工程科学学报.第42卷,第6期:715-722.2020年6月 Chinese Journal of Engineering,Vol.42,No.6:715-722,June 2020 https://doi.org/10.13374/j.issn2095-9389.2019.11.05.004;http://cje.ustb.edu.cn 高渗透压和不对称围压作用下深竖井围岩损伤破裂机理 刘力源12,纪洪广1,2四,王涛2),裴峰1,2),权道路2 1)北京科技大学城市地下空间工程北京市重点实验室,北京1000832)北京科技大学土木与资源工程学院,北京100083 区通信作者,E-mail:jihongguang@ces.ustb.edu.cm 摘要随着矿产资源开采深度的不断增大,地应力、地温和孔隙水压随之显著增大,岩石的非线性力学行为更加凸显.针 对高渗透压和不对称围压作用下深竖井围岩损伤破裂问题,构建了流固损伤耦合效应力学分析模型,分析了流固耦合条件下 深竖井开挖围岩有效应力,探讨了孔隙水压及地应力场对围岩损伤破裂演化的作用机制.研究结果表明:孔隙水压及孔隙水 压梯度越大围岩损伤破裂区面积越大,围岩损伤破裂区面积随围岩渗透率的减小逐渐增大并趋于稳定:地应力场对围岩破裂 形态具有重要控制作用,最大水平主应力与最小水平主应力差异较小时,围岩损伤破裂区集中在最小水平主应力方向,以剪 切损伤为主,最大水平主应力与最小水平主应力差异较大时,在最大水平主应力方向上会产生拉伸损伤破裂区.值得关注的 是,由于孔隙水压的存在,最大有效水平主应力与最小有效水平主应力之间的比值增大,即围岩发生拉伸破坏的风险增大 本文研究表明,竖井选址和设计过程中应避开构造应力大、孔隙水压大的区域,从而保障井筒施工安全 关键词深竖井;高渗透压:不对称围压;损伤破裂;数值模拟 分类号TD315 Mechanism of country rock damage and failure in deep shaft excavation under high pore pressure and asymmetric geostress LIU Li-yuan2)JI Hong-guang WANG Tao2),PEI Feng2,QUAN Dao-lu2) 1)Key Laboratory of Urban Underground Space Engineering,University of Science and Technology Beijing,Beijing 100083,China 2)School of Civil and Resource Engineering.University of Science and Technology Beijing.Beijing 100083,China Corresponding author,E-mail:jihongguang@ces.ustb.edu.cn ABSTRACT With the development of the mining industry,a large number of accessible shallow mineral resources are being depleted, and some have now been completely exhausted.The exploitation of the Earth's deep mineral resources has become the only way to meet the society's growing demand for minerals.With the increase in mining depth,the geostress,temperature,and pore pressure of water increase significantly,and the nonlinear mechanical behavior of rock becomes prominent.To assess the damage and failure of surrounding rock in deep shaft under high osmotic pressure and asymmetric geostress,a coupled mechanical-hydraulic-damage model was proposed to examine the effective stress of surrounding rock in deep shaft.This approach took into account the maximum tensile stress criterion with shear failure based on the Mohr-Coulomb criterion and was applied to simulate damage evolution in heterogeneous rocks.On this basis,the mechanisms of pore pressure,rock permeability,and geostress and its effects on rock damage evolution and fracture propagation were further investigated.The results indicate that the larger the pore pressure and its gradient are,the larger the damage and failure areas of surrounding rock.With the decrease of permeability of country rock,the damage and failure areas of country rock gradually increase and tend to be stable.The geostress field plays an important role in controlling the failure morphology of 收稿日期:2019-11-05 基金项目:国家重点研发计划资助项目(2016YFC0600801):国家自然科学基金资助项目(51874014.51534002):北京市自然科学基金资助 项目(2204084):中央高校基本科研业务费资助项目(FRF-TP.19-027A1)高渗透压和不对称围压作用下深竖井围岩损伤破裂机理 刘力源1,2),纪洪广1,2) 苣,王 涛1,2),裴 峰1,2),权道路1,2) 1) 北京科技大学城市地下空间工程北京市重点实验室,北京 100083 2) 北京科技大学土木与资源工程学院,北京 100083 苣通信作者,E-mail:jihongguang@ces.ustb.edu.cn 摘 要 随着矿产资源开采深度的不断增大,地应力、地温和孔隙水压随之显著增大,岩石的非线性力学行为更加凸显. 针 对高渗透压和不对称围压作用下深竖井围岩损伤破裂问题,构建了流固损伤耦合效应力学分析模型,分析了流固耦合条件下 深竖井开挖围岩有效应力,探讨了孔隙水压及地应力场对围岩损伤破裂演化的作用机制. 研究结果表明:孔隙水压及孔隙水 压梯度越大围岩损伤破裂区面积越大,围岩损伤破裂区面积随围岩渗透率的减小逐渐增大并趋于稳定;地应力场对围岩破裂 形态具有重要控制作用,最大水平主应力与最小水平主应力差异较小时,围岩损伤破裂区集中在最小水平主应力方向,以剪 切损伤为主,最大水平主应力与最小水平主应力差异较大时,在最大水平主应力方向上会产生拉伸损伤破裂区. 值得关注的 是,由于孔隙水压的存在,最大有效水平主应力与最小有效水平主应力之间的比值增大,即围岩发生拉伸破坏的风险增大. 本文研究表明,竖井选址和设计过程中应避开构造应力大、孔隙水压大的区域,从而保障井筒施工安全. 关键词 深竖井;高渗透压;不对称围压;损伤破裂;数值模拟 分类号 TD315 Mechanism of country rock damage and failure in deep shaft excavation under high pore pressure and asymmetric geostress LIU Li-yuan1,2) ,JI Hong-guang1,2) 苣 ,WANG Tao1,2) ,PEI Feng1,2) ,QUAN Dao-lu1,2) 1) Key Laboratory of Urban Underground Space Engineering, University of Science and Technology Beijing, Beijing 100083, China 2) School of Civil and Resource Engineering, University of Science and Technology Beijing, Beijing 100083, China 苣 Corresponding author, E-mail: jihongguang@ces.ustb.edu.cn ABSTRACT With the development of the mining industry, a large number of accessible shallow mineral resources are being depleted, and some have now been completely exhausted. The exploitation of the Earth’s deep mineral resources has become the only way to meet the society ’s growing demand for minerals. With the increase in mining depth, the geostress, temperature, and pore pressure of water increase significantly, and the nonlinear mechanical behavior of rock becomes prominent. To assess the damage and failure of surrounding rock in deep shaft under high osmotic pressure and asymmetric geostress, a coupled mechanical–hydraulic–damage model was proposed to examine the effective stress of surrounding rock in deep shaft. This approach took into account the maximum tensile stress criterion with shear failure based on the Mohr–Coulomb criterion and was applied to simulate damage evolution in heterogeneous rocks. On this basis, the mechanisms of pore pressure, rock permeability, and geostress and its effects on rock damage evolution and fracture propagation were further investigated. The results indicate that the larger the pore pressure and its gradient are, the larger the damage and failure areas of surrounding rock. With the decrease of permeability of country rock, the damage and failure areas of country rock gradually increase and tend to be stable. The geostress field plays an important role in controlling the failure morphology of 收稿日期: 2019−11−05 基金项目: 国家重点研发计划资助项目(2016YFC0600801);国家自然科学基金资助项目(51874014,51534002);北京市自然科学基金资助 项目(2204084);中央高校基本科研业务费资助项目(FRF-TP-19-027A1) 工程科学学报,第 42 卷,第 6 期:715−722,2020 年 6 月 Chinese Journal of Engineering, Vol. 42, No. 6: 715−722, June 2020 https://doi.org/10.13374/j.issn2095-9389.2019.11.05.004; http://cje.ustb.edu.cn