基于采动应力边界线的顶板巷道保护煤柱留设方法

针对平顶山一矿31010工作面回采期间顶板丁戊三乘人巷严重变形的问题，通过现场实测和数值模拟研究了巷道变形的原因及保护煤柱留设的问题。结果表明：工作面回采后，上覆顶板岩层中的应力发生改变，将应力值等于1.05倍原岩应力的点构成的曲线定义为采动应力边界线。采动应力边界线由开采煤层向上覆岩层呈外扩式发展，采动应力边界线距开采边界的水平距离随着距开采煤层高度的增大而逐渐增大，但增大趋势逐渐减小。采动应力边界线内侧岩层应力出现增压区和减压区，而外侧岩层仍处于原岩应力状态，采动应力边界线是划定工作面上覆岩层是否受工作面回采影响的边界线。目前顶板巷道保护煤柱宽度是按岩层移动角进行设计的，没有体现内部岩层移动变形及应力特征，导致顶板巷道保护煤柱宽度不合理而出现破坏，为此提出了基于采动应力边界线的顶板巷道保护煤柱宽度设计方法。按照此方法设计的平顶山一矿31010工作面顶板乘人巷保护煤柱宽度应为158 m。

Method of designing protective coal pillar on roof roadway based on mining induced stress boundary line

Aiming at the problem of severe deformation of the roof roadway because of 31010 working face’s mining，the numerical model and field observation were applied to study the reason of roadway’s deformation and how to design protective coal pillar.The results show that after mining，the stress changes in the roof，the point，whose stress equals to 1.05 times in-situ stress，constitutes the curve which is defined as mining induced stress boundary line.The line developments from the coal seam to the roof rock.The horizontal distance width between the mining boundary and induced stress boundary line is minimum in the coal seam，and the distance gradually increases with the seam distance father.However，the increasing trend gradually decreases.There are stress distressed zone and stress increased zone between the two line in the roof strata，but the others are also in the original rock stress state.We can differentiate whether the overburden rock is affected by the mining based on the mining induced stress boundary line.Now，strata movement angle is adapted to design protective coal pillar on roof roadway，however the characteristics of strata movement and deformation can not be reflected.Therefore，method of designing protective coal pillar on roof roadway based on mining induced stress boundary line is put forward.According to the method，the protective coal pillar’s width is 158 m for the roof roadway of 31010 working face.