【摘要】 获取寒区工程设计中冻土的物理力学指标及冻土本构模型中的模型参数都离不开冻土的力学试验.随着对冻土力学性质研究的深入,需要考察更多加载路径下冻土的力学行为,这也是检验已有冻土本构模型的有效途径.因此,精确的冻土力学试验是认识冻土力学性质的基本手段.为进一步考察冻土的力学性质,提高冻土力学试验的精度,应用MTS-810低温三轴仪及其配套的控制软件,在该设备上对冻土进行了两种各向等压试验和两种三轴剪切加卸载试验.根据试验结果,分析了这几种试验方法的适用范围,为考察等效剪应力对冻土试样体积变形的影响,提出了在MTS-810低温三轴仪上实现冻土等p试验的具体试验方案.更多还原

【Abstract】 Mechanical tests of frozen soil are essentially a process to obtain the physical and mechanical parameters of frozen soil for engineering design in cold regions and the model parameters in constitutive model of frozen soil.Along with the deepening of research,mechanical behaviors of frozen soil under different loading paths,which are effective approach to verify the existing models,should be investigated more.Thus,precise mechanical tests are fundamental mean to cognize the mechanical properties of frozen soil.For further examining the mechanical properties of frozen soil and increasing the accuracy of mechanical tests,two isotropic consolidation tests and two triaxial shear loading-unloading tests are conducted by using MTS-810 Triaxial Material Test Machine at low temperature.According to the test results,scope of application of the test method is analyzed.A testing program is proposed using the test machine for shear test with constant net mean stress,which is able to examine the effect of equivalent shearing stress on volumetric deformation of frozen soil.更多还原