高承台钢管桩受压稳定性的试验研究和数值分析  

Test study and numerical analysis of stability of high-level cap steel tubular pile under compression loads

作　　者：贾强[1] 郑爱萍[1] 张鑫[1] 

机构地区：[1]山东建筑大学山东省建筑结构鉴定加固与改造重点实验室,济南250013

出　　处：《岩土力学》2011年第6期1736-1740,共5页Rock and Soil Mechanics

基　　金：住房与城乡建设部科技计划资助项目(No.2007-K6-13)

摘　　要：利用微型钢管桩进行基础托换是既有建筑物地下增层改造的有效方法。钢管桩的下端插入到混凝土桩头内,上端与托换承台相连,桩四周的土方开挖后稳定性降低,其受压极限承载力无法按现行规范求出。分别用1:2模型试验和非线性屈曲数值分析的方法得到了钢管桩顶部受压的应力分布和极限承载力,并进一步确定出其计算长度系数和受压稳定性系数。用模型试验求得钢管桩受压稳定性的计算长度系数为0.616,数值分析的结果为0.683,此时钢管处于底端固定、顶端铰接的约束状态。用数值分析得到的钢管桩受压极限承载力偏安全,可为工程设计提供参考。Steel tubular pile underpinning technology is an effective method to develop underground space in retrofitting of existing buildings.The bottom of steel tubular pile inserted into concrete pile while top connected with underpinning cap.The stability of the pile under compression load decreased after the soil around the pile dug,but the stability coefficient and length factor of steel tubular pile can not be obtained by currently code.According to the 1：2 model test and nonlinear buckling analysis respectively,the stress distribution and the ultimate bearing capacity of the pile is derived.The effective length factor for stability calculation is 0.616 gotten by test study;and the numerical result is 0.683.So the pile is restricted with base edge fixed and top edge articulated.More safety stability of the pile can be obtained by buckling numerical analysis which can provide reference for pile design.

关 键 词：钢管桩 计算长度系数 屈曲分析 地下托换 

分 类 号：TU470[建筑科学—结构工程]