基于三维多重机构模型的土石坝地震反应分析

Seismic Response Analysis of Rockfill Dam Based on 3D Multi-mechanism Model

以Hardin-Drnevich模型和广义Masing准则为基础的三维多重机构模型,可以考虑颗粒材料的非线性和应力诱导各向异性。在有限元软件ABAQUS的平台上,开发了三维多重机构模型的UMAT子程序,实现了利用该模型进行土石坝地震反应分析的可能。利用三维多重机构模型和等价粘弹性模型,对某沥青混凝土面板堆石坝进行了地震反应分析,探讨了该坝在强震作用下的动力反应特性和本构模型对坝体动力反应的影响。结果表明,用三维多重机构模型与等价粘弹性模型计算得到的坝体动力反应有一定程度的差异,三维多重机构模型能够比较准确地模拟堆石料在地震荷载作用下的复杂应力应变关系,其计算结果可以更合理地揭示坝体的非线性地震反应特性。

The 3D multi-mechanism model based on the Hardin-Drnevich model and generalized Masing rule can take into account the nonlinearity and stress-induced anisotropy in stress-strain relationship for granular materials.Based on the platform of the finite element software ABAQUS,the subroutine of the 3D multi-mechanism model is implemented and then the seismic response analysis of a rockfill dam is possible by using this model.The seismic response analyses of the asphalt-concrete-faced rockfill dam are carried out by using the 3D multi-mechanism model and the equivalent viscoelastic model under a strong earthquake.The dynamic response characteristics of the dam and the effect of constitutive models on its response are investigated.The result shows that there exist some differences in the dynamic responses of the dam computed by using the two constitutive models.The 3D multi-mechanism model can accurately simulate the complex stress-strain relationships of rockfill materials under earthquake loading and the result obtained by it can reasonably reveal the nonlinear seismic response characteristics of the dam.