覆岩主关键层对地表下沉动态的影响研究

在对岩体内部移动与地表沉陷实测资料进行对比分析的基础上,采用物理和数值模拟方法,就覆岩主关键层对地表下沉动态过程的影响进行了研究。研究结果证明,覆岩主关键层对地表移动的动态过程起控制作用,覆岩主关键层的破断将引起地表下沉速度和地表下沉影响边界的明显增大和周期性变化。在此基础上,提出将控制覆岩主关键层不破断失稳作为建筑物下采煤设计原则的观点。

STUDY ON INFLUENCES OF PRIMARY KEY STRATUM ON SURFACE DYNAMIC SUBSIDENCE

Due to differences in formation time and mineral composition,rock strata contain numerous layers of different thickness and strength. Practical experiences have shown that one or several thick and strong strata have a dominant effect on the movements and subsidence of rock strata above the underground mining excavations. The key stratum is defined as the stratum that controls the movements of a part or all of the strata in the overburden. The former is called the subordinate key stratum,and the latter is called the primary key stratum. By means of comparative analysis on the field measurement data of stratum movement and the surface subsidence,numerical and physical simulation,the influences of the primary key stratum on surface dynamic subsidence are studied. The results prove that the primary key stratum in the overburden control the dynamic process of surface subsidence,the break of the primary key stratum will obviously augment the subsidence speed and the subsidence boundary,and the subsidence speed and the subsidence boundary will change periodically as the primary key stratum break periodically. Based on the key stratum theory in ground control,the basic principle in the design of mining under buildings should ensure that the primary key stratum would not break.