重复采动地表移动变形规律分析

Analysis of Surface Movement and Deformation Regularity under Repeated Mining

淮南矿区某矿11123工作面位于高潜水位矿区,因重复采动影响地表形成了大面积沉陷水域,给地表移动变形观测站的建立造成较大困难,并且地表移动变形较初采工作面复杂。综合分析了11123工作面地表水文环境和地质采矿条件,建立了重复采动条件下工作面地表移动变形观测站。通过全面观测建立了观测站与矿区的相对控制网系统,准确获取了观测站控制点的高程和平面坐标,为后期进行日常观测提供了精准的点位三维信息平差基准。根据日常观测中每一期观测站数据计算了11123工作面观测站3号倾向观测线的倾斜变形和曲率变形,从而根据两种变形曲线的特征点获取不同时期的拐点位置。并对日常观测中发现的地表采动裂缝进行了3个阶段的实测,采用钢尺量距法测量裂缝长度和宽度,通过改进前人采用的石灰浆作为追踪剂,采用石灰喷雾作为追踪剂开挖实测裂缝深度。利用拐点位置动态移动规律验证了地表实际调查裂缝的动态发育规律。研究表明:采用石灰喷雾作为追踪剂实测裂缝深度,可以防止开挖中石灰浆发生渗透造成测量误差大的问题;根据3号倾向观测线拐点从最初位于MS59点附近逐渐转移到MS56点,可知MS56~MS59点之间的拉伸变形区逐渐变为压缩变形区,位于先拉伸后压缩变形区间的裂缝也呈现出由产生到发育再到闭合的动态演变过程。

In response to the problems that 11123 working face of a mine in Huainan mining area located in the high underground water coal mining area due to repeated mining,resulting the ground to form a large subsidence water area,increasing the difficulty to establish the surface movement and deformation observatory,and that the surface movement deformation was more complicated than the initial mining working face.Based on the comprehensive analysis of the hydrological environment and geological mining conditions on the surface of the 11123 working face,a surface movement and deformation observatory of the 11123 working face under repeated mining conditions was established.The relative control network system between the observatory and the coal mine area through comprehensive measurement was constructed,so as to accurately obtain the elevation and plane coordinates of control points of the observatory.It provides an accurate reference for adjustment of three-dimensional point position information for daily observation.The inclination deformation and curvature deformation of the No.3 inclination observation line of the observatory of 11123 working face were calculated according to the data acquired from daily observatory measurement at each time,so as to obtain the position of the inflection point in different periods according to the characteristic points of the two types of deformation curves.The surface mining cracks found in daily observations were measured respectively in three stages.The length and width of the cracks were measured by using the steel ruler method.Through improving the method of adapting lime slurry as a tracer,lime spray was used as a tracer in the process of excavating and measuring the depth of cracks.The regularity of dynamic movement of the position of the inflection point was used to verify the dynamic development of cracks actually surveyed on the surface.The study results show that using lime spray as a tracer to measure crack depth can prevent the problem of enlarging measurement errors caused by the infiltration of lime slurry during excavation.The inflection point of the No.3 observation line was gradually shifted from the original location near point MS59 to point MS56,it can be inferred that the tensile deformation zone between point MS56 and point MS59 gradually changes into the compression deformation zone,and that the cracks located in the tensile-compression zone showed a dynamic evolution process from generation to development and then to closure.