数值分析

含裂隙岩体单轴压缩裂纹扩展机制离散元分析

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  • 1. 同济大学 土木工程地下建筑与工程系,上海 200092;2. 同济大学 土木工程防灾国家重点实验室,上海 200092;3. 同济大学 岩土及地下工程教育部重点实验室,上海 200092;4. 云南省交通规划设计研究院 陆地交通气象灾害防治技术国家工程试验室,云南 昆明 650011
蒋明镜,男,1965年生,博士,教授,博士生导师,主要从事结构性土、太空土、深海能源土的力学特性和离散元数值模拟的研究工作。

收稿日期: 2014-03-12

  网络出版日期: 2018-06-14

基金资助

国家重点基础科学研究发展计划(973)项目(No.2011BC013504,No.2014CB046901);国家杰出青年科学基金(No.51025932)。

DEM analyses of crack propagation in flawed rock mass under uniaxial compression

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  • 1. Department of Geotechnical Engineering, Tongji University, Shanghai 200092, China; 2. State Key Laboratory of Disaster Reduction in Civil Engineering, Tongji University, Shanghai 200092; 3. Key Laboratory of Geotechnical and Underground Engineering of Ministry of Education, Tongji University, Shanghai 200092, China; 4. Yunnan Provincial Plan Design And Research Institute of Communications, National Engineering Laboratory for Surface Transportation Weather Impacts Prevention, Kunming, Yunnan 650011, China

Received date: 2014-03-12

  Online published: 2018-06-14

Supported by

Project supported by the National Program on Key Basic Research Project (Grant Nos.2011BC013504 and 2014CB046901) and China National Funds for Distinguished Young Scientists (Grant No.51025932).

摘要

将由室内试验总结得到的岩石微观胶结模型嵌入离散元软件,对Lac du Bonnet花岗岩石进行预制单裂隙单轴压缩试验DEM数值模拟,分析了压缩过程中裂隙试样中应力的分布,并与理论计算结果进行对比分析,同时对各种断裂判据中裂纹起裂角的预测值进行了适用性的对比分析。结果表明,离散元模拟试样破坏形态与试验结果相近;离散元分析得到的应力分布与理论解在定性上相似;当预制角度较小时,侧向应力都处于拉压状态;由于裂隙左右两端压应变的集中造成了裂隙上下面拉应变的产生,造成了裂隙周围特殊的应力分布;当裂隙角度较大时,应力集中现象已不明显,因而,理论值与试验值有偏差;在断裂判据中最大周应力准则和最大能量释放率准则得到的裂纹扩展角与室内试验与DEM结果中的数值较为吻合。

本文引用格式

蒋明镜 ,张 宁 ,申志福 ,陈 贺, . 含裂隙岩体单轴压缩裂纹扩展机制离散元分析[J]. 岩土力学, 2015 , 36(11) : 3293 -3300 . DOI: 10.16285/j.rsm.2015.11.034

Abstract

A contact model for rock is established and imbedded into a DEM software by summarizing the bond granule tests. DEM simulation of uniaxial compression test on the pre-cracked Lac du Bonnet granite is performed, and then stress distributions are further analyzed and compared with the theoretical results. Different fracture criteria are employed to predict the crack initiation angles that are compared with theoretical ones. The results show that the failure modes obtained from DEM simulation are similar to experimental results, and stress distributions in DEM simulation are qualitatively similar to theoretical values. When the angle of pre-crack is small, the lateral stresses are compressive and tensile. The compressive strains concentrate at two edges, resulting in the tensile strains in the up- and downward cracks. When the angle of the pre-crack is large enough, the stress concentration is unobvious, leading to a discrepancy between the DEM and theoretical results. The crack extension angle resulting from uniaxial compression measured from DEM tests are in good agreement with those acquired from experimental tests. These angles are consistent with theoretical predictions by the maximum circumferential stress criterion and the maximum energy release rate criterion.
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