软岩蠕变特性的数值分析

Numerical simulation of creep characteristic for soft rock

为了对高应力条件下岩石的变形特性进行准确的预测和预报,根据软岩蠕变特征,基于伯格(M-K)蠕变模型,考虑材料的粘弹性应力偏量特性与弹塑性体积变化特性,假定粘弹性和塑性应变分量经串联方式共同作用,建立了软岩蠕变特性的数值模型,并对Ⅴ类围岩的蠕变特性进行了数值模拟。结果表明,在高应力条件下,蠕变使围岩变形加剧,且蠕变变形随主应力差的增加而增大。

In order to predict the characteristic of the rock under the condition of high stress, according to the creep characteristic of soft rock, the M-K creep model for simulating the creep characteristic of soft rock was obtained based on a typical combined creep model such as M-K creep model by considering the material visco-elastic stress. It emphasized simulating the creep characteristic of adjacent rock for type V , and the results indicated that under high stress condition, creep could drive the adjacent rock to deform greatly, on the other hand the creep deformation could be accelerated with principal stress gradient increasing.