基于堆石体Wang-Wu亚塑性本构模型的混凝土面板坝应力变形分析

Stress and deformation analysis of CFRD using Wang-Wu hypoplastic constitutive model for rockfill

简要介绍了Wang-Wu亚塑性模型及其基于常规三轴试验的参数求取方法,指出模型参数应用于堆石料时存在的不足,建立了围压与参数的关系,提出了新的模型参数。在模型中考虑了主应力轴旋转问题,并推导了模量矩阵,编写了相应的有限元计算程序并应用于混凝土面板堆石坝的应力变形分析。与沈珠江双屈服面模型、邓肯E-B模型的计算结果相比,Wang-Wu亚塑性模型计算的堆石体沉降量与沈珠江双屈服面模型较为接近,而计算的蓄水期堆石体水平位移、面板应力与变形的大小和分布与邓肯E-B模型较为接近,表明本文的Wang-Wu亚塑性模型可以应用于面板堆石坝的应力变形分析。

A 3D FEM stress-deformation analysis of the concrete-faced rockfill dam（CFRD） using the Wang-Wu hypoplastic model is presented. First, we analyzed this model and its parameters determined using conventional triaxial test curves of rockfill materials, and found out the defect of this method when applied to such materials. Therefore, for rockfill materials used in the present study, relationships of the parameters versus confining pressure were established and the model parameters were modified by using these relationships. We have considered the rotation of principal stress axes and derived a modulus matrix of the equations used in the model. Then, the model along with its modified parameters was applied to the stress-deformation analysis of a CFRD using the 3D finite element method, and compared with the Duncan E-B model and Shen Zhujiang＇s double-yield surface model. The analysis showed that, of the main results calculated using the modified Wang-Wu model, the settlement of rockfill was close to that of Shen Zhujiang＇s model, and the rest fell around those of the Duncan model, such as the distribution of rockfill horizontal displacements and the stress and deformation of face slabs in storage period. Thus, this paper recommends the Wang-Wu model along with the new calculations of its parameters as presented above for analysis of CFRD.