摘要
深厚软土地基上大面积堆载引起的沉降危害是建筑结构中出现的主要问题之一。然而,当前针对大面积堆载条件下地基沉降预测的规范方法仍为基于较小面积基础的沉降观测资料推算得到。由于大、小面积分别堆载时导致的下部地基压缩层深度的不同,在预测大面积堆载下地基基础沉降时,当前规范方法的适用性有待验证。为此,针对上海某物流仓库的沉降灾害开展实例分析,在此基础上,对当前我国GB 50007—2011《建筑地基基础设计规范》与上海规范DGJ 08-11—2010《地基基础设计规范》中地基沉降计算方法部分展开讨论。结果表明:地基过大沉降导致地坪板等平整度严重降低以及地坪板开裂等问题,极大危害了建筑结构的安全与正常使用;规范方法预测的沉降值远低于该工程的沉降监测值;不应取代表性分仓单元或局部面积进行沉降预测,而应取整体建模分析;上海规范的沉降计算经验系数取值不甚合理,导致随计算压缩层深度增加,最终沉降反而变小的不合理结果。
The excessive settlement is one of the major issues usually encountered by structures constructed on the ground consisting of very thick soft clayey soils subject to large area loadings. However, current design methods recommended by Chinese codes were proposed based on the observations on the settlements of foundations with smaller area loadings. Because the compression depth of ground soil induced by large area loading notably differs from that induced by small area loading, the current code methods require validation for the application to the settlement prediction of the ground under a large area loading. Therefore, a detailed case study was first conducted in this paper on the settlement damage of a logistics warehouse in Shanghai. And the extensive discussions on GB 50007—2011 ‘Code for design of building foundation’ and DGJ 08-11—2010 ‘Shanghai foundation design code’ were conducted. The main research findings show that the excessive settlements of ground soil change the flatness seriously and lead to obvious cracks of the ground floor, which affect the serviceability and safety of the structure. The settlements predicted by Chinese code-specified methods are far less than the monitoring values of the structure. The analyses based on the representative elementary or local loading area should be replaced by that based on the model considering the whole loading area. The empirical coefficient proposed by Shanghai code adopts unreasonable values, therefore, the calculated settlement decreases with increasing the compression depth of ground soil, which is unreasonable.
作者
李卫超
朱碧堂
张俊峰
杨敏
LI Weichao;ZHU Bitang;ZHANG Junfeng;YANG Min(College of Civil Engineering,Tongji University,Shanghai 200092,China;Engineering Research&Development Centre for Underground Technology of Jiangxi Province,Nanchang 330013,China;Shanghai Tongji Qimstar Technology Co.,Ltd.,Shanghai 200092,China)
出处
《建筑结构学报》
EI
CAS
CSCD
北大核心
2021年第5期187-194,共8页
Journal of Building Structures
基金
国家自然科学基金项目(41572258,41877236,41972291)
中央高校基本科研业务费专项(22120180093)。
关键词
物流仓库
大面积堆载
沉降预测
规范方法
logistics warehouse
large area loading
settlement prediction
code method
