矿井岩溶突水灾变机理

Disaster mechanism of karst water bursting in mine

结合湖南娄底市七一煤矿石坝井岩溶突水、突泥实例,运用损伤力学及岩体流体力学理论,研究矿井岩溶突水的渗流-损伤-断裂耦合成灾机理,通过FISH研制矿井岩溶突水的渗流-损伤-断裂耦合分析程序(扩展FLAC3D模型),对七一煤矿岩溶突水成灾过程进行耦合分析,探讨巷道掘进过程中围岩渗流场和岩柱的劈裂损伤演化规律。耦合研究认为:七一煤矿石坝井岩溶突水事故是裂隙渗透压与围岩次生应力场共同作用下茅口灰岩岩柱损伤演化;在高渗透体积力与围岩次生应力的耦合作用下,处于全损伤状态的岩柱水力劈裂导致矿井岩溶突水成灾;耦合分析发现矿井岩溶突水具有渗透系数突变、渗透体积力突变及位移突变等特性。探讨了防范矿井充填型溶洞突水高风险的应对措施及合理的岩溶突水临界岩柱。

Based on water disasters in Qiyi Mine in Loudi City Hunan Province,by comprehensive use of the theories of geometric damage mechanics and rock fluid mechanics,the seepage-damage-fracture coupling disaster mechanism of karst water bursting in mine was studied and the model of seepage-damage-fracture coupling（extended FLAC^3D model） was established.The seepage-damage-fracture coupling analysis on the disaster formation process of karst water bursting in Qiyi Mine was shown.The evolution law of surrounding rock seepage field and fracturing damage in rock pillar under combined action of mining influence and seepage was studied.Coupling analysis shows that with the coupling effect of high body force of seepage and secondary stress in surrounding rock,hydraulic fracturing in rock pillar which is in damage state results in karst water bursting.Coupling analysis aslo shows that sudden changes of permeability coefficient,body force of seepage and displacement occur in coupling analysis of karst water bursting in mine.Countermeasures to prevent high risk in karst water bursting filling-type karst cave and reasonable leaving water prevention coal rock pillar were discussed.