地震作用下核电站环行吊车动力响应的模型实验研究

基于量纲分析理论,提出地震作用下环行吊车缩尺模型动力响应的相似准则,确定核环吊原型和实验模型之间动力响应的相似关系。根据抗震规范要求和相似准则,采用El Centro 1979地震波作为实验台地震输入,对振动台震动输入进行调幅处理,水平地震输入幅值为0.3g,竖向地震输入幅值为0.2g,地震输入的时间缩尺为4。核环吊抗震实验结果表明,与实验台地震输入峰值相对比,吊车大梁跨中水平加速度峰值增加了56.0%,跨中竖向的加速度峰值增加了119.0%;环轨水平加速度峰值增加了66.7%,环轨竖向的加速度峰值增加了43.5%。研究表明,当水平地震波的输入方向与吊车大梁轴线相垂直时,吊车大梁跨中水平加速度峰值最大;当水平地震波的输入方向与吊车大梁轴线相平行时,环轨的水平加速度峰值最大;环轨的垂直加速度峰值受水平地震波的输入方向影响不显著。在地震荷载作用下,核环吊没有发生跳轨现象。

Scaled Model Tests on the Dynamic Response of Polar Cranesin Nuclear Power Plants under Seismic Action

Based on the dimensional analysis theory, in this paper, we propose a similarity criterion for the dynamic response of a scaled polar crane in a nuclear power plant under earthquake action. We determine the similarity relation of dynamic responses between a prototype nuclear polar crane and the scaled model. As the shaking table input, we used the El Centro wave, and based on the seismic code requirement and similarity criterion, we scaled the input amplitude to 0.3g and 0.2g in the horizontal and vertical directions, respectively, with a time scale of 4. Comparing the maximum accelerations of the shaking table inputs, the scaled model experiment results showed that the peak acceleration in the middle-span of the crane girder increases 56.0% in the horizontal direction and 119.0% in the vertical direction, and the peak acceleration in the polar girder increases 66.7% in the horizontal direction and 43.5% in the vertical direction. These experimental results indicate that when the direction of the earthquake input is vertical to a crane girder, the horizontal peak acceleration in the middle span of the crane girder is maximum. When the earthquake input is parallel to the crane girder, the horizontal peak acceleration in the polar girder is maximum. The influence of the direction of the earthquake input on the vertical peak acceleration in polar girder is not significant. Under earthquake loading, the polar crane experiences no derailing phenomenon.