基于应变非线性软化的衬砌压力隧洞弹塑性解析解

Elastic-plastic analysis of pressure tunnel with liner based on strain nonlinear softening rock model

基于岩体应变非线性软化本构模型,考虑中间主应力的影响,对等压荷载作用下的衬砌压力隧洞进行弹塑性分析。将围岩划分为裂缝区、塑性区、弹性区,推导出了围岩裂缝区、塑性区、弹性区及衬砌内任一点的应力和位移解析计算公式,并得到了使衬砌边缘岩体开始产生塑性变形的临界内压力。所得到的解与基于理想弹塑性体的Kaster’s解相比,更接近实际隧洞围岩受力变形情况。

According to the strain nonlinear softening constitutive model of practical rock, pressure tunnel with liner under the uniform pressure is analyzed. Different displacement and stress distribution laws of the plastic residual zone, plastic zone, elastic zone and liner are presented. All obtained results are more closely approach to actual values of surrounding rocks, comparing with Kastner＇s solution. The critical pressure leading to yield firstly that caused by inner pressure is introduced.