土体液化大位移条件下群桩动力反应振动台模型试验  

SHAKING TABLE MODEL TESTS ON DYNAMIC RESPONSE OF PILE GROUPS UNDER LIQUEFACTION-INDUCED LARGE GROUND DISPLACEMENT

作　　者：张鑫磊[1] 王志华[1,2] 许振巍 孙晋晶 

机构地区：[1]南京工业大学城市地下空间研究中心,南京210009 [2]南京工业大学岩土工程研究所,南京210009

出　　处：《工程力学》2016年第5期150-156,共7页Engineering Mechanics

基　　金：国家自然科学基金项目(51378257);江苏省自然科学基金项目(BK2011802)

摘　　要：设计并开展了可液化场地群桩基础大型振动台模型试验,再现了倾斜场地土体液化、流滑以及桩基倾斜等宏观现象,分析了场地土体及桩基结构地震反应特征。结果表明:群桩存在时的液化倾斜场地流滑可区分为局部流滑和整体流滑两个阶段;倾斜场地土体中的振动孔隙水压力演变过程和空间分布受土体流滑影响,桩间土相对不易液化;斜坡倾角越大,土体侧向大位移可引起更大的桩侧动土压力反应和桩基承台偏移量。但是,该文试验结果表明,桩基结构的倾斜在一定程度上弱化了其内力反应;无论是倾斜场地还是水平场地,桩身弯矩最大值均出现在非液化土层与液化土层分界面附近。A series of shaking table model tests on pile groups in liquefiable ground were designed and conducted. The tests reproduced the macroscopic phenomena of soil liquefaction, soil flow and the large displacement of pile caps. The study focused on the dynamic responses of the ground and pile foundations. Results indicated that for liquefied slope ground with pile groups, soil flow can be classified as partial and overall soil flow. The evolution process and space distribution of the vibration pore water pressure were influenced by soil flow, and the soil mass between piles was relatively difficult to be liquefied. The greater the slope angle, the greater the dynamic earth pressure acting on the pile side and the lateral displacement of pile caps. In the meantime, the inclination of pile foundation weakened the bending moment response of pile shaft. For both inclining and horizontal ground, the maximum bending moment occurred at the interface of the liquefied and non-liquefied layers along the shaft.

关 键 词：土体液化 群桩基础 倾斜场地 液化大位移 振动台试验 

分 类 号：TU435[建筑科学—岩土工程]