PCC桩复合地基离心模型制备及桩土接触模拟  

Simulating the PCC pile composite foundation for centrifuge modelling and pile-soil interaction

作　　者：姜彦彬[1] 何宁[1] 耿之周 蔡忍 任国峰[1] 石北啸[1] JIANG Yanbin;HE Ning;GENG Zhizhou;CAI Ren;REN Guofeng;SHI Beixiao(Key Laboratory of Failure Mechanism and Safety Control Techniques of Earth-Rock Dam of the Ministry of Water Resources,Nanjing Hydraulic Research Institute,Nanjing 210029,China)

机构地区：[1]南京水利科学研究院水利部土石坝破坏机理与防控技术重点实验室,江苏南京210029

出　　处：《水利水运工程学报》2020年第2期91-98,共8页Hydro-Science and Engineering

基　　金：国家重点研发计划课题资助项目(2018YFC1508505,2017YFC0404801);国家自然科学基金面上项目(51579152,51679149);中央级公益性科研院所基本科研业务费专项基金资助项目(Y317008);国家留学基金资助项目(CSC No.201808320413)。

摘　　要：针对现有刚性桩复合地基离心模型试验技术的诸多局限性,综合考虑模型在材料、几何及桩土接触上的相似,首次设计了PCC桩复合地基离心模型试验并探讨了模型制备方法。配合专用切削、取土及回填试验器材,可以整齐高效地实现削土刮平、引孔取土、压桩就位和桩内回填操作,将常重力场下模型制备引起的扰动最小化,优化PCC桩复合地基离心模型制作过程。设计并开展反映本次离心模型中桩土摩擦接触特性的直剪试验,结果表明,离心模型中的桩帽与路堤砂、粗糙化的模型桩与软土层及下卧层的接触面摩尔-库伦摩擦角取值均在合理范围内,能够较好地代表PCC桩的桩-土接触特性。The centrifuge modelling of PCC pile composite foundation is designed for the first time to consider the similarity of material,geometry and pile-soil interaction.The model preparation method which can eliminate many limitations of the existing centrifugal modelling technology of rigid pile composite foundation is well proposed.With special cutting,extraction and backfilling equipment,the operation of soil scraping and extraction,pile driving and backfilling can be realized neatly and efficiently.Therefore,the model preparation disturbance in 1g field can be minimized,and the centrifugal modelling of PCC pile composite foundation is well optimized.The values of Mohr-Coulomb interface friction angle of pile cap versus embankment sand,roughened model pile versus soft soil,and roughened model pile versus underlying soil derived from the direct shear test results are all within a reasonable range,and can reflect the pile-soil contact characteristics of cast-in-situ concrete piles in a reasonable way.

关 键 词：PCC桩复合地基 离心模型试验 接触面直剪试验 摩擦系数 插桩 

分 类 号：TU472[建筑科学—结构工程]