Research and Design of Centrifuge Model Tests on Lateral Mechanics Properties of Composite Foundation

doi:10.3969/j.issn.1674-0696.2016.02.18

Abstract

Abstract: The centrifuge model tests on lateral mechanics properties of composite foundation were designed, some feasible solutions to these key complex technological problems in the tests were achieved including preparation of the composite foundation models, fabrication of the simulating structures, arrangement of data acquisition system, application of the surcharge load on pit edge and development of excavation method. In addition, numerical software PLAXIS 3D was used to simulate all loading cases of tests. So expected results were achieved by which we can generally master ground deformation under all loading cases, supporting and CFG pile deformation under forces and retained soil pressure distribution and variation law. It is preliminarily assumed that both the horizontal deformation and its scope of CFG piles decrease with the increasing distance from the edges of the pit and the settlement at CFG piles is far smaller than the of the soil between piles. It is considered that the CFG piles have stuck in cushion. The surcharge load on pit edge can make CFG piles more effective in aspects of consolidating soil, reinforcing the retaining structure and controlling their own deformation. 

Key words: geotechnical engineering, composite foundation, lateral mechanics properties, foundation pit excavation, centrifuge model tests scheme, numerical simulation

摘要： 通过对复合地基侧向力学性状的离心模型试验方案研究，克服了复合地基模型制备、结构构件模拟、数采系统布置、坑边超载施加以及基坑开挖方式等试验关键技术困难；同时利用数值软件PLAXIS 3D模拟试验工况，预期试验结果，大体把握各工况下地基变形、支护和CFG桩受力变形以及墙后土压力等的分布和变化规律；初步认为CFG桩水平变形和变形范围均随与基坑边界距离的增大而减小，复合地基CFG桩处沉降远低于桩间土沉降，表现为上刺入褥垫层。坑边超载使得CFG桩对地基土体的加固作用、对支护结构的贡献以及CFG桩自身变形的有效控制效果凸显出来。

关键词: 岩土工程, 复合地基, 侧向力学性状, 基坑开挖, 离心模型试验方案, 数值模拟

CLC Number:

TU441
O346

LI Lianxiang, FU Qinghong, ZHANG Haiping, HU Xuebo. Research and Design of Centrifuge Model Tests on Lateral Mechanics Properties of Composite Foundation[J]. Journal of Chongqing Jiaotong University(Natural Science), 2016, 35(2): 80-88.

李连祥，符庆宏，张海平，扈学波. 复合地基侧向力学性状离心试验方案研究与设计[J]. 重庆交通大学学报（自然科学版）, 2016, 35(2): 80-88.

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