考虑SSI效应的核反应堆及地表地震反应

Seismic responses of a reactor structure and its adjacent ground surface considering the soil-structure interaction effect

以ABAQUS/Standard作为研究平台,将CPR1000型核反应堆结构简化为多质点集中质量模型,建立二维CPR1000型核岛反应堆结构与地基土相互作用模型,采用剪切变形梁单元模拟核反应堆结构,缩减积分平面单元模拟场地土,主要研究了SSI效应对于核反应堆结构及附近场地地表地震反应的影响,结果表明：SSI效应对核反应堆附近5~7倍基础半径范围场地地表的地震反应特性有显著影响,对地表峰加速度的影响超过15%,场地基本周期延长0.04 s以上;SSI效应使核反应堆安全壳结构及内部结构的基本周期由0.24 s、0.18 s依次增大为0.4 s、0.26 s,对核反应堆厂房结构节点的地震反应起着不利作用,使安全壳结构、内部结构的相对位移分别增大43%~76%和26%~59%,使两者的峰值加速度分别增大31%~65%和12%~75%。

Based on the ABAQUS/Standard software, the CPR1000 reactor structure was simplified to be a lumped mass parameter model with multi-particle system, then, an interaction system between a two-dimensional finite ele- ment model of the horizontal layer soil and a CPR1000 nuclear reactor structure was established. The reactor struc- ture and soil were simulated by a beam element including shear deformation effect and a reduced integration in 8- nodes plane element to study the effects of SSI on seismic responses on the reactor structure and its adjacent ground surface. The results show that, the SSI effects had greatly impact on seismic responses of the adjacent ground sur- face in five to seven times of the base dimension away from the base center of a reactor structure, the variation of peak acceleration of adjacent ground surface exceeded 15%, the predominant period of site was extended over 0.04 s. Meanwhile, due to the effects of SSI, the first fundamental period of the nuclear shield structure and its internal structure increased from 0.24 s and 0.16 s to 0.40 s and 0.26 s, respectively, the peak of relative displacement response of the nuclear shield structure and its internal structure was increased 43% ~ 76% and 26% ~ 59%, spectively, and the peak acceleration of the nuclear shield structure and its internal structure was increased 31% 65% and 12% -75%, respectively.