基于统一强度理论的热-力耦合作用下圆形隧洞的弹塑性解析解

Anelastoplastic analytical solution of circular tunnel under thermal-mechanical coupling based on the unified strength theory

为分析热-力耦合作用下隧洞围岩的塑性区及应力分布的规律,本文基于弹塑性理论及统一强度理论,推导出热-力耦合作用下针对不同强度理论的圆形隧洞围岩塑性残余区、塑性软化区边界线方程和应力表达式,并由算例分析得到中间主应力系数和温度场对隧洞围岩应力分布、塑性区半径的影响。研究结果表明:中间主应力系数对隧洞围岩应力分布有显著影响,随着中间主应力系数的增大,围岩塑性残余区、塑性软化区半径逐渐减小;温度场使得围岩峰值切向应力降低,塑性残余区、塑性软化区半径有所增长。本文研究结果可以为热-力耦合作用下围岩应力分析及塑性区范围的预测提供理论参考。

In order to analyze the plastic zone and the stress distribution law of the surrounding rock of the tunnel under the thermo-mechanical coupling,the boundary line equations and stress expressions of the plastic residual zone and plastic softening zone of the circular surrounding rock with different strength theories under the thermo-mechanical coupling are derived by using the elastic-plastic theory and the unified strength theory.The influence of the middle main stress coefficient and the temperature field on the stress distribution and the radius of the plastic zone of the surrounding rock of the tunnel is obtained by a numerical example.The results show:the intermediate principal stress coefficient has a significant influence on the stress distribution of the surrounding rock,with the increase of intermediate principal stress coefficient,the radius of the plastic residual zone and plastic softening zone of the surrounding rock decreases gradually;the temperature field reduces the peak tangential stress of the surrounding rock and increases the radius of the plastic residual zone and plastic softening zone.The results can provide a theoretical reference for the analysis of surrounding rock stress and the prediction of the range of plastic zone under the thermo-mechanical coupling.