上海地区基坑开挖数值分析中土体HS-Small模型参数的研究  

Study of parameters of HS-Small model used in numerical analysis of excavations in Shanghai area

作　　者：王卫东[1] 王浩然[1] 徐中华[1] 

机构地区：[1]华东建筑设计研究院有限公司地基基础与地下工程设计研究所,上海200002

出　　处：《岩土力学》2013年第6期1766-1774,共9页Rock and Soil Mechanics

基　　金：上海市青年科技启明星计划B资助项目(No.11QB1400400);国家科技支撑计划(No.2012BAJ01B02)

摘　　要：数值分析方法已成为分析敏感环境下基坑开挖对环境影响的最重要手段,其关键是选择合适的土体本构模型和计算参数。HS-Small模型可以同时考虑土体剪切硬化和压缩硬化,而且还可以考虑土体剪切模量在微小应变范围内随应变衰减的行为,因此,HS-Small模型在基坑开挖数值分析中具有很好的适用性。但HS-Small模型的参数较多,不仅包含了HS模型的参数,还包含了小应变参数,因此,获取完整的HS-Small模型参数存在一定困难。通过上海地区5个基坑开挖数值分析的实例对基于室内试验得出的上海典型土层HS模型参数进行了检验。通过参数的敏感性分析,对HS-Small模型的部分参数的确定方法进行了修正。在此基础上,采用反分析法确定了敏感性最强的小应变参数,从而初步完整地获取了上海典型土层土体HS-Small模型参数。采用文中确定的上海典型土层HS-Small模型参数对该地区若干典型基坑工程实例进行计算,结果表明,计算值与实测值吻合得较好,从而验证了确定的上海典型土层HS-Small模型参数的适用性。Numerical analysis has become the most important method for analyzing and predicting the deformation of excavations in close proximity to sensitive properties. One of the key problems in a numerical analysis is to select proper soil constitutive models and their corresponding parameters. HS-Small model including HS model parameters and small strain parameters is suitable for numerical analysis of deep excavations because HS-Small model can not only reflect shear and compression hardening but also account for shear modulus attenuating with strain in tiny strain range. However, it is difficult to obtain the whole set of parameters of HS-Small model. Parameters of HS model which determined by soil tests are firstly checked through numerical analysis of five excavation histories in Shanghai area. Determination of some parameters of HS-Small model is then modified based on parameter sensitivity analysis. The most sensitive parameter is determined by back analysis of the field measurements of five case histories. Validity of the whole set of parameters of the HS-Small model is verified by numerical analysis of several typical excavations in Shanghai.

关 键 词：HS-Small模型 参数 基坑 环境影响 数值分析 

分 类 号：TU476[建筑科学—结构工程]