三峡电站发电厂房动力特性与低水头振动问题研究

Study on dynamic characteristics and vibration of Three Gorges Powerhouse under low water head

本文对三峡电站发电厂房包括整个流道、网架、各种廊道在内的三维结构严格按照设计尺寸进行了比较真实的模拟,并采用有限元法对其结构进行了动力特性分析。在此基础上,根据VGS模型试验提供的6个测点数据,对整个流道内的脉动荷载作出合理假定,求得三峡发电厂房在63m水头运行时的动力响应。分析表明,对于复杂的厂房结构和复杂的脉动荷载,仅仅从共振的角度难以评估厂房结构的振动,而必须通过施加各种动力荷载求出厂房结构的振动响应,再在此基础上作出定量评估。

The paper built an actual three-dimensional structure model of Three Gorges Powerhouse according to the structure design dimension, including integral flow passages, grid structure and galleries and analyzed the dynamic characteristics of the powerhouse. Based on the measured data at 6 measuring points in a VGS model test and by applying a finite element model, the dynamic responses of Three Gorges Powerhouse under a water head of 63m were calculated under a reasonable hypothesis. The results showed that the evaluation of the vibration of powerhouse structure might be too coarse if only considering resonance, due to complexity of both the powerhouse structure and the pulsating load. The paper proposed an accurate method for evaluation by taking all dynamic loads into account to solve the dynamic responses of the powerhouse structure.