Loading...

Determination of Strain Dependent Dynamic Parameters of Unsaturated a Silty Soil During Drying path using Resonant Column-Torsional Shear Device

Zahed Kameh Olya, Vahid | 2022

115 Viewed
  1. Type of Document: M.Sc. Thesis
  2. Language: Farsi
  3. Document No: 55049 (09)
  4. University: Sharif University of Technology
  5. Department: Civil Engineering
  6. Advisor(s): Haeri, Mohsen
  7. Abstract:
  8. Shear modulus and damping ratio are the most important parameters for evaluating the performance of geotechnical systems under seismic and dynamic loads. According to the definition, secant shear modulus is the slope of the hysteresis shear stress-shear strain loop and damping ratio indicates the dissipation of wave energy during propagation in the soil. These parameters depend on stress state, shear strain and void ratio of the soil. Shear strain amplitude has an important effect on the behavior of shear modulus and damping ratio and it is necessary to study the behavior of these parameters in the range of small to large strains. In addition to dynamic loading, climate change and wet and drying cycles also change the dynamic behavior of soil, so it is important to study the dynamic behavior of soils in unsaturated conditions and the effect of hydraulic paths on shear modulus and damping ratio. Research on shear modulus and damping ratio of unsaturated soils shows the effect of matric suction on these two parameters and during drying with increasing matric suction, the soil shows hardening behavior that increases the shear modulus and decreases the damping ratio. Considering that the main research on the dynamic behavior of unsaturated soils is in the range of small strains, it is very important to study the effect of matric suction and wet and drying paths on the parameters and dynamic behavior of the soils. The aim of this study was to investigate the effect of suction and degree of saturation in the range of small to medium strains on the shear modulus and damping ratio of silts. For this purpose, a torsional shear-resonant column device with the ability to measure the shear modulus and damping ratio in different suction ranges in the hydraulic drying path has been used. This device can be used in the range of small to medium strains to measure soil dynamic parameters. This research is a small part of a large project and a PhD student and several master students are participating in this project, which aims to investigate the effect of fine content on the dynamic behavior of mixed sand-silt soils under hydromechanical stresses. In the present study the focus is on the dynamic behavior of a fine-grained silt in the hydraulic drying path. Expanding the concepts of dynamic response of unsaturated soils leads to enhanced accuracy in the design of geotechnical structures under dynamic loads and large-scale earthquakes
  9. Keywords:
  10. Unsaturated Soil ; Shear Modulus ; Damping Ratio ; Shear Strain ; Resonant Column-Torsional Shear Apparatus ; Drying Path

 Digital Object List

 Bookmark

No TOC