Dissertations / Theses on the topic 'Embankment construction'

The objective of this research work was to gain a better understanding of the interaction between loads applied on the surface of soils, and the behaviour of adjacent long, vertical piles, embedded at depth in a stiff substratum. The influence of lateral thrust on the piles in an upper soft clay layer, due to simulated embankment construction, was examined and soil- pile interaction mechanisms were identified both for behaviour at working load and at the ultimate lateral capacity. The performance of a row of free headed piles and of a pile group were investigated experimentally in the geotechnical centrifuge for different pile and foundation geometries. Pile response, in terms of bending moment, deflection and lateral pressure, was determined for surcharge loads applied to the centrifuge model. This experimental database was used to calibrate a three dimensional finite element analysis of the same, simplified, model. These investigations led to the development of an approximate formula for lateral loading, based on the differential movement between the piles and the surrounding soil, which accounted for pile spacing, relative pile-soil stiffness and the degree of soil strength mobilisation. This loading function was incorporated in a computer program, SIMPLE, which calculated the pile bending moment and deflection profiles for flexible piles and pile groups. The algorithm was checked against the centrifuge model test results and the numerical analyses, and design charts were produced for free headed piles only. Finally a design procedure was recommended for piled full-height bridge abutments and other facilities which feature passive lateral loading of piles by a nearby surcharge.

In-situ piezocone, flat dilatometer, and screw plate tests were carried out adjacent to the site of several large earth embankments, founded on a deep deposit of compressible soil. Settlement records since construction were available for two of the embankments. Geotechnical parameters were not back analyzed from the case record, rather, embankment performance was predicted on the basis of parameters interpreted from the in-situ tests alone. Consolidation characteristics were interpreted from the measurement of dissipation of excess pore pressures using the piezocone and dilatometer. Both devices provided complementary results in terms of an appropriate coefficient of consolidation. The excellent stratigraphic profile furnished by the piezocone (CPTU) tests proved to be a most valuable feature. The stratigraphic detail provided by the CPTU tests performed across the site identified continuous, free (framing soil layers which would generally be missed in a conventional geotechnical investigation using a drilled borehole with discrete sampling. The identification of these layers was of paramount importance in the prediction of settlement rate. A one-dimensional analysis formed the basis for the settlement predictions, and was found to be satisfactory. Settlement magnitudes were predicted within 10% of the observed measurements, parallelling the observed rate of settlement throughout the embankment construction period in the early 1970's and to the present date. Key words: settlement, deltaic soils, embankment, in-situ testing, piezocone, flat dilatometer, screw plate, coefficient of consolidation, compressibility, pore pressure dissipation.
Applied Science, Faculty of
Civil Engineering, Department of
Graduate

In this work, the effect of Fly Ash (FA) on fine sand and its suitability as a civil engineering material for construction of embankments is investigated. The thesis is concerned with the role of FA content in stabilised soil physical characteristics. The aim of the study presented in this thesis is to examine the suitability of class F FA as a construction material in geotechnical engineering projects. This is achieved through combination of experimental analysis and numerical simulations. Experimental analyses (in accordance with British Standards) were conducted by applying compaction, particle size distribution, bearing capacity tests and resilient modulus, derived from California Bearing Ratio (CBR), while numerical simulation was carried out using finite element and lagrangian finite difference analysis. For the purpose of this thesis, all the samples were tested before and after being treated with four different curing durations, 1 week, 2 weeks, 4 weeks and 8 weeks, and three variations of FA content, 5%, 10% and 15%. The samples were also mixed with 3% of cement as the activator. In this thesis, the research aims and objectives are stated in the introduction chapter, followed by the literature review on FA, soil stabilisation and ground improvement. The research methodology and details about the materials used, are then presented and discussed. The numerical simulations and results are finally presented. FA stabilized samples, with an accurate mixture, were shown to have lower dry densities while producing higher strengths than the sand. Potentially making it an effective material suitable for use in embankment construction and projects alike.

Thesis (M.S.)--University of Missouri-Columbia, 2008.
The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file. Title from title screen of research.pdf file (viewed on September 3, 2008) Includes bibliographical references.

It is envisaged that flood plains will be put into more active usage to meet the increasing demands for road infrastructural development as well as relieve the pressure exerted on arable lands owing to infrastructural development activities. This is consequent upon the general shortfall in the availability of soils possessing the right engineering properties to carry infrastructures such as roads which consume large tracks of land. Expanding the global infrastructural base is inevitable due to the ever increasing human population and the need to meet their social, economic, political and transportation needs. However, owing to the prevailing environmental awareness campaigns fronted by different environmental agencies, there is the need to regulate and monitor the interaction of the processes involved in the provision of these needs with the limited resources as well as the environmental aftermath associated with such operations. The stabilization of flood plain soils for road embankment construction is envisaged to reduce the demand on the material resources required to build classical high embankments in flood prone areas as well as offer implied mitigating dimensions in the restoration of environmental integrity. This impliedly will reduce the use of traditionally unsustainable methods of soil stabilization such as, the excavation and importation of new materials, to a more robust system that will offer environmental friendliness amidst value engineering for better strength and durability results. The experimental processes involved the simulation of flooding scenarios in the laboratory, to monitor the strength and durability aspects of low-bearing-capacity soils (such as Lower Oxford Clay) stabilized with blended mixes of the traditional stabilizer of lime and the novel materials of lime and Ground Granulated Blastfumace Slag (GOBS) by-product combined. Preliminary investigations were carried out on the Lower Oxford Clay soil to establish the moisture and compaction requirements of the material. Different mix compositions were formulated by incrementally replacing the amount of lime in the system with GOBS. This was based on the premise that high stabilizer contents could offer better stabilization to flood susceptible geo-materials upon flooding. A high stabilizer level of 16% was therefore investigated. Regimes of different blending ratios were established as follows: 16%Lime-0%GGBS, 12%Lime-4%GGBS, 8%Lime-8%GGBS, 4%Lime-12%GGBS and 0%Lime-16%GGBS and tested at moisture contents of 23%, 28%, 33% and 38%. The two extremes 16%Lime-0%GGBS and 0%Lime-16GGBS were used as controls. A system of elimination based on strength criteria was employed, where only the 8%Lime- 8%GGBS and 4%Lime-12%GGBS mixtures were deemed fit to be investigated further to determine their resistance to challenging environmental factors of flooding. The test samples were cylindrical, measuring 50 mm in diameter and 100 mm long, and these were compacted using a static compaction apparatus to achieve Maximum Dry Density (MDD). Depending on the testing regime to be applied to a given specimen, a curing pattern was defined and samples were wrapped in cling film to minimise moisture losses. At the end of each curing period of 7, 14, 28, 56 and 90 days, one of the experimental procedures which ranged from Unconfined Compressive Strength, Water Absorption, Volume Stability, Permeability, Soaked Strength and Durability Index Assessment or Compressibility Assessment was carried out on the moist cured samples. Following these assessments, the 4%Lime-12%GGBS mix composition was appraised to have overall improved characteristics with the added benefit of reduced cost of material utilisation. Based on the available data, regression analyses were carried out and equations established for predicting the strength values of stabilized materials. Using these equations further extrapolations were made and the observable trends were those of the dependence of compressive strength on the age of moist curing and the compaction moisture contents at which samples were produced at given blended mixture. Cost-benefit-risk analysis was also carried out with a further cost annualisation of the capital and operational cost of a selected system. It is reassuring to learn that at replacement level of lime with GOBS of 4%Lime-12%GGBS it was possible to establish multi-binder mixtures that could be effectively used for sustainable construction in flood prone areas with enormous savings accruing from the possible higher strength and enhanced durability indices achievable over traditional unsustainable options of continued over-reliance on lime and Portland cement.

Brownfield in Brno by the Svitava river. Proposal of conversion and completing of a part of the area in Brno – Husovice district, where you can find brownfield, as e.g. an old hall of former Zetor company. The goal is to design a functional district with respect to the original housing development. The territorial unit is designed so that it respects surrounding housing development and improves transportation situation. It complies with transportation connection to future reconstruction of Zbrojovka premises, for which a proposal is being designed. The main target is to create a comfortable place to live in and to cover basic needs of every person, to design interesting places for relaxation, cultural life, provide sports facilities and raise number of job opportunities in this area. The goal of this project is also to create a diverse place for living. Its meant for people from different social backgrounds and for people who use cars both with low frequency or who use them on a daily basis.

In this dissertation, the behavior of geosynthetic reinforced embankments constructed on soft cohesive foundations under undrained and partially drained conditions is examined by conducting a rigorous numerical analysis using the finite element method for some particular case studies. Special attention is given to the mobilized strains in the geosynthetic reinforcement at embankment failure, short and long-term working conditions state and during staged construction considering the influence of the time-dependency of the system in terms of construction rate, excess pore pressure dissipation and viscous deformations in the soil foundation (i.e., creep). The effects of reinforcement stiffness and adopted constitutive model are also investigated. The obtained results highlight the importance of assessing the allowable compatible reinforcement strain at failure and taking into account this soil-reinforcement interaction. It is illustrated the significant combined influence of consolidation process and soft soil creep deformation on the numerically observed embankment performance at working conditions, particularly in terms of mobilized reinforcements strains. Finally, an approximate approach for studying numerically staged constructed embankments is presented, pointing out the adequate definitions of Limit States for the considered stages and the effects of time in the embankment behavior.

The thesis deals with the back analysis of the instrumentated embankment on the subsoil, improved by prefabricated vertical drains. The first part is devoted to the theory of consolidation calculation. Furthermore, the author deals with a parametric study of the analytical calculation of prefabricated drains and the comparsion of the analytical and numerical solution. The last and the largest part of the work is a back analysis of the embankment which was built as a part of the subsoil improvement near the Suez Canal in Egypt by Keller GmbH.

Thesis (MScEng (Civil Engineering))--University of Stellenbosch, 2005.
There has always been some debate in the past about the most effective and economical type of revetment to be used to combat or prevent erosion in rivers and channels. Some of the most common materials used for these mitigation measures are gabions, Reno mattresses and rip rap. A study done by the Colorado State University (CSU, 1984), comprised hydraulic tests of Reno mattresses used as a channel bed revetment. The result were compared with those of rip rap. This thesis mainly deals with the evaluation of incipient motion conditions for rock used in Reno mattresses and as rip rap. In this thesis the results of the CSU study and the design criteria of Maccaferri are evaluated and compared with the result obtained when applying the stream power theory and the Shields' theory with respect to incipient motion. This thesis includes the theory with respsect to incipient motion conditions, background to the CSU study and comparisons of the results of the CSU study and Maccaferri's design criteria with theoretical calculations. A cost comparison of Reno mattresses and rip rap as channel bed revetment measures, as well as conclusions and recommendations with regard to the design and use of these options, are also included. The frame of reference for this thesis is the set of CSU test results. The calibrations achieved, proposals made and accuracy of conclusions thus depend on those results.

Soft soil reinforcement by inclusion is a growing technique caracterized by a pile grid and a granular embankment introduced between the reinforced soil and the structure. Unlike traditionnal methods, the load is partially transferred to the pile heads by arching in the embankment. The application area of this research focuses on the shallow foundations case, in which the thickness of the embankment is small. The litterature review shows that only a few studies were dedicated to that case, and that fundamental questions remains concerning the load transfer in the embankment. Chosen method for this research consists in two-dimensionnal physical modelling, analysis of the conducted simulations, and development of an analytical model in order to predict the load transfer to the piles by arching in the embankment. The results of this PhD thesis provide original elements of evidence of the load transfer in the studied system, proposes an analytical model based on block division of the granular embankment by shear bands - which is in good agreement with experimental data - and lead to a better understanding of arching in soils.
Doctorat en Sciences de l'ingénieur
info:eu-repo/semantics/nonPublished

Conception de cette structure par le laboratoire central des ponts et chaussées afin d'étudier expérimentalement le comportement de ce type d'ouvrage. Détermination des efforts internes dans le mur à l'aide de capteurs intégrés à la structure et étude du mécanisme de leur fonctionnement par des calculs aux éléments finis tridimensionnels, puis par photoélasticimétrie. On passe des mesures de déformation aux efforts internes dans la structure par des formules de régression linéaire qui résultent de l'analyse statistique d'un grand nombre de cas d'étalonnage sous sollicitations contrôlés. Détermination théorique des dimensions optimales à donner au remblai pour que les efforts dans le mur soient représentatifs d'un massif d'extension semi-infinie. L'étude est effectuée par un modèle numérique bidimensionnel aux éléments finis et également par des calculs bidimensionnels à l'aide d'un logiciel, utilisant également les éléments finis. Analyse des premiers essais réalisés à la station.

碩士
國立中央大學
營建管理研究所
104
Carbon emission estimation gradually becomes a requirement for public construction due to Taiwan government policy recently. The current method for carbon emission calculation is tedious and time-consuming. The study purpose is to develop a method so called construction activity portfolio to reduce calculation time and procedures for river embankment construction projects. Based on previous studies and the current calculation method, experts suggested the outline for construction activity portfolio, followed by the data collection from historical projects. There are 16 construction modules that need to take into consideration so as to establish the module database. A total of 45 river embankment construction projects were collected. Each module is predetermined and calculated for its carbon emission. Users can easily determine the project carbon emission by picking up corresponding modules and then having a summation of selected modules. The proposed method significantly reduces calculation time to only 3% of original calculation time.

碩士
朝陽科技大學
營建工程系碩士班
95
Taiwan Government spends great amount of money to build, repair or rehabilitate, and maintain river embankment every year. For instance, there were 234,560-meter-long and 45,242-meter-long river bank new built and rehabilitated in 2004, respectively. Due to the influence of typhoon, the flood prevention season normally is from June to October in each year. Thus, there is not much time left for contractor to finish river embankment project in a year in which is the time-span usually scheduled to complete an embankment project. As a result, how to implement such project efficiently becomes a more important issue than other type of construction projects. This study aims at developing a discrete event simulation system for facilitating the design and analysis of river embankment construction operations by conducting the following experiments: 1. collect field data including construction operations and activity duration; 2. build discrete event simulation models and fit collected duration data to probability density functions (PDFs); 3. install data base for storing the simulation models and PDFs describing activity duration; 4. examine the practicability for the models; 5. transfer the studied results to the related contractor.

This thesis considers some issues regarding geotechnical monitoring of settlement of subsoils on roads, highways in the Czech Republic. The first part try to explain process of construction embankments with following standards and prescriptions. Second part belongs to geotechnical monitoring of settlement of subsoils, where author had selected 7 measuring profiles for further work on archive exploration. From these exploration were excluded information about exact location. Third part is creation of 9 geotechnical models in 2D - Plaxis software, comparison with real data and short part about using this kind of work for practice use.