Experimental study on failure precursory characteristics and moisture content effect of pre-cracked rocks under graded cyclic loading and unloading  

作　　者：Wei Zhang Dongxiao Zhang Weiyao Guo Baoliang Zhang 

机构地区：[1]School of Architecture and Engineering,Liaocheng University,Liaocheng 252000,China [2]College of Energy and Mining Engineering,Shandong University of Science and Technology,Qingdao 266590,China

出　　处：《International Journal of Mining Science and Technology》2025年第2期249-264,共16页矿业科学技术学报(英文版)

基　　金：financially supported by National Natural Science Foundation of China(No.52304136);Young Talent of Lifting Engineering for Science and Technology in Shandong,China(No.SDAST2024QTA060);Key Project of Research and Development in Liaocheng(No.2023YD02)。

摘　　要：It is important to analyze the damage evolution process of surrounding rock under different water content for the stability of engineering rock mass.Based on digital speckle correlation(DSCM),acoustic emission(AE)and electromagnetic radiation(EMR),uniaxial hierarchical cyclic loading and unloading tests were carried out on sandstones with different fracture numbers under dry,natural and saturated water content,to explore the fracture propagation,failure precursor characteristics and damage response mechanism under the influence of water content effect.The results show that with the increase of water content,the peak stress and crack initiation stress decrease gradually,and the decreases are 15.28%-21.11%and 17.64%-23.04%,respectively.The peak strain and crack initiation strain increase gradually,and the increases are 19.85%-44.53%and 19.15%-41.94%,respectively.The precracked rock with different water content is mainly characterized by tensile failure at different loading stages.However,with the increase of water content,the proportion of shear cracks gradually increases,while acoustic emission events gradually decrease,the dissipative energy and energy storage limits of the rock under peak load gradually decrease,and the charge signal increases significantly,which is because the lubrication effect of water reduces the friction coefficient between crack surfaces.

关 键 词：Damage mechanisms Pre-cracked rocks Crack propagation Water-rock interaction Graded cyclic loading and unloading 

分 类 号：TD315[矿业工程—矿井建设]