Huaibei Coal Mining (Group) Co., Ltd.

为解决淮北矿区部分矿井面临的坚硬厚覆岩下采煤灾害防治问题,对海孜煤矿II102采区巨厚火成岩下隔离注浆充填减灾进行了试验研究,揭示了坚硬厚覆岩下采动致灾机理,火成岩厚120~170 m、单向抗压强度120 MPa、完整性好,在其下方煤层开采时该岩层将大面积悬顶,使载荷施加于实体煤上形成应力集中;加之采深大,在该岩层下该工作面安全生产面临极大威胁。为此,提出了隔离注浆充填减灾技术措施,即在已采与待采工作面之间留设隔离煤柱,并先对已采工作面进行注浆充填消除离层空间,在后续工作面开采中实施注浆充填,从而对覆岩形成有效支撑。试验结果表明:地面9个注浆钻孔,向采动离层带、采空区充填粉煤灰471 994 m~3,安全采出煤炭56.3万t,消除了采区动力灾害威胁。

In order to solve the problem of disaster prevention and control under the overlying thick and hard strata in Huaibei Mining Area, grouting for disaster red uction was tested below an extremely-thick igneous rock in the No. 1102 mining district of Haizi Mine. The mechanism of mining-induced disaster by the igneous rock W as revealed.The thick rock overlying the No. 1102 mining district had a thickness of 120 ~ 170 m and an uniaxial compressive strength of 120 MPa.During the mining, th is rock roof yielded the overburden load to solid coal due to the underlying bedding separation under igneous rock. Because of the stress concentration and the large d epth, this rock roof became the key issue for this area.A technical measure of isolated grouting was then proposed for disaster reduction.An isolated coal pillar was arra nged between the mined area and non-mined longwall panels. Grouting was first conducted for the mined panels, which was followed by the grouting of the subsequent panel during its extraction. Support was then produced for the overburden. Nine boreholes were drilled for the grouting of bedding plane separation zones and the cave d zones.A total volume of 471 994 m3 fly ash was injected with an extraction of 563 000 tons of coal.The risks for the disasters were eliminated for the mining area.