泳池式供热堆高耸子结构三维隔震方案分析

Analysis of three-dimensional Isolation scheme for high-rise substructure of swimming pool heating reactor

针对泳池式供热堆核岛厂房内部高耸子结构,提出了一种新型三维隔震方案。采用SAP2000有限元软件,系统分析了三维隔震方案的加速度时程、楼层反应谱和隔震层相对位移,并将三维隔震方案结果与抗震方案进行了对比。结果表明:(1)三维隔震方案在水平X、Y方向和竖向方向均有显著的隔震效果,且隔震层在设计基准地震下的三向相对位移均小于300 mm;(2)三维隔震方案在自重下的竖向变形大于地震工况,在方案设计时要综合考虑减震效果和隔震装置的竖向承载能力之间的平衡;(3)三维隔震方案的竖向刚度远小于水平隔震方案和抗震方案,其在地震下会出现较为明显的绕水平轴的刚体转动,会导致结构加速度时程峰值、反应谱峰值加速度和零周期加速度在水平向呈现沙漏型的数值变化趋势,在方案设计中要适当增大隔震装置的竖向刚度并减小结构的倾覆弯矩,以抑制刚体转动模态的影响。

A new three dimensional isolation scheme is proposed for the high-rise substructure of the swimming pool heating reactor nuclear island building.Using SAP2000 finite element software,the acceleration time history,floor response spectrum and relative displacement of isolation floor of the three-dimensional isolation scheme are analyzed systematically,and the results of the three-dimensional isolation scheme are compared with those of the seismic scheme.The results show that:①the three dimensional isolation scheme has significant isolation effect in the horizontal X,Y and vertical directions,and the three directional relative displacement of the isolation layer under the design reference earthquake is less than 300mm;②The vertical deformation of the three-dimensional isolation scheme under dead weight is larger than that under seismic condition.The balance between the damping effect and the vertical bearing capacity of the isolation device should be considered comprehensively in the design of the scheme;③The vertical stiffness of the three-dimensional isolation scheme is much less than that of the horizontal isolation scheme and the seismic scheme.The rigid body will rotate around the horizontal axis obviously under the earthquake,which will lead to the hourglass numerical variation trend of the peak duration,peak response spectrum and zero periodic acceleration of the structure acceleration.In the design of the scheme,the vertical stiffness of the isolation device should be increased appropriately and the overturning moment of the structure should be reduced to restrain the influence of the rotation mode of the rigid body.