（苏州九城都市建筑设计有限公司， 苏州 215123）

［摘要］苏州中心广场是一个大型商业综合体项目，由多幢超高层塔楼、裙楼及大底盘组成。在南区桩基设计中，参考周边项目桩基设计资料，结合本工程实际情况，对桩的类型和持力层进行了合理选择。试桩结果表明，采用后注浆既可提高钻孔灌注桩的成桩质量和单桩承载力特征值，又可减少基础沉降。采用桩基变刚度调平设计，即考虑上部结构形式、荷载和地层分布以及相互作用效应，通过调整桩径、桩长、桩距等改变桩基支承刚度分布，以控制建筑物的差异沉降。沉降实测数据表明，变刚度调平可有效减小塔楼与裙房及地下室之间的差异沉降。通过考虑最低水位和承台效应的有利作用及对上部荷载、桩配筋进行细化、优化等措施，可减少裙房及地下室的桩数和桩配筋，节约桩基造价约3 856-4万元。

［关键词］灌注桩基； 后注浆； 变刚度调平设计； 差异沉降； 优化设计

中图分类号：TU473文献标识码：A文章编号：1002-848X(2018)18-0101-06

Design and optimization of pile foundation in the southern district of Suzhou  Central Square project

Zhong Jianmin

(Suzhou Nine Urban Architectural Design Co.,  Ltd.， Suzhou 215123， China)

Abstract:Suzhou Central Square is a large-scale commercial complex project composed of several super high-rise towers, podiums and large chassis. In the design of pile foundation in the southern district，the type of pile and the bearing stratum were selected reasonably according to the information of pile foundation design of the surrounding projects  and the actual situation of this project. The pile test results show that  adopting post grouting technique can improve the pile forming quality and the bearing capacity of the single pile and reduce the foundation settlement. Optimized design of foundation stiffness to reduce differential settlement of pile foundation, namely taking into account the form of superstructure, load, stratum distribution and their interaction effect, was adopted to control the differential settlement of buildings by adjusting pile diameter, pile length and pile distance to change support stiffness distribution of pile foundation.The measured data of settlement show that this optimization design can effectively reduce the different settlement between the tower and the podium and basement subsidence. By considering the effects of the minimum water level and the favorable capping effect，and the measures for the refinement and optimization of the upper load and the pile reinforcement，the piles and pile foundation reinforcement of the podium and basement can be reduced. The cost of the pile foundation is saved by about 38-564 million yuan.

Keywords:cast-in-situ pile foundation; post grouting; optimized design of foundation stiffness to reduce differential settlement; different settlement; optimization design

作者简介：钟建敏，硕士，高级工程师，一级注册结构工程师，一级注册土木工程师（岩土），Email：82503755@qq.com。