两向不等压作用下圆形巷道弹塑性分析摄动解

Perturbation Solutions for Elasto-piastic Analysis of Circular Tunnel under Unequal Compression in Two Directions

本文研究两向不等压作用下圆形巷道围岩的弹塑性问题。假设材料是理想弹塑性的,在圆孔周围有一环状区域已进入塑性状态,在库仑屈服条件下,用摄动法给出弹塑性区域考虑二阶小量的应力分布及弹塑性交界线的解析表达式。与以往近似法的结果不同,本文的研究结果表明,巷道围岩的弹塑性交界线形状类似于椭圆,随着内摩擦角的增加更接近于圆形。

In this paper, we have discussed the elasto-plastic problems of the circular tunnel under unequal compression in two directions. It is assumed that the materials may be idealized as elasto-perfectly plastic and the media in the neighborhood of the hole have been already in the plastic state.Using the Coulomb Yielding Criterion and considering the second order infinitesimal, the stress distribution and elasto-plastic interface are given. Unlike the results given by previous approximate methods, the research results in this paper indicate that the elasto-plastic interface is similar to ellipse and becomes circular when the angle of internal friction increases.