不同横缝接触与库水模型对拱坝动力反应的影响

Effects of contraction joint contact and reservoir models on dynamic response of arch dams

本文基于有限元非线性动接触模型,对拱坝横缝非线性动力响应进行研究,重点讨论:(1)拱坝横缝键槽对限制缝面切向滑移的不同程度约束对反应的影响;(2 )分别采用Westergard模型和不可压缩流体有限元模型考虑上游库水对坝面的动压力作用,比较分析了上述不同水库模型对拱坝在地震作用下横缝开度响应分布的影响。计算结果表明:(1)考虑键槽对横缝两侧施加完全切向约束条件对降低拱坝两岸的横缝开度幅值有重要的意义;(2 )相比流体有限元模型,基于Westergaard动水压力公式计算得靠近两岸坝肩部位横缝开度响应有一定程度偏大。

Using the finite element method, two aspects of nonlinear dynamic response of contraction joint opening in arch dams are studied: (1) influence of different shear constraint of key-slots on joint opening; (2) comparison of dynamic reservoir pressure on the dam computed with the Westergaard formulation and 3D fluid FEM model. Computation results show that: (1) significant reduction of joint opening near the dam abutments is observed by the model under complete shear constraints of keyslots in joints; (2) comparing with the FEM model, the Westergaard formulation exaggerates the joint opening near the abutment region, which are also confirmed by the previous experimental results[7].