层状岩石不排气三轴压缩力学特性试验研究
Gas-undrained triaxial compression mechanical properties test of layered rock
王伟 1罗霄 1陈超 1刘世藩 1段雪雷 1朱其志1
作者信息
- 1. 河海大学岩土力学与堤坝工程教育部重点实验室,江苏南京 210098;河海大学岩土工程科学研究所,江苏南京 210098
- 折叠
摘要
为研究地下隧洞开挖过程中围压和孔隙气压对层状千枚岩力学特性及变形参数的影响,以氩气作为渗透介质,开展层状千枚岩不排气三轴压缩试验,分析层状千枚岩在不同围压和孔压下应力-应变关系、峰值强度、变形特性及破坏形式随层理倾角的演化特征.引入基于层理倾角的各向异性度公式,探讨围压和孔压对层状千枚岩各向异性的影响.结果表明:不排气条件下,当孔压减小或围压增大时,层状千枚岩峰值强度逐渐增大;岩石峰值强度σc、弹性模量及变形模量随层理倾角的增大呈"U"型变化;层理倾角在30°～60°之间,层状千枚岩存在层理弱面,破坏形式主要为沿层理面剪切滑移破坏;层状千枚岩在平行层理方向受围压、孔压影响较大,呈现明显各向异性特征.
Abstract
In order to study the influence of confining pressure and pore pressure on the mechanical properties and deformation parameters during underground tunnel excavation,a gas-undrained triaxial compression test of layered phyllite was carried out with argon as the permeable medium.The study analyzed the evolution characteristics of stress-strain relationship,peak strength,deformation characteristics and failure modes of layered phyllite with bedding inclinations under varying confining pressure and pore pressure.Additionally,an anisotropy degree formula based on bedding inclinations was introduced to discuss the impacts of confining pressure and pore pressure on the anisotropy of layered phyllite.The results show that the peak strength of layered phyllite increases gradually as the pore pressure decreases or the confining pressure increases.The peak strength σc,elastic modulus and deformation modulus exhibit'U'shaped changes with an increase in bedding inclinations.When the bedding inclination ranges between 30° and 60°,the layered phyllite has a low degree of hardness,and the predominant failure mode is shear slip along the bedding plane.Furthermore,the layered phyllite is greatly affected by confining pressure and pore pressure in the direction of parallel bedding,showing significant anisotropic characteristics.
关键词
层状岩石/层理倾角/各向异性/不排气三轴压缩/破坏形式Key words
layered rock/bedding inclinations/anisotropy/gas-undrained triaxial compression/failure mode引用本文复制引用
基金项目
国家自然科学基金项目(12072102)
江苏省六大人才高峰项目(JZ008)
江苏省青蓝工程项目()
出版年
2024
国家科技期刊平台
NSTL
万方数据