摘要
多元复合地基具有较好的技术效果和经济效益,但目前尚无比较成熟的分析方法供设计和检测使用。在桩、土顶部安装压力盒(计)和传感器,对三元和四元复合地基进行静载试验研究,结果表明:复合地基中桩、土应力随总荷载加大而增长,增长率与强度或相对刚度成正比;不同的桩、土应力增长率使桩体分担荷载比和桩土应力比随总荷载的变化规律有较大差别;两种复合地基的p-s曲线均呈缓变型,可用双曲线法模拟,便于建立破坏标准、获得切线模量;受压后,桩间土先达到塑性状态,大部分荷载增量由桩体承受,总效应是变形增大,故三元和四元复合地基宜按变形控制设计。本文结果可供进一步的理论研究和工程设计参考。
The multi-element composite foundation has the advantages of good te chnical and economic benefits,yet there are no mature analysis methods to follow in design and test at present.This paper has studied the three and four-elemen t composite foundation by the plate loading test,in which the pressure cells,pre ssure manometers and sensors are laid on the top of the piles and soil.The resul ts of study show that the stress on the top of piles and soil increase with the increase of total load,the increasing rate being directly proportional to the st rength or relative rigidity of piles and soil.The various increasing rates of pi les and soil stress versus load make great difference between the three and four-element composite foundation in the variation of the load sharing ratio and th e stress ratio versus load.The settlement of three and four-element composite f oundation varies gradually with pressure,and the p-s curve may be simulated by hyperbola curve so as to establish the failure criterion and obtain tangent modu lus.As the pressure increased,the inter-pile soil enters plastic state earlier than the piles,so the latter have to bear majority of the load,which make the se ttlement rise.The composite foundation should be designed according to settlemen t-control principle.The conclusions of this paper may serve as a reference for further theoretical research and engineering design.
出处
《建筑结构学报》
EI
CAS
CSCD
北大核心
2004年第5期124-128,i001,共6页
Journal of Building Structures
基金
湖南省教育厅科研项目(02C083)
