赵洪宝, 程 辉, 王 磊, 刘一洪, 吉东亮, 张一潇. 非静水压力条件下巷道围岩偏应力场分布特征与围岩破坏规律[J]. 煤炭学报, 2021, 46(2): 370-381.
引用本文: 赵洪宝, 程 辉, 王 磊, 刘一洪, 吉东亮, 张一潇. 非静水压力条件下巷道围岩偏应力场分布特征与围岩破坏规律[J]. 煤炭学报, 2021, 46(2): 370-381.
ZHAO Hongbao, CHENG Hui, WANG Lei, LIU Yihong, JI Dongliang, ZHANG Yixiao. Distribution characteristics of deviatoric stress field and failure law of roadway surrounding rock under non hydrostatic pressure[J]. Journal of China Coal Society, 2021, 46(2): 370-381.
Citation: ZHAO Hongbao, CHENG Hui, WANG Lei, LIU Yihong, JI Dongliang, ZHANG Yixiao. Distribution characteristics of deviatoric stress field and failure law of roadway surrounding rock under non hydrostatic pressure[J]. Journal of China Coal Society, 2021, 46(2): 370-381.

非静水压力条件下巷道围岩偏应力场分布特征与围岩破坏规律

Distribution characteristics of deviatoric stress field and failure law of roadway surrounding rock under non hydrostatic pressure

  • 摘要: 通过理论分析对受三向应力非静水压力条件下的巷道围岩偏应力场与应变能密度分布规律进行了深入研究,以此来探究巷道围岩破坏规律,巷道塑性区数值模拟结果与现场工程实例验证了理论结果的正确性。研究结果表明:(1)非静水压力条件下,不同的主导型应力场中,巷道围岩偏应力场分布规律差异较为明显。主导型应力场中,巷道顶底板偏应力大于两帮;主导型应力场中,巷道顶底板与两帮偏应力大小差别不大;主导型应力场中,巷道两帮处的偏应力大于顶底板。主导应力值的变化会引起巷道围岩偏应力分布数值上的变化,不引起偏应力分布形态的改变。(2)等p等q时,在与主导型应力场中,巷道顶底板应变能密度大于两帮,而在主导型应力场中,巷道两帮应变能密度大于顶底板。等p不等q情况下,三种主导型应力场中,巷道顶底板与两帮应变能密度均随偏应力比M的增大而增大;等q不等p情况下,巷道顶底板与两帮应变能密度均随偏应力比M的减小而增大。(3)三向应力状态下,巷道围岩应变能密度分布规律可以反映塑性区形态。M<1时,任意主导型应力场中,巷道围岩应变能密度呈椭圆形分布,M>1时,巷道围岩应变能密度呈“8”字形或“X”形分布。处于主导型应力场中的巷道需注重巷道顶底板的支护;对于主导型应力场,巷道在围岩条件较差时,应注重全断面支护;对于主导型应力场,需注意围岩塑性区出现“X”形扩展。(4)回坡底1021巷围岩偏应力场与应变能密度均呈倾斜的“8”字形分布,工程现场与巷道围岩偏应力场及应变能密度分布规律相互验证。基于理论分析结果,对回坡底1021巷提出非对称性支护技术,现场应用效果良好。深入探究三向应力非静水压力条件下的巷道围岩偏应力场与应变能密度分布规律,对分析巷道围岩破坏与支护设计具有一定的理论价值与指导作用。

     

    Abstract: The distribution law of deviatoric stress field and strain energy density of roadway surrounding rock under the condition of three dimensional stress and non hydrostatic pressure is studied by theoretical analysis,so as to explore the failure law of roadway surrounding rock.The correctness of theoretical results is verified by numerical simulation results of roadway plastic zone and field engineering examples.The results show that (1) under the condition of non hydrostatic pressure,the distribution law of deviatoric stress field of roadway surrounding rock is obviously different in different dominant stress fields.In the σx dominant stress field,the deviatoric stress of roadway roof and floor is greater than that of sidewalls.In the σy dominant stress field,the difference of deviatoric stress between the roof and floor of roadway surrounding rock and that of sidewalls is not significant.In the σz dominant stress field,the deviatoric stress of sidewalls of roadway is greater than that of roof and floor.The change of the dominant stress value will cause the change of the deviatoric stress distribution value of the surrounding rock,but will not cause the change of the distribution form of the deviatoric stress.(2) Under the condition of equal p and q,in the σx and σy dominant stress field,the strain energy density of roadway roof and floor is greater than that of sidewalls.While in the σz dominant stress field,the strain energy density of sidewalls of roadway is greater than that of roof and floor.In the case of equal p and unequal q,the strain energy density of roof and floor and sidewalls of roadway increases as the increase of deviator stress ratio M in the three dominant stress fields.In the case of equal q and unequal p,the strain energy density of roadway roof,floor and sidewalls increases as the decrease of deviatoric stress ratio M.(3) Under the state of three dimensional stress,the distribution law of strain energy density of surrounding rock can reflect the shape of plastic zone.When M1,the strain energy density of roadway surrounding rock will appear “8” shape and “X” shape distribution.In the σx dominant stress field,it should pay attention to the support of roof and floor of roadway.In the σy dominant stress field,when the surrounding rock condition is poor,it should pay attention to the full face support.In the σz dominant stress field,the attention should be paid to the “X” shape plastic zone expansion of surrounding rock.(4) The results show that the distribution of deviatoric stress field and strain energy density of surrounding rock of 1021 roadway in Huipodi coal mine is distributed in an oblique “8” shape,the distribution of deviatoric stress field and strain energy density of surrounding rock and the engineering site verify each other.

     

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