考虑桩刚度的桩筏基础设计  

Design of pile-raft foundation considering pile stiffness

作　　者：杨宁 戴柳丝 YANG Ning;DAI Liusi(Architectural Design&Research Institute of Tongji University(Group)Co.,Ltd.,Shanghai 200092,China;Department of Civil Engineering,School of Mechanics and Engineering Science,Shanghai University,Shanghai 200444,China)

机构地区：[1]同济大学建筑设计研究院(集团)有限公司,上海200092 [2]上海大学力学与工程科学学院土木工程系,上海200444

出　　处：《建筑结构》2021年第S02期1478-1482,共5页Building Structure

摘　　要：在超高层建筑的桩筏基础设计过程中,桩刚度的合理取值对桩基布置、筏板内力分布和挠度计算均至关重要。然而,由于桩周土地质条件的复杂性,桩刚度精确值很难得到。现有商业设计软件中桩土等效刚度的默认值大多基于以往工程经验,但考虑到项目工程的独特性,默认值往往与实际桩刚度存在较大的偏差。这种偏差可能导致设计方案与实际受力状态不符,使结构设计存在一定安全隐患。基于Mindlin解^([1,2]),重点分析单桩、群桩中桩刚度的合理取值。结合具体工程案例,分析不同桩刚度取值对桩筏基础计算结果的影响。同时,桩刚度的取值也会引起上部结构荷载在外框柱与核心筒之间的重新分配,在确定桩基布置方案时需考虑该因素的影响,在外框柱下预留一定的安全余量。The reasonable value of pile stiffness in pile-raft foundation of super high-rise building plays a decisive role in the layout of pile foundation,the internal force distribution and deflection in raft. Due to the complexity of the geological conditions around the pile, it is difficult to obtain accurate pile stiffness. The default values of the equivalent stiffness of pile-soil in existing commercial design software are mostly based on previous engineering experience. Considering the uniqueness of the project, the default pile stiffness may differ greatly from the actual pile stiffness, which may cause the design scheme to be inconsistent with the actual fore state and cause a certain safety hazard. Based on the Mindlin method^([1-2]),the paper focuses on the analysis of the reasonable value of the stiffness of single pile and pile group. Based on specific engineering cases, this paper analyzes the influence of different pile stiffness values on the calculation results of piled raft foundations. Meanwhile, the value of the pile stiffness will also cause the structure load to be redistributed between the outer frame column and the core tube. The influence of this factor should be considered when determining the pile foundation layout plan, and a certain safety margin should be reserved under the outer frame column.

关 键 词：桩筏基础 桩刚度 沉降计算 荷载分布 安全余量 

分 类 号：TU47[建筑科学—结构工程]