承压水体上岩浆岩底板采动效应的数值分析

Numerical Analysis for Mining Effect on Coal Seam Floor with Magmatic Rock over Confined Water

为防治卧龙煤矿首采区的底板突水,根据首采区煤层底板地质特征,分析了底板岩浆岩岩性及其组合特征,考查了太原组灰岩水的富水性和水压情况,并采用了应变软化本构关系,建立地质力学模型.运用快速拉格朗日元法对承压水体上底板的采动效应进行了数值模拟,分析了应力、位移场,确定10煤回采底板破坏深度为13 m.结果表明底板导水裂隙带深度未超出突水系数所确定的危险界限16 m,应用数值分析的结果判定太灰水对10煤回采无突水威胁.

To prevent water burst from floor in the first mining district of Wolong coalmine,the geological and mechanical model of the study area is built on the basis of analyzing geological characteristics of coal seam floor,lithology with magmatic rocks and their combined characteristics,and adopting the constitutive relation of strain softening.In addition,the watery and the hydraulic pressure for limestone aquifer of Taiyuan formation are investigated.The mining effect of coal seam floor over the confined water are numerically analyzed by fast Lagrangian analysis of continua and the failure depth of the coal seam floor are identified by analyzing their stress and displacement fields in the first mining district.The results show that the depth of fractured zone is 13 m and is not beyond the critical value established by the water inrush coefficient.In other words,there is not any risk of water inrush during the mining of NO.10 coal seam.