采动底板导水破坏深度滞后煤壁二次加深规律探测

Experimental study on mining-induced failure depth lagging coal wall secondary deepening rule

率先明确探测并提出底板采动导水破坏深度滞后煤壁二次加深的观点,并先后选择晋城、榆林、鄂尔多斯多个煤矿工作面做了验证,利用现场测试条件,在煤壁推过测点后,仍对底板采动破坏规律实施注水试验与底板岩层应变连续性探测。探测结果表明：1）底板岩层首次破坏发生在工作面刚推过测点的应力集中区;2）工作面推过测点15~20 m,即过测点后的第1次周期来压时,测点位置的底板导水破坏深度出现二次滞后加深,破坏加深程度一般在1~2 m;3）工作面推过测点2~4个周期来压后测点位置底板岩层变形状态趋于稳定;4）工作面推过测点后第1次周期来压到第4次周期来压之间（工作面推过测点15~60 m）这段距离为底板滞后突水高风险区域;5）底板注水试验与岩层应变探测试验的探测结果一致性很高。

The paper has firstly clearly detected and put forward the view of mining-induced failure depth lagging coal wall secondary deepening rule. Moreover, Jincheng, Yulin, Ordos coal mining working faces have been chosen to verify the point of view. By using better field test conditions water injection test and floor rock strain continuity of detection have been implemented to the floor damage rule after the coal wall pushing. The detection results have shown that： 1） Floor rock damage has occurred in the area of stress concentration when the working face is just pushed through the measuring point for the first time. 2） The working face has been 15 m to 20 m pushed away from point. After that point in the first periodic pressure, water-conductive failure depth of measuring point position has appeared secondary lagging deepening, and the degree of damage deepening is 1-2 m. 3） When the working face has been pushed away from point after 2-4 periodic pressure, the deformation state of floor rock in measuring point position tends to be stable. 4） When the working face has been pushed away from measuring point between the 1st periodic pressure and 4th periodic pressure（the working face pushed away from point 15 m to 60 m）, the distance is the high-risk areas for backplane lagging water-inrush. 5） Results of bottom water injection test and detection of rock strain detection test are of high consistency.