Failure behavior around a circular opening in a rock mass with non-persistent joints:A parallel-bond stress corrosion approach  

作　　者：YANG Xu-xu JING Hong-wen CHEN Kun-fu YANG Sheng-qi 杨旭旭;靖洪文;陈坤福;杨圣奇

机构地区：[1]State Key Laboratory for Geomechanics & Deep Underground Engineering,China University of Mining and Technology [2]Shandong Provincial Key Laboratory of Civil Engineering Disaster Prevention and Mitigation,Shandong University of Science and Technology [3]Rock Mass Modeling and Computational Rock Mechanics Laboratories,University of Arizona

出　　处：《Journal of Central South University》2017年第10期2406-2420,共15页中南大学学报（英文版）

基　　金：Project(2013CB036003)supported by the National Basic Research Program of China;Projects(51374198,51134001,51404255)supported by the National Natural Science Foundation of China;Project(BK20150005)supported by the Natural Science Foundation of Jiangsu Province for Distinguished Youth Scholar,China

摘　　要：The stability of underground excavations is influenced by discontinuities interspaced in surrounding rock masses as well as the stress condition. In this work, a numerical study was undertaken on the failure behavior around a circular opening in a rock mass having non-persistent open joints using PFC software package. A parallel-bond stress corrosion(PSC) approach was incorporated to drive the failure of rock mass around the circular opening, such that the whole progressive failure process after excavation was reproduced. Based on the determined micro parameters for intact material and joint segments, the failure process around the circular opening agrees very well with that obtained through laboratory experiment. A subsequent parametric study was then carried out to look into the influence of lateral pressure coefficient, joint dip angle and joint persistency on the failure pattern and crack evolution of the rock mass around the circular opening. Three failure patterns identified are step path failure, planar failure and rotation failure depending on the lateral pressure coefficient. Moreover, the increment of joint dip angle and joint persistency aggravates the rock mass failure around the opening. This study offers guideline on stability estimation of underground excavations.The stability of underground excavations is influenced by discontinuities interspaced in surrounding rock masses as well as the stress condition. In this work, a numerical study was undertaken on the failure behavior around a circular opening in a rock mass having non-persistent open joints using PFC software package. A parallel-bond stress corrosion(PSC) approach was incorporated to drive the failure of rock mass around the circular opening, such that the whole progressive failure process after excavation was reproduced. Based on the determined micro parameters for intact material and joint segments, the failure process around the circular opening agrees very well with that obtained through laboratory experiment. A subsequent parametric study was then carried out to look into the influence of lateral pressure coefficient, joint dip angle and joint persistency on the failure pattern and crack evolution of the rock mass around the circular opening. Three failure patterns identified are step path failure, planar failure and rotation failure depending on the lateral pressure coefficient. Moreover, the increment of joint dip angle and joint persistency aggravates the rock mass failure around the opening. This study offers guideline on stability estimation of underground excavations.

关 键 词：failure behavior circular OPENING non-persistent joint PFC software PACKAGE stress corrosion 

分 类 号：TU45[建筑科学—岩土工程]