Rock brittleness indices and their applications to different fields of rock engineering:A review  

作　　者：Fanzhen Meng Louis Ngai Yuen Wong Hui Zhou 

机构地区：[1]College of Science,Qingdao University of Technology,Qingdao,266033,China [2]Department of Earth Sciences,The University of Hong Kong,Pokfulam,Hong Kong,China [3]State Key Laboratory of Geomechanics and Geotechnical Engineering,Institute of Rock and Soil Mechanics,Chinese Academy of Sciences,Wuhan,430071,China

出　　处：《Journal of Rock Mechanics and Geotechnical Engineering》2021年第1期221-247,共27页岩石力学与岩土工程学报（英文版）

基　　金：We gratefully acknowledge financial support from the National Natural Science Foundation of China(Grant Nos.51879135 and 41877217);The work in this paper was also supported by the Hong Kong Scholars Program(Grant No.XJ2017043).

摘　　要：Brittleness is an important parameter controlling the mechanical behavior and failure characteristics of rocks under loading and unloading conditions,such as fracability,cutability,drillability and rockburst proneness.As such,it is of high practical value to correctly evaluate rock brittleness.However,the definition and measurement method of rock brittleness have been very diverse and not yet been standardized.In this paper,the definitions of rock brittleness are firstly reviewed,and several representative definitions of rock brittleness are identified and briefly discussed.The development and role of rock brittleness in different fields of rock engineering are also studied.Eighty brittleness indices publicly available in rock mechanics literature are compiled,and the measurement method,applicability and limitations of some indices are discussed.The results show that(1)the large number of brittleness indices and brittleness definitions is attributed to the different foci on the rock behavior when it breaks;(2)indices developed in one field usually are not directly applicable to other fields;and(3)the term“brittleness”is sometimes misused,and many empirically-obtained brittleness indices,which lack theoretical basis,fail to truly reflect rock brittleness.On the basis of this review,three measurement methods are identified,i.e.(1)elastic deformation before fracture,(2)shape of post-peak stressestrain curves,and(3)methods based on fracture mechanics theory,which have the potential to be further refined and unified to become the standard measurement methods of rock brittleness.It is highly beneficial for the rock mechanics community to develop a robust definition of rock brittleness.This study will undoubtedly provide a comprehensive timely reference for selecting an appropriate brittleness index for their applications,and will also pave the way for the development of a standard definition and measurement method of rock brittleness in the long term.

关 键 词：Rock brittleness Practical applicability Hydraulic fracturing Rockburst proneness Crack propagation Fragmentation efficiency 

分 类 号：TU45[建筑科学—岩土工程]