国家体育场桩基工程的分析与实践  

Evaluation and engineering Practice of the pile foundation for the National Stadium of China

作　　者：张在明[1] 沈小克[1] 周宏磊[1] 唐建华[1] 杨素春[1] 韩煊[1] 

机构地区：[1]北京市勘察设计研究院有限公司,北京100038

出　　处：《土木工程学报》2009年第1期66-75,共10页China Civil Engineering Journal

摘　　要：国家体育场工程规模宏大,岩土工程条件复杂,基桩数量大,桩长、桩径变化大,桩基持力层变化显著,组合柱基础荷载高,对岩土工程工作形成极大的挑战。首先概述本工程的工程地质、水文地质条件,采用统计方法研究后压浆对桩基承载力的影响,利用腔体扩张理论研究桩端注浆压力控制数据。针对基桩载荷试验数据,研究后压浆桩的荷载传递规律与承载特性。最后,介绍考虑桩-土-基础(承台)的变形协调的沉降分析方法PSFIA在本工程中的应用。由于考虑了荷载分布、地基土层变化、基础刚度调整、桩间土荷载分担、桩端刺入变形、群桩效应等诸多因素的影响,因此成功地预测了桩基沉降和筏板内力的分布。在精确勘察的基础上,通过上述系列的工程类比、理论研究、现场载荷试验、协同作用分析等深入工作,使国家体育场桩基工程得以顺利实施。Construction of the foundation for the National Stadium of China, also known as the Bird＇s Nest, encountered sophisticated and challenging geotechnical problems due to the significant variations in composition and distribution of the bearing strata of the large number of piles of various types and the extraordinarily large loads from the giant composite columns. The geological and hydrogeological conditions of the site are briefly introduced first, followed by a statistical study of the post-grouting bearing capacity of the piles and a theoretical analysis of the grouting pressure using the cavity-expansion theory. Based on the comprehensive in-situ static load tests, the load transfer pattern and the post-grouting bearing capacity of the piles are discussed in detail. Application of a pile-raft-soil interaction analysis （PSFIA） method is introduced to predict the settlement of the structure. Because many important factors, such as load distribution, non-uniform geological condition, structural stiffness, bearing capacity of soil, punching deformation of pile tip and group pile effects, are all considered in the analysis, good agreement between the predicted and measured settlements is achieved. This case study shows that based on efficient site investigation, integrated engineering judgment with theoretical studies, in-situ tests and interaction analyses may lead to cost-effective foundation design and construction.

关 键 词：国家体育场 桩基 后压浆桩 沉降 

分 类 号：TU473.1[建筑科学—结构工程]