A statistical damage-based constitutive model for shearing of rock joints in brittle drop mode  

作　　者：Xinrong Liu Peiyao Li Xueyan Guo Xinyang Luo Xiaohan Zhou Luli Miao Fuchuan Zhou Hao Wang 

机构地区：[1]School of Civil Engineering,Chongqing University,Chongqing 400045,China [2]National Joint Engineering Research Center of Geohazards Prevention in The Reservoir Areas(Chongqing),Chongqing 400045,China [3]Key Laboratory of New Technology for Construction of Cities in Mountain Area(Chongqing University),Ministry of Education,Chongqing 400045,China [4]Chongqing Vocational Institute of Engineering,Chongqing 402260,China

出　　处：《International Journal of Mining Science and Technology》2024年第8期1041-1058,共18页矿业科学技术学报（英文版）

基　　金：funded by the National Natural Science Foundation of China(No.41972266);Chongqing Natural Science Foundation(No.CSTB2024NSCQ-MSX0006).

摘　　要：Some rock joints exhibit significant brittleness,characterized by a sharp decrease in shear stress upon reaching the peak strength.However,existing models often fail to accurately represent this behavior and are encumbered by numerous parameters lacking clear mechanical significance.This study presents a new statistical damage constitutive model rooted in both damage mechanics and statistics,containing only three model parameters.The proposed model encompasses all stages of joint shearing,including the compaction stage,linear stage,plastic yielding stage,drop stage,strain softening stage,and residual strength stage.To derive the analytical expression of the constitutive model,three boundary conditions are introduced.Experimental data from both natural and artificial rock joints is utilized to validate the model,resulting in average absolute relative errors ranging from 3%to 8%.Moreover,a comparative analysis with established models illustrates that the proposed model captures stress drop and post-peak strain softening more effectively,with model parameters possessing clearer mechanical interpretations.Furthermore,parameter analysis is conducted to investigate the impacts of model parameters on the curves and unveil the relationship between these parameters and the mechanical properties of rock joints.Importantly,the proposed model is straightforward in form,and all model parameters can be obtained from direct shear tests,thus facilitating the utilization in numerical simulations.

关 键 词：Rock joints Brittle rock Direct shear test Damage-based constitutive model Parameters analysis 

分 类 号：TU45[建筑科学—岩土工程]