重力坝纵缝梯形键槽的静动工作性态研究

Study on Static and Dynamic Working Behaviors of Trapezoidal Shear Keys of Gravity Dam

基于约束函数法的热应力耦合接触模型对重力坝纵缝梯形键槽的非线性接触进行模拟。应用粘结单元实现键槽精细网格与坝体网格的衔接,从而细致地模拟了梯形键槽的实际布置方式和构造形式。采用动力分析软件ADINA对某带梯形键槽纵缝的重力坝进行了非线性分析,研究了纵缝梯形键槽随季节温度变化的变形、开度变化规律,地震作用下纵缝的开度和键槽破坏模式,以及纵缝键槽的初始间隙对大坝动力响应的影响。结果表明,梯形键槽沿上斜边随季节温度变化的错动导致纵缝张开,进而会增大重力坝在地震中的动力响应。

The thermomechanical contact model for the trapezoidal shear keys at the longitudinal joints of gravity dams based on the constraint function method was investigated here .The glue mesh was applied to implement the multi-scale modeling .The finite element model for the trapezoidal shear keys are established on the basis of their real construction and arrangement ,and the dam-foundation-reservoir interaction with the longitudinal joints of trapezoidal shear keys was analyzed by ADINA .The contact deformation with seasonal variation as well as the opening variation and failure mode of the shear keys under seismic load were investigated and the effects of the initial opening of the shear keys on the seismic resistance of gravity dam were also discussed .The results suggest that the dislocation with seasonal variation along the up -per bevel-edge of the trapezoidal shear keys would cause the opening of the longitudinal joints ,which would lead to the increase of the dynamic response of the gravity dam under seismic loading .