Borehole Investigation of the Effectiveness of Grout Injection Technology on Coal Mine Subsidence Control

摘要: Grout injection into the horizontal fracture at bed separation of an overburden is used as a surface subsidence control measure in coal-producing countries such Poland, China, and Australia. However, stiffness distribution grouting mass post-injected overburden, well its effect on control, have not been investigated. To address these issues, two boreholes were drilled above longwall panel study site. It was found that fly ash injected more than 7 months previously had become compacted. More 90 % total fill concentrated main section (MIS) (thickness 4.8–18.4 m). The MIS located between bottom borehole key stratum immediately above. Following injection, central gob area received maximum possible compression served foundation support for grout, allowing grout to restrain deformation strata it, thus reducing subsidence. results this investigation may facilitate future design, improving