Experimental verification of parameter m in Hoeke-Brown failure criterion considering the effects of natural fractures  

作　　者：Xu Wei Jianping Zuo Yue Shi Haiyan Liu Yunqian Jiang Chang Liu 

机构地区：[1]School of Mechanics and Civil Engineering,China University of Mining and Technology,Beijing,100083,China [2]State Key Laboratory of Coal Resources and Safe Mining,China University of Mining and Technology,Beijing,100083,China

出　　处：《Journal of Rock Mechanics and Geotechnical Engineering》2020年第5期1036-1045,共10页岩石力学与岩土工程学报（英文版）

基　　金：financial support from Beijing Outstanding Young Scientist Program,China(Grant No.BJJWZYJH01201911413037);the National Natural Science Foundation of China(Grant No.41877257);Shaanxi Coal Group Key Project,China(Grant No.2018SMHKJ-A-J-03)。

摘　　要：HoekeBrown failure criterion is one of the widely used rock strength criteria in rock mechanics and mining engineering.Based on the theoretical expression of HoekeBrown parameter m of an intact rock,the parameter m has been modified by crack parameters for fractured rocks.In this paper,the theoretical value range and theoretical expression form of the parameter m in HoekeBrown failure criterion were discussed.A critical crack parameter B was defined to describe the influence of the critical crack when the stress was at the peak,while a parameter b was introduced to represent the distribution of the average initial fractures.The parameter m of a fractured rock contained the influences of critical crack(B),confining pressure(s3)and initial fractures(b).Then the triaxial test on naturally fractured limestones was conducted to verify the modification of the parameter m.From the ultrasonic test and loading test results of limestones,the parameter m can be obtained,which indicated that the confining pressure at a high level reduced the differences of m among all the specimens.The confining pressure s3 had an exponential impact on m,while the critical crack parameter B had a negative correlation with m.Then the expression of m for a naturally fractured limestone was also proposed.

关 键 词：HoekeBrown parameters Critical crack parameter Naturally fractured limestone Ultrasonic test 

分 类 号：TU452[建筑科学—岩土工程]