本构模型对面板堆石坝动力特性影响及敏感性分析

Effect of Constitutive Models on the Dynamic Characteristics of Concrete Face Rockfill Dam and Sensitivity Analysis

为研究堆石料本构模型及模型参数对面板堆石坝动力响应特性的影响,基于有限元方法和动力时程分析,分别采用邓肯-张E-B模型和南水模型对某沥青混凝土堆石坝进行动力计算,比较了两种本构模型下坝体的静动位移、动应力和地震永久变形的分布规律和数值大小,在此基础上针对堆石料参数设计了正交试验,采用极差和方差分析方法研究了参数敏感性。结果表明,两种本构模型下面板坝的动位移分布规律相似但数值大小不同,动应力大小和分布规律均不同,参数K和Rd分别是邓肯-张E-B模型和南水模型中对坝体动位移最敏感的参数。

The finite element approach and dynamic time-history analysis are used to investigate the impact of different constitutive models and their parameters on the dynamic response of a concrete face rockfill dam with face slab.Dynamic calculations on an asphalt concrete face rockfill dam were carried out using the Duncan-Chang E-B model and the NHRI model.The corresponding distribution patterns and numerical values of the static and dynamic displacements,dynamic stresses,and seismic permanent deformation of the dam were compared.Orthogonal tests were designed for the parameters of rockfill.Moreover,range and variance analysis were used to carry out the sensitivity evaluations of the key model parameters.The results show that whereas the numerical values of the dynamic displacements of the concrete face rockfill dam under the two constitutive models are different,the distribution pattern is identical.Additionally,the magnitude and distribution pattern of dynamic stresses are different under the two models.K and Rd are found to be the most sensitive parameters of the Duncan-Chang E-B and NHRI models for the dynamic displacement of the dam,respectively.