整体大面积筏形基础试验与设计研究

Experimental Study and Design of Large-area Raft Foundation

目前城市建设中,高层、超高层建筑越来越多,主裙楼结构也越来越普遍,成为城市建筑的主要结构形式,其地基基础设计比常规的中小建筑、单体建筑更加复杂。通过开展一系列的主裙楼结构与地基基础共同作用的模型试验、数值分析、工程实测等研究,总结出主裙楼结构的地基反力、变形分布特征,提出了主裙楼结构的变形控制标准。工程实践表明:主裙楼结构随着主楼外裙房跨数的增加,筏形基础的变形特征由刚性、半刚性向柔性转化;裙房结构和一定刚度的筏形基础可以起到扩散主楼荷载及调整差异沉降的作用;通过合理的设计,当主裙楼的差异沉降控制在规范许可的范围内时,可以实现主裙楼结构的整体连接。当主裙楼差异沉降不能满足规范要求时,可以设置沉降后浇带,并应合理确定设置位置和封闭时间。

Nowadays there are more and more high-rise buildings and buildings with annex,and the foundation design of this kind of buildings are more complicated than that of multi-storey buildings and single buildings. A series of model tests,numerical analysis and actual measurement were carried out by Foundation Engineering Institute,China Academy of Building Research,contact stress and deformation behavior of buildings with annex were summarized,and the deformation control standard was put forward for buildings with annex. It is demonstrated that with the outstretching of annex the deformation characteristics of raft foundation vary from rigidity,semi-rigidity and gradually to flexibility. The annex and raft foundation,to certain extent,can play a role of spreading the load from main building to annex and adjusting differential settlement. By means of rational design,integral raft connection between main building and annex can be achieved when their differential settlement can be controlled within code allowance,otherwise the post-poured strip must be set,and the location and pouring time should be confirmed rationally.