【摘要】 为克服传统接触面单元方法中非线性计算收敛困难的问题,首先提出一种新的考虑基础提离的方法——弹簧单元法,即在结构基础与下卧地基土之间设置弹簧单元考虑土-结构相互作用,再通过设置弹簧单元的荷载-变形曲线(即F-D曲线)使弹簧单元只能提供压力,而不能提供拉力考虑结构基础的提离效应;然后基于某简化核电站结构计,对比分析两种方法的计算效率及结构地震响应。对比分析表明:1弹簧单元法在计算效率上显著优于传统的接触面单元方法;2由于两种方法得到的结构响应差异较小,且弹簧单元法更合理,因而推荐采用文中提出的弹簧单元法考虑基础的提离效应。本文的研究成果可为核电站结构抗震设计分析方法的完善提供参考。更多还原

【Abstract】 A new method to consider foundation uplift was suggested to overcome the difficulty of nonlinear calculation convergence problem in traditional contact interface element method. Spring elements were added between the foundation and soil in the newly suggested method to simulate soil structure interaction, and then the spring elements can provide pressure only and tensile forces are not allowed by setting the spring’s load-deformation curve(F-D curve) to consider the foundation uplift effect. Based on a simplified nuclear power plant structure, the computational efficiency and structure seismic responses obtained by the two methods are analyzed and compared. The analyzed and compared results showed that: 1 Spring element method is significantly superior to traditional contact interface element in computational efficiency; 2 Spring element method is suggested to be used to consider structure foundation uplift effect because the differences between the structure seismic responses obtained by the two methods were small, and the spring element method is more rational. The research results in the paper can provide references to improve the seismic response analysis method for nuclear power plant structure.更多还原