采煤区地表拉张裂缝演化及其控制因素物理模拟试验

基于自制装置室内模拟试验和现场试验，研究了黏土体含水量变化及应力环境改变对采煤区地表拉张裂隙发育的影响，研究结果表明:在30%、35%、40%三种含水量情况下，随着黏土体含水量增高，土样表面拉张裂隙发育宽度和深度均明显降低，且拉张裂隙发育呈现时间上的滞后；当含水量增至40%时，土样表面不会产生拉张裂隙；在土样表面人为形成应力薄弱区，可以有效改变拉张裂隙发育位置；在孙疃煤矿1047工作面通过增湿试验地表“切眼裂隙”发育得到有效抑制；应力引导对地表“风机裂隙”的发育方向造成一定影响。

Physical model experiment on formation of surface tension fractures and their controlling factors in a coal mining area

Based on the indoor simulation test of self-made device and field test, the influence of clay water content and stress environment change on the development of surface tension fracture in coal mining area is studied. The results show that the width and depth of surface tension fracture of soil sample decrease obviously with the increase of clay water content while the water content is 30%, 35% and 40%;when the water content increases to 40%, there will be no tension cracks on the surface of the soil sample;the artificially formed stress weak area on the surface of the soil sample can effectively change the development position of the tension fracture;in the 1047 working face of Suntuan coal mine, the development of surface “cut fissure” is effectively restrained;the stress guidance has a certain impact on the development direction of surface “fan crack”.