（西安建筑科技大学建筑设计研究院， 西安 710055）

［摘要］西安高新NEWORLD的3#办公楼为8度区超B级高度的超高层结构，采用普通混凝土框架-核心筒结构体系，结构高度169-7m，建筑高度190-95m，其东西两侧与1 跨3层的裙房连为一体，采用钻孔灌注桩桩筏基础。在基础设计中，采用变刚度调平设计对桩筏进行优化，通过不同桩径桩基成本控制比较，选择合理的布桩平面和筏板厚度，同时根据试桩结果优化桩长；对主楼采用钻孔灌注桩的桩基，裙房和纯地下室采用天然地基，根据外力特点和预期的差异沉降，选择裙房和纯地下室合理的筏板厚度；同时分析主楼灌注桩桩底、桩侧后注浆对桩基承载力的影响。为控制主楼与裙房的差异沉降，在主楼与裙房之间设置沉降后浇带。通过计算设置后浇带前后的差异沉降并加以对比分析，可以有效控制主楼自身及主楼与裙房的差异沉降，改善了筏板的内力并降低了上部结构的次内力，从而减少了桩基础工程量与筏板材料的消耗。

 

［关键词］桩筏基础； 变刚度调平设计； 桩长优化； 后注浆钻孔灌注桩； 差异沉降； 沉降后浇带

 

中图分类号：TU202文献标识码：A文章编号：1002-848X(2018)01-0083-05

 

Pile raft foundation design of No. 3 super high-rise building of Gaoxin NEWORLD project

 

Li Bo, Zheng Yue, Liu Xiaofan

 

(Architectural Design and Research Institute, Xi′an University of Architecture and Technology， Xi′an 710055, China)

 

Abstract:The No.3 building of Gaoxin NEWORLD project in Xi′an is a  super B-grade high-rise building in 8 degree area. It adopts frame-corewall structure, with structural height of 169-7 m and building height of 190.25m. The building is connected to a single-span three-story podium on its east and west sides. It adopts cast-in-place bored pile raft foundation. In the foundation design, variable stiffness leveling design was carried out to optimize the pile raft foundation for balance settlement, and proper pile lay-out and raft foundation thickness were selected through comparing the cost control of pile foundations of different pile diameters. Meanwhile, the pile length was optimized based on the pile trial result. Cast-in-place bored pile raft foundation was applied to the main building, and natural foundation was applied to the podium and basement. According to the external forces characteristics and expected differential settlement, reasonable raft thickness of the podium and pure basement were chosen. At the same time, the impact of bearing capacity of pile foundation for post-grouting on bottom and lateral sides of cast-in-situ piles of the main building was analyzed. In order to control the differential settlement between the main building and the podium, the post-pouring settlement belt was set between the main building and the podium. By calculating and comparing the differential settlements before and after setting post-pouring settlement belt, the differential settlement of the main building and the differential settlement between main building and the podium can be effectively controlled to improve the internal force of the raft and reduce the secondary internal force of the superstructure, thus reducing the pile foundation engineering quantity and raft material consumption.

 

Keywords:pile raft foundation; variable rigidity leveling design; pile length optimization; post-grouting cast-in-place bored pile; differential settlement; post-pouring settlement belt

 

 

作者简介：李勃，本科，工程师，一级注册结构工程师，Email:523607329@qq.com。