构筑物下覆岩离层注浆控制地表变形模拟试验研究

Study on Simulation Experiment of Overburden under Buildings Abscission Layer Grouting Control Ground Surface Deformation

为掌握离层注浆开采控制地表变形的规律,以数值模拟与相似模拟相结合研究了采空区形变及应力变化和覆岩运移演化规律,并进行现场工程试验。研究结果表明:(1)在离层注浆作用下,顶板压力增加,采空区被压实,采空区应力无明显变化;(2)离层上方关键层应力受到向上的注浆压力作用,内部应力在短距离范围内出现下降,随着向上远离离层,注浆压力作用影响下降,在巨大覆岩压力作用下,岩层向下的压力有所增加;(3)塑性区发育高度在离层注浆后基本不再向上扩展,转而变为横向扩展,关键层上方由于注浆充填作用未出现明显大面积破坏。由此可见,关键层下方离层空间注浆充填,对于关键层上方的岩层起到了很好的保护作用;(4)注浆区域的关键层及其上覆岩层下沉量较小,而注浆层位下方岩层和未注浆区域的岩层下沉量普遍明显较大,表明离层注浆对控制关键层及其上覆岩层的运移发挥了良好的作用。

To master the regular pattern of abscission layer grouting mining control surface deformation,combined with numerical simulation and similarity simulation to study the goaf movement deformation and stress change,and stress evolution rule,and carry on field engineering test.The results show that:(1)in the goaf under the action of roof abscission layer grouting pressure by compaction,goaf stress has no obvious change;(2)above the abscission layer grouting pressure by the upward,key strata stress within the scope of internal stress in the short fall,as far away from the abscission layer upwards,grouting pressure influence decline,under the influence of strata pressure,downward pressure on rock increases;(3)the height of the plastic zone development basic no longer scaling up after abscission layer grouting,turned into a horizontal extension,key strata above as grouting filling does not appear obvious damage.Thus,key space below the abscission layer grouting filling for key layer at the top of the rock has played a very good protection effect;(4)grouting area of key strata and its overlying strata subsidence quantity is small,and the area below the horizon of strata and grouting of strata subsidence is generally significantly larger,showing that the abscission layer grouting displacement of key strata and its overlying strata subsidence and played a good control effect.