等应变增量比试验控制功能的开发与实现

Development of constant strain increment ratio path tests

研究砂土在沿着应变增量比(侧向应变增量与轴向应变增量的比值)为常数的路径加载时的力学响应具有十分重要的意义。对常规三轴试验设备进行了改造,增加量测试样体变的传感器,通过改变围压的大小来控制试样加载过程中的应变增量比,使其保持为常数。研制开发的试验设备可用于研究砂土在等应变增量比加载条件下的应力应变响应。针对砂土进行了等应变增量比的三轴试验,对试验结果的分析与比较表明系统具有足够的控制精度,从而验证了设备的有效性。

It is of vital importance to study the mechanical response of sand in strain-path controlled tests during which the ratio of lateral to axial strain increments is kept constant. By employing a transducer for measuring the volumetric strain of the sample and adjusting the lateral stress in axial strain controlled tests, a conventional triaxial test apparatus is improved to control the strain increment ratio, defined as the ratio of lateral to axial strain increments, constant in the strain path test. The device can be applied in the investigation of stress-strain behavior of sand loaded along constant strain increment ratio paths. In addition, the constant strain path tests are conducted for sand. Comparison and analysis of the test results indicate the satisfactory experimental precision of the apparatus, thus showing its effectiveness.