荷载作用下采空区附加沉降的相似材料模拟研究

Study of Similar Material Simulation on Goaf Extra Subsidence under Load

通过相似材料模拟实验,研究了不同煤层倾角的采空区在地表新增荷载后,地表和采空区上覆岩层内附加沉降的变化规律。研究表明:地表加载点与采空区的相对位置不同时,加载后地表的附加沉降量有明显不同,靠近采空区边界处的残余沉降量大,倾斜变形大;老采空区的附加沉降近似地随着荷载的增加线性增加,且采空区的附加沉降一般不超过地表最大下沉值的1/3,与采厚的比值小于5%;在相同的荷载作用下,倾斜煤层采空区的附加沉降比水平煤层大,且最大附加沉降值偏向下山方向;采空区上覆岩层下沉值随着岩层距地表深度的增加线性地减小;松散层的再次压实和冒落裂隙带的残余沉降是采空区附加沉降的主要影响因素。

Based on the simulation experiment with similar material, with newly load on the surface increased at goaf with different angle, the variation laws of the extra subsidence on the surface and overlying strata above goaf were researched. The study shows that the extra subsidence of the surface after the newly increased load on the surface exist remarkable difference when the loading place is not simultaneous with relative location of workedout area. The extra subsidence and inclined deformation on the surface is increasingly large when the location draws near to boundary of worked-out area. With the increase of load, extra subsidence on the surface of goal increased linearly, and it always is less than one third of maximum subsidence or the 5% of minable coal thickness. The extra subsidence of the goaf with inclined coal seam is more than that with the horizontal coal seam, and the maximum extra subsidence of ground surface usually is on the down-up directions. With the increase of rock strata in depth, extra subsidence decreased linearly. The compaction of unconsolidated layers and the residual subsidence of the caving area are the key factors for the extra subsidence of goaf.