考虑土-结构相互作用下基岩深度对核反应堆厂房基础地震响应的影响

地震会对核电站安全造成影响。随着核电站的数量越来越多，有必要关注在地震下核电站的安全。核反应堆厂房是核电站重要的组成部分，研究其地震响应对核电站有着重要意义。基于直接法，考虑了3种不同场地(中硬土、软岩、硬岩)在地震下的塑性变形和土的滞回阻尼，使用FLAC3D对土-核反应堆厂房模型系统进行了三维建模。为了捕捉上部结构与下部岩石/土壤之间的分离与滑动，在核反应堆厂房基础与岩石/土壤表面设置接触面单元。上层结构以集总质量模型模拟，同时考虑土-结构相互作用下基岩深度对核反应堆厂房基础地震响应的影响，最终得到核反应堆厂房结构杆件的加速度反应谱、剪力、基础的摇动和基础不均匀沉降以及侧向位移。结果表明：在中硬土场地中，位移、剪切力随基岩深度的增大而减小；在硬岩场地中，位移和剪切力响应的规律呈相反趋势；在软岩场地中，上部结构响应的规律较为复杂。对于基础摇动和基础不均匀沉降，在中硬土场地中，其呈现的规律随基岩深度增大而减小；在软岩和硬岩场地中，并无明显规律。基础不均匀沉降可直接反映结构的破坏情况。中硬土场地下基础不均匀沉降超过容许值，所以基础不均匀沉降对核反应堆厂房的影响不容忽视，这对核电站的安全设计...

Influence of bedrock depth on the seismic response of a nuclear reactor building foundation considering soil structure interaction

Earthquakes events can impact on safety of nuclear power plants. With the increasing number of nuclear power plants, the necessity of seismic safety of nuclear power plants becomes higher than ever before. Nuclear reactor building is an important part of nuclear power plant, so the importance to understand its seismic response is critical.Adopting the direct method, this paper utilized FLAC3D to model the soil-nuclear reactor building three-dimensionally on three different site conditions(medium hard soil, soft rock and hard rock).To capture the separation and sliding between the superstructure and the rock/soil deposit, Interface elements were set between the foundation of the nuclear reactor building and the rock/soil surface. The superstructure was simulated by lumped mass model, and the influence of bedrock depth on the seismic response of nuclear reactor building was investigated considering soil structure interaction. Finally, the acceleration response spectrum, shear force, foundation rocking, foundation differential settlement and lateral displacement of the structural members of the nuclear reactor building were obtained. The results show that the displacement and shear force decreased with the increasein bedrock depth in medium hard soil; In the hard rock site, the trends tended to be opposite; However, under the condition of soft rock site, the response of superstructure is more complex. For the foundation rocking and differential settlement, in the medium hard soil site, the reactions decreased with the increase in bedrock depth; In soft and hard rock sites, there is no obvious trend. The differential settlement of foundation can directly reflect the damage of structure. The results show that the differential settlement of foundation in medium hard soil site exceeded the allowable value, so the influence of differential settlement of foundation on nuclear reactor building can not be ignored, which is important for the safety design of nuclear power plant.