摘要
在常规的空间结构设计中,通常把上部结构和基础分开独立计算,这种做法会导致空间结构边界条件假设与基础实际设计方案提供的支承刚度不符.另外,设计人员普遍采用包络设计方法以简化复杂荷载工况下的结构设计问题,对于短柱的基础而言,这种简化往往放大了对基础的承载力要求.在现有的设计水平下,基础优化的潜力未能得到充分发挥.本文提出一种基于空间结构与基础协同分析的优化方法,该方法通过将空间结构与基础的优化分析纳入每一次迭代计算中,减少不正确的边界条件假设给结构受力分析带来的误差;同时基础设计以上部结构各组合工况支座反力计算结果为依据,以避免因采用最不利荷载效应组合而带来不合理的承载力冗余.以三心圆张弦桁架为例的优化结果表明,该优化方法能显著降低基础材料用量,取得较为理想的经济效益.
In conventional spatial structure design,superstructure and foundation are designed independently,resulting in the inconsistency between the assumption of boundary conditions of spatial structure and the support stiffness provided by foundation.In addition,designers generally apply envelope design to simplify the structural design work with complex load combination conditions.For short-column-supported foundations,this simplification often exaggerates the bearing capacity requirements of a foundation.With current design level,the potential of foundation optimization has not been fully realized.This paper proposes an optimal design method for collaborative analysis of large-span spatial structure and foundation.This method reduces errors caused by incorrect assumptions of boundary conditions,by considering optimal analysis of both spatial structure and foundation through iterative calculation.The foundation design is based on calculation results of support reaction forces of every combination,so as to avoid unreasonable bearing capacity redundancy due to the application of envelope design.As an application example,optimization results of a three-centered cylindrical chord-tension truss structure show that the optimization method can greatly reduce material consumption of foundations and achieve ideal economic benefits.
作者
陈东琳
张宜杰
龚景海
CHEN Dong-lin;ZHANG Yi-jie;GONG Jing-hai(Department of Civil Engineering,Shanghai Jiao Tong University,Shanghai 200240,China;Shanghai Key Laboratory for Digital Maintenance of Buildings and Infrastructure,Shanghai Jiao Tong University,Shanghai 200240,China)
出处
《空间结构》
CSCD
北大核心
2024年第2期61-69,共9页
Spatial Structures
关键词
大跨空间结构
基础
荷载组合工况
协同分析
优化设计
large-span spatial structure
foundation
load combination
collaborative analysis
optimization design
