耿村煤矿巨厚煤层区段煤柱综放复采可行性研究

为延长矿井服务年限、提高煤炭资源回收率和缓解矿井接替紧张状况,以耿村煤矿巨厚煤层区段煤柱为研究对象,提出复采巨厚煤层区段煤柱的综放开采技术,建立工作面覆岩破断模型,确定复采工作面布置在与区段煤柱相距30 m处的煤矸互层中,保障巷道的安全使用。通过判定工作面冲击地压等级,提出防控冲击地压、巷道支护失效、瓦斯超限爆炸和煤炭自燃发火等灾害技术方案。结果表明,复采区段煤柱及老空区遗煤是安全可行的,区段煤柱的复采延长了矿井服务年限,提高了煤炭资源回收率,缓解了矿井工作面接替紧张状况。研究结果可为类似条件矿井提供复采参考依据。

三软煤层复采沿空巷道底鼓机理及支护技术

为解决新庄煤矿三软煤层复采煤柱时沿空巷道底鼓问题,对现工字钢梯形棚式支护下的巷道顶底板移动变形及支架受力情况进行了观测。根据巷道变形实际情况,分析了该沿空巷道围岩应力分布特点、底鼓类型、影响因素,预测了底鼓量及构成,以此对底板加固采取了锚网支护技术,现场应用试验表明该巷道支护技术取得较好的效果。

Ground pressure and overlying strata structure for a repeated mining face of residual coal after room and pillar mining

To investigate the abnormal ground pressures and roof control problem in fully mechanized repeated mining of residual coal after room and pillar mining, the roof fracture structural model and mechanical model were developed using numerical simulation and theoretical analysis. The roof fracture characteristics of a repeated mining face were revealed and the ground pressure law and roof supporting condi- tions of the repeated mining face were obtained. The results indicate that when the repeated mining face passes the residual pillars, the sudden instability causes fracturing in the main roof above the old goal and forms an extra-large rock block above the mining face. A relatively stable ＂Voussoir beam＂ structure is formed after the advance fracturing of the main roof. When the repeated mining face passes the old goaf, as the large rock block revolves and touches gangue, the rock block will break secondarily under overburden rock loads. An example calculation was performed involving an integrated mine in Shanxi province, results showed that minimum working resistance values of support determined to be reason- able were respectively 11,412 kN and 10,743 kN when repeated mining face passed through residual pillar and goaf. On-site ground pressure monitoring results indicated that the mechanical model and support resistance calculation were reasonable.