Dissertations / Theses: 'Cone penetration test'

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Butlanska, Joanna. "Cone penetration test in a virtual calibration chamber." Doctoral thesis, Universitat Politècnica de Catalunya, 2014. http://hdl.handle.net/10803/279364.

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Cone penetration test (CPT) is a fast and reliable site investigation tool for exploring soils and soft ground. While the interpretation of the test results in clay has advanced considerably from a theoretical and numerical viewpoint that of tests in sands still relies largely on empirical correlations. A major source of such correlations comes from tests done in calibration chambers (CC), where soil state and properties might be tightly controlled. Calibration chambers are relatively large pieces of equipment, and calibration chamber testing is expensive and time consuming. Moreover, CC tests are performed on freshly reconstituted sands whose fabric may vary from that of natural sand deposits. Hence, correlations developed for one type of sand might not be suitable for another sand deposit. Numerical DEM-based calibration chambers might offer an interesting alternative to the more cumbersome physical tests. This study is the first attempt to perform a three-dimensional DEM-based simulation of cone penetration test. The three-dimensional commercial DEM code (PFC3D) is used to develop Virtual Calibration Chamber CPT (VCC CPT) model. To achieve that objective, several steps were necessary. First, calibration of an analogue discrete material to represent Ticino sand was performed using single-element tests. Afterwards, the mechanical response of the discrete material was further validated by performing additional triaxial tests with different initial conditions. The VCC CPT model was then constructed. Comprehensive dimensional analysis showed that the best option to balance computational efficiency and realism was to fill the chamber with a scaled-up calibrated discrete material. An original filtering technique was proposed to extract steady state cone resistances. A basic series of simulations was performed to explore the effect of initial stress and relative density in cone resistance. The results obtained from the simulations did fit closely the trends that had been previously established using physical chambers. That result was taken as a general validation of the proposed simulation approach. From the micromechanical point of view, the granular material is highly discontinuous and inhomogeneous. Obtaining a homogeneous initial state (especially in the zone of the penetrating cone) is crucial to obtain easily interpretable results. Specific procedures to assess initial state inhomogeneities were developed. DEM-based models can provide results at various level of resolution i.e. the microscale, the meso-scale and the macro-scale. A large series of VCC CPT has been performed. Simulations were performed for models with different horizontal servo-control walls, various sizes of chamber, cone and particles and two boundary conditions. The results were analyzed, focusing on aspects such as chamber size, particle size and boundary condition effects on steady state cone resistance values. A smaller number of tests have also been examined from the point of view of shaft resistance. Most trends and results obtained are shown to be in agreement with previous physical tests. When disagreements appear, the causes are identified: the most severe disagreements result from initial inhomogeneities in the discrete model. The work described in this thesis showed ease the burden of future CPT calibrations in granular materials. Los ensayos de penetración estática de cono (CPT) son una de las herramientas más importantes en el reconocimiento geotécnico. La interpretación de los resultados de ensayo en arcilla ha avanzado considerablemente desde un punto de vista teórico y numérico. Sin embargo la interpretación de los resultados en los materiales granulares por ejemplo arena) todavía está basada en correlaciones empíricas provenientes de las pruebas realizadas en cámaras de calibración (CC), donde el estado del suelo y sus propiedades pueden ser controlados. Las cámaras de calibración son equipos relativamente grandes, y los ensayos en ellas son bastante costosos en tiempo y recursos. Por otra parte, las pruebas se realizan en muestras de arenas reconstituidas cuyas propiedades varían respecto de los depósitos naturales de donde provienen. Por lo tanto, las correlaciones desarrolladas en un tipo de arena podrían no ser adecuadas para otro depósito distinto. Cámaras de calibración numéricas (virtuales) basadas en el método de elementos discretos (DEM) podrían ofrecer una alternativa interesante a los ensayos físicos. Este estudio es el primer intento de realizar una simulación basadas en el método de los elementos discretos tridimensionales de ensayos de penetración de cono. El código comercial tridimensional (PFC3D) ha sido usado para desarrollar el modelo de CPT de Cámara de Calibración Virtual (CPT VCC). Para alcanzar este objetivo fueron necesarios varios pasos. En primer lugar, se llevó acabo la calibración de un material discreto análogo a arena de Ticino mediante ensayos elementales. A continuación se construyó el modelo CPT VCC. Un análisis dimensional exhaustivo mostró que la mejor opción para crear un modelo eficiente y real era llenar la cámara con un material con el tamaño de grano 50 veces mayor que el de la arena de Ticino. Se propuso una técnica original de filtrado para extraer la resistencia de punta estacionaria. Se realizó una serie básica de simulaciones para explorar el efecto de la tensión inicial y la densidad relativa sobre la resistencia de cono. Los resultados obtenidos de las simulaciones se ajustan estrechamente a las tendencias establecidas previamente en cámaras físicas. Este resultado fue tomado como una validación general del programa de simulación propuesto. Desde el punto de vista de la micro-mecánica, el material granular es muy discontinuo y no homogéneo. La obtención de un estado inicial homogéneo (especialmente en la zona de penetración del cono) es crucial para obtener resultados fácilmente interpretables. Por lo tanto se han desarrollado procedimientos específicos para evaluar heterogeneidades del estado inicial. Los resultados manifestaron el papel clave del contorno de modelo (paredes rígidas), tanto pasivo como activo (servo-controlados), durante la formación del modelo. Los modelos basados en el DEM puede proporcionar resultados a varios niveles de la resolución, es decir del micro-, meso- y macro escala. Se ha realizado una gran serie de VCC CPT. Las simulaciones se realizaron para modelos con diferentes posiciones en las paredes horizontales de servo-control, varios tamaños de cámara, varios tamaños del cono y de las partículas y dos condiciones de contorno. Los resultados se analizaron centrándose en varios aspectos como el tamaño de la cámara, el tamaño de las partículas y los efectos de condiciones de contorno sobre el valor de la resistencia de punta. Un número limitado de los CPT fue examinado desde el punto de vista de la resistencia del fuste del cono. Se observó que la mayoría de las tendencias y los resultados obtenidos estaban de acuerdo con resultados previos obtenidos en ensayos físicos. El trabajo presentado en esta tesis debería facilitar futuras calibraciones CPT en materiales granulados.

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Teh, Cee-Ing. "An analytical study of the cone penetration test." Thesis, University of Oxford, 1987. http://ora.ox.ac.uk/objects/uuid:e339b846-021c-4d25-9f56-0f969c77ead2.

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The quasi-static penetration of a cone penetrometer into clay can be formulated as a steady state problem by considering a steady flow of soil past a stationary cone. The soil velocities are estimated from the flow field of an inviscid fluid, and the incompressibility condition is achieved by adopting a stream function formulation. Emphasis is placed on obtaining an accurate velocity estimate and this is accomplished by a solution of the Navier-Stokes equations. The strain rates are evaluated from the flow field using a finite difference scheme. The clay is modelled as a homogeneous incompressible elastic-perfectly plastic material and the soil stresses are computed by integrating along streamlines from some initial stress state in the upstream region. These stresses do not in general obey the equilibrium equations, although one of the two equations can be satisfied by an appropriate choice of the mean stress. Several attempts have been made to use the remaining equilibrium equation to obtain an improved velocity estimate and three plausible iterative methods are detailed in this thesis. In a second study, a series of finite element calculations on the cone penetration problem is performed. In modelling the penetration process, the cone is introduced in a pre-formed hole and some initial stresses assumed in the soil, incremental displacements are then applied to the cone until a failure condition is reached. Although the equilibrium condition is satisfied very closely in the finite element calculations, it is extremely difficult to achieve a steady state solution. In a third series of computations, the stresses evaluated by the strain path method are used as the starting condition for the finite element analysis. This is believed to give the most realistic solution of the cone penetration problem because both the steady state and equilibrium conditions are approximately satisfied. Numerically derived cone factors are presented and these are found to depend on the rigidity index of the soil and the in situ stresses. The pore pressure distribution in the soil around the penetrometer is estimated using Henkel's empirical equation. The dissipation analysis is based on Terzaghi's uncoupled consolidation theory. The governing equation is formulated in the Alternating-Direction-Implicit finite difference scheme. This formulation is unconditionally stable and variable time steps are used to optimise the solution procedure. The dissipation curves are found to be significantly affected by the rigidity index of the soil and a dimensionless time factor is proposed to account for this effect.

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Eslami, Abolfazl. "Bearing capacity of piles from cone penetration test data." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp05/nq21000.pdf.

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Walker, James. "Adaptive finite element analysis of the cone penetration test." Thesis, University of Nottingham, 2007. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.438553.

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Eid, Walid Khaled. "Scaling effect in cone penetration testing in sand." Diss., Virginia Polytechnic Institute and State University, 1987. http://hdl.handle.net/10919/49849.

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The Cone Penetration Test (CPT) was developed originally in Holland in the 1930’s as a device which provides a small scale model of a pile foundation. Early versions were simple cone points for which the only measurement was the thrust required to push the point through the ground. Over the past 20 years, the cone was standardized to a tip area of 10 cm², and an electrical version was produced, which allows for continuous measurement of the cone tip resistance and sleeve friction along with a computer-based data acquisition system. The electrical cone represents a significant step forward for the CPT, since it provides a continuous profile of information that can be used to identify soil type and define important engineering parameters. More recently, the CPT has shown considerable potential for calculation of settlements of footings on sand, determination of pile capacity, assessment of ground pressures, and evaluation of liquefaction potential for cohesionless soils. Along with the widening application of the CPT, new varieties of cone penetrometers have appeared, with different sizes than the standard. Smaller cones are used for instances where relatively small depths of soil need to be penetrated, and larger cones have been developed for penetrating dense and gravelly soils. With the introduction of the new cones, there has been a tendency to assume that the methods for reducing CPT data for the standard sized cone can be extrapolated to the other sizes of cones. That is, it is assumed that there are no scale effects in cones of different sizes. While this may be true, to date, little direct evidence has been produced to support this view, and the issue is an important one from two points of view: 1. The present data analysis technology is based on that primarily from testing with a standard cone. lt is important to know if any changes are needed in this approach, or if the existing methods can be used with confidence for any size cone. 2. If it can be shown that no scale factor exists, then this will allow the use of new, smaller cones in experimentation in modem calibration chambers with the knowledge that the test results are applicable for the cones that a.re more widely used in practice. The smaller cones offer several advantages in this type of work in that they facilitate the research considerably by reducing the effort involved in sample preparation, and they are less likely to produce results influenced by boundary conditions in the chamber. One of the major objectives of this research is to develop an insight into the issue of the scale factor caused by the use of different sizes of cones. This is accomplished through an experimental program conducted in a new large scale calibration chamber recently constructed at Virginia Tech. Many of the latest developments in cone penetration testing have been forthcoming from testing done in calibration chambers where a soil mass can be placed to a controlled density under known stress conditions. To conduct the experimentation of this work, it was necessary to design, fabricate, and bring to an operational stage a calibration chamber. The Virginia Tech chamber is one of the largest in the world. A significant portion of the effort involved in this thesis research was devoted to this task. In particular, attention was devoted to the development of a system for placement of a homogeneous soil mass in the chamber, and the implementation of a microcomputer-based data acquisition unit to record and process the test results. The scale effects investigation was performed using three different sizes of cone penetrometers in a test program conducted in the calibration chamber. Of the three cones, one is smaller than the standard with a tip area of 4.23 cm², one was a standard cone with a tip area of 10 cm², and one was larger than the standard cone with a tip area of 15 cm². A total of 47 tests were carried in the chamber using two different levels of confining stress and two different sand densities. The test results show that while a scale factor might exist, the degree of its influence on interpreted soil parameters for a practical problem does not appear significant. Ph. D. incomplete_metadata

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Greig, James William. "Estimating undrained shear strength of clay from cone penetration tests." Thesis, University of British Columbia, 1985. http://hdl.handle.net/2429/25076.

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This paper discusses several proposed methods for estimating undrained shear strength from cone penetration tests. This correlation has been studied in the past, however, most have focussed only on the cone bearing. In addition to discussing these traditional methods, this paper evaluates recently proposed methods of estimating Su from CPT pore pressure data. The results of field vane and cone penetration tests from five lower mainland sites are presented in relation to the different proposed correlation techniques. The results show that there is no unique cone factor for estimating Su from CPT for all clays, however, a reasonable estimate of Su can be made by comparing the predictions from several of the proposed methods. With local correlations these techniques can be quite reliable. The results also show that the estimation of Su from CPT is influenced by various factors relating to: the choice of a reference Su, cone design, CPT test procedures and the soil characteristics. In particular, the estimation of Su from CPT is strongly influenced by such soil parameters as stress history, sensitivity and stiffness. Increases in OCR and sensitivity were reflected by increases in the traditional cone factors Nc and Nk. The use of pore pressure data appears to be a promising means of estimating. Su from CPT. Expressions have been developed that predict excess pore pressures based on cavity expansion theory and attempt to include the effects of sensitivity, stress history and stiffness. In addition, comparisons between friction sleeve measurements and Su and a method for estimating sensitivity from friction ratios are presented. Lastly, recommended procedures for estimating Su from CPT are given. Applied Science, Faculty of Civil Engineering, Department of Graduate

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Payoongwong, Chatchawahn. "Field and laboratory studies of the behavior of spread footing for highway bridge construction (HAM-32-0.14)." Ohio : Ohio University, 1997. http://www.ohiolink.edu/etd/view.cgi?ohiou1177085999.

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Cargill, Patrick Ethan. "The influence of friction sleeve roughness on cone penetration test measurements." Thesis, Georgia Institute of Technology, 1999. http://hdl.handle.net/1853/23002.

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Talbot, Michael H. "Dynamic Cone Penetration Tests for Liquefaction Evaluation of Gravelly Soils." BYU ScholarsArchive, 2018. https://scholarsarchive.byu.edu/etd/7542.

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Dynamic Cone Penetration Tests for LiquefactionEvaluation of Gravelly SoilsMichael H. TalbotDepartment of Civil and Environmental Engineering, BYUDoctor of PhilosophyIn North American practice, the Becker Penetration Test (BPT) has become the primary field test used to measure penetration resistance of gravelly soils. However, this test is expensive and uncertainties exist regarding correlations and corrections for rod friction. As an alternative, the dynamic penetration test (DPT) developed in China has recently been correlated with liquefaction resistance in gravelly soils. The DPT equipment consists of a 74 mm diameter cone tip driven by a 120 kg hammer with a free fall height of 100 cm using 60 mm drill rod to reduce friction. The DPT is a very rugged, economical device, capable of penetrating dense gravel layers. During DPT field investigations following the 2008 Wenchuan earthquake in China, liquefaction resistance was correlated with DPT blow count.Dynamic Cone Penetration tests (DPT) tests were also performed adjacent to Becker Penetration test (BPT) sites at Pence Ranch, Whiskey Springs, and Larter Ranch in Idaho where gravel liquefaction was observed during the 1983 Mw6.9 Borah Peak earthquake. Companion DPT tests were performed using an automatic hammer at two energy levels, namely the energy specified in the original Chinese standard and the energy typical of SPT testing which would be easier to use in practice. Companion testing was undertaken to determine if the cone could be driven in gravelly soil with more standard drilling equipment available to geo-professionals. The second energy level also offers the potential to provide more resolution on the soil layering. PDA measurements were made to determine the energy transferred to the cone rods and the statistical variation in the energy transferred.Additionally, companion DPT tests were undertaken at the downstream toe of Millsite Dam near Ferron, Utah, where gravelly soils are predicted to liquefy in an earthquake. Two energy levels were used, one using an automatic hammer and the other a manual donut hammer. The blow counts from the BPT and DPT correlated reasonably well for gravels using the automatic hammer, but poor correlation was obtained with the donut hammer. Liquefaction resistance for the BPT and DPT soundings were also in reasonable agreement for gravel layers suggesting that the DPT can provide liquefaction hazard evaluations more economically than the BPT using direct correlations with field performance.Correlations suggest that the standard energy corrections developed for the SPT can be used for the DPT. In general, the liquefaction resistance from the BPT and DPT correlated reasonably well when using the 30% probability of liquefaction resistance curve developed for the DPT.Keywords: Michael H Talbot, liquefaction, Chinese dynamic penetration test, gravelly soils.

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Gustafson, Ellen, and Emelie Strömgren. "Cone Penetration Test - a comparative study of the equipment and the performance." Thesis, Linköpings universitet, Kommunikations- och transportsystem, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-121130.

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Inom geotekniken behövs ofta jordlagerföljden och jordens egenskaper bedömmas. För att göra detta används ofta sonderingsmetoden Cone Penetration Test (CPT), som används främst till att ge en preliminär bedömning av jordlagerföljden och en uppskattning av geotekniska egenskaper. CPT-sondering är en avancerad metod som ställer högre krav på både fältgeotekniker och handläggande geotekniker jämfört med andra metoder och är en metod där många faktorer påverkar resultatet. Detta examensarbete undersöker vilka faktorer som påverkar CPT-sondering med fokus på utrustning och handhavandet hos teknikkonsultföretaget WSP i Östergötland. Syftet med arbetet är att jämföra och utvärdera metod och resultat hos WSP för att se om det finns några skillnader i handhavandet och mellan de tre olika sonderna som är använda i studien. I studien utfördes 12 stycken CPT-sonderingar i samma område och dessa utfördes av samma fältgeotekniker, där häften av sonderingarna var utförda med förborrning och vattenfyllt sonderingshål och den andra hälften utförda med endast förborrning. Dessutom utfördes en skruvprovtagning i området. När sonderingarna var gjorda utvärderades resultaten i programvaran Conrad. Sonderingarna utfördes i ett område mellan Vånga och Göten, väster om Norrköping och området består främst av silt med lager av sand. Resultatet av studien visar att sond A har de jämnaste resultaten och orsaken till detta är troligtvis att denna sond är den som senast har kalibrerats. Efter sondering 2-C upptäcktes en skada på friktionshylsan för sond C, friktionshylsan byttes ut och trots detta ser resultatet för denna sond bra ut. Den första sonderingen gjord efter byte av friktionshylsan avviker dock i resultatet jämfört med de andra sonderingarna gjorda med sond C. Resultatet från sond B visar att denna sond uppnår lägre värde jämfört med de andra sonderna. En orsak till detta anses vara att denna sond är den sond som är kalibrerad med det tidigaste datumet. Slutsatsen i studien är att de faktorer som påverkar resultatet mest är kalibrering, att sonden är vätskemättad och att kontroller har utförts av sonden innan och efter sonderingen.

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Rahardjo, Paulus P. "Evaluation of liquefaction potential of silty sand based on Cone Penetration Test." Diss., Virginia Polytechnic Institute and State University, 1989. http://hdl.handle.net/10919/53844.

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Liquefaction ls a phenomenon where a saturated soil can temporarily lose its shear strength during an earthquake as a result of the development of excess pore pressures. For the past 25 years since Iiquefaction phenomenon was first explained, it was thought to be mainly a problem with clean sand, and most of the research has focused on these soils. However, as case history information has come to light, it has become apparent that silty sands are commonly involved, and in some cases even silts. This has generated a need for knowledge about the response of silty sands and silts under seismic loading. Related to this issue is the question of how best to determine the Iiquefaction resistance of these soils in a practical setting. This research has the objectives of providing an understanding of the behavior of saturated silty sands under seismic loading, and developing a rational basis for the use of the Cone Penetration Test (CPT) to predict Iiquefaction resistance in these materials. The study is primarily experimental, relying on laboratory and field testing and the use of a unique, large scale calibration chamber. The calibration chamber allows the field environment to be duplicated in the laboratory where conditions can be closely controlled and accurately defined. One of the first problems to be overcome in the research was to determine how to prepare specimens of silty sands that would reasonably duplicate field conditions in both the small scale of the conventional laboratory tests, and the large scale of the calibration chamber. Out of four different methods explored, consolidation from a slurry proved to be best. Two silty sands were located which had the desired characteristics for the study. Field work, involving both the Standard Penetration Test (SPT) and CPT was done as part of this investigation. The behavior of the silty sands were determined in the laboratory from monotonic and cyclic loading tests. The test results show that the effect of fines is to reduce the cone penetration resistance, but not to affect the liquefaction resistance. The steady state shear strength of the soils seems to be correlated to the cone tip resistance, however, this correlation shows a higher steady state shear strength than those back figured from case history data. The results were also used to define state parameters for both of the soils tested. The state parameter was found to be a reliable index to the liquefaction potential and further study in this area is recommended. Ph. D.

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Ozan, Cem. "Estimation Of Grain Characteristics Of Soils By Using Cone Penetration Test (cpt) Data." Master's thesis, METU, 2003. http://etd.lib.metu.edu.tr/upload/1088988/index.pdf.

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Due to lack of soil sampling during a conventional cone penetration testing (CPT), it is necessary to classify soils based on recorded tip and sleeve friction and pore pressure (if available) values. However, currently available soil classification models are based on deterministic and judgemental determination of soil classification boundaries which do not address the uncertainties intristic to the problem. Moreover, size and quality of databases used in the development of these soil classification models are undocumented and thus questionable. Similar limitations do also exist in the development of SPT-CPT correlations which are widely used in SPT dominated design such as soil liquefaction triggering. To eliminate these discussed limitations, within the confines of this study it is attempted to present (1) a new probabilistic CPT- based soil classification methodology, and (2) new SPT-CPT correlations which address the uncertainties intrinsic to the problems. For these purposes, a database composed of 400 CPT/SPT boring data pairs was compiled. It is intended to develop probabilistic models, which will correlate CPT tip and sleeve friction values to actual soil classification and CPT tip resistance to SPT blow count N. The new set of correlations, model parameters of which estimated by implementing maximum likelihood methodology, presented herein are judged to represent a robust and defensible basis for (1) prediction of soil type based on CPT data and, (2) estimation of SPT-N value for given CPT data.

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Deshpande, Kedar M. "A Cone Penetration Test (CPT) based assessment of explosive compaction in mine tailings." Thesis, University of British Columbia, 2009. http://hdl.handle.net/2429/8660.

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Failure of tailings dams can occur due to liquefaction of saturated and loosely deposited silt and sand sized tailings under both seismic and static conditions. The consequences in terms of loss of lives and property are severe. As tailings possess soil-like structure and grain size distribution, it is possible to use ground improvement measures typically used for soils to improve the stability of these dams. It is also possible to use densification techniques to reduce the volume of the in-place tailings to provide greater storage space. This thesis reviews the assessment of ground densification at a tailings facility in Northern Ontario at which a section of tailings dam was densified by explosive compaction (EC). The EC was complemented by surface compaction using Dynamic Compaction and Rapid Impact Compaction. Due to the nature of tailings deposition, the grain size distribution and density of materials in the dam varied considerably both laterally and with depth. This complicated the assessment of the improvement obtained. Piezometer cone penetration test data obtained before and at various times after ground treatment were reviewed to assess the range of tailings types encountered in the dam and the level of tip resistance achieved by the ground treatment. Settlement and piezometer data were also reviewed but were of insufficient quality or quantity to be useful as indicators of the degree of improvement obtained. Cone data were normalized for stress level and were sorted according to a unified soil behaviour type classification scheme previously used in soils and tailings. The soil behaviour type index, Ic, was found to be a useful indicator of tailings type. Despite the extreme variability of the deposits, it proved possible to identify the level of tip resistance achieved by the ground treatment in various material types at the site.

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Zhuang, Peizhi. "Cavity expansion analysis with applications to cone penetration test and root-soil interaction." Thesis, University of Nottingham, 2017. http://eprints.nottingham.ac.uk/42772/.

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As one of the most versatile and reliable in-situ devices, cone penetrometers have been extensively used in soil exploration (e.g. soil classification, soil profiling, back-calculation of soil properties etc.) both experimentally and theoretically over the past 80 years. To improve its site accessibility, reduce the required sample size with minimal boundary effects, or model soil penetration by plant roots or earthworms, cone penetrometers with various sizes are often employed both in the field and laboratory. Consequently, size-dependent performance may appear, and this is one of the subjects of this research. A series of cone penetration tests with three sized cone penetrometer (12mm, 6mm, 3mm) on the Leighton Buzzard sand with two fractions (E and C) was performed at the 1g condition. Evident size effects were observed both in the cone tip resistance and shaft friction. To account for the observed size-dependent behaviour, theoretical methods based on the cavity expansion theory were developed in addition to the available experimental findings. Firstly, a size-dependent quasi-static cavity expansion solution was developed by improving the conventional cavity expansion theory incorporating with a strain gradient theory of plasticity. A stiffer response is modelled for a smaller cylindrical/ spherical cavity with this solution. Based on the analogy of cone penetration and quasi-static cavity expansion, the developed size-dependent expansion solution for spherical cavities was employed to quantify the size effect in the cone tip resistance, and fair good agreements were achieved between the theoretical prediction and experimental results. Subsequently, the scale effect observed in shaft friction resistance was explained in terms of the interface frictional strength and mobilised lateral soil stress. The size-dependent interface frictional strength was discussed based on the available experimental data of other researchers, and an improved solution based on the elastic cylindrical cavity expansion solution was derived to quantify the size dependency of the mobilised lateral stress on the shaft. In the light of above discussions, dominating factors influencing the size-dependent behaviours in the cone penetration test are summarised. The other objective of the present research was to model the mechanical interaction between a growing root tip and the surrounding soil. Two elastic solutions for computing the stress and displacement fields around a displacement-controlled ellipse were developed based on the complex variable theory of elasticity and Fourier series method. By assuming the axial cross section of a root tip as a half-ellipse, the two-dimensional soil response to a short-term growing root tip was discussed with the derived elastic solutions. Benefits of radial swelling of the root tip to its axial penetration were summarised, and an approximate analytical method to estimate the soil resistance mobilised by a short-term root growth was suggested and employed in the present root tip-soil interaction analyses. In addition, influences of the additional shear stress in the process of static and quasi-static cavity expansion were analysed with an elastic-perfectly-plastic model. For Tresca materials, a non-equal initial stress field was considered in the static stress solution, and a quasi-static expansion solution was then derived for a cavity deforming in a hydrostatic stress field considering the material compressibility. The static stress solution is capable of calculating the stress redistribution around a circular rotating probe, and the large-strain quasi-static solution may be useful in theoretical predictions of the tip resistance of a rotating penetrometer (or pile) which has been often utilised in needle cone penetration tests for modelling the root tip elongation. Then the introduced methods in above solutions were applied to the static stress analysis of a circular cavity surrounded by the Mohr-Coulomb material under a non-equal stress field. Based on the conformal mapping function proposed by Detournay and Fairhurst (1987), both a loading and unloading analysis were carried out with the derived analytical solution. It can provide a simple method to predict the plastic failure zone and calculate the stress redistribution around a circular excavation (e.g. tunnel, pipeline) either under loading or unloading.

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Mo, Pin-Qiang. "Centrifuge modelling and analytical solutions for the cone penetration test in layered soils." Thesis, University of Nottingham, 2014. http://eprints.nottingham.ac.uk/14319/.

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The interpretation of measurements from the cone penetration test is still predominately based on empirical correlations, which can be attributed to the lack of understanding of penetration mechanisms, that involve severe stress-strain and shear dilatancy close to the probe. Even so, it remains one of the most widely used in-situ tools for site characterisation, and several methods for displacement pile design have been developed using CPT data. This research investigates the response of penetrometers and the behaviour of layered soils during installation of probes using geotechnical centrifuge modelling and cavity expansion analysis. Two series of centrifuge tests were performed in stratum configurations of silica sand in a half-cylindrical axisymmetric model, allowing the observation of the induced soil deformation through a Perspex window. The variations of penetration resistance and soil deformation with penetration depth, soil density, stress level and soil layering are examined from the results of the centrifuge tests. The quantified soil displacements and the resulting strains in the axisymmetric model have provided an effective approach for investigation of penetration mechanisms with soil element trajectories, strain paths and rotations of principal strain rate. The effects of layering on both resistance and soil deformation are shown with dependence of the relative soil properties and profiles. The results presented also serve as a base for applications of cavity expansion solutions, back analyses and further studies. Analytical solutions for cavity expansion in two concentrically arranged regions of soil are developed using a non-associated Mohr-Coulomb yield criterion for large strain analysis of both spherical and cylindrical cavities. The solutions are validated against finite element simulations and a detailed parametric study of the layered effects on the pressure-expansion curves is performed. To apply the proposed solutions to penetration problems, a simplified combination approach is suggested to eliminate the discrepancy between concentric layering and horizontal layering. The analytical study of penetration in two-layered and multi-layered soils is therefore achieved, with comparisons to elastic solutions and numerical simulations provided. The back analyses based on the resistance and soil deformation emphasise the influences of small-strain stiffness, soil-probe interface friction angle, and relative density/state parameter. The correlation between the cone tip resistance and the pile bearing capacity is also discussed, and the scale effects are examined through the ground surface effect and the layering effect by the developed cavity expansion solutions. The penetration mechanisms are summarised from the aspects of soil stress-strain history, particle breakage, soil patterns, and penetration in layered soils. The layered effects emphasised in this research indicate that the penetration resistance is strongly dependent on the soil properties within the influence zones above and below the probe tip, and also related to the in-situ stress gradient along the penetration path. It is also suggested that correlations from calibration chamber tests using uniform soil and a constant stress field may not be suitable for direct interpretation of CPT data. Finally, the averaging technique for pile design is suggested based on the transition curve of tip resistance in layered soils with consideration of the scale effects.

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16

Arndt, Alex Michael. "Performance-Based Liquefaction Triggering Analyses with Two Liquefaction Models Using the Cone Penetration Test." BYU ScholarsArchive, 2017. https://scholarsarchive.byu.edu/etd/6945.

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This study examines the use of performance-based engineering in earthquake liquefaction hazard analysis with Cone Penetration Test data (CPT). This work builds upon previous research involving performance-based liquefaction analysis with the Standard Penetration Test (SPT). Two new performance-based liquefaction triggering models are presented herein. The two models used in this liquefaction analysis are modified from the case-history based probabilistic models proposed by Ku et al. (2012) and Boulanger and Idriss (2014). Using these models, a comparison is made between the performance-based method and the conventional pseudo-probabilistic method. This comparison uses the 2014 USGS probabilistic seismic hazard models for both methods. The comparison reveals that, although in most cases both methods predict similar liquefaction hazard using a factor of safety against liquefaction, by comparing the probability of liquefaction, the performance-based method on average will predict a smaller liquefaction hazard.

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Gillespie, Donald G. (Donald Gardner). "Evaluating shear wave velocity and pore pressure data from the seismic cone penetration test." Thesis, University of British Columbia, 1990. http://hdl.handle.net/2429/30573.

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Recent developments in cone penetration testing have resulted in the addition of both pore pressure measurements and seismometers. The seismometers allow shear wave velocity testing to be performed at designated intervals. Both of these additions were researched to improve their application and interpretation. The significant factors effecting the pore pressure generated during cone penetration tests are discussed. The importance of various factors is especially dependent upon permeability, strength, and stiffness. For all sands tested, pore pressures lower than static were recorded behind the tip and higher than static were recorded on the face of the cone. It is believed that the large compressive stresses on the cone face result in positive pore pressures. As the cone tip passes a soil element unloading and continued shearing generate pore pressures lower than static in all sands. The sign of this pore pressure (higher or lower than static) was therefore considered primarily a function of the test equipment. Pore pressure response and the rate of dissipation of excess pore pressures were found useful in distinguishing fine granular soils and explaining soil stratigraphy. In cohesive soils the details of pore pressure measurement were found to be important only in stiff soils. Pore pressures at all measurement locations were found to increase with soil strength in soft to firm clays but may be negative of static in very stiff clays. Pore pressures behind the cone tip were often negative of static in stiff clays. Measurement techniques were refined to improve the accuracy of downhole shear wave velocity measurements. Comparisons of downhole and crosshole measurements were made at three well documented sites validating the technique. At several sites it was found useful to consider the Gmax values determined from shear wave velocity and density to distinguish soil type. Gmax to cone resistance ratios were shown to vary systematically with cone resistance values in sands. A wide range in Gmax to cone resistance was observed in clays. The dependence of both cone penetration resistance and Gmax to increased stress level or overburden stress is discussed. Applied Science, Faculty of Civil Engineering, Department of Graduate

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Taskinen, Timo I. "On the steady-state flow of an elastic-plastic material past cones and wedges." Thesis, University of Oxford, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.302330.

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Corob, Alexander Edward. "Analysis of Applied Modifications to a Cone Penetration Test-based Lateral Spread Displacement Prediction Model." BYU ScholarsArchive, 2019. https://scholarsarchive.byu.edu/etd/9065.

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This study set out to examine the effectiveness and reliability of six modifications to the Zhang et al. (2004) CPT-based lateral spread model. A regression analysis, distribution charts, and a discriminant analysis are performed to determine how effective the modifications are on the model. From the comparisons and statistical analysis performed in this study, application of these modifications reduces over-predictions from strain-based prediction methods. Unfortunately, the tendency to under-predict displacements on average is also increased.

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Schneider, James A. "Liquefaction response of soils in Mid-America evaluated by seismic cone tests." Thesis, Georgia Institute of Technology, 1999. http://hdl.handle.net/1853/20147.

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21

Monahan, Patrick Alistair. "The application of cone penetration test data to facies analysis of the Fraser River Delta, British Columbia." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp02/NQ37354.pdf.

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22

Blonquist, Jenny Lee. "Development of a Simplified Performance-Based Procedure for Assessment of Liquefaction Triggering for the Cone Penetration Test." BYU ScholarsArchive, 2020. https://scholarsarchive.byu.edu/etd/8438.

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Soil liquefaction can cause devastating damage and loss and is a serious concern in civil engineering practice. One method for evaluating liquefaction triggering potential is a risk-targeted probabilistic approach that has been shown to provide more consistent and accurate estimates of liquefaction risk than traditional methods. This approach is a “performance-based” procedure which is based off of the performance-based earthquake engineering (PBEE) framework developed by the Pacific Earthquake Engineering Research (PEER) Center. Unfortunately, due to its complexity, performance-based liquefaction assessment is not often used in engineering practice. However, previous researchers have developed a simplified performance-based procedure which incorporates the accuracy and benefits of a full performance-based procedure while maintaining a more simplistic and user-friendly approach. Until now, these simplified performance-based procedures have only been available for the SPT (Standard Penetration Test). With the increasing popularity of the CPT (Cone Penetration Test), a simplified procedure is needed for CPT-based liquefaction assessment. This thesis presents the derivation of a simplified performance-based procedure for evaluating liquefaction triggering using the Ku et al. (2012) and Boulanger and Idriss (2014) models. The validation study compares the results of the simplified and full performance-based procedures. The comparison study compares the accuracy of the simplified performance-based and traditional pseudo-probabilistic procedures. These studies show that the simplified performance-based procedure provides a better and more consistent approximation of the full performance-based procedure than traditional methods. This thesis also details the development of the liquefaction loading maps which are an integral part of the simplified method.

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23

Žaržojus, Gintaras. "Analysis of the results and it influence factors of dynamic probing test and interrelation with cone penetration test data in Lithuanian soils." Doctoral thesis, Lithuanian Academic Libraries Network (LABT), 2010. http://vddb.laba.lt/obj/LT-eLABa-0001:E.02~2010~D_20101230_093807-41798.

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The object of the thesis is soils that occur within the territory of Lithuania and may be used as basis for building foundations. The thesis studies the interpretation of the results of Dynamic Penetration Test (DPT) and Cone Penetration Test (CPT) of soils, reliability of direct (number of blows (Nx)) and de-rivative (dynamic point resistance (qd)) DPT parameters, analyses the result influencing factors and interrelation between DPT and CPT parameters. The data analysis has been performed by means of mathematical methods of statistics, also using analytical and empirical solutions. Having examined calculation data it was determined that the indirect parameter of Dy-namic Penetration Test – dynamic point resistance (qd) should not be used due to calculation de-faults and replaced with the direct parameter – number of blows (Nx). The analysis of DPT re-sults influencing factors shows that the lateral overburden pressure together with friction of rods are those with the greatest impact on penetration data. Within the scope of the work, it has re-vealed that the number of blows (Nx) and static cone resistance (qc) are closely correlated and it depends on the grain size distribution of soil, geotechnical properties and depth of occurrence. Disertacijos objektas yra Lietuvos teritorijoje slūgsantys gruntai, kurie gali būti statinių pamatų pagrindu. Disertacijoje nagrinėjama grunto tyrimo dinaminiu (DPT) ir statiniu (CPT) zondavimu rezultatų interpretacija, tiesioginio (smūgių skaičiaus (Nx)) ir išvestinio (dinaminės kūgio smigos (qd)) DPT rodiklių patikimumas, analizuojami rezultatus įtakojantys veiksniai ir sąsajos tarp DPT bei CPT zondavimo rodiklių. Duomenų analizė atlikta matematiniais statistiniais metodais, taip pat panaudojant analitinius ir empirinius sprendinius. Išnagrinėjus skaičiavimo duomenis buvo nustatyta, kad netiesioginis dinaminio zonda-vimo rodiklis – dinaminė kūgio smiga (qd) dėl skaičiavimo trukumų yra nenaudotinas ir keisti-nas į tiesioginį rodiklį – smūgių skaičių (Nx). DPT rezultatus įtakojančių veiksnių analizė paro-dė, kad zondavimo duomenims didžiausią įtaką turi gruntų šoninis geostatinis slėgis ir kartu zondavimo štangų trintis į gruntą. Darbo metu buvo gauta, kad egzistuoja tamprus koreliacinis ryšys tarp smūgių skaičiaus (Nx) ir statinės kūgio spraudos (qc), kuris priklauso nuo grunto gra-nuliometrinės sudėties, mechaninių savybių ir slūgsojimo gylio.

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24

Liao, Tianfei. "Post processing of cone penetration data for assessing seismic ground hazards, with application to the New Madrid seismic zone." Diss., Available online, Georgia Institute of Technology, 2005, 2005. http://etd.gatech.edu/theses/available/etd-05042005-133640/.

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Thesis (Ph. D.)--Civil and Environmental Engineering, Georgia Institute of Technology, 2006. Mayne, Paul W., Committee Chair ; Goldsman, David, Committee Member ; Lai, James, Committee Member ; Rix, Glenn J., Committee Member ; Santamarina, J. Carlos, Committee Member.

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25

Hatch, Mikayla Son. "Development of a Performance-Based Procedure to Predict Liquefaction-Induced Free-Field Settlements for the Cone Penetration Test." BYU ScholarsArchive, 2017. https://scholarsarchive.byu.edu/etd/6455.

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Liquefaction-induced settlements can cause a large economic toll on a region, from severe infrastructural damage, after an earthquake occurs. The ability to predict, and design for, these settlements is crucial to prevent extensive damage. However, the inherent uncertainty involved in predicting seismic events and hazards makes calculating accurate settlement estimations difficult. Currently there are several seismic hazard analysis methods, however, the performance-based earthquake engineering (PBEE) method is becoming the most promising. The PBEE framework was presented by the Pacific Earthquake Engineering Research (PEER) Center. The PEER PBEE framework is a more comprehensive seismic analysis than any past seismic hazard analysis methods because it thoroughly incorporates probability theory into all aspects of post-liquefaction settlement estimation. One settlement estimation method, used with two liquefaction triggering methods, is incorporated into the PEER framework to create a new PBEE (i.e., fully-probabilistic) post-liquefaction estimation procedure for the cone penetration test (CPT). A seismic hazard analysis tool, called CPTLiquefY, was created for this study to perform the probabilistic calculations mentioned above. Liquefaction-induced settlement predictions are computed for current design methods and the created fully-probabilistic procedure for 20 CPT files at 10 cities of varying levels of seismicity. A comparison of these results indicate that conventional design methods are adequate for areas of low seismicity and low seismic events, but may significantly under-predict seismic hazard for areas and earthquake events of mid to high seismicity.

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26

He, Jingwen. "Development of a Simplified Performance-Based Procedure for Assessment of Post-Liquefaction Settlement Using the Cone Penetration Test." BYU ScholarsArchive, 2019. https://scholarsarchive.byu.edu/etd/7532.

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Earthquake-induced liquefaction can cause severe damage to infrastructure is a serious concern in civil engineering practice. Post-liquefaction settlement is one of the common effects of liquefaction. The ability to predict and quantify post-liquefaction free-field settlement is a crucial part of seismic design. Many approaches have been developed during the past 50 years to perform liquefaction hazard analysis. The performance-based earthquake engineering (PBEE) framework developed by the Pacific Earthquake Engineering Research (PEER) center is a probabilistic framework that can provide a more accurate and complete seismic hazard analysis than other traditional methods. However, the PBEE framework is not widely used in routine projects due to its complexity.Previous researches have been performed to develop simplified performance-based procedures that can combine the simplicity of a traditional method and the accuracy of the full performance-based method. Unfortunately, these simplified performance-based procedures are only available for SPT. With the increase use of CPT, there is a need to develop simplified performance-based procedures for CPT. This study develops simplified performance-based procedures for the assessment of post-liquefaction free-field settlement for CPT, using the Boulanger and Idriss (2014) and the Ku et al. (2012) triggering models. The Juang et al. (2013) model, which is a probabilistic version of the Ishihara and Yoshimine (1992) model, is used in this study to performance free-field settlement calculations. The simplified procedure is based on the idea of liquefaction reference parameter maps. Reference values obtained from these parameter maps are then adjusted, using correction equations, to site-specific conditions. This study presents the deviations of the correction equations for the simplified performance-based procedure. The simplified procedure will then be validated in which 18 cities across the United States are analyzed using both the simplified procedure and the full performance-based procedure. The simplified performance-based procedure is shown to reasonably estimate the results of the full performance-based procedure. Finally, a study is performed to compare the accuracy and consistency of the simplified performance-based and the conventional pseudo-probabilistic procedures. The simplified performance-based procedure is found to provide better approximations of the full performance-based procedure with more consistency and precision.

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27

Coutu, Tyler Blaine. "Development of a Performance-Based Procedure for Assessment of Liquefaction-Induced Lateral Spread Displacements Using the Cone Penetration Test." BYU ScholarsArchive, 2017. https://scholarsarchive.byu.edu/etd/7216.

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Liquefaction-induced lateral spread displacements cause severe damage to infrastructure, resulting in large economic losses in affected regions. Predicting lateral spread displacements is an important aspect in any seismic analysis and design, and many different methods have been developed to accurately estimate these displacements. However, the inherent uncertainty in predicting seismic events, including the extent of liquefaction and its effects, makes it difficult to accurately estimate lateral spread displacements. Current conventional methods of predicting lateral spread displacements do not completely account for uncertainty, unlike a performance-based earthquake engineering (PBEE) approach that accounts for the all inherent uncertainty in seismic design. The PBEE approach incorporates complex probability theory throughout all aspects of estimating liquefaction-induced lateral spread displacements. A new fully-probabilistic PBEE method, based on results from the cone penetration test (CPT), was created for estimating lateral spread displacements using two different liquefaction triggering procedures. To accommodate the complexity of all probabilistic calculations, a new seismic hazard analysis tool, CPTLiquefY, was developed. Calculated lateral spread displacements using the new fully-probabilistic method were compared to estimated displacements using conventional methods. These comparisons were performed across 20 different CPT profiles and 10 cities of varying seismicity. The results of this comparison show that the conventional procedures of estimating lateral spread displacements are sufficient for areas of low seismicity and for lower return periods. However, by not accounting for all uncertainties, the conventional methods under-predict lateral spread displacements in areas of higher seismicity. This is cause for concern as it indicates that engineers in industry using the conventional methods are likely under-designing structures to resist lateral spread displacements for larger seismic events.

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Diemer, Francielle. "Caracterização da resistência de um solo tropical a partir do ensaio de penetração dinâmica de cone com energia variável (panda)." Universidade Federal de Goiás, 2014. http://repositorio.bc.ufg.br/tede/handle/tede/4364.

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Submitted by Erika Demachki (erikademachki@gmail.com) on 2015-03-26T18:02:39Z No. of bitstreams: 2 Dissertação - Francielle Diemer - 2014.pdf: 13400647 bytes, checksum: f1a5d38d2e6c6298ee648ff2cf652ac3 (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) Approved for entry into archive by Erika Demachki (erikademachki@gmail.com) on 2015-03-26T19:27:34Z (GMT) No. of bitstreams: 2 Dissertação - Francielle Diemer - 2014.pdf: 13400647 bytes, checksum: f1a5d38d2e6c6298ee648ff2cf652ac3 (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) Made available in DSpace on 2015-03-26T19:27:34Z (GMT). No. of bitstreams: 2 Dissertação - Francielle Diemer - 2014.pdf: 13400647 bytes, checksum: f1a5d38d2e6c6298ee648ff2cf652ac3 (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) Previous issue date: 2014-08-08 Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES Get soil resistance is critical to making any geotechnical design with confidence, thus, laboratory tests are used to determine the strength and deformability of the ground in discrete points involved in the volume of soil mass. Due to heterogeneity of soil formation is that field trials are needed to supplement this determination and enrich the bank information. Field trials were able to identify and estimate the mechanical parameters of the soil, an adequate prediction of the behavior of retaining structures, excavation, foundation, floor sizing, etc., and determine the characteristics of the soil profile, and have was used to estimate the mass of strength parameters involved ground. In this sense a new tool for the characterization of the soil profile from dynamic penetration of a metal cone with variable energy (PANDA) has been studied to find a relationship with the strength parameters of a tropical soil obtained in a vertical slope of about 4, 0 m high, located in Alexânia - GO with sandy visual tactile characteristics. Therefore, we performed PANDA tests up to 4.0 meters and determining the moisture profile through a survey to auger up to 3.70 meters and laboratory characterization tests were performed, determining the strength parameters in natural moisture condition and flooded , deformation parameters and determination of soil water characteristic curve (CCSA). PANDA the results were compared with the laboratory tests for this ground and found a range of variation between them always considering the trials of natural moisture condition. With the results it was possible to see the influence of suction in the PANDA test. In terms of resistance parameters was possible to find a friction angle of the relationship with the penetration of energy (qd) for this soil. Overall the strength parameters showed the same trend as the qd values obtained by PANDA compared with respect to depth. Finally, with the results it is recommended to carry out further testing on different soil types in different humidity conditions to improve relations found and increase the database. Obter a resistência do solo é fundamental para elaborar qualquer projeto geotécnico com confiança, sendo assim, ensaios de laboratório são usados para determinar a resistência e deformabilidade do solo, em pontos discretos no volume da massa de solo envolvido. Devido a heterogeneidade da formação do solo é que são necessários ensaios de campo para complementar essa determinação e enriquecer o banco de informações. Os ensaios de campo são capazes de identificar e estimar os parâmetros mecânicos do solo, para uma adequada previsão do comportamento de estruturas de contenção, escavações, fundações, dimensionamento de pavimentos, entre outros, além de determinar as características do perfil do solo, e têm sido utilizados para estimar parâmetros de resistência do maciço de solo envolvido. Nesse sentido uma nova ferramenta para caracterização do perfil do solo a partir de penetração dinâmica de um cone metálico com energia varíavel (PANDA) foi estudado para encontrar uma relação com os parâmetros de resistência de um solo tropical obtido em um talude vertical de aproximadamente 4,0 m de altura, localizado em Alexânia – GO, com características tatil visuais arenosas. Para tanto foram realizados ensaios de PANDA até 4,0 metros e determinação do perfil de umidade através de uma sondagem à trado até 3,70 metros e em laboratório foram realizados ensaios de caracterização, determinação dos parâmetros de resistência na condição de umidade natural e inundado, parâmetros de deformação e determinação da curva característica solo água (CCSA). Foram comparados os resultados do PANDA com os ensaios de laboratório para este solo e encontrou-se uma faixa de variação entre eles sempre considerando os ensaios da condição de umidade natural. Com os resultados encontrados foi possível ver a influência da sucção no ensaio PANDA. Em relação aos parâmetros de resistência foi possível encontrar uma relação do ângulo de atrito com a energia de penetração (qd) para este solo. No geral os parâmetros de resistência apresentaram a mesma tendência que os valores de qd obtidos pelo PANDA quando comparados em relação a profundidade. Por fim, com os resultados encontrados recomenda-se realizar mais ensaios com diferentes tipos de solo em diferentes condições de umidade para melhorar as relações encontradas e aumentar o banco de dados.

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Svensson, Axel. "Jämförelse av odränerad skjuvhållfasthet mellan CPT-sondering och fallkonförsök på Uppsalalera." Thesis, Uppsala universitet, Institutionen för geovetenskaper, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-325059.

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The knowledge about the shear strength of a soil is important because it is a key parameter that is used in many calculations in construction engineering. Some examples of what’s possible to calculate are slope stability, the soil pressure against retaining walls and the carrying capacity of building foundations. Great economic losses or, in the worst case scenario the risk for human lives, could be the result if the geotechnical properties of the soil are ignored. This report considers the undrained shear strength of clay from Uppsala. There are different methods based on empirical experiences which are used to determine the undrained shear strength of a clay. In this project the methods and the results in undrained shear strength are compared between CPT-probing, which is carried out in-situ, and the drop cone test which is done in a laboratory. The reason for this comparison is that they usually don’t show the same results.The tests had already been made before this project started and therefore it is only the comparison of the results between the methods that has been done. The comparison was done by creating charts in Excel where the results from CPT and the drop cone test from was put together from the same point. The shear strength values from the methods were also statistically analysed with a t-test to see if they show the same hypothetical expected value with 95 % significance in every test point Kunskap om skjuvhållfastheten är viktig då den används för beräkningar inom byggoch anläggningsbranschen. Exempel på vad som kan beräknas är släntstabilitet, jordtrycket mot en spont eller bärförmågan hos en byggnadsgrund. Stora ekonomiska förluster och i värsta fall fara för människoliv kan bli resultatet om jordens geotekniska egenskaper ignoreras. Denna rapport tar upp den odränerade skjuvhållfastheten i Uppsalalera. Det finns olika metoder som bygger på empiriska erfarenheter som kan användas för att ta reda på den odränerade skjuvhållfastheten i lera. I föreliggandeprojekt jämförs metoderna och resultaten i odränerad skjuvhållfasthet mellan CPT-sondering som utförs in-situ och fallkonförsök som utförs på lerprover i ett laboratorium. Anledningen till studien är att metoderna inte alltid ger samma mätvärden. Undersökningarna utfördes innan projektet började. Jämförelsen har gjorts genom den statistiska jämförelsen t (student)-test. Resultatet från t-testet visar att skjuvhållfasthetsvärdena från CPT respektive fallkonförsöken från samma undersökningspunkt och från samma nivå har samma hypotetiska förväntade värde på 95 % signifikansnivå. Genom sammanställda grafer syns att metoderna i de flesta fall överensstämmer till ett djup på minst 20 m.

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30

Shamsabadi, Pegah Jarast. "Numerical and Physical Modeling of Cone Penetration in Unsaturated Soils and Numerical Simulation of Fracture Propagation in Shale Rock during Brazilian Test." Thesis, University of New Hampshire, 2018. http://pqdtopen.proquest.com/#viewpdf?dispub=10622976.

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Partially water saturated condition in soils may change the cone penetration resistance comparing with that of dry or saturated conditions. This effect was investigated in this study using numerical finite element modeling and experimental centrifuge testing. The results showed suction in unsaturated soil significantly influenced the soil resistance to cone penetration. Two approaches were implemented to numerically consider the partially saturated soil condition; i.e. modifying simple constitutive models using an apparent cohesion strategy and implementing Barcelona Basic Model for unsaturated soils. Both successfully captured the cone resistance profiles inside a calibration chamber and also in free field. In addition, details of developing a miniature cone setup capable of for cone penetration inside geotechnical centrifuge was explained. Further, the use of Linear Softening Cohesive Model (LCFM) to predict the fracture growth in shale rocks during Brazilian Test was examined. The application and importance of considering two different compressive and tensile elastic modulus and soil anisotropy during the fracture modeling of shales were demonstrated.

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31

McGillivray, Alexander Vamie. "Enhanced Integration of Shear Wave Velocity Profiling in Direct-Push Site Characterization Systems." Diss., Georgia Institute of Technology, 2007. http://hdl.handle.net/1853/19714.

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Enhanced Integration of Shear Wave Velocity Profiling in Direct-Push Site Characterization Systems Alexander V. McGillivray 370 Pages Directed by Dr. Paul W. Mayne Shear wave velocity (VS) is a fundamental property of soils directly related to the shear stiffness at small-strains. Therefore, VS should be a routine measurement made during everyday site characterization. There are several lab and field methods for measuring VS, but the seismic piezocone penetration test (SCPTu) and the seismic dilatometer test (SDMT) are the most efficient means for profiling the small-strain stiffness in addition to evaluating large-strain strength, as well as providing evaluations of the geostratigraphy, stress state, and permeability, all within a single sounding. Although the CPT and DMT have been in use for over three decades in the USA, they are only recently becoming commonplace on small-, medium-, and large-size projects as more organizations begin to realize their benefits. Regrettably, the SCPTu and the SDMT are lagging slightly behind their non-seismic counterparts in popularity, in part because the geophysics component of the tests has not been updated during the 25 years since the tests were envisioned. The VS measurement component is inefficient and not cost effective for routine use. The purpose of this research is to remove the barriers to seismic testing during direct-push site characterization with SCPTu and SDMT. A continuous-push seismic system has been developed to improve the integration of VS measurements with SCPTu and SDMT, allowing VS to be measured during penetration without stopping the progress of the probe. A new type of portable automated seismic source, given the name RotoSeis, was created to generate repeated hammer strikes at regularly spaced time intervals. A true-interval biaxial seismic probe and an automated data acquisition system were also developed to capture the shear waves. By not limiting VS measurement to pauses in penetration during rod breaks, it is possible to make overlapping VS interval measurements. This new method, termed frequent-interval, increases the depth resolution of the VS profile to be more compatible with the depth intervals of the near-continuous non-seismic measurements of the SCPTu and the SDMT.

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Ahlgren, Mattsson David. "Jämförelse av portrycksmätning i Uppsalalera mellan portrycksmätare och dissipationstest." Thesis, Uppsala universitet, Institutionen för geovetenskaper, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-383929.

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Portrycket är en viktig parameter för att bestämma jordens egenskaper, såsom dränering, permeabilitet och stabilitet (då portrycket har en påverkan på den effektiva spänningen i jorden). Portrycket kan mätas med portrycksmätare men det kan även mätas under ett Cone penetrating test (CPT) med ett s.k. dissipationstest. Fördelar med ett dissipationstest jämfört med traditionell portrycksmätning skulle vara att det skulle spara tid och pengar, då man slipper trycka ner portrycksmätare och sedan vänta på att få portrycket ifrån dem, istället kan portrycket mätas under sondering med CPT.Detta självständiga arbete har som syfte att jämföra portrycksmätningar mellan portrycksmätning med BAT-spets och dissipationstest under CPT-sondering för att se hur bra mätvärden dissipationstester ger och om de eventuellt kan ersätta portrycksmätare. Fältförsöken av metoderna skedde i Uppsalalera, på en tomt i Kungsängen i Uppsala.Två stationer med BAT-spetsar på 5 meter, 7,5 meter och 10 meters djup sattes ner i leran. Sondering med CPT genomfördes sedan, där borren stoppades på samma djup som BAT-spetsarna. CPT:n stoppades på dessa djup i drygt 24 timmar, för att tillåta det generade portrycket som skapades när borren trycks ner i leran att skingras åt sidan. Jämviktsportrycket kommer vara det portryck som finns kvar efter att det generade portrycket har försvunnit. Portrycken från de två olika metoderna jämfördes sedan för att se hur nära dissipationstestet kommer värdena från portrycksmätningen med BAT-spetsarna.Resultatet av dissipationstesterna blev att inga av dem nådde referensvärdena från BAT-spetsarna efter 24 timmar. Beroende på användningsklass ligger dissipationstesterna inom den tillåtna minsta noggrannheten. Dissipationstest är antagligen inte så praktiskt tillämpbart i jordar med låg permeabilitet. The pore pressure is an important parameter for determining the properties of thesoil, such as drainage, permeability and stability (since the pore pressure has aneffect on the effective stress in the soil). The pore pressure can be measured withpore pressure gauges but it can also be measured during a Cone penetration test(CPT) with a dissipation test. Advantages of a dissipation test compared tomeasurement with traditional pore pressure gauges would be that it would save timeand money, since you don’t have to press down pore pressure gauges and then waitto get the pore pressure from them, instead the pore pressure can be measuredduring probing with CPT.The purpose of this project is to compare pore pressure measurements betweenpore pressure measurements with BAT-tips and dissipation test during CPT probing,to see how good measured values the dissipation tests will provide and if theyeventually can supersede pore pressure gauges for pore pressure measurements.The field tests of the methods were done in Uppsala clay, on a site in Kungsängen inUppsala.Two stations with BAT-tips at 5 meters, 7.5 meters and 10 meters depth wereinstalled in the clay. Probing with CPT was then carried out, by stopping the CPT atthe same depth as the BAT-tips. Measurements with the CPT were done at thesedepths for just over 24 hours, to allow the generated excess pore pressure createdwhen the cone is pushed into the clay to disperse to the sides. The equilibrium porepressure is the pore pressure that remains after the generated pore pressure hasdissipated. The pore pressure from the two different methods was then compared tosee how close the dissipation test results were to the values from the pore pressuremeasurements with the BAT tips.The result of the dissipation tests was that none of them reached the referencevalues from the BAT-tips after 24 hours. Depending on the chosen application class,the dissipation tests are within the permitted minimum accuracy. Dissipation tests areprobably not practically applicable to soils with low permeability.

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Peinke, Isabel. "Étude à micro-échelle du test de pénétration du cône dans la neige." Thesis, Toulouse 3, 2019. http://www.theses.fr/2019TOU30159.

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La prévision du risque d'avalanche, les prévisions hydrologiques et l'estimation du bilan énergétique de la Terre dépendent d'une connaissance précise de la stratigraphie du manteau neigeux. Le test de pénétration du cône, qui consiste à enregistrer la force nécessaire pour faire pénétrer un cône dans le matériau d'intérêt, est largement utilisé pour mesurer des profils de neige. La sonde de battage, développée et utilisée depuis 1930, a été continuellement améliorée. Aujourd'hui, des pénétromètres numériques, tel que le SnowMicroPenetrometer, permettent de mesurer la résistance à la pénétration à vitesse constante avec une résolution verticale de quelques microns. Les fluctuations de force mesurées à cette résolution contiennent des informations sur la microstructure essentielles pour compléter la connaissance de la dureté moyenne de chaque couche de neige. Néanmoins, le lien entre le profil de dureté et la microstructure de la neige n'est pas encore entièrement compris. En effet, les modèles d'inversion existants négligent certaines des interactions entre la pointe du cône et la neige, comme la formation d'une zone de compaction, et ils n'ont été évalués que par des relations empiriques avec des propriétés macroscopiques. L'objectif de cette thèse est d'étudier l'interaction entre le cône et la neige à une échelle microscopique, à l'aide de la tomographie à rayons X, afin d'extraire, de manière plus précise, les propriétés microstructurelles de la neige à partir des mesures de résistance à la pénétration. Dans ce travail, nous analysons des tests de pénétration du cône de quelques centimètres de profondeur, qui contiennent une partie transitoire non négligeable due à la formation progressive d'une zone de compaction. Afin de prendre en compte explicitement ce processus, nous avons développé un modèle statistitique non-homogène de Poisson, qui prend en compte une dépendance à la profondeur du taux d'occurrence de rupture entre grains de neige. Nous avons utilisé ce modèle pour caractériser le frittage de la neige par des tests de pénétration du cône sous conditions contrôlées dans une chambre froide. D'après le modèle, l'hétérogénéité verticale des profils de dureté était due aux variations du taux d'occurrence de rupture, tandis que l'évolution temporelle de la force macroscopique était contrôlée par un renforcement des ponts. Cette partition est cohérente avec les processus de frittage connus et fournit une validation indirecte du modèle proposé. Une deuxième partie de la thèse a porté sur des expériences en chambre froide combinant des tests de pénétration du cône et de l'imagerie par tomographie X. Des images tri-dimensionnelles à haute résolution d'un échantillon de neige ont été prises avant et après le test du cône. Sur ces images, un nouvel algorithme de suivi de grains a été appliqué pour déterminer les déplacements granulaires induits par le test. Nous avons quantifié avec précision la taille de la zone de compaction et sa relation avec les caractéristiques de la neige. Nous avons montré que les déplacements verticaux observés compliquent l'utilisation de modèles d'expansion de cavité comme modèles d'inversion. Enfin, nous avons lié les propriétés microstructurelles obtenues par tomographie, telles que la taille ou le nombre de ruptures de ponts, à des propriétés dérivées des profils de dureté. Nous avons montré que les propriétés estimées à partir des tests de pénétration du cône sont des approximations de la microstructure de la neige, mais restent trop conceptuelles pour espérer une relation directe. A l'avenir, ces études devraient permettre de dériver, de manière objective, la stratigraphie du manteau neigeux à partir d'une mesure de terrain simple et rapide Precise knowledge of the snowpack stratigraphy is crucial for different applications such as avalanche forecasting, predicting the water runoff, or estimating the Earth energy budget. The cone penetration test, which consists of recording the force required to make a cone penetrate the material of interest, is widely used to measure in situ snow profiles. The ramsonde developed in the 1930's was continuously improved into highly-resolved digital snow penetrometers. In particular, the SnowMicroPenetrometer measures the snow penetration resistance at constant speed with a vertical resolution of four microns. The force fluctuations measured at such a resolution contain information about the snow microstructure, which is essential to complete the knowledge of the mean hardness of each snow layer. Nevertheless, the link between the measured hardness profile and the snow microstructure is not yet fully understood. Indeed, existing inversion models neglect obvious interactions between the cone tip and the snow, such as the formation of a compaction zone, and have only been evaluated through empirical relations to macroscopic properties. The goal of this thesis is to investigate the interaction between the cone and the snow at a microscopic scale using X-ray tomography in order to better invert the hardness profiles into microstructural properties. In this work, we analyze cone penetration tests of a few centimeters and thus the measured profiles contain a non negligible transient part due to the progressive formation of a compaction zone. In order to explicitly account for this process in the inversion model, we successfully developed a non-homogeneous Poisson shot noise model which considers a depth dependency of the rupture occurrence rate. We used this model to characterize snow sintering with cone penetration tests under controlled cold-lab conditions. According to the model, the vertical heterogeneity of hardness profiles was due to variations of the rupture occurrence rate, while the time evolution of the macroscopic force was controlled by bond strengthening. This partition is consistent with the expected sintering processes and provides an indirect validation of the proposed model. The second part of the thesis consists of cold-lab experiments combining cone penetration tests and X-ray tomography. High resolution three dimensional images of the snow sample before and after the cone test were measured. On these images, a novel tracking algorithm was applied to determine granular displacements induced by the test. We precisely quantified the size of the compaction zone and its relation to the snow characteristics. Furthermore, we showed that the observed vertical displacements challenge the use of standard cavity expansion models as inversion models. Finally, we linked the microstructural properties obtained from tomography, such as the bond size or the number of failed bonds, to properties derived from hardness profiles. We showed that the properties estimated from cone penetration tests are proxies of the snow microstructure, but remain too conceptual to expect a straightforward relation. In the future, these studies should make it possible to derive in an objective way the stratigraphy of the snowpack from a simple and fast field measurement

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Žaržojus, Gintaras. "Dinaminio zondavimo rezultatų ir juos įtakojančių veiksnių analizė bei sąsajos su statinio zondavimo duomenimis Lietuvos gruntuose." Doctoral thesis, Lithuanian Academic Libraries Network (LABT), 2010. http://vddb.laba.lt/obj/LT-eLABa-0001:E.02~2010~D_20101230_094020-91165.

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Disertacijos objektas yra Lietuvos teritorijoje slūgsantys gruntai, kurie gali būti statinių pamatų pagrindu. Disertacijoje nagrinėjama grunto tyrimo dinaminiu (DPT) ir statiniu (CPT) zondavimu rezultatų interpretacija, tiesioginio (smūgių skaičiaus (Nx)) ir išvestinio (dinaminės kūgio smigos (qd)) DPT rodiklių patikimumas, analizuojami rezultatus įtakojantys veiksniai ir sąsajos tarp DPT bei CPT zondavimo rodiklių. Duomenų analizė atlikta matematiniais statistiniais metodais, taip pat panaudojant analitinius ir empirinius sprendinius. Išnagrinėjus skaičiavimo duomenis buvo nustatyta, kad netiesioginis dinaminio zonda-vimo rodiklis – dinaminė kūgio smiga (qd) dėl skaičiavimo trukumų yra nenaudotinas ir keisti-nas į tiesioginį rodiklį – smūgių skaičių (Nx). DPT rezultatus įtakojančių veiksnių analizė paro-dė, kad zondavimo duomenims didžiausią įtaką turi gruntų šoninis geostatinis slėgis ir kartu zondavimo štangų trintis į gruntą. Darbo metu buvo gauta, kad egzistuoja tamprus koreliacinis ryšys tarp smūgių skaičiaus (Nx) ir statinės kūgio spraudos (qc), kuris priklauso nuo grunto gra-nuliometrinės sudėties, mechaninių savybių ir slūgsojimo gylio. The object of the thesis is soils that occur within the territory of Lithuania and may be used as basis for building foundations. The thesis studies the interpretation of the results of Dynamic Penetration Test (DPT) and Cone Penetration Test (CPT) of soils, reliability of direct (number of blows (Nx)) and de-rivative (dynamic point resistance (qd)) DPT parameters, analyses the result influencing factors and interrelation between DPT and CPT parameters. The data analysis has been performed by means of mathematical methods of statistics, also using analytical and empirical solutions. Having examined calculation data it was determined that the indirect parameter of Dy-namic Penetration Test – dynamic point resistance (qd) should not be used due to calculation de-faults and replaced with the direct parameter – number of blows (Nx). The analysis of DPT re-sults influencing factors shows that the lateral overburden pressure together with friction of rods are those with the greatest impact on penetration data. Within the scope of the work, it has re-vealed that the number of blows (Nx) and static cone resistance (qc) are closely correlated and it depends on the grain size distribution of soil, geotechnical properties and depth of occurrence.

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Doria, Katerin Guerrero. "Desenvolvimento de uma sonda TDR helicoidal para uso em conjunto com o ensaio CPT." Universidade de São Paulo, 2015. http://www.teses.usp.br/teses/disponiveis/18/18132/tde-06012016-094209/.

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A reflectometria no domínio do tempo permite estimar o teor de umidade de um meio através da sua correlação com a constante dielétrica. Uma sonda helicoidal TDR, que pode ser cravada em conjunto outros ensaios de penetração in situ para a estimativa do teor de umidade em diversas profundidades, tem aplicação interessante para a investigação geotécnica do subsolo. No presente trabalho, uma sonda TDR foi adaptada e utilizada em conjunto ao ensaio CPT para caracterização de um perfil de solo arenoso não saturado que ocorre na região de Bauru (SP). A calibração dessa sonda foi feita em laboratório especificamente para esse solo. As equações de calibração que mostraram os melhores resultados foram definidas correlacionando a constante dielétrica, condutividade elétrica aparente e a massa específica seca com o teor de umidade. Com o intuito de melhorar a acurácia na determinação do teor de umidade em campo e eliminar possíveis interferências no registro da onda eletromagnética, foram efetuadas modificações em algumas características do projeto original dessa sonda. Tais modificações consistiram em separar os eletrodos condutores e as partes metálicas da sonda, e eliminar o cabo coaxial de extensão, conectando a sonda diretamente a um cabo coaxial de 12 m de comprimento. Tais mudanças levaram a uma melhoria significativa na determinação do perfil de teor de umidade do local estudado. Os valores de teor de umidade de campo determinados usando o TDR ao longo de 8 m de profundidade foram comparados com os valores de referência obtidos de amostras deformadas retiradas com trado mecânico. O erro médio na estimativa do perfil de teor de umidade gravimétrico utilizando a sonda TDR helicoidal foi de 1.61%, na última campanha de ensaios realizados. Os resultados dessa pesquisa indicam que esta ferramenta é adequada para estimar do perfil de teor de umidade para uso em conjunto com o ensaio CPT. The time domain reflectometry allows estimating the moisture content of a medium by means of its correlation with the dielectric constant. A coil TDR probe, which can be driven into the ground together with others in situ penetration tests, can be used to estimate the moisture content at different depths. It is an interesting approach for geotechnical site characterization. In this work, a coil TDR probe was adapted and used in combination with the CPT test for the site characterization of an unsaturated sandy soil profile which occurs in the region of Bauru (SP). The probe calibration was performed in laboratory specifically for that soil. The calibration equation, which presented the best results, were defined correlating the dielectric constant, electrical conductivity and dry density with the moisture content. In order to improve the accuracy for determining the water content in the field and to eliminate possible interference on the electromagnetic wave registration, modifications were made in some characteristics of the original design of this probe. Such modifications consisted in separating the conductive electrodes from the metal parts of the probe, and eliminating the coaxial extension cable, connecting the probe directly to a coaxial cable 12 m long. Such changes have led to a significant improvement in the determination of the moisture content profile of the studied site. The moisture content values determined in situ by using the TDR along 8 m depth were compared with reference values obtained from disturbed soil samples collected using mechanical augers. The root mean square error of the gravimetric water content profile using the TDR coil probe was 1.61% in the last test campaign. The results of this research indicate that this tool is suitable to estimate the gravimetric moisture content together with the CPT test.

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Ozkahriman, Fatma. "Cpt Based Compressibilty Assessment Of Soils." Master's thesis, METU, 2004. http://etd.lib.metu.edu.tr/upload/12605144/index.pdf.

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One of the most critical problems geotechnical engineers face with is the determination of the amount of consolidation settlement that will occur at a site as a result of the construction of a structure. The compressibility behavior of the soil is an important parameter in determining the amount of consolidation settlement. The goal of this study is to develop probabilistically based correlation between the compressibility behavior of soil and in-situ test data. Within the scope of this research effort, performed CPT tests and the recorded settlement case histories where consolidation settlements at the field under various surcharge loads were compiled from the Bursa East and West Waste Water Treatment Plant soil investigation projects. A database was composed of the results of 45 CPT and 57 settlement plate recordings. For the compilation of this database, a series of finite difference software FLAC-3D analyses were carried out to calculate the change in stress distribution under the settlement plates. A maximum likelihood framework was used for the development of compressibility behavior of soils. As a result of careful processing of available data, the cone tip resistance (qc), soil behavior type index (Ic) were selected as two important parameters effecting the value of the one-dimensional constraint modulus, M. The regression analysis which uses the settlement values recorded at the site and those computed using the change in the stress distribution, the thickness of the sublayers and the proposed one-dimensional constraint modulus were carried out to calculate the values of these model parameters. Two correlations based on the cone tip resistance and soil behavior type index were developed for the computation of the one-dimensional constraint modulus, M.

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Hosseini, Sadr Abadi Hamid. "Identificiation in-situ des sols liquéfiables par pénétromètre statique cyclique : modélisations physiques et numériques." Thesis, Université Grenoble Alpes (ComUE), 2019. http://www.theses.fr/2019GREAI078.

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L’identification des sols liquéfiables et le comportement de sols face aux sollicitations cycliques représentent des défis important en géotechnique. Différents essais, en laboratoire ou in-situ,sont utilisés pour évaluer ce phénomène. Le groupe Equaterre, en particulier, développe un pénétromètre statique à pointe cyclique qui permet d’imposer une variation cyclique de la force sur la pointe, par le biais de tiges centrales coulissantes, et de mesurer les déformations qui en résultent. Ceci permet d’accéder directement à la réponse du sol en place, et potentiellement de mettre en évidence une tendance à la liquéfaction ou à la mobilité cyclique. Cette thèse comporte deux parties principales: modélisation physique en chambre de calibration et modélisation numérique.La modélisation physique consiste à réaliser des tests de faisabilité de la méthode développée par Equaterre en chambre de calibration au sein de laboratoire 3SR Grenoble. Les tests en chambre de calibration ont été réalisés sur du sable de Fontainebleau, avec deux états de densité moyennement dense et lâche. Des tests CPTU et pénétromètre cyclique Equaterre ont été réalisés dans ces deux situations. Les résultats ont montré le bon potentiel de cette méthode pour identifier le risque de la liquéfaction.La modélisation numérique repose sur un couplage entre la méthode des éléments discrets(DEM) pour la phase solide et une méthode de volumes finis définis à l’échelle des pores (méthode PFV) pour l’écoulement interne. La géométrie de révolution est exploitée pour réduire le domaine modélisé à un quart du problème, et une gradation des tailles de particules en fonction de la distance à la pointe est également mise en oeuvre pour réduire le nombre totale de particules (et donc les temps de calcul) tout en maintenant une discrétisation fine au voisinage immédiat de la pointe. Deux types de matériaux, dense et lâche, sont simulés et pour chacun on analyse la réponse mécanique pour le cas sec et pour le cas saturé, sous chargement monotone et cyclique. L’analyse des réponses en terme de force et de pression intersticielle montre un bon accord qualitatif avec les résultats en en chambre de calibration.Mots clés: Pénétromètre statique cyclique; Chambre de calibration; Liquéfaction de sol; Méthode des éléments discrets (DEM); Méthode de volumes finis à l’échelle des pores (PFV) The identification of liquefiable soils and the behaviour of soils in response to cyclic stresses are important challenges in geotechnical engineering. Various laboratory and in-situ tests are used to evaluate this phenomenon. The Equaterre group, in particular, is developing a static penetrometer with a cyclic tip that allows a cyclic variation of the force to be imposed on the tip by means of sliding central rods and the resulting deformations to be measured. This provides direct access to the response of the soil in place, and potentially highlights a tendency towards liquefaction or cyclic mobility. This thesis has two main parts: physical modeling in a calibration chamber and numerical modeling.Physical modelling consists in carrying out feasibility tests of the method developed by Equaterre in a calibration chamber in the 3SR Grenoble laboratory. The tests in the calibration chamber were carried out on Fontainebleau sand, with two states of medium density and loose. CPTU tests and Equaterre cyclic penetrometer were performed in both situations. The results showed the good potential of this method to identify the risk of liquefaction.Numerical modelling is based on a coupling between the discrete element method (DEM) for the solid phase and a finite volume method defined at pore scale (PFV method) for internal flow. The geometry of revolution is used to reduce the modelled domain to a quarter of the problem, and a gradation of particle sizes according to the distance to the tip is also implemented to reduce the total number of particles (and therefore the computation times) while maintaining a fine discretization in the immediate vicinity of the tip. Two types of materials, dense and loose, are simulated and for each one the mechanical response is analyzed for the dry case and for the saturated case, under monotonous and cyclic loading. The analysis of the responses in terms of force and interstitial pressure shows a good qualitative agreement with the results in the calibration chamber.Keywords: Static cyclic penetrometer; Calibration chamber; Soil liquefaction; Discrete element method (DEM); Pore-scale finite volume method (PFV)

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38

Mahajan, Sandeep Prakash. "Viscous Effects on Penetrating Shafts in Clay." Diss., Tucson, Arizona : University of Arizona, 2006. http://etd.library.arizona.edu/etd/GetFileServlet?file=file:///data1/pdf/etd/azu%5Fetd%5F1689%5F1%5Fm.pdf&type=application/pdf.

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39

Savary, Aymerick. "Détection de vulnérabilités appliquée à la vérification de code intermédiaire de Java Card." Thèse, Université de Sherbrooke, 2016. http://hdl.handle.net/11143/9584.

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La vérification de la résistance aux attaques des implémentations embarquées des vérifieurs de code intermédiaire Java Card est une tâche complexe. Les méthodes actuelles n'étant pas suffisamment efficaces, seule la génération de tests manuelle est possible. Pour automatiser ce processus, nous proposons une méthode appelée VTG (Vulnerability Test Generation, génération de tests de vulnérabilité). En se basant sur une représentation formelle des comportements fonctionnels du système sous test, un ensemble de tests d'intrusions est généré. Cette méthode s'inspire des techniques de mutation et de test à base de modèle. Dans un premier temps, le modèle est muté selon des règles que nous avons définies afin de représenter les potentielles attaques. Les tests sont ensuite extraits à partir des modèles mutants. Deux modèles Event-B ont été proposés. Le premier représente les contraintes structurelles des fichiers d'application Java Card. Le VTG permet en quelques secondes de générer des centaines de tests abstraits. Le second modèle est composé de 66 événements permettant de représenter 61 instructions Java Card. La mutation est effectuée en quelques secondes. L'extraction des tests permet de générer 223 tests en 45 min. Chaque test permet de vérifier une précondition ou une combinaison de préconditions d'une instruction. Cette méthode nous a permis de tester différents mécanismes d'implémentations de vérifieur de code intermédiaire Java Card. Bien que développée pour notre cas d'étude, la méthode proposée est générique et a été appliquée à d'autres cas d'études.

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40

Makusa, Gregory Paul. "Mechanical properties of stabilized dredged sediments : for sustainable geotechnical structures." Licentiate thesis, Luleå tekniska universitet, Geoteknologi, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-17437.

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Dredging activities at Ports and Harbors are inevitable for the safe navigation of ships and vessels. Dredged material may range from very fine and contaminated sediments to sand and gravels. While, granular dredged material can be directly utilized in civil engineering applications, fine sediments may require further treatment before use. In geotechnical context, fine sediments are characterized by low shear strength and high compressibility. However, these unfavorable properties do not rule out the suitability of these fine dredged sediments for use in geotechnical construction, such as, road embankment, building foundation or as structural backfill in land reclamation. Mass stabilization solidification provides a comprehensive technology for amending fine sediments at high initial water content, resulting into construction materials of improved strength and reduced compressibility. The ultimate in-situ soil behavior types, stiffness and strength properties of stabilized mass depend on various factors such as binders, mixing equipment, curing temperature, in-situ boundary conditions and mostly important the applied preloading weight during the period of curing. However, despite improved mechanical properties for geotechnical applications, the performance of treated materials becomes susceptible to repeated freeze-thaw cycles. Understanding geotechnical design process, which includes evaluation of material properties, loading condition and selection of appropriate constitutive model, is an important task for settlement and stability analysis of structures founded on stabilized mass. The selection of suitable material model is vital for successful finite element analysis. Nevertheless, among all existing constitutive soil models, none of them can capture all aspects of soil behavior. Therefore, the meaningful and quantifiable predictions of field behaviors are possible only if, undisturbed samples or in-situ tests are used for determination of mechanical properties, and the predictive capacity of selected constitutive model comes from the comparison with field observations In the present research work, utilization of cone penetration test (CPT) data for evaluating the mechanical properties of stabilized dredged sediments for geotechnical design and analysis was presented. A large-scale field test at the Port of Gävle was utilized as a case study, to verify the simulated settlement of preloaded stabilized dredged sediments. The stabilized mass–soil classification behavior type was studied utilizing CPT classification charts. Computation of the primary consolidation settlement due to preloading weight were carried out in PLAXIS 2D geotechnical software and verified against field measurements. A suggestion to protect the stabilized mass against severe weather condition was discussed. Godkänd; 2013; 20130409 (makusa); Tillkännagivande licentiatseminarium 2013-04-25 Nedanstående person kommer att hålla licentiatseminarium för avläggande av teknologie licentiatexamen. Namn: Gregory Paul Makusa Ämne: Geoteknik/Soil Mechanics and Foundation Engineering Uppsats: Mechanical Properties of Stabilized Dredged Sediments for Sustainable Geotechnical Structures Examinator: Professor Sven Knutsson, Institutionen för samhällsbyggnad och naturresurser, Luleå tekniska universitet Diskutant: Civ.ing. Forskningsdirektör Göran Holm, Statens Geotekniska Institut, Linköping Tid: Torsdag den 16 maj 2013 kl 10.00 Plats: F1031, Luleå tekniska universitet

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Škapová, Pavla. "Problematika testování stříkaných betonů." Master's thesis, Vysoké učení technické v Brně. Fakulta stavební, 2014. http://www.nusl.cz/ntk/nusl-226742.

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The master‘s thesis focuses on testing the shotcrete prepared in laboratory conditions. The main observed properties are compresive strenght of shotcrete and modulus of elasticity. The aim is assessment of methods for measuring those parameters. The calibrating correlations for strenght characteristics of shotcrete are given by obtaining the results of used methods. The shotcrete composition, amount and type of accelerating additive as well as economic aspect of using shotcrete is also assessed.

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Chuang, Chwan-Yeh, and 莊傳業. "Application of Acoustic on Cone Penetration Test." Thesis, 1996. http://ndltd.ncl.edu.tw/handle/40349832623836388132.

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碩士 國立中央大學 土木工程學系 84 This research described the properties of the acoustic emission signal gen-erated on the static cone penetration tests. As a penetrometer is penetrating into the soils, the acoustic emissions are generated by soil grains sliding and rolling over the penetrometer, sliding and rolling over one another and being rushed. The major purpose of this paper is to improve the technique of site investigation.This research includes the development of measuring system of the acoustic emission, understanding of the noise vibration control, ensur-ing of the acoustic emission of rocks, application of the calibration chamber,selection variables of tested soils, preparation method of soils specimens, design of the acoustic penetrometer and establishment the analytic models of measuring data. The research establishes the relationship between the engineering behavior and property of tested soils and the amplitude of the spectral analysis which is treated by root- mean-square operation and fast Fourier transform. In order to understand the relationship between the amplitude of the acoustic signal and soil variables which included grain size, relative density, stress state and state of saturation. The frequency of the acoustic signal indicates the constitution of predominant frequency of soils. Once acoustic data have been fully analyzed and the soil profile establish-ed, it should be possible to determine the accuracy with which the acoustic data indicated layering and other soil characteristics.

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Chang, Jia-Wei, and 張嘉偉. "Calibration of Cone Penetration Test in Silty Sand." Thesis, 1997. http://ndltd.ncl.edu.tw/handle/99186993405273763505.

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碩士 國立交通大學 土木工程學系研究所 85 Abstract Because of the lack of cohesion, it is very difficult to obtain undisturbe dsamples for sand. In situ tests are often used to determine the engineering properties of sand. The cone penetration test (CPT) is a popular in situ test method. As in many other types of in situ test methods, the interpretation of CPT data is mostly empirical. These empirical interpretation rules are mostly developed based on chamber calibration tests in the laboratory, and limited theoretical considerations. Most of the availle empirical rules came from Europe or Northern America, based on tests in uniformly graded, clean sand. The sand on the West Coast of Taiwan, including that at the 6th Naptha project site in Mai Liao, Yuen Lin, contains significant amount of silt. Experiments have indicated that this type of sand is compressible and crushable, but has a less tendency to dilate. The difference between a uniformly graded clean sand and a silty sand can be significant. Hence, to directly adopt the empirical CPT interpretaon rules developed in the West, to the sand on the West Coast of Taiwan is not desirable. The main objective of this research project is to establish an empirical method for the interpretation results of CPT performed silty sand. This method applied directly to the soils at the 6th Naptha project site in Mai Liao, considering the effects of high fines content and the effects of soil improvement. Experiments to determine the basic physical properties and triaxial tests have been completed. The calibration chamber system has been established. A seies of cone penetration tests have been perford in this chamber system. This thesis describes the background of the research, its objetives, research approach, procedures of the CPT calibration tests and test results. The CPT data are analyzed and a new empirical rule is proposed specifically for CPT in silty sand. Keywords : in situ test, dilatancy, horizontal stress, shear strength of sand , calibration of cone penetration test

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Chang, Jyh-Haur, and 張致豪. "Evaluation of Liquefaction Potential by Cone Penetration Test." Thesis, 1998. http://ndltd.ncl.edu.tw/handle/65894703357733503437.

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Liang, Nerg, and 梁能. "Acoustic emissions during the cone penetration test of soils." Thesis, 1998. http://ndltd.ncl.edu.tw/handle/14767005260573720268.

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碩士 國立中央大學 土木工程學系 86 Soil classification and profiling are the major applications of in-situ cone penetration tests (CPT). Generally, using an electrical piezocone, the tip resistance (qc), sleeve friction (fs), and pore pressure (u) can be logged continuously with depth during the test .With certain interpretations, profile of a site and soil type of each layer are characterized. Since cone resistance responds to soil changes within 5 to 10 tip diameters above and below the cone (the distance increases with increasing soil stiffness), there will be some imprecision in locating soil interfaces using cone resistance.The research described in the dissertation is concerned with the acoustic noise generated during the static penetration of soils using an acoustic cone penetrometer. As the penetrometer is advanced into a soil specimen, acoustic emissions are generated by soil grains sliding and rolling over the penetrometer, sliding and rolling over one another and being crushed. These acoustic emissions are recorded by data acquisition system. With root-mean-square (RMS) calculation and Fast Fourier Transform (FFT) operation, an acoustic emission is characterized by its root-mean-square voltage (Vrms) and frequency spectrum. These are the major properties of acoustic emissions which are related to soil types.This research focuses on eliminating the affections of background noises on acoustic emissions during penetration, improving soil interface locating, and establishing relationships between soil types and acoustic emissions. The result of tests reveal that:1. With damping materials (sponge and silicon gel) installed in the acoustic cone penetrometer and the signal filtration program, the affections of environmental and mechanical noises can be ignored.2. Estimation of Vrms during penetration provides a more accurate and convenient method to locate the interface of layered soils and to predict the average grain size (D50) of each layer.3. Sand and clay layers can be distinguished from one to another through examinations of each frequency spectrum and its Vrms.4. Soil itself provides a good damping effects on environmental noises when penetrometer is advanced into the ground.

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Hung, Jaw-Ching, and 洪兆慶. "Correlative Research of Acoustic Cone Penetration Test and Sand Parameters." Thesis, 1997. http://ndltd.ncl.edu.tw/handle/78435454926272535283.

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碩士 國立中央大學 土木工程學系 85 The cone penetration test is becoming increasingly more popular as an in-situ test for site investigation and geotechnical design. However, the interpretation of CPT data is various in different area, and there are few empirical equations in Taiwan. In addition, the cone penetration resistance is effected by layer interface of soil, so that the characteristics of fine sand profile can not be detected accurately, but acoustic cone penetration test(ACPT) can improve this defect because of it*s sensitivity. This research is hope to establish our own empirical equations of cone penetration tests with Mai-Liao sand, and discuss the correlation between sand parameter and acoustic characteristics by using ACPT in a calibrationchamber. When refer to all results obtained, the following conclusions can be achieved: (1) The relative friction angle is effected by particle size, but it is constant for the same sand. (2) The increasing rate of cone penetration resistance is decreases with increasing vertical stress. (3) The relationship between cone penetration resistance, relative density and vertical stress can be unique if correlated with the average grain size. (4) It is possible that the frequency distribution of the acoustic signal is depended only on mineralogy of sand and surface texture of cone tip. (5) RMS sound pressure which between 2kHz and 8kHz is decreases with increasing relative density and cone penetration resistance, but increases with increasing average grain size. (6) The ratio of spectrum density of predominant frequency to secondary frequency is increases with increasing relative density.

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Ou, Po-Stun, and 歐柏村. "The Elementary Research of Geotechnical Engineering Using Cone Penetration Test." Thesis, 1997. http://ndltd.ncl.edu.tw/handle/42934103425976300904.

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Kokan, Matthew J. "Dilatancy characterization of sands using the resistivity cone penetration test." Thesis, 1992. http://hdl.handle.net/2429/3073.

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The determination of in situ dilatancy in sands has been a difficult and elusive objective in site investigations. Difficulty with sampling, as well as problems with extrapolating laboratory results to field performance have caused geotechnical engineers to place increased reliance on in situ tests. One such test which is gaining acceptance in the geotechnical profession is the cone penetration test (CPT). As with other in situ tests, the CPT can be used to predict dilatancy behaviour of sands based on empirical correlations. As with most empirical methods, correlations are often site specific and sensitive to variables that are not readily measurable. A new, geophysically based, technique has been developed to determine dilatancy characteristics of sands in situ. The resistivity cone penetration test (RCPT) employs a standard 10 sq cm piezo cone, paired with a module which measures soil resisitivity at different electrode spacings. The resistivity is recorded in a semi—continuous manner along with regular CPT data. The resistivity measurements at different electrode spacings can be used to infer sand densities at different distances from the penetrating probe. By comparing the resistivity close to the probe with the resistivity further away from the probe, it is possible to observe the shear induced volume change caused by penetration of the probe. This approach is analytical and does not require water sampling, nor is it site specific. Data are presented to illustrate the effectiveness of this technique in determining in situ dilatancy of sands. The technique is compared to existing empirically based approaches for prediction of dilatancy. Finally, possible future applications of the RCPT are discussed.

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Yeh, Yi-Pin, and 葉逸彬. "Study of Acoustic Emission Characteristics in Sand of Cone Penetration Test." Thesis, 2004. http://ndltd.ncl.edu.tw/handle/86462917163024600673.

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碩士 國立中央大學 土木工程研究所 92 Cone Penetration Test (CPT) can be operated easily and quickly. CPT is usually applied in investigation of soil classification and soil layer verification. This research used the technique of sound measurement with a small microphone installed in the cone tip to measure the acoustic signal during the penetration of cone tip. One circular chamber and a movable sand pluviator were used to carry out a series of laboratory cone penetration tests under different relative densities and overburden pressures. The data waa recorded by data acquisition system, and acoustic emission (AE) rate, root mean squar (RMS) of sound pressure and frequency spectrum were analyzed. From the experimental results, the root mean square of sound pressure and AE rate increased with the increase of average grain size. The influences of average grain size on cone resistance ate small. Furthermore, it is shown that the cone resistance would be increased with the increase of relative density and overburden pressure. However, the root mean square of sound pressure is slightly varied with the change of relative density and overburden pressure. Then the difference between the root mean square of sound pressure and cone resistance under different pressure mode is not great. Besides, the analyses of frequency spectrum of Shiluo Sand showed that the major frequency distribution of these tests are located at the range of 3~4kHz.

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Wang, Jiun-Shiang, and 王俊翔. "Stratigraphic profiling and probabilistic site characterization based on cone penetration test." Thesis, 2016. http://ndltd.ncl.edu.tw/handle/53006556052024244811.

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碩士 國立臺灣大學 土木工程學研究所 104 As the reliability analysis and reliability-based design become more popular in geotechnical engineering, it attracts much attention and can not be ignored that how to estimate the random field parameters of specific geotechnical parameters in geotechnical design. In practice, the design parameters for sands and for clays are totally different. Thus, we should get the information about the underground profiling and the distribution of soil layers before we start to estimate the random field parameters for the design parameters we need. In this study, a stratigraphic profiling approach is proposed with some comparison with others appearing in the previous literatures, and a robust and convenient algorithm for probabilistic site characterization in geotechnical design parameters is introduced. In the afore part of this study, one stratigraphic profiling approach is proposed based on the soil behavior type index, Ic, obtained from cone penetration tests (CPT). Different from other methods’ in the literature, the basic idea of this approach is simple: the layer boundaries can be identified as the points at which a change occurs in the Ic profile. It is shown that these change points can be easily identified using the wavelet transform modulus maxima (WTMM) method. This method is able to accurately pinpoint the locations of change points in the Ic profile and to produce graphs and plots that fit well with engineers’ methods of visualization and intuition. Moreover, by virtue of the fast Fourier transform, the computation is very fast. Case studies show that the WTMM method is effective for the detection of change points in the Ic profile. It is also capable of detecting thin soil layers. Another, this study applies the transitional Markov chain Monte Carlo (TMCMC) algorithm to probabilistic site characterization problems. The purpose is to characterize the statistical uncertainties in the spatial variability parameters based on the cone penetration test (CPT) dataset. The spatial variability parameters of interest include the trend function, standard deviation and scale of fluctuation for the spatial variability, and so on. In contrast to the Metropolis–Hastings (MH) algorithm, the TMCMC algorithm is a tune-free algorithm: it does not require the specification of the proposal probability density function (PDF), hence there is no need to tune the proposal PDF. Also, there is no burn-in period to worry about, and the convergence issue is mild for TMCMC because the samples spread widely. Moreover, it can estimate the model evidence, a quantity essential for Bayesian model comparison, without extra computation cost. The effectiveness for the TMCMC algorithm in probabilistic site characterization for geotechnical design parameters is demonstrated through simulated examples and a real case study. Besides, Betz et al. (Betz et al. 2016) have proposed several possible modifications to the original transitional Markov chain Monte Carlo method. The modifications are applied on original TMCMC method respectively to investigate which ones are really helpful; also, the performance of each modified TMCMC method, including iTMCMC, on probabilistic site characterization is surveyed. In conclusion, this study proposed one characterized process based on CPTu dataset, including stratigraphic profiling and probabilistic site characterization. With these underground information and random field parameter of geotechnical design parameters, the reliability analysis and the reliability-based design can be done.

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