端承刚性桩复合地基增强体上刺入试验研究  

Model Tests Research on Pile Penetrating into Cushion in End-bearing Pile Composite Foundation

作　　者：张东刚[1] 张震[1] 闫明礼[1] 李涛[1] 李帅[1] 罗鹏飞[1] 

机构地区：[1]中国建筑科学研究院地基所,北京100013

出　　处：《建筑科学》2014年第5期52-57,共6页Building Science

基　　金：住房和城乡建设部软科学研究项目(20101602330740004)

摘　　要：对不同桩径、不同褥垫层厚度在不同荷载水平下桩顶向褥垫层刺入的变形特性进行模型试验,主要探讨复合地基褥垫层的变形机理和端承刚性桩与桩间土能否构成复合地基的问题。试验结果表明,在加荷初期,桩顶向褥垫层的刺入变形主要以褥垫层的压密变形和挤出变形为主;在加荷后期,桩顶向褥垫层的刺入变形主要以褥垫层的挤出变形和压碎变形为主;褥垫层可以有效地调节桩土相对变形,在实际工程中,端承刚性桩复合地基只要保证桩间土的压缩变形量小于桩顶向褥垫层的许可刺入变形量就可以保证桩间土与基础间不出现脱空现象,并给出了端承刚性桩复合地基褥垫层铺设厚度的建议值。本文的研究成果对端承刚性桩复合地基的推广应用具有一定的指导意义。The model tests are carried out to study the deformation characteristics of pile cap penetrating into cushion with different pile diameter and cushion thickness under different loading levels. Two aspects are discussed in this paper： the deformation mechanism of cushion in composite foundation and possibility of forming composite foundation by end bearing pile and soil between the piles. The test results show that the deformation of pile cap penetrating into cushion mainly contains compaction and extrusion deformation of cushion in the initial stage of loading and the deformation mainly contains extrusion compaction and crush deformation of cushion in the later stage of loading. The cushion can effectively adjust pile-soil relative deformation,and in the practical engineering, as long as the compression deformation of soil between piles is smaller than the allowable deformation of pile cap penetrating into cushion,it can guarantee that the soil between the piles and basis always contact in end-bearing pile composite foundation. Simultaneously,the recommended value of cushion thickness is given. The research results have certain guiding significance for the application of end-bearing pile composite foundation.

关 键 词：复合地基 端承刚性桩 褥垫层 刺入效应 

分 类 号：TU473.1[建筑科学—结构工程]