高荷载水平下超长桩承载性状试验研究  

EXPERIMENTAL STUDY ON THE BEARING BEHAVIORS OF OVERLENGTH PILES UNDER HEAVY LOAD

作　　者：辛公锋[1] 张忠苗[1] 夏唐代[1] 陈张林 

机构地区：[1]浙江大学岩土工程研究所,浙江杭州310027 [2]杭州市民中心,浙江杭州310027

出　　处：《岩石力学与工程学报》2005年第13期2397-2402,共6页Chinese Journal of Rock Mechanics and Engineering

基　　金：国家自然科学基金资助项目(50478080)

摘　　要：通过对深厚软土地基中超长桩静荷载试验和桩身应力测试结果的分析,研究了高荷载水平下超长桩的荷载传递机理和承载性状。研究表明,超长桩在高荷载水平下表现为端承摩擦桩,桩侧摩阻力和桩端摩阻力的发挥是异步发挥且互相耦合。桩底沉渣会同时影响桩侧摩阻力和桩端摩阻力的发挥,在高荷载水平下,超长桩存在清渣干净的要求。在高荷载水平下,超长桩会产生桩侧土摩阻力软化,出现软化的桩土相对位移临界值与桩顶沉降有较好的相关性,表现为桩径D的正比例函数,软土中当桩顶位移为(0.01～0.02)D时,桩土将发生滑移而使桩侧摩阻力软化。同时,基于其承载机理对超长桩的设计应用作了进一步的探讨,得到的结论对超长桩的理论研究和工程设计具有重要的指导意义。Based on the static load test and stress measurement of overlength piles in deep soft soil foundation, the load transfer mechanism and bearing behavior of overlength piles under heavy load have been studied. Under heavy load, the overlength piles behave as end-bearing frictional piles, and their frictional resistance and end resistance are asynchronous and coupling. The slime affects the exertion of frictional resistance and end resistance, so it is necessary to clear up the slime of overlength piles' bottom under heavy load. At the same time, the frictional resistance will be degraded. The critical value of pile-soil relative displacement has a good correlation with settlement of pile top, and it is a function of pile diameter. When the settlement of overlength piles' top exceed (0.01-0.02)D in soft soil, the soil around pile will slide. Some suggestions for design and appliance of overlength piles have been discussed farther on the bearing mechanism; and guidances for theoretical research and technical design of overlength piles have been provided.

关 键 词：土力学 超长桩 高荷载 承载性状 试验研究 摩阻力软化 

分 类 号：TU473[建筑科学—结构工程]