不同动水压力质量阵对面板堆石坝动力特性的影响

Influence of Different Hydro dynamic Pressure Mass Matrix on Dynamic Characters of Concrete Facing Rockfill Dams

分别研究了附加质量集中阵和分布阵对百米高面板堆石坝作用有Ｅｌｃｅｎｔｒｏ地震波的动力反应以及幅频反应。认为集中阵相当于附加了较多的水体质量，与分布阵相比，坝水系统的频率偏低，给坝体的动力反应带来误差。集中阵隐含了坝体刚性的假设，这一点与Ｗｅｓｔｅｒｇａｒｄ简化公式相同，计算表明，集中阵与Ｗｅｓｔｅｒｇａｒｄ简化公式动力反应非常接近。因此，混凝土面板堆石坝动力分析，应采用分布的动水压力附加质量阵。

Now,in order to analysis the dynamic characters of concrete facing rockfill dams,the method of adding mass concentrated matrix of incompressible liquid model to the mass matrix of the dam is widely used.In fact,the mass matrix of the dam is a kind of distributed matrix.Till now,no research paper has discussed the calculation error of dynamic analysis when the concentrated matrix and the distributed matrix are used separately.This paper makes comparison on dynamic response and amplitude frequency response of Elcentro earthquake wave of 100 height concrete facing rockfill dam when the additional concentrated matrix and the distributed matrix is separately used.The study shows that the use of concentrated matrix is equal to adding more liquid mass on dam.As a result,compared with the method of using distributed matrix,the frequency of dam water system is lower and the use of concentrated matrix also brings calculation error to hydro dynamic analysis.The method of concentrated matrix and the Westergaard simplified equation both assume that the dam is made of rigid material.Moreover,the calculation results of the concentrated matrix method is closely similar to the result of Westergaard theory.Therefore,for the analysis of concrete facing rockfill dams,the additional mass distributed matrix of hydro dynamic pressure should be adopted,while for lower dams,the simplified equation of Westergaard should be used.It is unnecessary to adopt the concentrated matrix.