竖向荷载作用下劲性复合桩承载能力研究  

Bearing Capacity Analysis of Stiffened Composite Pile under Vertical Load

作　　者：张晓东[1] 程子龙 包小华 沈俊 蘧树清 潘飞超 ZHANG Xiaodong;CHENG Zilong;BAO Xiaohua;SHEN Jun;QU Shuqing;PAN Feichao(College of Civil and Transportation Engineering,Shenzhen University ,Shenzhen 518060,China;China Railway Construction Investment Group Co.,Ltd.,Shenzhen 518054,China)

机构地区：[1]深圳大学土木与交通工程学院,深圳518060 [2]中铁南方投资集团有限公司,深圳518054

出　　处：《广东土木与建筑》2023年第2期11-14,共4页Guangdong Architecture Civil Engineering

基　　金：国家自然科学基金(52022060&52090084);深圳市科技创新项目(JCYJ20190808112203700)。

摘　　要：劲性复合桩作为一种新型复合桩在软土地基处理中得到了大量的应用,为深入研究该桩型的承载能力,对劲性复合桩进行了现场静载试验,并建立了劲性复合桩的三维有限元模型,分析了竖向荷载作用下劲性复合桩的Q-s曲线、芯桩轴向应变和芯桩轴向应力的分布,最后讨论了水泥土摩擦系数、桩芯截面比和芯桩混凝土弹性模量对劲性复合桩承载能力的影响。结果表明:施加在劲性复合桩上的竖向荷载主要由侧摩阻力承担;水泥土摩擦系数对桩的承载能力影响较小,主要影响桩的轴向应力分布,是劲性复合桩由摩擦桩朝着端承摩擦桩转变;劲性复合桩存在一个最优桩芯截面比;适当地提高芯桩混凝土的弹性模量可显著地提高劲性复合桩的承载力。研究成果可为劲性复合桩的优化设计提供参考依据。Stiffened composite pile as a new form of composite pile in soft soil foundation is processing to get a number of applications,for further research on the bearing capacity of this type of pile,right composite pile static load test was carried out,and established the three-dimensional finite element model of stiffened composite pile,and analyzed the Q-s curve,core pile axial strain and core pile axial stress distribution of composite pile under the vertical load. Finally,the effects of soil-cement friction coefficient,cross section ratio of pile core and elastic modulus of concrete to the bearing capacity of composite pile are discussed. The results show that the vertical load on the composite pile is mainly beared by the lateral friction resistance. The friction coefficient of soil-cement has little effect on the bearing capacity of pile,but mainly affects the axial stress distribution of pile,and the dynamic composite pile changes from friction pile to end-bearing friction pile. There is an optimal core section ratio of stiffened composite pile. Appropriately increasing the elastic modulus of concrete of core pile can significantly improve the bearing capacity of reinforced composite pile. The research results can provide a reference for the optimal design of reinforced composite piles.

关 键 词：劲性复合桩 竖向荷载 现场静载试验 承载能力 摩擦桩 

分 类 号：TU473.11[建筑科学—结构工程]