摘要
为探究层状板岩的各向异性力学特征和破坏机理,揭示层理倾角和围压对岩石扩容的影响规律,开展了不同层理倾角的板岩常规三轴压缩试验。结果表明:层理弱面的存在对板岩的应力-应变曲线特征有较大影响,层理倾角α=90°的试样应力-应变曲线受围压影响最为显著;板岩的峰值强度随层理倾角呈“U”形分布,围压显著降低了板岩强度的各向异性程度;弹性模量和泊松比随层理倾角表现出变形各向异性特征,弹性模量与围压正相关,但弹性各向异性程度受围压的影响变化幅度不大;板岩的破坏模式具有各向异性现象,破坏的典型特征表现为沿层理面和贯穿层理面的破坏,层理弱面的存在对试样的破坏模式起控制作用;层状板岩的起裂应力和扩容应力随层理倾角具有各向异性特征,围压对起裂应力的影响远大于对峰值应力的影响;同一应力水平下,当层理倾角为60°时,试样的强度最低,起裂应力水平最高,扩容应力水平接近于1,试样未发生扩容,当即发生脆性破坏。
In order to explore the anisotropic mechanical characteristics and failure mechanism of layered slate,and to reveal the influence of strata inclination angle and confining pressure on rock expansion,conventional triaxial compression tests of slate with different strata inclination angles were carried out.The results show that the presence of weak strata surfaces has a great influence on the stress-strain curve characteristics of slate,and the stress-strain curve of specimen with strata inclination angleα=90°is most significantly affected by confining pressure.The peak intensity of slate is distributed in a“U”shape with the strata inclination angle,and the confining pressure significantly reduces the degree of strength anisotropy of slate.The elastic modulus and Poisson's ratio shows the characteristics of deformation anisotropy with different strata inclination angles,and the elastic modulus is positively correlated with confining pressure,but the degree of elastic anisotropy is not greatly affected by confining pressure.The failure mode of slate has anisotropy,and the typical characteristics of failure are failure along the strata plane and through the strata plane,and the presence of weak strata surface controls the failure mode of sample.The initiation stress and expansion stress of layered slate have anisotropic characteristics with the strata inclination angle,and the influence of confining pressure on initiation stress is much greater than the influence on peak stress.Under the same stress level,when the strata inclination angle is 60°,the strength of specimen is the lowest,the cracking stress level is the highest,the expansion stress level is close to 1,and the brittle failure occurs immediately when the specimen is not expanded.
作者
奚家米
苟陇平
王磊
原鑫磊
XI Jiami;GOU Longping;WANG Lei;YUAN Xinlei(College of Architecture and Civil Engineering,Xi'an University of Science and Technology,Xi'an 710054,Shaanxi,China;College of Architectural Engineering,Yan'an University,Yan'an 716000,Shaanxi,China)
出处
《建筑科学与工程学报》
北大核心
2025年第4期136-145,共10页
Journal of Architecture and Civil Engineering
基金
国家自然科学基金项目(12172280)。
关键词
层状板岩
各向异性
三轴压缩试验
起裂应力
扩容应力
layered slate
anisotropy
triaxial compression test
initiation stress
expansion stress
