桩土界面荷载传递双曲线函数的一种确定方法  

An approach for determining the hyperbolic function of load-transfer for pile-soil interface

作　　者：陈武 CHEN Wu(Shanghai Municipal Engineering Design Institute(Group)Co.Ltd.,Shanghai 200433,China)

机构地区：[1]上海市政工程设计研究总院(集团)有限公司,上海200433

出　　处：《四川建筑科学研究》2021年第3期62-69,共8页Sichuan Building Science

摘　　要：围绕桩刚度计算中荷载传递函数的参数取值问题,进行了系统的研究。首先介绍了桩刚度计算方法位移协调法的原理,并自编了VBA计算程序。利用VBA计算程序分析了荷载传递双曲线模型桩侧土起始剪切刚度、极限桩侧摩阻力以及桩端土起始抗压刚度和极限桩端阻力等4个参数对桩刚度曲线的影响。结果表明,起始剪切刚度和起始抗压刚度控制着桩的前期刚度,而极限桩侧摩阻力和极限桩端阻力影响着桩的后期刚度,且桩侧土的起始剪切刚度、极限桩侧摩阻力对桩刚度的影响远比桩端土起始抗压刚度和极限桩端阻力的大。最后,对汉口滨江国际商务区地下环路工程12根试桩进行了桩的刚度计算,结果显示桩的计算刚度一般较实测结果小,并推断其原因在于依据规范确定的起始剪切刚度偏小。为此依据设计经验,合理地选取了试验数据,得到桩刚度实测值Kst与对应各级荷载下桩刚度计算值K的散点对,并进行了线性拟合,依据拟合结果,给出了一种简便的参数标定方法。该研究成果将对武汉地区桩基设计提供一定的依据。The parameters’value problem of the load transmission function in the calculation of pile stiffness was systematically studied in this paper.Firstly,the principle of displacement coordination method for pile stiffness calculation was introduced,and the VBA calculation program was compiled.Appling the VBA calculation program,the influence of the load transfer hyperbolic model parameters,including the initial shear stiffness and the ultimate side friction of pile-side soil and the initial compression stiffness and ultimate pile end resistance of pile-end soil,on the pile stiffness curve was analyzed.The results indicated that the initial shear stiffness and the initial compressive stiffness controlled the initial stiffness of the pile,while the late stiffness of the pile was largely influenced by the ultimate side friction and the ultimate pile end resistance.And the initial shear stiffness and ultimate side friction had much greater influence on the pile stiffness than the initial compressive stiffness and the ultimate pile end resistance.Finally,the stiffness of 12 test piles in the underground loop project of Hankou Binjiang International Business District was calculated.The results showed that the calculated stiffness of the pile was generally smaller than the measured results,which was inferred to the reason that the initial shear stiffness determined according to the specification was small.Therefore,based on the design experience,the test data was reasonably selected,and the scatter point pair of the measured value Kst and the calculated value K of the pile stiffness under the corresponding load was obtained,then a linear fitting was performed.According to the fitting result,a simple approach of parameter calibration was proposed.The research results will provide a basis for the design of pile foundations in Wuhan area.

关 键 词：荷载传递函数 位移协调法 双曲线模型 起始剪切刚度 线性拟合 

分 类 号：TU473.1[建筑科学—结构工程]