非饱和土化学-水力-力学耦合行为数值模拟  

The numerical modeling for the coupled chemo-hydro-mechanical behavior of unsaturated clay

作　　者：刘泽佳[1] 李锡夔[2] 

机构地区：[1]华南理工大学土木与交通学院,广州510641 [2]大连理工大学工业装备结构分析国家重点实验室,大连116024

出　　处：《岩土力学》2008年第11期2977-2982,共6页Rock and Soil Mechanics

基　　金：国家自然科学基金(No.10590354);广东省计算机网络重点实验室开放基金项目(No.CN200602)

摘　　要：在描述非饱和土力学本构行为的Gens-Alonso模型[1]的基础上,结合化学浓度对前固结压力的软化公式[2],并考虑了化学浓度对黏聚力的软化作用,建立了描述非饱和土化学-水力-力学耦合行为的本构模型。对包括化学-水力-力学本构关系、流体流动和污染物传输的控制方程的平衡方程组进行有限元离散,并采用此非饱和土化学-水力-力学耦合行为的数值模型对非饱和土中隧道周围化学-水力-力学耦合过程进行了模拟,对纯粹的力学响应、弹性化学力学响应、弹塑性化学力学响应3种情况进行了分析,数值结果显示了化学浓度作用下隧道周围的体积变化量和应力状态比单纯的力学响应有较大的提高,隧道表面的收缩量也有明显的增大。数值模拟的结果显示了该方法对模拟非饱和土复杂的耦合行为的可行性。Basing on the Gens-Alonso model describing the constitutive behavior of unsaturated soils presented in reference , the softening mechanism of contaminant concentration on preconsolidation pressure presented in reference and the softening mechanism of contaminant concentration on the cohesion, a constitutive model to describe the chemo-hydro-mechanical coupling behavior of unsaturated soil is developed. The governing equation of the coupling problem consisting with the equilibrium equations combined with the chemo-hydro-mechanical constitutive relations, the governing equations for flow of fluids and contaminant transport, are solved numerically using finite elements. The numerical analyses are carried out to simulate the chemohydro-mechanical coupling progress of unsaturated soil around tunnel. Three cases mechanical response, chemo-mechanical elastic response, chemo-mechanical elastoplastic response etc. are compared. The increases in the stress state and the strains in the region close to the tunnel and the shrinkage of the tunnel surface are observed due to the presence of chemistry. The numerical results show the feasibility of the present method to simulate the composite coupling behavior of unsaturated soil.

关 键 词：塑性 非饱和土 化学软化 本构模型 

分 类 号：TU411[建筑科学—岩土工程]