基于状态相关本构模型的松砂静态液化失稳数值分析  

INSTABILITY AND STATIC LIQUEFACTION ANALYSIS OF LOOSE SANDS WITH A STATE-DEPENDENT CONSTITUTIVE MODEL

作　　者：黄茂松[1,2] 曲勰[1,2] 吕玺琳[1,2] 

机构地区：[1]同济大学岩土及地下工程教育部重点实验室,上海200092 [2]同济大学地下建筑与工程系,上海200092

出　　处：《岩石力学与工程学报》2014年第7期1479-1487,共9页Chinese Journal of Rock Mechanics and Engineering

基　　金：国家重点基础研究发展计划(973)项目(2012CB719803);国家自然科学基金资助项目(11372228)

摘　　要：采用有限元数值方法分析饱和砂土稳定性时,需结合能够正确反映体变特性的弹塑性本构模型来模拟可能出现的静态液化现象。推导出状态相关砂土本构模型的隐式积分计算方法,指出计算过程中可能出现的两类数值错误,并给出相应的数值处理方法。以二阶功为负作为液化判别准则,分析并对比不排水条件下松砂平面应变试件在快速加载和慢速加载2种情况下静态液化现象与规律的不同。以整体二阶功为负作为松砂边坡稳定的判别条件,对海底人工堆积松砂边坡进行稳定性分析。算例分析结果表明,该判别条件具有一定的合理性且该数值计算方法是可靠的。When the finite element method is used to simulate the instability of saturated sand, an elastoplastic constitutive model which can accurately reflect the plastic volumetric response of the sand is needed. An implicit algorithm of integration for the state-dependent sand model is derived. Two types of numerical errors occurred during the calculation process; and an appropriate numerical treatment is presented. Loose sand specimens under plane strain and undrained conditions are analyzed. The numerical results demonstrate differences of the static liquefaction phenomenon between rapid and slow loading cases. Another numerical example concerning the man-made slope of loose sand on seabed is analyzed with the negative work of second-order as the criterion of instability. The numerical results demonstrate the rationality of the criterion and reliability of the numerical algorithm.

关 键 词：土力学 有限元 隐式积分 静态液化 二阶功 

分 类 号：TU43[建筑科学—岩土工程]