岩体变形参数的应力状态效应研究

岩体力学参数存在随应力状态不同而变化的特性，称为应力状态效应。岩体力学特性的实测值具有空间场分布特征，分析表明地应力（或围压）的有规律变化是造成岩体力学参数空间变化的主要原因。考虑到实测地应力多具有较大的离散型，尝试利用反演方法获取地应力场信息，通过多元回归分析得到实测岩体变形参数与地应力的经验关系，以研究岩体变形参数的应力状态效应。通过一工程实例研究：得到地下厂房区域的岩体变形模量为16GPa左右，与反演分析结果也比较符合；通过应力状态效应研究得到的岩体变形参数物理场，是一个渐变的物理场模型，是更为符合工程实际的；主要考虑了岩体力学参数的应力状态影响，通过一系列的计算得到，人为因素少，计算结果可供工程实践参考。

Study on Stress State Effects of Rock Deformation Parameters

The rock mass parameters can change with the stress state, which is called the stress state effect. Insitu-measured values of the rock mass parameters show spatial field characteristics, which is caused by the regular change of the geo-stress or confining pressure. The measurements of geostress always show a large discreteness. In order to avoid the disadvantage of the parameter discreteness, the methods of initial geostress back analysis is introduced. Then the empirical relationship between the measured rock mass parameters and the back analysed geostress is established through multiple regression method, which is the mathematical expression of the stress state effects. The study of an engineering example shows that the deformation modulus of the rock mass around the underground factory house is about 16GPa either from this method or the back analysis method of the measured deformation. Rock mass parameters are got through this method, which are relatively conforming to engineering reality. As the results are got by a series calculation, the error of human factor can minimize compared with the insitu measure method, which provides a good reference for geotechnique engineering.