A Triaxial Testing System to Evaluate Stress-Strain Behavior of Soils for Winde Range of Strain and Strain Rate

摘要

Some important modifications were made to an existing triaxial testing apparatus to more accurately evaluate the stress-strain behavior of geomaterials for wide ranges of strain and strain rate. An electro-mechanical loading device was specifically designed to control strain states and stress paths and to study the quasi-elastic properties of geomaterials at any given stress state. The device is now driven by an a-c servo motor, allowing for changing the strain rate about three orders of magnitude without any intermission in each test. A 16-bit A/D card has been adopted also to increase the resolution in data acquisition. The long-term stability of a local axial gage, LDT, has been ensured to evaluae creep deformations as well as post-creep behavior of geomaterials, which should be properly understood for many practical engineering applications.