行波效应对大型水电站厂房地震响应的影响

Traveling wave effect on seismic response of large-scale hydropower house

为研究行波效应对平面尺寸较大的水电站厂房结构地震响应的影响,选取某实际厂房结构,建立三维有限元模型,借助ABAQUS有限元软件,采用振型分解时程分析法进行结构动力计算。调整Koyna水平地震波加速度峰值为0.246 g作为地震荷载。结果表明行波效应影响厂房结构位移响应主要体现在动位移峰值上,波速不大时可能使动位移峰值最大减小25%;对加速度响应峰值和响应时程影响都较明显,波速较小时可能使得结构加速度峰值滞后于地震加速度峰值出现;不考虑行波效应对厂房结构设计是偏安全的。如工程所在地地震波传播速度不大,可以适当考虑行波效应,以使结构设计更趋科学合理。

In order to study the traveling wave effect on seismic response of hydropower house structure of a large plane scale,a three-dimensional finite element model of an actual powerhouse structure was created.The dynamic structural analysis was carried out with ABAQUS software,using modal superposition time-historic analytical method.Koyna earthquake transverse ground acceleration was selected as seismic load,with its peak value adjusted to 0.246g.The result shows that traveling wave mainly affects the peak value concerning dynamic displacement of powerhouse structure.On condition that the wave speed is small,the peak of dynamic displacement may decrease by 25% at the most.With regard to acceleration,the effect on peak value and time history is significant.The peak structural acceleration may lag behind the peak seismic acceleration due to a small wave speed.Ignoring the traveling wave effect is safe to structural design of powerhouse.If the earthquake wave speed at the project site is small,the traveling wave effect could be taken into proper consideration to optimize structural design more rationally.