巨厚松散层下防水煤柱合理留设及其数值模拟

Waterproof coal pillar reasonable design and numerical simulation under extremely thick unconsolidated strata

防水煤柱合理留设是巨厚松散层下煤炭开采设计的基本参数。通过对东欢坨矿第四系巨厚松散层地质特征分析,揭示了本区第四系巨厚松散层中的含、隔水层厚度及其结构分布特征和对煤炭开采充水的影响,建立了巨厚松散含水层下防水安全煤柱计算模型和理论,提出了在巨厚松散层下的防水煤柱留设的非线性计算方法,计算东欢坨矿8煤层防水煤岩柱的高度为65.62 m。根据流-固耦合理论,应用FLAC3D数值模拟计算软件,模拟了东欢坨矿8煤层开采过程中上覆岩层变形破坏规律,揭示了煤层顶板岩体冒落带、导水裂隙带和弯曲下沉带的分布规律,获得了防水煤柱高度及相关工程技术参数,验证了巨厚松散层下防水煤柱留设的非线性设计方法和计算模型的可靠性,为巨厚松散层下防水煤柱合理留设探索了可行途径。

Waterproof coal pillar reasonable design is a fundamental parameter of coal extraction devising under extremely thick unconsolidated strata.By analysis of Quaternary extremely thick unconsolidated strata geological characteristics,the influence of thickness and structural distribution properties of a quifer and aquifuge under extremely thick unconsolidated strata on water inrush during coal extraction was revealed,the waterproof coal pillar design computing model and theory under extremely thick unconsolidated strata were established,nonlinear computational method under extremely thick unconsolidated strata was put forward,and the waterproof coal pillar design height of number 8 coal seam in Donghuantuo coal mine is 65.62 m.According to fluid-mechanical interaction theory,using FLAC3D numerical simulation calculation software,further simulation on overlying strata deformation and failure law of number 8 coal seam exploitation in Donghuantuo coal mine was carried out.Distribution law of coal seam roof rock caving zone,aquiferous crevice zone and curve subsidence zone was revealed,waterproof coal pillar design height and related engineering technique parameters were acquired,the reliability of nonlinear design method and computational model of waterproof coal pillar design under extremely thick unconsolidated strata is validated,and the feasible approaches to waterproof coal pillar reasonable design under extremely thick unconsolidated strata were explored.