核电厂预应力混凝土安全壳结构抗震裕度评估

为了探究不同强度地震作用下核安全壳结构发生开裂的失效概率,评估结构抗震裕度,对其进行静力弹塑性分析,确定发生开裂破坏时的顶点水平位移损伤指标.选取15条地震动记录对结构进行增量动力分析,对结果进行线性回归分析,得到结构地震概率需求模型及地震易损性曲线.利用对数正态地震易损性分析模型进行结构抗震裕度分析,确定了结构高置信度低失效概率值为0. 254g,该值为安全停堆地震水平的1. 27倍.结果表明,核安全壳结构具有良好的抗开裂能力,地震易损性分析可以较好地反应其发生开裂破坏的概率与地震动强度水平之间的关系.

Seismic margin evaluation of prestressed concrete containment vessel structure in nuclear power plant

In order to explore the cracking failure probability of nuclear containment vessel structure under different intensity earthquakes and evaluate the seismic margin of structure, the static elasto-plastic analysis was performed to determine the horizontal displacement damage index at vertex during the cracking failure. The incremental dynamic analysis of structure was performed through selecting fifteen earthquake records, and the linear regression analysis was carried out for the results. Furthermore, the seismic probabilistic demand models and seismic fragility curves of structure were obtained. The seismic margin analysis of structure was conducted with the lognormal seismic fragility analysis model. In addition, the high confidence and low failure probability value of structure was determined as 0.254g, which was 1.27 times as that of the safe shutdown earthquake level. The results show that the nuclear containment vessel structure has good cracking resistance. The seismic fragility analysis can better reflect the relationship between the cracking probability of nuclear containment vessel structure and earthquake intensity level.