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为研究中国西部黄土矿区地表开采裂缝的形成机理,采用理论分析和试验的方法,运用土力学原理,结合开采沉陷理论,探讨土体剪切破坏与黄土层采动裂缝的形成机理.将理论应用到彬长矿区B40301工作面进行验证分析.研究结果表明:采动黄土层下沉弯曲引起的土体水平变形,造成土体单元水平方向应力松弛,达到剪切破坏的极限平衡状态;地表土层中的侧向水平应力近似为零,当存在克服土体凝聚力或抗拉强度的拉伸应变时,地表将会产生裂缝;推算出开采裂缝产生的临界深度预算公式,及地表产生裂缝的临界水平变形值计算公式.
In order to study the formation mechanism of surface mining cracks in the loess mining area in western China, the mechanism of shear failure and the mining crack of loess layer are probed by using the theory of soil mechanics and mining subsidence theory, and the theoretical application To B40301 working face in Binchang mining area for verification.The results show that horizontal deformation of the soil caused by subsidence and bending of the mining loess layer leads to stress relaxation in the horizontal direction of the soil body and reaches the limit equilibrium state of shear failure. The lateral horizontal stress is approximately zero. When there is tensile strain to overcome the cohesion or tensile strength of the soil, cracks will be generated on the surface; the critical depth budget formula for the production of mining fractures and the critical level of cracks on the surface Deformation value calculation formula.