原岩应力井下测量钻孔合理深度研究  

Reasonable depth of the borehole for in⁃situ stress measurements

作　　者：马文顶[1] 周嘉乐 张源[1,2] 郝佑民 杜广立 MA Wending;ZHOU Jiale;ZHANG Yuan;HAO Youmin;DU Guangli(School of Mines,China University of Mining and Technology,Xuzhou,Jiangsu 221116,China;State Key Laboratory for Fine Exploration and Intelligent Development of Coal Resources,China University of Mining and Technology,Xuzhou,Jiangsu 221116,China;Kongzhuang Coal Mine,Datun Coal Power Group Co Ltd,Xuzhou,Jiangsu 221611,China)

机构地区：[1]中国矿业大学矿业工程学院,江苏徐州221116 [2]中国矿业大学煤炭精准勘探与智能开发全国重点实验室,江苏徐州221116 [3]大屯煤电(集团)有限责任公司孔庄煤矿,江苏徐州221611

出　　处：《采矿与安全工程学报》2024年第4期845-852,共8页Journal of Mining & Safety Engineering

基　　金：国家自然科学基金项目(52074266)。

摘　　要：围绕地应力测试钻孔合理深度,采用弹性力学理论,建立了巷道围岩应力分布的无量纲数学模型,分析了不同侧压系数和误差等级下巷道围岩中原岩应力边界范围;采用数值模拟方法,研究了不同巷道宽度和高度时巷道围岩中的应力分布规律,揭示了巷道围岩中原岩应力边界深度与巷道尺寸的关系,得到了地应力测试钻孔的合理深度并在现场进行了验证。结果表明:巷道围岩应力分布与巷道无量纲半径R及侧压系数λ密切相关;巷道开挖应力影响范围为3~5倍巷道半径;当λ<1时,巷道围岩应力影响范围边界为长轴过巷道中心且水平的椭圆形;当λ>1时,影响范围边界为长轴过巷道中心且竖直的椭圆形;|λ-1|的值越大,长轴与短轴的比值越大;垂直巷道帮部施工地应力测试孔时,钻孔深度取1~2倍的巷道宽度;垂直巷道顶板施工钻孔时,深度为1.5~2.5倍巷道宽度;随着巷道宽度和高度的增加,巷道围岩中原岩应力边界深度逐渐增加;巷道宽度对原岩应力深度的影响明显大于巷道高度。综合来看,2倍巷道宽度可以作为地应力测试钻孔深度下限。Based on the elastic mechanics theory,a dimensionless mathematical model for the stress dis⁃tribution in the adjacent rock of the roadway was established to investigate the reasonable depth of the borehole for in⁃situ stress measurement.The boundary range of the original rock stress in the surrounding rock of the roadway was analyzed under different lateral pressure coefficients and error levels.By numer⁃ical simulation the stress distribution in the surrounding rock with different roadway widths and heights were studied,revealing the relationship between the depth of the original rock stress boundary in the roadway surrounding rock and the roadway size.The findings validated the appropriate depth of boreholes for in⁃situ stress measurements on site.The results indicated that the stress in the surrounding rock of the roadway is related to the dimensionless radius R and lateral pressure coefficient of the roadwayλ;the influence range of roadway excavation is 3-5 times the roadway radius;whenλ<1,the boundary of the stress influence range of the surrounding rock of the roadway is an ellipse with the long axis parallel to the horizontal axis passing through the center of the roadway;whenλ>1,the boundary of the influence area is an ellipse with a long axis parallel to the vertical axis passing through the center of the roadway;the value,|λ-1|,is larger,the greater the ratio of the long axis to the short axis is;the depth of the in⁃situ stress measurement borehole should be 1-2 times the width of the roadway when the borehole is on the vertical roadway side;however,when the borehole is vertical to the roof of the roadway,the depth should be 1.5-2.5 times the width of the roadway;the depth of the original rock stress boundary in the surrounding rock also increases with the increase of roadway;the influence of roadway width on the depth of original rock stress is significantly pronounced than that of roadway height.Overall,twice the width of the roadway can be used as the minimum depth limit of the borehole

关 键 词：地应力 钻孔深度 应力解除 数值模拟 

分 类 号：TD353[矿业工程—矿井建设]