芯桩承载扩体预制桩的荷载传递计算分析  

Calculation and analysis of load transfer behaviors of reamed precast concrete piles under bearing of core piles

作　　者：张浩[1,2] 赵宇[3] 王中[1] 刘维正 ZHANG Hao;ZHAO Yu;WANG Zhong;LIU Weizheng(School of Civil Engineering,Zhengzhou University,Zhengzhou 450001,China;National Engineering Research Center of High-speed Railway Construction Technology,Changsha 410075,China;Anhui Transport Consulting&Design Institute Co.,Ltd.,Hefei 230088,China;School of Civil Engineering,Central South University,Changsha 410075,China)

机构地区：[1]郑州大学土木工程学院,河南郑州450001 [2]高速铁路建造技术国家工程研究中心,湖南长沙410075 [3]安徽省交通规划设计研究总院股份有限公司,安徽合肥230088 [4]中南大学土木工程学院,湖南长沙410075

出　　处：《岩土工程学报》2024年第12期2503-2512,共10页Chinese Journal of Geotechnical Engineering

基　　金：国家自然科学基金项目(52078500);高速铁路建造技术国家工程研究中心开放基金项目(HSR202102);河南省重点研发与推广专项项目(科技攻关)(232102240026);河南省交通运输厅科技项目(2021-2-14);河南省住房与城乡建设科技计划项目(HNJS-2022-K45)。

摘　　要：扩体预制桩由内芯预制桩和外围扩体材料固结体组成,竖向承载时涉及到芯桩、外围扩体和周围土三者的相互作用,荷载传递机制十分复杂。针对芯桩承载全长扩体预制桩的荷载传递特点,采用弹性-破坏模型模拟芯桩-扩体界面相互作用,理想弹塑性模型模拟扩体-土界面非线性相互作用,并综合考虑内、外两界面剪切特性发挥及其耦合作用,构建了芯桩承载扩体预制桩荷载传递计算分析模型,给出了简化计算方法。与工程实例的对比,验证了方法的可靠性,并对芯桩承载扩体预制桩荷载传递规律进行分析。结果表明:外围扩体可有效地将芯桩荷载传递至周围土,扩体厚度和刚度的增加可提升整体承载性能,但较厚的扩体会制约芯桩承载能力的发挥,扩体刚度的提高有利于芯桩与扩体的共同作用。工程设计与实践中,可通过调整扩体厚度和性能来调配芯桩、扩体和周围土的相互作用。The reamed precast concrete(RPC)pile is composed of core precast concrete(PC)pile and peripheral reamed material condensate,and its load transfer behaviors are very complex due to the cooperative bearing mechanism of the core pile,reamed material and surrounding soil.To investigate the load transfer behaviors of the whole reamed precast concrete pile under bearing of the core pile,an elastic-failure model is adopted to characterize the interaction performance of the core pile-reamed body interface,and an ideal elastic-plastic model is used to simulate the nonlinear interaction between reamed body and soil interface.Considering the shear characteristics of the inner and outer interfaces and their coupling effects,a load transfer model is established for the RPC pile under bearing of the core pile,and the computational method is further provided.The applicability of the proposed method is examined by comparing the results with those of the field tests,and the load transfer behaviors of the RPC pile is discussed.The results indicate that the peripheral reamed body can effectively transfer the core pile load to the surrounding soil.Increasing the thickness and stiffness of the reamed body can improve the bearing performance of the composite pile.However,thicker reamed body may also restrict the play of the bearing capacity of the core pile.Increasing the stiffness of the reamed body is conducive to the joint action of the core pile and peripheral reamed body.In engineering design and practice,the interaction between core pile,reamed body and surrounding soil can be coordinated by adjusting the thickness and performance of the reamed body.

关 键 词：扩体预制桩 荷载传递 承载性能 计算模型 植入桩 

分 类 号：TU473.1[建筑科学—结构工程]