Engineering Commons^™

Undrained Cyclic Loading Of Low Plasticity Silty Soils In The Pacific Northwest Using Laboratory And Field Cyclic Shear Testing, Angelica Melissa Preciado Reyes

Dissertations and Theses

The cyclic behavior of a fine-grained low plasticity silty soil (plasticity index of approximately 15) at a site in Portland, Oregon, is characterized using a field and laboratory cyclic shear test program. The field cyclic tests were performed using the NHERI@UTexas large mobile shakers T-Rex and Rattler. The laboratory tests were performed using resonant column torsional shear and cyclic direct simple shear devices. This testing program's results were used to evaluate the soil's potential to develop excess pore water pressure with cyclic shear strains ranging from 0.00001% to 3%. The laboratory cyclic test results are compared against field cyclic test …

Engineered Cementitious Composite For Pavement Applications: Materials Development And Design Framework, Hassan Noorvand

LSU Doctoral Dissertations

Engineered Cementitious Composites (ECCs) are a novel class of high-performance fiber-reinforced cementitious composites characterized by their high tensile strain capacity. While ECCs have been presented as a promising material alternative for the construction of durable pavements and overlays, the cost of these materials is a major drawback, which limits their widespread implementation. More importantly, performance prediction models for ECC pavements existing in the literature are incomplete as the effect of ECC plasticity has not been considered in the integration of finite element (FE) analysis and beam flexural fatigue experimental test results. Moreover, the existing ECC pavements performance prediction models are …

Computational Design Of Nonlinear Stress-Strain Of Isotropic Materials, Askhad M.Polatov, Akhmat M. Ikramov, Daniyarbek Razmukhamedov

Chemical Technology, Control and Management

The article deals with the problems of numerical modeling of nonlinear physical processes of the stress-strain state of structural elements. An elastoplastic medium of a homogeneous solid material is investigated. The results of computational experiments on the study of the process of physically nonlinear deformation of isotropic elements of three-dimensional structures with a system of one- and double-periodic spherical cavities under uniaxial compression are presented. The influence and mutual influence of stress concentrators in the form of spherical cavities, vertically located two cavities and a horizontally located system of two cavities on the deformation of the structure are investigated. Numerical …

Constitutive Model For Rate Dependent Behavior Of Clay Internal Geotechnical Report 2011-3, Harry Martindale, Dipanjan Basu

Technical Reports

This report presents a strain-rate dependent plastic constitutive model for clays. Based on the concepts of critical-state soil mechanics and bounding surface plasticity theory, the model reproduces the mechanical response of clays under multi-axial loading conditions and predicts both the drained and undrained behavior. The model parameters are determined for Boston Blue Clay, London Clay and Kaolin Clay, and the performance of the model in simulating the mechanical response of these clays is demonstrated for low to medium strain rates. The sensitivity of each model parameter is checked by perturbing the calibrated values by ±20%. Subsequently, a probabilistic analysis using …

Computational Simulation Of Strain Localization: From Theory To Implementation, Shouxin Wu

Doctoral Dissertations

Strain localization in the form of shear bands or slip surfaces has widely been observed in most engineering materials, such as metals, concrete, rocks, and soils. Concurrent with the appearance of localized deformation is the loss of overall load-carrying capacity of the material body. Because the deformation localization is an important precursor of material failure, computational modeling of the onset and growth of the localization is indispensable for the understanding of the complete mechanical response and post-peak behavior of materials and structures. Simulation results can also be used to judge the failure mechanisms of materials and structures so that the …

Stabilization Of Residual Soil With Rice Husk Ash And Cement, Hilmi Mahmud

Hilmi Mahmud

Stabilization of residual soils is studied by chemically using cement and rice husk ash. Investigation includes the evaluation of such properties of the soil as compaction, strength, and X-ray diffraction. Test results show that both cement and rice husk ash reduce the plasticity of soils. In term of compactability, addition of rice husk ash and cement decreases the maximum dry density and increases the optimum moisture content. From the viewpoint of plasticity, compaction and strength characteristics, and economy, addition of 6-8% cement and 10-15% rice husk ash is recommended as an optimum amount. © 2004 Elsevier Ltd. All rights reserved.

The Plastic Design Of Steel Cofferdam, Robert O. Disque

Theses

The fundamental purpose of this thesis is to employ the plastic theory in the design of a hypothetical steel sheet pile cofferdarm. Prior to undertaking this work, the author had had no previous experience with the plastic theory. Therefore, a portion of this thesis is devoted to the development of the fundamentals necessary for the actual design computations.

The theory of plastic analysis has been used as far back as the 1920's in Hungary for the structural design of apartment buildings. It is, however, only in recent years that the theory has been utilized to a significant degree in this …