深部巷道开挖过程中围岩体的时程响应分析

Time-history response analysis of surrounding rock mass in process of excavating deep tunnel

为了解释深部巷道围岩体拉压交替变化和分区破裂化现象,本文建立深部巷道开挖的动力响应分析模型,推导出扰动应力、扰动应变和扰动位移满足的扰动平衡方程、扰动物理方程、扰动几何方程和扰动边界条件。利用Ham ilton时域变分原理,导出扰动的积分-变分方程。在给定开挖卸荷路径和零初始条件下,采用杜哈梅积分推导出系统的稳态时程响应,求出系统的扰动应力、扰动应变和扰动位移的近似解析解。算例结果表明,本文的理论和方法能正确地反应出深部巷道开挖引起的围岩体的动态过程,并能有效地评价开挖引起的围岩体的破坏形态。

In order to explain the tension-compression alternating and zonal disintegration phenomena,the dynamic model of deep tunnel excavation were found for the deep tunnel excavation unloading.The equilibrium equations,physics equations,geometry equations and the boundary conditions were derived,which are satisfied by the disturbance stress,disturbance strain and disturbance displacement.The disturbance integral-variational equations were given out by Hamilton time domain variation principle.The steady-state time-response of the system was obtained using Duhamel integral in the given excavation unloading path and zero initial condition.The approximate analytic solutions of disturbance stress,strain and displacement of the system were obtained.The results of example show that the theory and method can correctly be reflected the dynamic process caused by excavation and effectively simulate the zonal disintegration phenomena of the rock mass.