 24, and 72 hours post race. The GSSG of erythrocyte was significantly elevated 125.57%, 160.66%, 195.36%, and 115.07% at 3, 7, 72, and 120 hours post race. No significant changes were found the SOD of erythrocyte and the plasma UA, NO, and MDA. Plasma PC was a marker of protein oxidative damage, decreased 56.10%, 48.44%, and 46.01% significantly at 7, 24, and 72 hours post race. Conclusion: A road race may induce endogenous antioxidant production and muscle damage. High intensity exercise induces oxidative stress, but there is no evidence that this affects sports performance in the short term. In this study, we hope that this information may contribute to understand oxidative stress and muscle damages caused by strenuous exercise. The coaches can be inspired to set up the proper training model to promote sports performance. Moreover, this information may also contribute to set up antioxidants supplement or nutrition plans.
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Mukandila, Estime Mambula Wa Kanyinda. "Investigation of rheological response cohesion and adhesion fatigue damage of bituminous road seal materials." Thesis, 2016. http://hdl.handle.net/2263/57496.
Full textAbstract:
Most of the current seal designs are based on the volumetric properties of materials and voids. In order to improve seal design, the possibility of introducing mechanistic principles into the seal design was investigated. Introducing mechanistic concepts into the seal design meant that principles such as elasticity and viscoelasticity could be used in terms of stress-strain to explain phenomena such as damage in the seal structure. Viscoelastic parameters of bituminous materials such as complex modulus (G?) and phase angle (?) are key elements in the understanding of performance, damage and failure of seal bituminous materials. Two main failure parameters of seal are cohesion failure (fatigue cracking due to ageing of binder and loss of elasticity) and adhesion failure or stripping (occurring between stone to bitumen or bitumen to base).
The aim of this study was to model the response of a seal?s binder and the cohesion and adhesion damage of seals materials This Research also investigates the testing procedure of Cohesion Fatigue Damage (CFD) and Adhesion Fatigue Damage (AFD) of bituminous seal material using the Dynamic Shear Rheometer (DSR). The research was based on the Lifetime Optimisation Tool (LOT) research programme from Delft University of Technology.
The response model was performed by means of the DSR parallel plate and modelled using the linear viscoelastic rheological master curves. In addition to the binder models an ageing model was developed base on the G* master curve using the recovered field-aged bitumens and the fresh binder from the plant.
The modelling of CFD and AFD of the seal was based on investigated DRS test protocols results and was established on the ?stiffness reduction? principle of materials under the action of cyclic stress.
From the ageing model it appeared that PAV ageing does not necessary simulate the long term ageing of bitumen. An investigation into ageing of non-modified and modified binder is suggested (e.g. by comparing PAV ageing with Q-sun ageing). The recovery of bitumen method needs to be revisited using technique such centrifugal force.
The CFD and AFD models offer a practical advantage consisting of the possibility to be adapted and incorporated in the recursive simulation models as developed in the South African Road Design System (SARDS). It was observed that the generalised model for CFD depends more on stress, while the generalised model for AFD appears to depend more on temperature. This observation seems to agree with the fact that adhesion damage is more sensitive to temperature change, whereas cohesion damage is more prone to be influenced by applied fatigue stress. The CFD and AFD models provide an indication of non-linear development of the fatigue damage during-life period within bitumen and between bitumen and stone in the case of seal. This is represented by the modelling of the change of G?, as suggested in this investigation.Thesis (PhD)--University of Pretoria, 2016.
tm2016
Civil Engineering
PhD
Unrestricted
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Lee, Lin-Chyuan, and 李林泉. "The Processing and Damage Analysis of the Three-Dimensional Woven Composites Reinforced by Pumtrudee Rods." Thesis, 1997. http://ndltd.ncl.edu.tw/handle/08654779611808040244.
Full textAbstract:
碩士逢甲大學
紡織工程研究所
85
This work is aimed at the improvement of the 3-D woven fabrics by using thepultruded rods. Experimental characterization of the materials has been condu-cted based upon various static and dynamic loadings. From the damage modes, the material properties were correlated with the processing and microstructures of the materials. The results indicate that using the solid rods can effectively improve the fabric geometric configuration of the 3-D composites. The problem of fibercrimp was essentially eliminated due to the solid nature of the rods. Because of the beat-up and the contact with the rods, the soft yarns were found to swell between rods. However, the global direction of the weaving yarns remains straight, despite the yarn swelling. The material tests show that the three-axis Kevlar fabrics of the single-shuttle type have higher flexure modulus, while the two-rods fabric composites are lower. In the short beam tests, the three-axis and 5-axis fabrics are found to result in rod push-out and pull-in. ! ! The impct tests indicate that on the impact side, matrix cracks with concenric ellipses were formed. On the non-impact side, mari x cracks along radius t directions were found. These crack patterns may suggest the dominat-cstrsess state caused by the impact. Increase the fabric thickness by using larger tows for the weaving arns tends to result in lower energy absorption rate. The dominant damage modes in the impact specimens include matrix cracks, rod pull-in and push-out, rod debonding, rod kink, aniber breakage.
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Chen, Horn-I., and 陳鴻毅. "The Elastic and Damage Behavior of the Three-Dimensional Braided Composites Using Pultruded Rods as Reinforcements." Thesis, 1996. http://ndltd.ncl.edu.tw/handle/39641533676013892882.
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Almeida, Arminda Maria Marques. "A methodological framework for pavement damage estimation considering simulated axle load spectra." Doctoral thesis, 2015. http://hdl.handle.net/10316/26240.
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Tese de doutoramento em Engenharia Civil, na especialidade de Urbanismo, Ordenamento do Território e Transportes, apresentada ao Departamento de Engenharia Civil da Faculdade de Ciências e Tecnologia da Universidade de CoimbraDespite being crucial to the economic and social development of any country or region, road freight transport is one of the players responsible for environmental impact of transport increasing in the last decades. In order to minimise these impacts, heavy vehicles have been evolving. Consequently, road pavement design must keep up with it since a road pavement is designed for a foreseeable heavy traffic flow that will pass on the pavement during its considered life time. The current pavement design procedures convert the heavy traffic flow into a number of Equivalent Standard Axle Load (ESAL) applications. In particular, the Portuguese procedure uses Aggressiveness Factors (AFs) to make that conversion. However, the Portuguese AFs have remained unchanged since at least 1995 and subsequently they are not up-to-date with the evolutions in heavy vehicles. This thesis addresses the development of a methodological framework for AFs (and pavement damage) estimation. For that, axle load spectra are simulated by using a commercial software TruckSIM®. The methodological framework is applied to two case studies, a ‘baseline’ case study and an ‘empty running’ case study. For that, two pavement structures and two trucks are considered. The trucks carry different payload weights and run with different travel speeds over road profiles with different levels of roughness. In the third of a three level-hierarchical approach assumed, an application was created which allows the consideration of the degradation of the Asphalt Concrete (AC) modulus and the roughness growth along the pavement design period. It is used to quantify (a) the effect of the initial International Roughness Index (IRI) value of the road profile on the pavement damage, (b) the effect of the AC modulus degradation on the pavement damage and (c) the effect of the roughness growth on the pavement damage. The results show that the AFs are strongly affected by the truck configuration, the pavement structure, the roughness level of the road profile and the design criterion. For example, the fatigue’s AF for a specific truck running fully loaded at 60 km/h over a road profile with IRI equal to 1 m/km is 53% higher in the thinner structure. The initial IRI value and the amount of AC modulus degradation have a great effect on the pavement damage. The AC modulus degradation can increase the pavement damage, at the end of the considered life cycle, within the range of 136% to 391%. In its turn, the roughness growth can increase the pavement damage within the range of 5% to 18%. The ‘empty running’ case study is intended to show how the methodological framework can be applied to quantify the impact of some transport policies on the pavement damage. When the empty running percentage reduces from 25% to 0%, the pavement damage, at the end of the considered life cycle, increases by more than 26% whichever case is analysed. These results are closely related to the flexible pavement structures, the trucks and the models considered in the analysis. However, the methodological framework developed has the advantage of being easily applied and extendable to other situations.
Apesar de ser fundamental para o desenvolvimento social e económico de qualquer região ou país, o transporte rodoviário de mercadorias é um dos responsáveis pelo crescimento do impacto ambiental dos transportes nas últimas décadas. No sentido de minimizar estes impactos, os veículos pesados têm vindo a sofrer alterações. É assim necessário que o dimensionamento de pavimentos rodoviários acompanhe essas alterações, uma vez que um pavimento é dimensionado para suportar um determinado fluxo de veículos pesados que irá solicitar o pavimento ao longo do seu tempo de vida. Os procedimentos de dimensionamento de pavimentos correntemente usados convertem o fluxo de veículos pesados num número equivalente de aplicações de eixos-padrão. Por exemplo, o procedimento usado em Portugal utiliza fatores de agressividade para efetuar essa conversão. No entanto, estes fatores de agressividade permanecem inalterados desde pelo menos 1995, pelo que não têm acompanhado a evolução dos veículos pesados. Esta tese apresenta o desenvolvimento de uma metodologia para estimar fatores de agressividade (e o dano em pavimentos). Neste sentido foram simulados espetros de carga por eixo usando o programa comercial TruckSIM®. A metodologia é aplicada a dois casos de estudo, um caso de estudo de ‘referência’ e um caso de estudo de ‘viagens sem carga’. Para tal, foram consideradas duas estruturas de pavimento e duas configurações de veículos pesados de mercadorias. Os veículos pesados podem transportar cargas com pesos diferentes e circular com velocidades de circulação diferentes sobre pavimentos com diferentes níveis de irregularidade. No terceiro dos 3 níveis da abordagem hierárquica usada, foi criada uma aplicação que permite considerar a degradação do módulo das misturas betuminosas e o aumento da irregularidade do pavimento ao longo do período de dimensionamento. Esta aplicação é usada para quantificar (a) o efeito que a irregularidade inicial do pavimento tem no dano do pavimento, (b) o efeito que a degradação do módulo das misturas betuminosas, ao longo do período de dimensionamento, tem no dano do pavimento e (c) o efeito que o aumento da irregularidade do pavimento, ao longo do período de dimensionamento, tem no dano do pavimento. Os resultados mostram que os fatores de agressividade são fortemente afetados pelo tipo de veículo, pela estrutura do pavimento, pelo nível de irregularidade do pavimento e pelos critérios de dimensionamento considerados. Por exemplo, o fator de agressividade para o critério de fadiga e para um determinado tipo de veículo, que circula completamente cheio a 60 km/h sobre um pavimento com um Índice de Irregularidade Internacional (IRI) igual a 1 m/km, é 53% superior na estrutura delgada. O valor de IRI inicial e o modelo degradação do módulo das misturas betuminosas têm um grande efeito no dano do pavimento. A degradação do módulo pode aumentar os danos, no fim do ciclo de vida considerado, numa percentagem que pode variar entre 136% e 391%. Por sua vez, a evolução da irregularidade pode aumentar o dano do pavimento entre 5% e 18%. O caso de estudo ‘viagens sem carga’ pretende demonstrar a aplicabilidade da metodologia na quantificação do impacto que algumas políticas de transporte podem ter no dano dos pavimentos. Quando a percentagem de viagens sem carga reduz de 25% para 0%, o dano dos pavimentos, no fim do ciclo de vida considerado, aumenta em mais de 26%, seja qual for o caso analisado. Os resultados apresentados estão intrinsecamente relacionados com as estruturas de pavimento, as configurações dos veículos pesados e os modelos considerados na análise. Contudo, a metodologia desenvolvida tem a vantagem de poder ser facilmente utilizada e de poder ser facilmente estendida a outras situações.
EMSURE - (CENTRO-07-0224-FEDER-002004)
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Cheng, Hsu Chih, and 許志誠. "The research on equilibrium between willingness to accept and to pay for damage compensation of road accident." Thesis, 2000. http://ndltd.ncl.edu.tw/handle/53j7c4.
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碩士中央警察大學
交通管理研究所
88
Abstract The paper is a study on how to establish an objective and reasonable valuation basis of the compensation for damages in a traffic accident. The content of this study includes the overall review of the compensation for damages defined in the civil law, the derivation of the loss of any kinds of possible costs followed by a traffic accident that corresponds with the concepts of cost analysis of an accident to build up the necessary covering range of the compensation for damages, and the actual investigation in both property loss and non-property loss of those victims of a traffic accident and their corresponding analysis to determine the required valuation basis of the compensation for damages. Meanwhile, as a whole, five analysis methods are utilized in this study to simplify the procedure of determining the required valuation basis of the compensation for damages, such as the Questionnaire Survey Method used for estimating the aggressive property loss, the Method of Human Capital Approach, the Compensation for Damages Calculation Method and the Method of Expected Earning Value Approach used for calculating the negative property loss, and the Contingent Valuation Method used for estimating non-property loss by dealing with a simulated market for the mental loss of a person who is directly concerned with the damage to find the real value of the compensation for damages, besides, the real value mentioned above must be required to be a suitable amount of money and also be acceptable for both plaintiff who demands it and defendant who should be in charge of. Finally, there are two main results of the actual investigation of this study. The first one is based on the amount of the compensation for damages, it shows that the average loss of a victim of a traffic accident resulted in injury is about NT$ 2,717,000 ~ 5,328,000, and the average loss of a victim of a traffic accident resulted in death is about NT$ 3,762,000; the second one is based on the total cost of a traffic accident, it shows that the average loss of a victim of a traffic accident resulted in injury is about NT$ 5,454,000 ~ 8,065,000, and the average loss of a victim of a traffic accident resulted in death is about NT$ 10,601,000. These two results will be considered a reasonable reference not only for the victims but also for the examining committee of a traffic accident.
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LI, Han-Hsin, and 李漢鑫. "The Responsibility and Risk of Bike-Sharing Industries -A Case Study of the Situation in which Shared Bikes Parked on Public Roads Cause Damage to Pedestrians." Thesis, 2018. http://ndltd.ncl.edu.tw/handle/fqkpbg.
Full textAbstract:
碩士國立臺灣科技大學
財務金融研究所
106
Under the tendency of sharing economy and the Internet of Things, bike-sharing is like a hundred flowers in bloom all over the place. The trace of shared bikes is everywhere at Taiwan metropolitan areas. Besides satisfying the citizens with short-distanced movement, bike-sharing also provides the function of traveling and exercising at the metropolitan area, letting people roam around the city in a free and easy way, which makes more people go after becoming the knight on a bicycle like a flock of ducks. The business model of bike sharing is distinguished into whether the government is be part of it or not. One type of bike- sharing is with governmental participation, also known as public bicycle, which usually has stationed/fixed rental places, whom we can see in Taipei, New Taipei, Taoyuan, Hsinchu, Taichung and Changhua. In addition to YouBike(Taipei), which has more than one thousand fixed rental place, there are other different kinds of bike-sharing such as iBike(Taichung), TBike (Tainan), cBike(Kaohsiung, PBike (Pingtung), and so on； The other type of bike- sharing is without governmental participation. Owing to smart technologies, enterprisescreate the anywhere-and-anytime mode of renting and returning throw the cell phones commercial platform and the Internet of Things. The bike-sharing which provides the mode of renting at anywhere and anytime without fixed rental places, is called dockless bike- sharing. Contributed to the dockless type, the convenience and consumers’ use-stickiness of bike-sharing promotes, which makes it to be seen everywhere at metropolitan areas. However, the roads in Taiwan are usually narrow, and most of them aren’t be marked a bike lane off. As a result, bicycles compete against not only pedestrians but also motorcycles and cars, making bicyclists conflict with other users. Therefore, besides delighting in the increasing usage rate of bike-sharing, the government and bicycle industry should teach bicyclists the correct etiquette , put great efforts into publicizing the trafficregulations, and perfect the policy formulation, in order to reduce the car-accident rate, which let it possible for shared bicycles to coexist in peace with pedestrians and car drivers. Otherwise, the regulations of parking shared bicycles in different local governments aren’t all the same. Part of local governments such as Taipei City and New Taipei City prohibit people from parking shared bicycles on motorcycle parking spaces. In areas where people are allowed to do so, there is no appropriate plan of amount. Moreover, our compatriots haven’t built up the basic bicycle etiquette yet in general. As a result, we can still frequently see that the bicycles are parked not on motorcycle parking spaces appropriately and also in an inappropriately way, as be abandoned on roads at will. The situation above particularly happens to dockless bike-sharing. Let us think about the situation that a pedestrian falls down because he/she incautiously kicks a bicycle while walking in a dark orrainy day with unclear sight. When the accident happens, whom the pedestrian is going to lodge a claim with？ Who should take the relevant liabilities for compensation？ Are bike- sharing industries under the obligation to maintain and manage their own shared bikes and take the liability for compensation or not？ However, the bike-sharing industry must take the responsibility. But, will the unsure limitation of liability, causing unpredictable risks,makes the enterprises take too much risks, which holds Green Industry back and obstruct the development of bike-sharing？ Therefore, it is worth for us to think deeply about how to strike a balance. Rather than traffic accidents of bicycles ridden on the roads, this thesis’ study area focused on the situation that shared bikes parked on public roads cause damage to pedestrians, in which whether the bike-sharing industry has to take the liability for compensation. In other words, who should take the liability for compensation for the danger of inappropriately-parked shared bikes causing damage to pedestrians, the bike-sharingindustry or the lessee(bicyclist)？ Can their property bear the liability for compensation tosatisfy the victim？ It matters to the trilateral balance and protection between the bike-sharing industry, bicyclist and pedestrian. If the irregularly parked bicycles belong to the bike-sharing industry’s operating risk, bike-sharing industries reorganize it and work on it. Then, the effect on inside enterprise autonomy shoud works than on outside governmentalban. It may be more helpful to solve this problem. But, does the bike-sharing industry have any technique to manage bicyclists’ behavior of parking randomly？ With an eye on the uncertainty and uncontrollable of bicyclists’ behavior, if the bike-sharing industry takes toomuch liability for compensation and duty of care of bicyclists’ randomly-parking behavior, it is afraid that the enterprises under the extreme company risk can’t afford it. In order notto obstruct the innovation of business model and not to strangle the existence of bike-sharing, is there any method to decrease the risk or control it reasonably？ This is also one of points in the thesis.
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Oliveira, Luís Miguel dos Santos Paulo. "Análise da estrutura de pavimento do projeto de execução da ligação da EN329 à EN229 (Vila de Sátão)." Master's thesis, 2019. http://hdl.handle.net/10316/93505.
Full textAbstract:
Dissertação de Mestrado Integrado em Engenharia Civil apresentada à Faculdade de Ciências e TecnologiaCom a falta de investimentos governamentais em estradas locais, as câmaras municipais veem-se obrigadas a fazer grandes investimentos na construção de vias, de modo a criarem alternativas ao tráfego de atravessamento de pesados do centro das suas vilas e cidades.A necessidade de reduzir custos, mantendo a qualidade das estradas, é fundamental para o equilíbrio financeiro das autarquias, por isso deve-se garantir um projeto de qualidade e um baixo custo em obra. As vias de comunicação municipais são importantes, a sua complementaridade à rede nacional é fundamental, para garantir a acessibilidade a algumas populações e o escoamento do produto das suas atividades económicas. Na pavimentação de estradas tem-se presenciado uma evolução técnica que é extremamente importante, de modo a encontrar e aperfeiçoar o melhor método de dimensionamento, um objetivo que a engenharia deverá alcançar.Com este trabalho prende-se analisar o projeto de dimensionamento da estrutura de pavimento da ligação da EN229 com a EN329, uma ligação que visa retirar o tráfego de atravessamento de veículos pesados do centro da vila de Sátão. O projeto em questão baseou-se apenas nas estruturas de pavimento definidas no Manual de Conceção de Pavimentos para Rede Rodoviária Nacional (MACOPAV) desenvolvido pela Junta Autónoma de Estradas, agora Infraestruturas de Portugal. Assim sendo, pretende-se avaliar o efeito de diferentes variáveis (nomeadamente, volume de tráfego, sua agressividade e crescimento, velocidade do tráfego, temperatura, capacidade de suporte da fundação e tipo de betume) na estrutura do pavimento. Para tal, comparam-se procedimentos do MACOPAV e do método da Shell, calcula-se a resposta estrutural nos prontos críticos da estrutura do pavimento, recorrendo ao KENPAVE, e compara-se essa resposta com a obtida nas leis de transferência da Shell, de modo a obter o dano que deverá ser cerca de 80%. Adicionalmente, são estudados cenários associados ao tráfego que poderá ser gerado pelo parque empresarial de Sátão, até agora reduzido.Da análise efetuada, concluiu-se que as variáveis com maior impacto na estrutura do pavimento são o módulo de deformabilidade do solo de fundação, a agressividade do tráfego, o tipo de betume e a velocidade.
With the lack of government investment on local roads, city councils are forced to make major investments in road construction in order to create alternatives to heavy-crossing traffic from the center of their towns and cities.The need to reduce costs while maintaining the quality of roads is fundamental for the financial equilibrium of municipalities, so a quality project and a low labor cost must be guaranteed. The municipal roads are important, their complementarity to the national network is fundamental, to guarantee the accessibility to some populations and the disposal of the product of their economic activities. In the paving of roads has been witnessed a technical evolution that is extremely important to find and perfect the best method of design, a goal that engineering must achieve.The aim of this work is to analyze the design of the EN229 link pavement structure with EN329, a link that aims to remove heavy traffic from the center of the town of Sátão. The project in question was based only on the pavement structures defined in the Manual for the Design of Pavements for National Road Network (MACOPAV) developed by the Autonomous Roads Board, now Infrastructures of Portugal. Thus, it is intended to evaluate the effect of different variables (namely, traffic volume, its aggressiveness and growth, traffic speed, temperature, foundation support capacity and type of bitumen) in the pavement structure. For this, MACOPAV and Shell method procedures are compared, the structural response is calculated on the critical ready-made pavement structure using KENPAVE and this response is compared with that obtained in the Shell transfer laws, in order to obtain the damage that should be about 80%. In addition, scenarios associated with traffic that can be generated by the business park of Sátão, until now reduced, are studied.From the analysis carried out, it was concluded that the variables with the greatest impact on the pavement structure are the deformability modulus of the subgrade, the agressiveness factor, the bitumen grade and the speed.