工程科学学报，第39卷.第10期：1470-1476,2017年10月 Chinese Journal of Engineering,Vol.39,No.10:1470-1476,October 2017 DOI:10.13374/j.issn2095-9389.2017.10.002;http://journals.ustb.edu.cn 基于XFEM的岩体卸荷过程裂纹起裂扩展规律研究 邓青林12)四，赵国彦)，谭彪)，邹玉良)，李夕兵2) 1)核工业西南勘察设计研究院有限公司，成都6100612)中南大学资源与安全工程学院，长沙410083 3)同济大学土木工程学院，上海200092 ☒通信作者，E-mail:nicekenny@126.com 摘要地下和边坡工程开挖常涉及岩体卸荷问题，采用ABAQUS软件中的扩展有限单元法(extended finite element method,. XFEM)对开挖卸荷过程岩体内部裂纹的起裂扩展进行了模拟，通过计算裂纹尖端应力强度因子研究了其起裂特征，并探讨了 起裂影响因素，通过记录裂纹扩展形态研究了其动态演化模式.结果表明，卸荷过程中卸荷速率越快，裂纹长度越长，倾角越 大，其起裂越容易：并且裂纹面受到的正应力不断减小，剪应力不断增大，裂纹扩展主要由剪应力控制，这与理论分析结果一 致.裂纹最终扩展演化形态也与物理试验相近，充分表明运用扩展有限单元法研究岩体裂纹问题的可靠性 关键词岩体卸荷：裂纹；起裂扩展；扩展有限单元法 分类号TU457 Study on crack initiation and propagation in rock mass during unloading based on XFEM DENG Qing-lin)ZHAO Guo-yan?),TAN Biao,ZOU Yu-liang?,LI Xi-bing?) 1)Southwest Geotechnical Design Institute of China Nuclear Industry Co.Ltd.,Chengdu 610061,China 2)School of Resources and Safety Engineering,Central South University,Changsha 410083,China 3)School of Civil Engineering,Tongji University,Shanghai 200092.China Corresponding author,E-mail:nicekenny@126.com ABSTRACT Rock-mass unloading often occurs during underground and slope engineering excavations.Here,rock-mass crack initi- ation and propagation during the excavation unloading progress was simulated using the extended finite element method(XFEM)in ABAQUS.Crack propagation and its influencing factors were studied and discussed after calculating the stress intensity factors at the crack tips,and by recording the crack's shape a dynamic evolution model was produced.The results show that the faster the unloading rate,the longer the crack,and the greater the crack dip angle,the easier the crack initiates.The normal stress on a crack surface de- creases while shear stress increases during unloading,and that crack propagation is mainly controlled by shear stress.This is consist- ent with the theoretical analysis.The final shape of the modeled crack was also close to the result of the physical experiments,indica- ting the reliability of this study. KEY WORDS rock-mass unloading;crack;initiation and propagation;extended finite element method 进入21世纪以来，随着国民经济的飞速发展，我愈来愈多的传统矿山被迫进入超千米深井开采阶 国基础建设得以迅速推进，各类大型土木工程相继兴 段]，其复杂多变的高应力环境，导致一系列片帮冒 建，各种资源能源被大量消耗，随之带来了各种复杂的 顶、岩爆等灾害，严重威胁工作人员的生命财产安全， 岩石力学工程问题.例如在地下硬岩采矿工程方面， 需要研究找到更为理想的支护措施.另外一些大型的 收稿日期：2016-11-02 基金项目：国家自然科学基金面上资助项目(51374244)工程科学学报,第 39 卷,第 10 期:1470鄄鄄1476,2017 年 10 月 Chinese Journal of Engineering, Vol. 39, No. 10: 1470鄄鄄1476, October 2017 DOI: 10. 13374 / j. issn2095鄄鄄9389. 2017. 10. 002; http: / / journals. ustb. edu. cn 基于 XFEM 的岩体卸荷过程裂纹起裂扩展规律研究 邓青林1,2) 苣 , 赵国彦2) , 谭 彪3) , 邹玉良2) , 李夕兵2) 1)核工业西南勘察设计研究院有限公司, 成都 610061 2)中南大学资源与安全工程学院, 长沙 410083 3)同济大学土木工程学院, 上海 200092 苣通信作者, E鄄mail: nicekenny@ 126. com 摘 要 地下和边坡工程开挖常涉及岩体卸荷问题,采用 ABAQUS 软件中的扩展有限单元法( extended finite element method, XFEM)对开挖卸荷过程岩体内部裂纹的起裂扩展进行了模拟,通过计算裂纹尖端应力强度因子研究了其起裂特征,并探讨了 起裂影响因素,通过记录裂纹扩展形态研究了其动态演化模式. 结果表明,卸荷过程中卸荷速率越快,裂纹长度越长,倾角越 大,其起裂越容易;并且裂纹面受到的正应力不断减小,剪应力不断增大,裂纹扩展主要由剪应力控制,这与理论分析结果一 致. 裂纹最终扩展演化形态也与物理试验相近,充分表明运用扩展有限单元法研究岩体裂纹问题的可靠性. 关键词 岩体卸荷; 裂纹; 起裂扩展; 扩展有限单元法 分类号 TU457 Study on crack initiation and propagation in rock mass during unloading based on XFEM DENG Qing鄄lin 1,2) 苣 , ZHAO Guo鄄yan 2) , TAN Biao 3) , ZOU Yu鄄liang 2) , LI Xi鄄bing 2) 1) Southwest Geotechnical & Design Institute of China Nuclear Industry Co. Ltd. , Chengdu 610061, China 2) School of Resources and Safety Engineering, Central South University, Changsha 410083, China 3) School of Civil Engineering, Tongji University, Shanghai 200092, China 苣Corresponding author, E鄄mail:nicekenny@ 126. com ABSTRACT Rock鄄mass unloading often occurs during underground and slope engineering excavations. Here, rock鄄mass crack initi鄄 ation and propagation during the excavation unloading progress was simulated using the extended finite element method (XFEM) in ABAQUS. Crack propagation and its influencing factors were studied and discussed after calculating the stress intensity factors at the crack tips, and by recording the crack爷s shape a dynamic evolution model was produced. The results show that the faster the unloading rate,the longer the crack,and the greater the crack dip angle, the easier the crack initiates. The normal stress on a crack surface de鄄 creases while shear stress increases during unloading, and that crack propagation is mainly controlled by shear stress. This is consist鄄 ent with the theoretical analysis. The final shape of the modeled crack was also close to the result of the physical experiments, indica鄄 ting the reliability of this study. KEY WORDS rock鄄mass unloading; crack; initiation and propagation; extended finite element method 收稿日期: 2016鄄鄄11鄄鄄02 基金项目: 国家自然科学基金面上资助项目(51374244) 进入 21 世纪以来,随着国民经济的飞速发展,我 国基础建设得以迅速推进,各类大型土木工程相继兴 建,各种资源能源被大量消耗,随之带来了各种复杂的 岩石力学工程问题. 例如在地下硬岩采矿工程方面, 愈来愈多的传统矿山被迫进入超千米深井开采阶 段[1鄄鄄2] ,其复杂多变的高应力环境,导致一系列片帮冒 顶、岩爆等灾害,严重威胁工作人员的生命财产安全, 需要研究找到更为理想的支护措施. 另外一些大型的