基于FDM-PFM耦合方法的刚性桩复合地基性能  

Properties of Rigid-Pile Composite Foundation Based on FDM-PFM Coupling Method

作　　者：韩小雷[1,2] 李耀琨[1] 季静[1,2] 林远东[1] 

机构地区：[1]华南理工大学土木与交通学院,广东广州510640 [2]华南理工大学亚热带建筑科学国家重点实验室,广东广州510640

出　　处：《华南理工大学学报（自然科学版）》2014年第6期88-95,共8页Journal of South China University of Technology(Natural Science Edition)

基　　金：亚热带建筑科学国家重点实验室重点研究课题(2011ZA05)

摘　　要：为揭示褥垫层颗粒材料的力学本质,深入研究其对刚性桩复合地基性能的影响,开发了有限差分-颗粒流(FDM-PFM)耦合方法,建立了刚性桩复合地基静载试验耦合模型;将耦合模型计算结果与某高层建筑结构现场静载试验结果进行了对比,吻合良好,证明该耦合方法有效,材料宏观、细观参数取值正确.并进一步模拟分析了不同褥垫层材料对刚性桩复合地基性能的影响,结果表明:随褥垫层刚度增大,沉降减小,桩土应力比增大,桩顶对褥垫层刺入量减小;不同褥垫层材料桩顶负摩阻区范围为中粗砂0.30L、碎石0.25 L、级配砂石0.20 L(L为桩长);随褥垫层刚度增大,负摩阻力减小,桩身轴力则增大.In order to reveal the mechanical nature of granular cushion and deeply investigate the effect of granular cushion on the performance of rigid-pile composite foundation, a finite differential-particle flow （FDM-PFM） coupling method is proposed, and a coupling model for the static loading test of a single rigid-pile composite foundation is set up. Then, the calculation results are compared with the in-situ test results of a composite foundation of a high-rise building, with good accordance being found, which means that the proposed coupling method is effective, and that the macro and micro parameters are properly selected. Finally, further simulations are performed to analyze the effects of different cushion materials on the properties of rigid-pile composite foundation. The results show that （ 1 ） with the increase of cushion stiffness, the settlement decreases, the pile-to-soil stress ratio increases, and the penetration of the pile top into the cushion decreases ; （2） the range of negative skin friction area of the pile is determined as follows： 0.30L of medium and coarse sand, 0.25 L of crushed stone, and 0.20L of graded sand and stone; and （3） with the increase of cushion stiffness, the negative skin friction decreases, while the axial force of the pile increases.

关 键 词：刚性桩复合地基 FDM-PFM耦合 褥垫层 桩土应力比 刺入量 桩侧负摩阻 

分 类 号：TU443[建筑科学—岩土工程]