不整合地层下开采防水煤柱合理宽度的研究

开采煤层与富含水的第四系呈角度不整合接触。煤层开采时,为防止覆岩导水裂隙带在侧面与第四系连通,需留设一定宽度的横向防水煤柱。用数值模拟方法对防水煤柱留设宽度取经验值时,导水裂隙带的发育特征进行了分析。数值结果表明,经验值留设宽度下,导水裂隙带已经在侧面方向与不整合面接触。假设工作面两侧导水裂隙带的形状为半圆弧,对竖向防水煤柱的经验公式进行修正,提出横向防水煤柱留设宽度的计算公式,为不整合地层下开采横向防水煤柱的留设提供了依据。在计算出的横向防水煤柱留设宽度下,通过控制工作面宽度,使导水裂隙带在竖直方向上不与第四系连通。

Research on reasonable width of waterproof coal pillar when mining under the unconformity strata

The seam and quaternary are angular unconformity.In order to prevent water flowing fractured zone of overlying strata connected quaternary,it is necessary to set a certain width of the lateral waterproof pillar.Analyzed the discipline of fractured zone above mine goaf with empirical value of waterproof coal pillar by the method of UDEC2D numerical simulation.The result of numerical simulation showed that water flowing fractured zone connected unconformity surface with waterproof coal pillar’s empirical value.Supposed the shape of the water flowing fractured zone on both sides of the work-face was semicircular.Revised the empirical formula for vertical waterproof coal pillar,and deduced the new formula of lateral waterproof coal pillar’s reasonable width.The new formula provides basis for setting lateral waterproof pillar.In the vertical direction,by adjusting the length of work-face,made water flowing fractured zone don’t connected with quaternary under the pillar width computed by new formula.