潞宁煤矿地应力实测及分布规律分析

Analysis on in-situ stress measurement and distribution law in Luning Coal Mine

针对潞宁煤矿埋深较大、地质生产条件复杂等问题,采用小孔径水压致裂原位地应力测试技术,完成10个测点的地应力测试工作,分析表明,潞宁煤矿地应力场为典型构造应力场,最大主应力始终为最大水平主应力,矿井地应力量值总体属于高应力区,且随着埋深增大,应力场发生偏转,垂直主应力逐渐由小于最小水平主应力演化为大于最小水平主应力。揭示了最大水平主应力与垂直主应力的比值、最小水平主应力与垂直主应力的比值、最大主应力与最小主应力之差与垂直主应力的比值等不同侧压比随埋深变化规律,分析了最大剪应力随埋深变化规律,为潞宁煤矿巷道布置及支护设计提供可靠基础参数。研究表明,潞宁煤矿沿空掘巷合理送巷时机为滞后邻近工作面约270 m,采用顶板全锚索与巷帮锚杆、锚索联合支护的形式可有效控制巷道围岩变形。

Aiming at the problems of large buried depth and complex geological production conditions in Luning Coal Mine,the in-situ stress test technology of small aperture hydraulic fracturing was used to complete the in-situ stress test of 10 measuring points.The analysis showed that the in-situ stress field of Luning Coal Mine was a typical tectonic stress field.The maximum principal stress was always the maximum principal stress,and the overall stress value of the mine belonged to a high stress zone.As the buried depth increases,the stress field deflected,and the vertical principal stress gradually evolved from less than the minimum horizontal principal stress to greater than the minimum horizontal principal stress.The different lateral pressure ratios with burial depth,such as the ratio of maximum horizontal principal stress to vertical principal stress,the ratio of minimum horizontal principal stress to vertical principal stress,and the ratio of maximum principal stress to minimum principal stress to vertical principal stress,were revealed.The variation law of maximum shear stress with buried depth was analyzed,providing reliable basic parameters for the layout and support design of roadways in Luning Coal Mine.Furthermore,it could be concluded that the reasonable timing for driving the roadway along the goaf in Luning Coal Mine was about 270 meters behind the adjacent working face.The deformation of roadway surrounding rock could be effectively controlled by the combined support of roof full anchor cable,roadway side bolt and anchor cable.