斜孔掏土应力解除法治理煤矿生根井塔偏斜研究

为验证斜孔掏土应力解除法治理华东某双向偏斜生根井塔的适应性和有效性，综合理论分析、数值模拟和现场实测研究了斜孔掏土孔周塑性区发展、纠偏机制及掏土各因子对纠偏效果的影响规律。结果表明，开孔后孔周塑性区半径与孔径和孔周应力成正比，且随钻孔深度增加而增大。掏土纠偏的内在机制在于钻孔能有效解除孔周一定范围内的应力，使孔周土体不断向孔内坍塌，进而减小开孔侧井筒的外荷载，与对侧产生应力差值，促使井塔回纠。通过正交试验设计极差分析得出钻孔孔排宽度为影响掏土纠偏的最主要因子，其次为钻孔深度、孔径和孔距井筒中心线距离，且斜孔纠偏效果优于竖直孔。最后，基于模拟获得的最优纠偏参数组合设计了现场纠偏方案，并对井塔偏斜和井筒受力进行施工监测得出，斜孔掏土应力解除法有效逆止了生根井塔的偏斜发展，目前井塔偏斜和井壁受力均处于安全可控状态。

Research on inclined digging technology for deviation rectification of rooting mine shaft tower

To verify the adaptability and effectiveness of inclined digging technology in the rectification of a deviated rooting mine shaft tower in East China, the plastic zone around the inclined hole, the mechanism of the technology, and the influence of various factors on the rectification effect are studied by theoretical analysis, numerical simulation and field measurement. The results show that the radius of the plastic zone is proportional to the diameter of the hole and the stress around circle hole, and it increases with the depth of drilling hole. Drilling can effectively reduce the stress within a certain range of the digging hole, so that the soil around continuously collapses, and then the difference between external load on drilling side and the shaft lining can be reduced, which produces a stress difference with the opposite to promote the shaft tower back to correct. Based on the orthogonal experiment design, we find that the most important factor to influence the deviation is the row width of the drilling, and depth, diameter and the distance between drilling row and shaft centreline. Last, according to the study results, the optimal deviation scheme is designed by long term monitoring of the shaft tower deflection and lining stress, we conclud that this drilling technology is effective in the deviation rectification of rooting mine shaft tower.