某工程试验洞的有限元流变计算分析

FEM Analysis of the Experimental Tunnel,Considering Reck Rheologic Behavior

把岩体作为粘弹塑介质，用组合模型描述岩体流变特性，对某工程试验洞的粘土岩进行有限元流变计算，计算结果与实测结果相当一致。计算表明，岩体流变特性对岩体、特别对软弱岩体的围岩稳定的影响是不容忽视的。在围岩稳定分析中，粘弹塑性方法能更好地预测洞室塑性区的发展和洞周位移的变化情况，并为寻求合理的支护时间、支护形式提供依据。

in this paper, the rock mass is regarded as a viscoelastic-plastic mdeium and the rheologicbehaviors of rock mass are simulated by a combined rheologic model. The computation results of theexperiment tunnel excavated in clay rock has a good agreement with the measured result. This showes thatthe influence of rock rheologic behavior on the stability of rock mass can not be neglected, especially for thecase of the soft rock masses. The method considering rock massas viscoelastic-plastic media is morereasonable. The development of the plastic zones in rock mass and the variation of displacements around theexcavation can be predicted more accurately by using this method. And it can provide the basis for the choiceof reasonable supporting time and forms.