考虑土拱效应的疏排桩支护基坑内力和变形分析  

Analysis of internal forces and displacement of pit supporting structure with scattered row piles considering soil arching effect

作　　者：古海东 杨敏[2] 

机构地区：[1]浙江省交通规划设计研究院,杭州310006 [2]同济大学地下建筑与工程系,上海100092

出　　处：《岩土力学》2014年第12期3531-3540,共10页Rock and Soil Mechanics

基　　金：国家自然科学基金项目(No.40972179)

摘　　要：采用同济大学中型岩土离心机进行了2组疏排桩支护基坑的离心机模型试验,结合三维有限元数值分析探讨了采用规范方法计算疏排桩支护基坑桩身内力与变形的适宜性,并提出了考虑土拱效应的疏排桩支护基坑桩侧土压力的理论计算方法,最后建立了考虑土拱效应的疏排桩支护基坑桩身内力和变形的计算模型。研究结果表明：对于桩间距与桩径之比为2、3和8的疏排桩支护基坑,桩间土体无法形成土拱效应;对于桩间距与桩径之比为4-7的疏排桩支护基坑,桩间土拱效应明显;规范法计算得到桩身内力与变形结果要比离心机试验结果偏大,与规范方法相比,采用文中提出的计算方法计算疏排桩支护基坑桩身内力与变形更为合理。Two groups centrifuge tests of pit foundation supporting with scattered row piles are carried out by Tongji University. Combined with three-dimensional finite element numerical simulation, the suitability that the specification method is used to calculate the internal forces and displacement of pit supporting structure with scattered row piles is explored. In addition, a theoretical calculation method of earth pressure of pile considering soil arching effect is proposed. Finally, the calculation model of internal forces and displacement of scattered row piles considering soil arching effect is created. The results show that, for pit supporting structure with scattered row piles when the ratios of pile spacing and pile diameter are 2, 3 and 8, the soil between piles can＇t form soil arching effect. In addition, when the ratios are 4-7, the soil arching effect between piles is obvious. The results of pile internal forces and displacement by specification method are larger than the result by centrifuge test. Furthermore, the pile internal forces and displacement of pit supporting structure with scattered row piles calculated by the proposed calculation method are more reasonable.

关 键 词：疏排桩 基坑 离心机模型试验 土拱效应 内力分析 

分 类 号：TU431[建筑科学—岩土工程]