爆破方法改变分区破裂巷道围岩应力传递

Blasting Method to Change Stress Transfer of Confining Rock in Tunnels with Zonal Fracturing

深部开采中的高地应力对巷道围岩的稳定造成很大的影响。地应力的大小虽然不可以改变,但是其分布却可以通过爆破方式,人为干预的方法,造成的局部的改变。笔者提出了一种新的解决高地应力下解决巷道围岩稳定的方法:通过巷道外部围岩内的装药结构,引爆后通过装药的内部作用在巷道顶部的装药区域贯通,造成分区破裂;分区破裂的强度降低,在周围高应力作用下,起到"孔洞"的作用,改变局部地应力的传递路径,一定程度上起到应力"间隔"的作用。计算结果表明,分区破裂的"孔洞"效应,改变了地应力在局部的传递路径,改变了地应力对巷道围岩的作用,使得巷道围岩及其支护趋于安全。本文提出的方法对维持巷道的安全、稳定具有很大的实用价值。

High ground stress has an important impact on the stability of confining rock in deep mining activity. Although the value of ground stress cannot be changed,its distribution can be altered locally by artificial blasting method. A new procedure has been put forward to keep confining rock stable： by igniting the charge in the confining rock mass,the broken areas have connected in the roof of a drift and therefore a zonal fracturing has been made by the interior effect of blasting; the rock strength of zonal fracturing decreases and can be treated as cavern,and it changes the route of stress and to some extent plays a role as＂stress cushion＂. The calculating result suggested that the zonal fracturing changed the stress path and the effect of the confining rock,making the confining rock safer. The method proposed in this paper has great practical value to keep underground lane safe and stable.