Abstract

The existence of joints is the key factor for the instability of underground caverns. In this paper, the instability failure behaviours, acoustic emission (AE) characteristics and damage evolution rules of green sandstone caverns with different joint angles were investigated. First, the influences of joint angles on the strength and failure behaviour of the caverns were analysed. Then, the AE characteristics and damage evolution rules of jointed caverns in the process of failure were discussed. The research results showed that the UCS and elastic modulus presented obvious anisotropy. Furthermore, the existence of joints with various angles had a strong influence on the failure pattern of caverns. However, the damage of the cavern is mainly concentrated on the side wall, the top and bottom and the maximum value of AE in jointed caverns are smaller than that in intact cavern, but the occurrence time of AE maximum value is generally earlier than that of intact cavern. The damage progress of jointed caverns is divided into four stages: damage stable stage, damage slow increase stage, damage rapid increase stage and damage termination stage. The joint angle mainly affected the second and third stages of damage variable of the caverns.

摘要

节理的存在是地下洞室失稳的关键因素。本文研究了不同节理角度的绿砂岩洞室失稳破坏行为、声发射（AE）特征及损伤演化规律。首先，分析了节点角度对洞室强度和破坏行为的影响。然后，讨论了节理洞室在破坏过程中的声发射特征和损伤演化规律。研究结果表明，UCS和弹性模量呈现明显的各向异性。此外，不同角度节点的存在对洞室的破坏模式有很大的影响。但洞窟的破坏主要集中在侧壁，节理洞室的 AE 顶底和最大值均小于完整洞室，但 AE 最大值出现时间普遍早于完整洞室。节理洞室破坏进展分为破坏稳定阶段、破坏缓慢增加阶段、破坏快速增加阶段和破坏终止阶段四个阶段。节理角度主要影响洞室二、三期破坏变量。