首页|Swelling behaviors of heterogeneous red-bed mudstone subjected to different vertical stresses

Swelling behaviors of heterogeneous red-bed mudstone subjected to different vertical stresses

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In this study,the axial swelling strain of red-bed mudstone under different vertical stresses are measured by swell-under-load method,and the microstructure of mudstone after hygroscopic swelling is studied by mercury intrusion porosimetry(MIP).The weakening coefficient and Weibull distribution function are introduced into the coupling model of mudstone moisture diffusion-swelling deformation-fracture based on finite-discrete element method(FDEM).The weakening effect of moisture on mudstone's mechanical parameters,as well as the heterogeneity of swelling deformation and stress distribution,is considered.The microcrack behavior and energy evolution of mudstone during hygroscopic swelling deformation under different vertical stresses are studied.The results show that the axial swelling strain of mudstone decreases with increase of the vertical stress.At low vertical stresses,moisture absorption in mudstone leads to formation of cracks caused by hydration-induced expansion.Under high vertical stresses,a muddy sealing zone forms on the mudstone surface,preventing further water infiltration.The simulation results of mudstone swelling deformation also demonstrate that it involves both swelling of the mudstone matrix and swelling caused by crack expansion.Notably,crack expansion plays a dominant role in mudstone swelling.With increasing vertical stress,the cracks in mudstone change from tensile cracks to shear cracks,resulting in a significant reduction in the total number of cracks.While the evolution of mudstone kinetic energy shows similarities under different vertical stresses,the evolution of strain energy varies significantly due to the presence of different types of cracks in the mudstone.The findings provide a theoretical basis for understanding the hygroscopic swelling deformation mechanism of red-bed mudstone at various depths.

Heterogeneous red-bed mudstoneSelf-sealing bandMatric swelling and crack expansionFDEMMicrocracksEnergy evolution

Kang Huang、Zhangjun Dai、Chengzeng Yan、Fei Yu、Wei Zhang、Shanxiong Chen

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State Key Laboratory of Geomechanics and Geotechnical Engineering,Institute of Rock and Soil Mechanics,Chinese Academy of Sciences,Wuhan,430071,China

University of Chinese Academy of Sciences,Beijing,100049,China

Faculty of Engineering,China University of Geosciences,Wuhan,China

International Joint Research Center for Deep Earth Drilling and Resource Development,China University of Geosciences,Wuhan,430074,China

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国家自然科学基金Youth Innovation Promotion Association CAS

421723082022331

2024

岩石力学与岩土工程学报(英文版)
中国科学院武汉岩土力学所中国岩石力学与工程学会武汉大学

岩石力学与岩土工程学报(英文版)

CSTPCD
影响因子:0.404
ISSN:1674-7755
年,卷(期):2024.16(5)
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