厚松散层下下沉系数与采动程度关系研究

采动程度对控制地表移动变形起着关键作用,而地表下沉系数取值的准确性决定了地表移动变形的预计精度.为了探讨厚松散层开采条件下采动程度与下沉系数之间的关系,在分析矿区厚松散层地表移动观测站实测资料的基础上,研究了松散层厚度对充分采动影响的程度,揭示了传统方法评价采动程度不合理性的原因,分析了厚松散层下开采引起的覆岩应力分布与移动机理.给出了应将松散层与基岩作为开采深度的不同介质评定采动程度的标准,通过计算分析,提出了厚松散层开采条件下充分采动的临界宽度,得到了厚松散层下的下沉系数.通过与实测资料相比,下沉系数较为符合现场实际,为矿区厚松散层下“三下”采煤提供了科学依据.

Study on the Relationship Between Subsidence Coefficient and Mining Degree Under A Thick Alluvium Stratum

Mining effect plays key role to control deformation of the surface,and whether value of subsidence coefficient is precise or not can directly determinate the accuracy of the prediction results of surface movement deformation.In order to discuss the relationship between subsidence coefficient and mining range under thick alluvium,based on the observation data’s of surface movement observation stations under thick alluvium,the influence degree of thickness of alluvium to supercritical mining de-gree was studied,the unreasonable reason was proclaimed that tradition method estimates mining de-gree,then stress distribution of overlying strata and movement mechanism caused by mining were analyzed under thick alluvium.Then the estimation criterion that the bedrock and alluvium is regarded as the different composite medium was provided for mining degree,by calculated and analyzed,the critical mining width was provided for supercritical mining,and subsidence coefficient was obtained under thick alluvium.Compared with actual measurement,subsidence coefficient was in accord with actual situation comparatively,which provided science prediction for"under railways,under water bodies and under buildings"under thick alluvium in mine-area.