混凝土芯水泥土复合桩竖向承载特性分析方法  

Analytical approach to axially loaded concrete core-cement soil composite pile

作　　者：张晓笛 段冰 吴健 王金昌[1,2] 杨仲轩[1,2] 龚晓南[1,2] 徐荣桥[1,5] ZHANG Xiao-di;DUAN Bing;WU Jian;WANG Jin-chang;YANG Zhong-xuan;GONG Xiao-nan;XU Rong-qiao(College of Civil Engineering,Zhejiang University,Hangzhou,Zhejiang 310058,China;Center for Balance Architecture,Zhejiang University,Hangzhou,Zhejiang 310058,China;Zhejiang Institute of Communications Co.,Ltd.,Hangzhou,Zhejiang 310006,China;Zhejiang Jiaogong Underground Engineering Co.,Ltd.,Hangzhou,Zhejiang,310051,China;Zhejiang Provincial Engineering Research Center for Digital&Smart Maintenance of Highway,Hangzhou,Zhejiang 310051,China)

机构地区：[1]浙江大学建筑工程学院,浙江杭州310058 [2]浙江大学平衡建筑研究中心,浙江杭州310058 [3]浙江数智交院科技股份有限公司,浙江杭州310006 [4]浙江交工地下工程有限公司,浙江杭州310051 [5]公路数智养护浙江省工程研究中心,浙江杭州310051

出　　处：《岩土力学》2024年第1期173-183,共11页Rock and Soil Mechanics

基　　金：浙江省“尖兵”“领雁”研发攻关计划(NO.2022C03180);浙江省交通运输重大研发项目(NO.ZJXL-JTT-202201A);国家自然科学基金项目(NO.52078457);浙江大学-浙江交工协同创新联合研究中心资助(NO.ZDJG2021001)。

摘　　要：基于Euler梁理论和状态空间法,建立了综合考虑非线性芯桩-水泥土-桩周土界面作用的双层叠合直梁分析模型及其状态方程,推导了成层土中不同组合形式的复合桩截面内力与变形的统一解析解,有效地考虑了复合桩分析中土与结构相互作用、结构局部参数发生变化等难点。通过与已有文献中现场试验和数值计算结果对比,验证了该方法的有效性,并讨论了桩径比、芯长比和水泥土弹性模量对桩承载特性的影响。研究结果表明:(1)桩径比增大,可提供的桩侧摩阻力和桩端阻力增大,复合桩竖向承载力基本呈线性增长;(2)芯长比增大,复合桩竖向承载力的增长幅度逐渐增大;(3)水泥土弹性模量对于桩竖向承载力影响较小。The authors propose a double-layer composite straight beam model that incorporates the Euler beam theory and the state space method to account for the nonlinear interaction between concrete core,cement soil,and surrounding soil interfaces.This model allows for convenient derivation of general solutions for internal forces and deformations for different combinations of piles in layered soil.By employing the state space method,the model effectively considers soil-structure interactions and variations in local structural parameters when analyzing composite piles.To validate the proposed solution,field test results and numerical analysis findings from existing literature are compared.The obtained analytical solution aligns well with these validation sources.Additionally,using the derived analytical solution,the authors investigate the effects of various pile parameters on pile loading responses.Specifically,they analyze the impacts of pile diameter ratio,core length ratio,and Young’s modulus of the cement soil.The results indicate that increasing the diameter ratio reduces pile settlement and increases pile bearing capacity due to enhanced total side friction resistance and tip resistances.Increasing the core length ratio also leads to higher pile bearing capacity with an increasing growth rate.However,the Young’s modulus of the cement soil has a negligible influence on pile bearing capacity.

关 键 词：混凝土芯水泥土复合桩 竖向受荷 桩-土相互作用 Euler梁 状态空间法 

分 类 号：TU435[建筑科学—岩土工程]