摘要
用沈珠江建议的双屈服面模型对洪家渡面板堆石坝进行了三维有限元分析 .计算中考虑到堆石材料的非线性和模拟运行过程 ,采用了逐级增量与不平衡力修正迭代相结合的算法 ,经与中点增量法的结果对比 ,表明该算法是有效的 .通过对堆石坝体在施工和逐级蓄水加载过程中的应力和变形分析 ,探讨了坝体中某些特定单元在运行过程中的主应力轴旋转状态 .对于坝体中部单元 ,在填筑过程中 ,主应力轴的偏转程度多在 10°以内 ;蓄水加载时偏转程度增加约2 0 % .而对于坝体上下游单元 ,主应力轴偏转则更加明显 .对τ σ3 平面、q p平面内的一些坝体单元的应力路径比较表明 ,不论是施工还是蓄水加载 ,q p
Three dimensional finite element analysis is performed using the selected material parameters to evaluate the stresses and deformations of Hongjiadu concrete faced rockfill dam during both construction and reservoir filling stages. The double yielding surface model developed by Shen is employed to characterize the inelastic deformation behavior of rockfill material. An incrementally iterative numerical technique is developed and incorporated into the computer program which is able to simulate the nonlinearity of the rockfill material in loading sequences during construction and reservoir filling. The computed results by the present method are found to be in good agreement with those achieved by the conventional mid point incremental method. In fact, the present method can gain a better understanding on the rotation of principal stress axes for certain elements in dam. It has been found that the rotations of the principal stress axes occur even for the elements beneath the axis of the dam. The rotation angle of principal stress axes is about 10° during the construction phase, increased by 20 percent during the reservoir impounding. In addition, the rotation angle of the principal stress axes for the elements located near the upstream and downstream sides become larger. By comparing the results of the loading paths plotted in τ σ 3 plane and in p q plane, it can be seen that the relations between the effective mean principal stress p and the deviatoric stress q can more reasonably describe the actual change of the loading paths for both construction and reservoir filling. In addition, the displacement and the stress of the concrete faced slab during the construction and the reservoir filling are discussed.
出处
《大连理工大学学报》
CAS
CSCD
北大核心
2000年第5期602-608,共7页
Journal of Dalian University of Technology
基金
国家自然科学基金!资助项目 (重点项目 5 963 92 5 0 )
关键词
非线性
弹塑性
面板堆石坝
有限元计算
rockfill dam
nonlinearity
jelasto plasticity
iterative method
stress path
