基于变形功的有效应力力学机理探究  

Exploration of effective stress mechanics mechanism based on deformation work

作　　者：胡亚元[1] 王超[1] HU Ya-yuan;WANG Chao(Research Center of Coastal and Urban Geotechnical Engineering,Zhejiang University,Hangzhou 310058,China)

机构地区：[1]浙江大学滨海和城市岩土工程研究中心,浙江杭州310058

出　　处：《浙江大学学报（工学版）》2019年第5期925-931,共7页Journal of Zhejiang University：Engineering Science

基　　金：国家自然科学基金资助项目(51178419);广东省中科化灌工程与材料院士工作站科研基金资助项目(2016GZZ07)

摘　　要：针对Terzaghi有效应力公式在饱和多孔介质力学中的适用性问题,提出新的饱和多孔介质的体积变形功方程,基于变形功探究有效应力力学机理.当忽略固流相基质变形时,运用机械功原理证明Terzaghi有效应力公式的正确性.当考虑固流相基质变形时,根据混合物理论将固相体应变分为固相体积分数应变和固相基质体应变.通过推导和分析体积变形功守恒方程,揭示Terzaghi有效应力与固相体积分数应变之间的功共轭力学关系.在小应变条件下,当固相基质变形、固相体积分数变化和流相基质变形之间的受力机理相互独立时,Terzaghi有效应力唯一地决定饱和多孔介质的固相体积分数应变.同时采用固相基质压力和Terzaghi有效应力才能够完全确定固相体积变形.研究结果表明,Terzaghi有效应力作为影响固相体积变形的内在因素之一,其表达式无须修正.A new volume deformation work conservation equation of saturated porous media was proposed, and the effective stress mechanics mechanism was explored based on deformation work, in view of the validity of Terzaghi effective stress formula in saturated porous media. The mechanical work principle was used to prove the validity of Terzaghi effective stress formula without taking the deformations of solid and fluid matrix into account. The volume strain of solid phase was divided into solid volume fraction strain and solid matrix volume strain based on mixture theory, considering the deformations of solid and fluid matrix. The mechanical relationship of work conjugate between Terzaghi effective stress and solid volume fraction strain was obtained through the derivation and analysis of volume deformation work conservation equation. Terzaghi effective stress can only determine the solid volume fraction strain when the stress mechanisms among solid matrix deformation, solid volume fraction change and fluid matrix deformation were mutually independent under infinitesimal strain condition. The volume deformation of solid phase can be closely determined only if both solid matrix stress and Terzaghi effective stress were used. Results show that Terzaghi effective stress, as one of the internal factors affecting the volume strain of solid phase, does not need to be corrected.

关 键 词：有效应力 饱和多孔介质 混合物理论 体积变形功 

分 类 号：TU43[建筑科学—岩土工程]