岩石三轴实验中的应力路径与应力应变分析

Relationship between the stress path and the stress-strain in triaxial test

通过对砂岩、大理岩、角砾大理岩三轴实验中应力路径与应力-应变分析,揭示了在各种试验应力环境中大多数岩样的最大主应力方向的应变为最大;保持围压快速卸荷轴压时出现了-ε1,及与围压无关的岩石弹性泊松比等现象。建议采用以LVDT控制模式保持轴向位移方式下卸围压来模拟人工开挖工程引起的隧道围岩应力重新分布现象。

The stress and strain parameters of sandstone, marble and breccia marble samples are measured in the triaxial test of various stress paths. Data analysis shows that the strain in the maximal-stress direction is maximum. The negative axial strain appears under the quickly unloading axial pressure and maintaining confining pressure, and the rock poisson＇s ratio has nothing to do with confining pressure. It is suggested that in the triaxial test the stress redistribution of the tennel surrounding rock is simulated under the condition of maintaing axial displacement by the LVDT model and unloading confining pressure.