围岩与衬砌相互作用的隧洞力学分析

发布时间：2018-01-13 05:12

本文关键词：围岩与衬砌相互作用的隧洞力学分析　出处：《华北电力大学》2015年硕士论文　论文类型：学位论文

【摘要】：基于平面弹性复变函数中的保角变换方法,可以获得在原始地应力作用下非圆形隧洞考虑支护滞后过程的应力和位移解析解。实际工程中衬砌与围岩将产生相互作用,本文分别考虑了两种不同的接触类型,分别是： (1)围岩与衬砌完全接触；(2)围岩与衬砌光滑接触。当假设围岩与衬砌为完全接触时,根据衬砌内边界的应力边界条件及围岩衬砌接触面上的应力和位移连续条件,在考虑支护滞后于开挖过程的前提下,通过柯西积分解法,可以获得求解围岩和衬砌解析函数的基本方程。当假设围岩与衬砌为光滑接触时,围岩和衬砌解析函数的基本方程不能使用常规的柯西积分方法求解,而需利用幂级数方法进行求解。当取解析函数为级数表达式时,级数表达式中的系数则为待求未知量,通过基本方程推导出求解这些系数的线性方程组,由此可以计算围岩和衬砌中的应力和位移。以马蹄形隧洞与直墙半圆拱形隧洞两种常见隧洞形状为例,求解隧洞围岩开挖边界和衬砌内外边界的环向应力及围岩与衬砌接触面上的接触应力。本文运用ANSYS有限元数值分析软件模拟隧洞开挖过程,求解围岩开挖边界和衬砌内外边界的切向应力及围岩与衬砌接触面上的接触应力,将结果与上述解析方法所获得的应力结果对比,两种方法的结果吻合很好。说明本文在推导解析函数的过程中并未发生错误。并且在光滑接触工况下,各边界的应力分布均优于完全接触工况下的应力分布,可得出当在对隧洞进行支护时,可选择在混凝土中掺入能够降低摩擦系数的添加剂,有利于提高衬砌与围岩的稳定性。
[Abstract]:Based on the conformal transformation method in the plane elastic complex variable function. The analytical solution of stress and displacement of non-circular tunnel considering the process of supporting lag can be obtained under the action of original in-situ stress, and the interaction between lining and surrounding rock will occur in practical engineering. In this paper, two different contact types are considered, namely: (1) complete contact between surrounding rock and lining; (2) smooth contact between surrounding rock and lining. When the contact between surrounding rock and lining is assumed to be complete, the stress boundary condition of lining inner boundary and the continuous stress and displacement condition on the contact surface of surrounding rock lining are considered. On the premise that the support lags behind the excavation process, the basic equation of solving the analytic function of surrounding rock and lining can be obtained by Cauchy integral solution. When the wall rock and lining are assumed to be smooth contact. The basic equations of the analytical function of surrounding rock and lining can not be solved by the conventional Cauchy integral method, but need to be solved by the power series method, when the analytic function is taken as a series expression. The coefficients in the series expression are unknowns, and the linear equations for solving these coefficients are derived from the basic equations. The stresses and displacements in surrounding rock and lining can be calculated, taking the common tunnel shapes of horseshoe tunnel and straight wall semi-circular arch tunnel as examples. In order to solve the circumferential stress of surrounding rock excavation boundary and lining inner and outer boundary and the contact stress between surrounding rock and lining, this paper simulates the excavation process of tunnel by using ANSYS finite element numerical analysis software. The tangential stress of surrounding rock excavation boundary and lining inner and outer boundary and the contact stress between surrounding rock and lining contact surface are solved, and the results are compared with the stress results obtained by the above analytical method. The results of the two methods are in good agreement with each other. It shows that there is no error in the derivation of the analytic function in this paper, and the stress distribution of each boundary is better than that of the complete contact condition under smooth contact conditions. It can be concluded that when supporting the tunnel, the additive can be added to the concrete to reduce the friction coefficient, which is helpful to improve the stability of lining and surrounding rock.
【学位授予单位】：华北电力大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：U451

【共引文献】