赵固矿区厚松散层下开采地表移动特征实测研究

Field research on surface movement characteristic by coal mining under thick alluvium in Zhaogu mine area

为了掌握赵固矿区厚松散层条件下地表移动特征,以相邻的赵固一矿和赵固二矿地表移动观测站实测数据为基础,通过数据拟合方法,得到厚松散层下开采地表概论积分法参数;总结分析了厚松散层下开采地表移动特征,以及造成上述特有规律的地质原因和开采技术原因;以实测和拟合数据得出了赵固矿区走向地表移动各角量参数。研究表明:由于采动后地表含水层失水固结,造成采动附加下沉,导致下沉系数较大,主要影响角正切值偏小,且覆岩中松散层厚度占比越大,其下沉系数越大;煤层顶板基岩较薄,顶板悬臂效应大大减小,另外在采动压力作用下应力拱轴线位置土体固结压缩,造成拐点偏移距减小或者为负值,地表下沉盆地边缘收敛过慢;由于覆岩中松散层厚度占比较大,造成赵固一矿地表移动各角量参数均小于赵固二矿参数。

In order to master the surface movement characteristic by coal mining under thick alluvium in Zhaogu mine area,based on the measured data of surface movement observation station on the Zhaogu No.1 mine and Zhaogu No.2 mine,the probability integral method parameters are obtained by data fitting method.Surface movement characteristic is summary analyzed,as well as the geological and mining technical reasons for the above unique laws.Based on the measured and fitted data,the angular parameters of surface movement in Zhaogu mine area are obtained.The results show that additional subsidence is caused by the water loss and consolidation of the deep aquifer after mining,resulting in a large subsidence coefficient and a small main influence angle tangent,and the larger the thickness of the loose layer in the overburden layer,the larger the subsidence coefficient,but the small main influence angle tangent value.Roof cantilever effect reduces caused by the thinner the roof bedrock of the coal seam,in addition,the soil at the stress arch axis is consolidated and compressed with the action of pressure caused by mining.The above two actions results in the decrease of inflexion offset or negative value,and the convergence of surface subsidence basin edge is too slow.Due to the large thickness of alluvium in overburden,the angular parameters of surface movement in Zhaogu No.1 mine are smaller than those in Zhaogu No.2 mine.