注浆加固与含水层改造底板采动效应孔巷电阻率CT探测研究

The electronic resistivity CT detection and research of holes and roadways on the mining effect of floors after grouting reinforcement and reconstruction of aquifers

底板注浆加固与含水层改造是承压水体上煤层安全开采底板岩溶水害防治的有效方法之一.为了评价注浆加固和含水层改造底板的采动效应特征.以皖北恒源煤矿Ⅱ615工作面为研究对象,采用孔巷电阻率CT法,按照采动底板活动规律设计观测方案.进行了注浆底板破坏深度的动态电阻率CT探测试验.获得了Ⅱ615工作面底板强破坏带深度为8.0 m.裂隙带深度为14.0 m以及煤层底板采动裂隙演化过程的电阻率响应特征.结果表明:孔巷间电阻率的变化较好地反映了底板岩体的受力状态、结构变化以及破坏程度,探测结果直观准确;注浆后底板采动影响范围和破坏深度均减小,反映了注浆后底板抗破坏能力增强,提高了承压水体上煤层开采的安全性.

The grouting reinforcement and construction of aquifers of floors are effective methods in preventing and controlling of karstie water disaster in coal seam floor above confined aquifer during safe mining. In order to evaluate the characteristics of mining effect in floors after grouting reinforcement and the construction of aquifers, we set the H 615 working face of Hengyuan coal mine in the north of Anhui province as the object of research and adopted electronic resistivity CT method, as well as did dynamic electronic resistivity CT detective test on the damage depth of grouted floors according to the observation scheme of design about the activity routines of mined floors. We have got that the depth of damage zones in the floor of II 615 working face is 8. 0 m and the depth of fissure zone is 14. 0 m, as well as we have got the response characteristics of electrical resistivity during the evolution of cracks in the mining of coal seam floor. The results show that the change of the electrical resistivity in the holes and roadways shows the strained condition, structural changes and the degree of damage of floor rocks well and the probe＇s result is intuitional and accurate. The influencing area and damage depth of the mining of floors decrease after grouting, which shows that the damage resistance of floor enhanced after grouting and the grouting increases the safety of mining above confined aquifer.