CCTEG Coal Mining Research Institute
Coal Mining and Design Department, Tiandi Science and Technology Co. , Ltd.
Tiandi (Yulin) Mining Engineering Technology Co. , Ltd.

探究煤柱应力向底板传递特征对确定近距离煤层巷道围岩控制方法具有指导作用。以山西杜儿坪矿近距离煤层为原型,开展上煤层开挖相似模型试验,利用DIC技术采集底板深度不同水平层位应变数据,分析垂直、水平、及剪切三种应变的分布特征和应变峰值距煤柱边界水平距离的变化规律,探究上煤层开采后区段煤柱集中应力向底板的传递特征。结果表明:煤柱底板区,三种应变均以煤柱中心为轴呈非对称双峰分布特征,垂直、剪切两种应变峰值为先开挖面煤柱侧小于后开挖面煤柱侧,而水平应变峰值则恰好相反,三种应变峰值均随底板深度增加而减小;采空区底板,垂直、剪切两种应变远离煤柱边界逐渐趋于0,而水平应变则显现出反复增减多变特征。三种应变峰值距煤柱边界的水平距离表现为垂直应变为先开挖面煤柱侧大于后开挖面煤柱侧,但剪切应变则刚好相反,而水平应变则先后开挖面煤柱侧均相等,且三种应变距煤柱边界水平距离均随底板深度增加而增大。垂直、水平应力分别为压、拉应力,而先后采面煤柱侧剪切应力则不同分别为拉、压应力;垂直、剪切两种应力均显现为高应力水平,但水平应力甚小;垂直、水平两类应力峰值均位于煤柱底板区,而剪切应力峰值却位于采空区底板;垂直、剪切两种应力随远离煤柱边界均趋于0,水平应力则显现反复转化增减特征。选择近距离煤层巷道围岩控制方法既应重视垂直应力的作用,也应关注剪切应力对其失稳破坏的影响。

The research on the characteristics of stress transfer from coal pillars to floor is directive to determine the control method of roadway surrounding rock in contiguous coal seams. Based on the contiguous seam in Duerping coal mine in Shanxi province, the similar model test of upper seam excavation is carried out, and the horizontal strain data of different floor depths were collected by using DIC technology, the distribution characteristics of vertical, horizontal and shear strains and the variation law of the horizontal distance between the peak strain and the boundary of coal pillar are analyzed, which explores the concentrated stress transmission to floor from sectional pillars in upper seams after mining. The results show that: in the floor area of the coal pillar, the three strains are distributed asymmetrically in twin peaks with the center of the coal pillar as the axis, the peak values of vertical and shear strains on the first excavation face is smaller than that on the later excavation face, the horizontal strain peak value is just the opposite, the three strain peak values decrease as the floor depth increases. The vertical and shear strains of the goaf floor tend to far from the coal pillar boundary, however, the horizontal strain showed the character of repeated increase and decrease. The horizontal distance among the three strain peaks and the boundary of the coal pillar shows that the vertical strain is larger on the side of the coal pillar by the first excavation face than on the side of the coal pillar by the later excavation face, but the shear strain is just the opposite, and the horizontal strains of successive faces are equal on the side of the coal pillars, the horizontal distance between the three strains and the boundary of coal pillar increases with the increase of floor depth. The vertical and horizontal stresses are compressive and tensile stresses respectively, while the shear stresses at the side of coal pillar in successive mining faces is tensile and compressive stresses respectively, the vertical and shear stress are both high stress level, but the horizontal stress is very small, the peak values of vertical and horizontal stress are located in the floor area of coal pillar, while the peak values of shear stress occurs in the floor area of goaf, the vertical and shear stresses tend to with the distance increase from the boundary of coal pillar, and the horizontal stress shows the character of repeated transformation. The selection of wall rock control of contiguous seams roadway should concern vertical stress, and shear stress on instability and failure.

国家自然科学基金项目(51774186)

张剑,李建忠,刘慧妮.近距离煤层区段煤柱集中应力传递特征试验研究[J].煤炭工程,2024,56(10):208-215.