Author: Osama Tahseen Abu-SafaqahPublisher:
ISBN:
Category :
Languages : en
Pages : 590
Book Description
Development and Validation of the Downhole Freestanding Shear Device for Measurement of the Dynamic Properties of Clay
Author: Osama Tahseen Abu-SafaqahPublisher:
ISBN:
Category :
Languages : en
Pages : 590
Book Description
Development and Validation of the Downhole Freestanding Shear Device (DFSD) for Measuring the Dynamic Properties of Clay
Author: Dissertation Abstracts International
Author: Publisher:
ISBN:
Category : Dissertations, Academic
Languages : en
Pages : 806
Book Description
News
Author: Torsional Shear Testing Technique for Dynamic Properties of Clay
Author: AG. FranklinPublisher:
ISBN:
Category : Buildings
Languages : en
Pages : 23
Book Description
The testing technique and apparatus described herein implement the determination of dynamic stress-strain-time properties of clay soils over several decades of the frequency spectrum, including the normal frequency range of most earthquakes. The basic device used for these tests is the Weissenberg rheogoniometer, with some modifications to enhance its adaptability to testing soils. The soft clay test specimens are held in a cone-and-plate sample holder, while a hollow cylinder geometry is more suitable for stiff clay specimens. These geometries satisfy reasonably well the desirable condition that stresses and strains be homogeneous within the test specimen, and they allow tests to be conducted over a wide range of moisture contents. The specimens are subjected to oscillatory torsional shear deformations, and the moment response is measured; with the use of the specimen geometry and the homogeneity of stress and strain, these deformations and forces are readily converted to shear stresses and shear strains. In addition to the magnitudes of stress and strain, the time difference between corresponding points on the stress and strain curves is measured, allowing computation of a phase angle between stress and strain. Two types of oscillatory tests are particularly convenient to perform in this apparatus; in one case, the frequency is maintained constant while the deformation amplitude is varied, while in the other case, deformation amplitude is held constant and frequency is varied. Data obtained by this technique allow the evaluation of several aspects of the dynamic clay behavior, such as the effect of stress history, the degree of nonlinearity in the stress-strain response, and the extent to which presently available theories, such as linear viscoelasticity, can be used to interpret the mechanical behavior. For example, the energy dissipated in a unit volume of the sample over a single cycle of deformation can be calculated by using the phase angle and the stress and strain amplitudes; alternatively, this dissipated energy can be measured directly by means of a hysteresis loop, and the two values can be compared.
Feasibility of a Tool for In Situ Measurement of Material Properties of Clays Over a Wide Strain Range
Author: CK. ChanPublisher:
ISBN:
Category : Clay
Languages : en
Pages : 28
Book Description
Initial feasibility findings of a research program directed toward the development of a practical tool for rapid in situ determination of material properties (modulus and damping) of soft to medium-stiff clays over a wide range of strain (0.0001% to 10%) are presented. The motivation for this work is discussed in terms of both the sensitivity of earthquake ground response analyses to input material properties, as well as the limitations of existing design methodologies for specifying material behavior. The scope and objectives of the research program are outlined. Results are presented from numerical analyses used to establish typical stress and strain fields caused by borehole installation. The merits of several tool-design alternatives are considered, and preliminary design concepts for a new tool called the "Freestanding Torsional Shear (FTS)" device are introduced. Critical issues and future directions of the research program are discussed.
Development of the Directional Shear Cell for Measuring Cross Anisotropic Clay Properties
Author: John T. GermainePublisher:
ISBN:
Category : Anisotropy
Languages : en
Pages : 1060
Book Description
The Effects of Saturation and Stress Ratio on the Dynamic Properties of Clay Using Cyclic Triaxial Shear Testing Methods
Author: Bradley W. BarthTorsional Simple Shear Device, Liquefaction and Dynamic Properties of Sands
Author: Isao IshibashiPublisher:
ISBN:
Category : Soil liquefaction
Languages : en
Pages : 286
Book Description
Development of an Apparatus for the Dynamic Direct Shear Testing of Soils
Author: H. C. SaxePublisher:
ISBN:
Category :
Languages : en
Pages : 79
Book Description
The objective of the work reported herein was to design and develop a pneumatic direct shear device which can force soil failures on a chosen plane by either dynamic or static loadings. Discussed in detail are the establishment of design criteria, design, construction, and operation of the device, as well as the instrumentation used to control, measure, and record the soil loading phenomena. The apparatus, referred to in this report as DACHSHUND I, can accommodate specimens up to 4 inches in diameter and 0.75 inch thick. Time interval for the strain loadings can be varied from 1.0 millisecond to days. The present facility is operable and an extensive soil testing program is currently being undertaken.