在受到采动影响下,为了预计湿陷性黄土地表生成裂缝的区域,提出了湿陷性黄土极限抗拉强度与采动影响而形成的拉伸变形相结合的方法,判断地表生成裂缝的区域.如果在采动影响下的拉伸变形量大于湿陷性黄土极限抗拉强度,则在该区域生成地表裂缝,否则不生成裂缝.利用概率积分法求得移动变形分量,并推导出了最大拉伸变形和最小压缩变形;根据黄土的力学参数,求得地表产生裂缝的极限抗拉变形.以常村矿为例,得到在该工程地质条件下,地表产生最小拉伸变形为3.9 mm/m,裂缝角为60 °.
We propose the method of using the ultimate tensile strength of collapsed loess in combination with the tensile deformation formed by mining to determine the damage region.If the tensile deformation formed by mining exceeds the collapsed loess ultimate tensile strength,the surface cracks are generated in the region,or do not generate cracks.According to the basic theory of probability integral,the deformation components on the suiface are deduced.On this basis,the maximum principal strain and the minimum principal strain are deduced.Based on the collapsed loess mechanical parameters,we can obtained the ultimate tensile strength.Using Changcun Coal Mine as an example,we obtain the ultimate tensile strength of 3.9 mm/m,predict the surface crack formation region,and calculate the crack angle of 60°.