Dynamic monitoring research on displacement of rock mass in coal seam floor on the 1604 workface in NanTun coalmine, Shandong Province, China

摘要

In order to understand the displacement regular of rock mass in coal seam floor, displacement monitoring sensors were arranged in underground boreholes and realized the dynamic monitoring displacement of rock mass. First, the geological and the hydrogeological condition of the 1604 workface and NanTun coalmine were analyzed. Second, boreholes was constructed in roadway on the 1604 workface, displacement monitoring sensors were arranged in boreholes in different depth, when the distance of mining position and borehole was 110 m, the displacement monitoring sensor started monitoring, which the different depth displacement data were collected. Last, through comparing displacement data in different depth, the paper point out as the development of mining the influence degree of the displacement of rock mass in coal seam floor can be divided into initial influence stage, obvious influence stage and significant influence stage. Workface mining caused the depth of the rock mass displacement variation from 11.95 to 13.94 m below coal seam. The result will guide the coalmine prevention and control of water inrush from coal seam floor.