软土地基条件下基于UPFs的核电厂房结构地震响应分析

Seismic response analysis of nuclear power plant structure based on upfs under soft soil foundation condition

等价线性法是求解土体动力非线性特征以及分析评价层状土场地条件下核电结构地震动响应的重要方法之一。通过研究等价线性法和有限元的基本理论,开发了一种可在时域中实现的三维等价线性单元,并利用二次开发工具UPFs将其嵌入至ANSYS中。以某建立在层状土场地条件上的内陆核电厂为对象,在考虑土体非线性的前提下,进行原状土厂址条件下的结构-地基相互作用分析,并与不考虑土体非线性的计算结果进行对比分析。结果表明,对建设在层状土场地条件上的核电厂房进行抗震安全性评价以及地基适应性分析时,考虑土体动力非线性特征是十分必要的。

Equivalent linearization technique is one of the important techniques to solve nonlinear characteristics of soil and analysis appraisal the seismic response of nuclear power plant under layered soil site condition.In this paper,the basic theory of equivalent linearization technique and the finite element theory is studied,a 3-D equivalent linearization element is developed,which can be solved in 3-D and time-domain,and the element is embedded in ANSYS with UPFs.Based on an inland nuclear power plant based on the conditions of a layered soil site,considering the nonlinearity of soil,the structure soil interaction(SSI)under the condition of original soil site is analyzed,and compared with the calculation results without considering the nonlinearity of the soil.The results show that it is necessary to consider the nonlinear characteristics of the soil when considering the seismic safety evaluation and the foundation adaptability analysis of the nuclear power plant on the condition of the layered soil site.