(悉地（北京）国际设计顾问有限公司， 上海 200235)

［摘要］考虑基础刚度的影响对超长结构的温度作用分析非常关键，基础刚度宜以实测刚度为依据，进行合理取值。以某大型步行天桥的温度作用分析为例，根据桩的水平和竖向静载试验，推算了基础的实际刚度，并全面比较了固定支座约束、线性弹簧支座约束、非线性弹簧支座约束时结构的内力状态。结果表明，固定支座约束过分限制了类似核心筒这样刚度很大的构件的变形，改变了结构的温度内力分布状态，与实际情况有很大偏差。讨论了基础刚度取值中一些假定的局限性，对基础刚度的合理取值给出具体建议。

［关键词］超长结构; 基础刚度; 温度作用; 水平刚度; 竖向刚度; 桩基

中图分类号：TU318.1，TU398.1       文献标识码：A       文章编号：1002-848X(2014)12-0044-04

Effect of foundation stiffness on temperature analysis of a pedestrian bridge

Yang Bifeng, Zhang Yu, Gu Li

 (CCDI Group, Shanghai 200235, China)

Abstract:Foundation stiffness is a critical factor in overlong structure temperature action analysis, which should be obtained by field measurement. According to the temperature action analysis of some overlong pedestrian bridge, the actual foundation stiffness can be calculated by the lateral and vertical load test of piles. Different internal force distributions of fixed supports, linear spring supports and nonlinear spring supports were compared. The results show that the fixed supports have brought excessive constrain to some high stiffness structural members, such as concrete core shear wall, and have changed the configurations of temperature internal forces, which are quite different from the actual conditions. The limitations of some assumptions about foundation stiffness were discussed. The specific suggestions on the proper value of foundation stiffness were given.

Keywords: overlong structure; foundation stiffness; temperature action; lateral stiffness; vertical stiffness; pile

作者简介：杨必峰，硕士，一级注册结构工程师，高级工程师，Email：yang.bifeng@ccdi.com.cn。