为了分析金川深部巷道底臌形成过程以及支护对巷道稳定性的影响,运用声波单孔探测法,使用水做耦合剂,对巷道围岩松动圈进行测试。根据测出的深度-孔深曲线和各测孔漏水情况得出3个断面松动圈厚度以及围岩破碎程度。研究结果表明:初次支护设计对围岩松动圈有重要影响,巷道开挖支护一段时间后,松动圈厚度趋于稳定,返修后巷道围岩松动圈厚度不会有很大变化。巷道顶板和底角的围岩松动圈比两帮的厚,特别是底角处的松动圈较厚,在巷道两帮传递的集中应力的作用下,易发生破碎与移动,对于巷道围岩稳定性也有较大的影响。因此,使用锚索或者长度大于2.5 m的锚杆支护顶底角,对于延长巷道使用期限、减少返修周期具有重要意义。
In order to analyze the deformation process of the floor heave and the effect of support on the stability of roadway, based on acoustic single-hole probe method, and using water as a coupling agent, measurement of deep roadway surrounding rock zone was made in Jinchuan mine. The thicknesses of there roadways surrounding rock loose zone and their degree of fragmentation were gotten after analyzing the curve of depth-speed of sound and hole leaks. The results show that the initial support design is important in the expansion of surrounding rock loose zone, after the excavation and support of the roadway, its thickness of surrounding rock zone will tend to be constant and won’t change too much even after resupported. The loose zones in the roof and bottom corner are thicker than those in the sidewall, especially ones in the apex angle and bottom corner. Under the concentrated stress from the sidewall, the surrounding rock in the apex angle and bottom corner are easy to crush and mobile. So it is important to use anchor or anchor cable whose length is greater than 2.5 m to brace them. This design is meaningful to make longer use of the roadway.