采矿与岩层控制工程学报2025，Vol.7Issue(2)：59-72,14.DOI:10.13532/j.jmsce.cn10-1638/td.2025-1048
含孔洞砂岩双轴压缩力学特性及破裂机制
Mechanical properties and fracture mechanism of porous sandstone under biaxial compression
摘要
Abstract
A series of biaxial compression tests were conducted to investigate the macroscopic mechanical response and fracture mechanism of porous sandstone under different intermediate principal stress conditions.The stress-strain behavior,mechanical parameters,failure modes,and the influence of intermediate principal stress were systematically analyzed.The results show that the mechanical evolution of porous sandstone under biaxial loading can be divided into four stages:pore compaction,linear elasticity,plastic deformation,and post-peak fracture.A distinct yield plateau was observed during the plastic deformation stage,while a sharp drop in strength and an almost complete loss of residual strength feature in post-peak fracture stage,exhibiting a hybrid ductile-brittle failure behavior.The intermediate principal stress σ2 plays a crucial role in strengthening the strength parameters of sandstone.When σ2<24 MPa,an increase in σ2 significantly enhances the peak stress,elastic modulus,closure stress,and crack initiation stress of porous sandstone.However,as σ2 continues to increase beyond this threshold,the strengthening effect gradually diminishes.At the lower intermediate principal stress levels,crack propagation is predominantly governed by tensile cracks,whereas at the higher intermediate principal stress levels,the failure mode gradually transitions to overall instability dominated by compressive-shear cracks.Biaxial stress confinement significantly influence the spatial evolution characteristics of cracks in sandstone.Differnt from the isotropic crack propagation under the uniaxial loading,the confining effect of σ2 in biaxial loading induces preferential crack propagation along the σ1-σ2 or σ2 plane,substantially reducing crack coalescence and penetration perpendicular to the σ2 direction.关键词
岩石力学/双轴压缩/含孔洞砂岩/中间主应力/破裂机制Key words
rock mechanics/biaxial compression/porous sandstone/intermediate principal stress/fracture mechanism分类
土木建筑引用本文复制引用
苗胜军,尚向凡,常宁东,马渊凯,杨鹏锦..含孔洞砂岩双轴压缩力学特性及破裂机制[J].采矿与岩层控制工程学报,2025,7(2):59-72,14.基金项目
国家重点研发计划资助项目(2022YFC3004601) （2022YFC3004601）
国家自然科学基金资助项目(52374077) （52374077）
