钻孔应力计初始应力对围岩应力监测影响的试验研究  

Experimental study on the influence of initial stress of borehole stress gauges on surrounding rock stress monitoring

作　　者：许海亮 魏亚博 安栋 XU Hai-liang;WEI Ya-bo;AN Dong(School of Civil Engineering,North China University of Technology,Beijing 100144,China)

机构地区：[1]北方工业大学土木工程学院,北京100144

出　　处：《河南城建学院学报》2025年第1期9-14,共6页Journal of Henan University of Urban Construction

基　　金：国家自然科学基金项目(51774015)。

摘　　要：针对围岩钻孔应力受初始应力影响造成的测量误差问题,基于钻孔孔壁应力与钻孔应力计初始应力的相对关系,开展了相似材料钻孔应力监测试验,探讨了不同初始应力下监测应力与竖向位移的变化规律,分析了监测应力与理论孔壁应力的相对误差。结果表明:围岩破坏前产生的竖向位移和应力计开始工作时的围岩应力受初始应力影响,初始应力越大,围岩产生的竖向位移越小,导致应力计开始工作时所需的围岩应力越小。当应力计监测应力与孔壁应力越接近时,钻孔应力计与围岩耦合状态越好,围岩不会发生剧烈的破坏过程。当初始应力为1.5 MPa时,应力计监测应力与钻孔孔壁应力最接近,监测应力增加73.33%,围岩产生的竖向位移与理论位移相差最小,相对误差的绝对值为0.94%,监测精度最好。研究结果对围岩动力灾害的预测和评价具有重要的应用价值。To address the issue of poor monitoring effectiveness in surrounding rock borehole stress due to initial stress influences,a similar material borehole stress monitoring test was conducted based on the relative relationship between borehole wall stress and the initial stress values of borehole stress gauges.The study explored the variation patterns of monitored stress and vertical displacement under different initial stresses and analyzed the relative errors between the monitored stress and the theoretical borehole wall stress.The results indicate that the vertical displacement generated before the failure of the surrounding rock and the surrounding rock stress required for the stress meter to start functioning are influenced by the initial stress.The larger the initial stress,the smaller the vertical displacement generated by the surrounding rock,resulting in a smaller surrounding rock stress required for the stress meter to start functioning.When the monitored stress by the borehole stress gauge is closer to the borehole wall stress,the coupling state between the borehole stress gauge and the surrounding rock is better,and no intense failure process occurs in the surrounding rock.When the initial stress is 1.5 MPa,the monitored stress by the stress gauge is closest to the borehole wall stress,with an increase of 73.33%in the monitored stress.The vertical displacement of the surrounding rock is closest to the theoretical value,with the absolute relative error at 0.94%,indicating the highest monitoring accuracy.The study results have significant application value for the prediction and assessment of dynamic disasters in surrounding rock.

关 键 词：钻孔应力计 初始应力 相似材料 应力监测 

分 类 号：TD322[矿业工程—矿井建设]