【摘要】 为了研究在不同卸荷量影响下,岩石的应力应变关系和蠕变模型参数的变化规律,采用MTS815.02试验机对砂岩进行室内分级非等卸荷量蠕变试验研究,并通过建立考虑卸荷量的变参数本构模型,与试验数据进行对比验证。试验结果表明:在同一试验条件下,随着每一级卸荷量的增大,其瞬时应变量和卸荷量等差比也越大,岩石更快进入加速蠕变阶段且蠕变时间变短,最终岩石破坏变形量越大、破坏更彻底;基于试验结果对各卸荷量各时刻下蠕变参数进行拟合分析,可以较好地反映岩石内部损伤演化规律和结构劣化,并较好地描述原有西原体难以描述的阶段,说明了所建立考虑卸荷量影响下砂岩变参数蠕变模型是合适可行的,同时,对巷道围岩支护理论以及卸荷过程中岩石失稳破坏形式分析具有指导作用。更多还原

【Abstract】 In order to study the stress-strain relationship of rock and the variation of creep model parameters under the influence of different unloading,the sandstone unbalanced unloading creep test was carried out by MTS815.02 Testing Machine. The variable parameter constitutive model considering the unloading quantity was established and compared with the experimental data. The test results show that under the same test conditions,with the increase of the unloading amount of each stage,the difference between the instantaneous strain and the unloading amount also becomes larger. The rock enters the accelerated creep stage more faster and the creep time becomes shorter. The rock deformation eventually becomes larger and the destruction is also more thorough. Based on the test results,the fitting analysis of the creep parameters at each moment of the unloading amount can better reflect the internal damage evolution law and structural deterioration of the rock and describe the stage that was difficult to describe. It shows that the established parametric creep model is suitable and feasible. Meanwhile,the research results provide guiding significance for the surrounding rock support in the roadway and the rock failure during the unloading process.更多还原