Damage degradation mechanism and macro-meso structural response of mudstone after water wetting  

作　　者：SHAO Zhixin SONG Yanqi ZHENG Junjie SHEN Fuxin LIU Chuanpeng YANG Juntao 

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

出　　处：《Journal of Mountain Science》2024年第8期2825-2843,共19页山地科学学报（英文）

基　　金：We gratefully acknowledge the financial support by the National Key Research and Development Program of China(2022YFC2904100);the State Key Laboratory of Coal Resources and Safe Mining,China University of Mining and Technology,Beijing(SKLCRSM20KFA11).

摘　　要：The predominant presence of weak interlayers primarily composed of mudstone renders them highly susceptible to a reduction in bearing capacity due to the water-rock weakening effect,significantly impacting the safety of open-pit mining operations.This study focuses on the weak mudstone layers within open-pit mine slopes.The mineral composition of mudstone and the microstructure evolution characteristics before and after water wetting were analyzed by X-ray diffraction(XRD)and scanning electron microscope(SEM).The meso-structure and parameter variation characteristics of mudstone interior space after water-rock interaction were quantified by computed tomography scanning test,and the damage variable characterization method was proposed.Additionally,according to the uniaxial compression test,the degradation characteristics of the macroscopic mechanical behavior of mudstone under different water wetting time were explored,and the elastic modulus and strength attenuation model of mudstone based on mesoscopic damage were established.Finally,building upon the macro-meso structural response characteristics of mudstone,an exploration of the failure characteristics and deterioration mechanism under the influence of water-rock interactions was undertaken.The results show that the water-rock interaction makes the internal defects of mudstone gradually develop and form a fracture network structure,which eventually leads to the deterioration of its macroscopic mechanical properties.The porosity,fractal dimension and damage characteristics of mudstone show an exponential trend with the increase of water wetting time.Moreover,the deterioration mechanism of mudstone after water wetting are postulated to encompass factors such as the hydrophilicity of mineral molecular structures,hydration stress and expansion effects on clay particles,as well as the spatial distribution of microcracks and the phenomenon of fracture adsorption.The outcomes of this research endeavor aim to provide certain reference value for further understanding t

关 键 词：Moisture absorption of mudstone Computed tomography scanning test Fracture structure evolution Macro-meso structural response Deterioration mechanism 

分 类 号：TD313[矿业工程—矿井建设]