Mechanical behaviours of sandstone containing intersecting fissures under uniaxial compression  

作　　者：Fei Xiong Xinrong Liu Xiaohan Zhou Guangyi Lin Dongshuang Liu Yafeng Han Bin Xu Chunmei He Zijuan Wang 

机构地区：[1]School of Civil Engineering,Chongqing University,Chongqing,400045,China [2]State Key Laboratory of Coal Mine Disaster Dynamics and Control,Chongqing University,Chongqing,400044,China [3]National Joint Engineering Research Center of Geohazards Prevention in the Reservoir Areas,Chongqing University,Chongqing,400045,China [4]State Key Laboratory for Geomechanics and Deep Underground Engineering,China University of Mining and Technology,Xuzhou,221116,China [5]College of Architectural Engineering,Neijiang Normal University,Neijiang,641100,China [6]School of Management Science and Engineering,Chongqing Technology and Business University,Chongqing,400067,China

出　　处：《Journal of Rock Mechanics and Geotechnical Engineering》2022年第2期460-476,共17页岩石力学与岩土工程学报（英文版）

基　　金：supported by the National Key R&D Program of China(Grant No.2018YFC1504802);the National Natural Science Foundation of China(Grant No.52074042);the Basic Research and Frontier Exploration Project of Chongqing,China in 2018(Grant No.cstc2018jcyj AX0453)。

摘　　要：Predicting rock cracking is important for assessing the stability of underground engineering.The effects of the intersecting angle a and the distribution orientation angleβof intersecting fissures on the uniaxial compressive strength and the failure characteristics of sandstone containing intersecting fissures are investigated through laboratory experiments and two-dimensional particle flow code(PFC2D).The relationship between the mechanical properties of sandstone and the intersecting angle a and the distribution orientation angleβis analysed.Crack initiation forms and the final failure modes are then categorised and determined via empirical methods.In addition,the cracking processes of intersecting fissures with different a andβvalues are discussed.The results show that variations in the peak stress,peak strain,average modulus,and crack initiation stress of sandstone containing intersecting fissures show a“moth”shape in the space of the a-β-mechanical parameters.Two crack initiation forms are identified:inner tip cracking(usually accompanied by one outer tip cracking)and only outer tips cracking.Two failure modes are observed:(1)the main fracture planes are created at the inner tip and one outer tip,and(2)the main fracture planes are formed at the two outer tips.Two main crack evolution processes of sandstone containing intersecting fissures under uniaxial compression are found.Approaches for quickly determining the crack initiation form and the failure mode are proposed.The combination of the determination equations for the crack initiation form and the failure mode can be used to predict the crack evolution.The approach for determining the crack evolution processes is hence proposed with acceptable precision.

关 键 词：Intersecting fissures SANDSTONE Uniaxial compression Fracture determination Cracking evolution 

分 类 号：TU45[建筑科学—岩土工程]