汽机弹簧隔振基础地震反应及弹簧变形分析

Seismic Response of Spring Vibration-isolated Foundation for Turbo-generators and Associated Spring Deformation Analysis

摘要:

采用SeismoStruct软件建立有限元模型对某汽轮发电机组弹簧隔振基础进行时程分析，研究弹簧隔振基础的频率振型和地震响应、层间变形、弹簧变形等特性。研究表明，弹簧隔振基础的自振频率较低，竖向自振频率远离机组工作扰频；弹簧隔振装置能够在地震作用时减小台板加速度反应，并根据刚度重新分配水平地震作用，充分发挥立柱的抗震能力。结果表明基础设计符合《建筑抗震设计规范》标准，达到了弹簧隔振抗震的目标，基础设计合理、安全可靠。SeismoStrcut作为有限元分析软件，对汽机基础的模拟能够达到工程需要。

Abstract:

A finite element model of the spring vibration-isolated foundation for a turbo-generator was established by using SeismoStruct for time history analysis. The frequency, vibration mode, seismic responses, inter-story deformation, and spring deformation of the foundation were analyzed. Results show that the natural frequencies of the spring vibration-isolated foundation are lower than those of common ones and the vertical frequencies are far from the working disturbance frequency of the units. The spring vibration-isolated device can reduce the acceleration response of the bedplate under an earthquake and redistribute the horizontal earthquake action according to the stiffness, thus ensuring the maximum seismic capacity of the column. A numerical simulation shows that the foundation design meets the standard of the Code for Seismic Design of Buildings in China and achieves the goal of spring vibration isolation. Overall, the foundation design is reasonable, safe, and reliable.