为研究管桩的承栽性状,基于管桩的现场试桩资料,对管桩桩身的总侧阻力分配函数进行研究,建立了管桩桩身总侧阻力分配函数的方程式,并对函数中各参数的取值进行了说明。研究发现,对各桩长及对各长径比的管桩,桩身总侧阻力占比一桩顶沉降曲线大部分呈现程度不等的线性关系,且这种线性关系与桩顶荷载、桩身总侧阻力是否达到了极限状态无关;基于该侧阻力分配函数计算了3根桩的桩身总侧阻力.并将计算值与实测值进行了对比,发现误差绝对值在15%以内。对只有桩顶荷载、桩顶沉降的桩,可以通过该方法建立桩身总侧阻力分配函数,从而获得桩身总侧阻力和端阻力,进而可分析管桩的承载性状。但因桩身侧阻力分配问题的复杂性,研究还是初步的,有待积累更多的现场实测资料,从而完善和深化该分配函数。
In order to study the bearing capacity of pipe piles, this paper investigates on the distribution function of pile total skin friction for pipe piles based on the field test data of pipe piles.Meanwhile, the equation of distribution function of pipe pile total skin friction is established, and the parameters in the equation are illustrated. It is found that most of the curves of the distribution of pile total skin friction and versus pile head settlement present linear relationship for all types of pile length and length diameter ratio, and there's no relation between the linear correlativity and that pile head load, pile total skin friction reach ultimate state or not. The pipe pile total skin frictions are calculated based on the distribution function, and the results are compared with the measured values, the error is within 15%.The equation of distribution function of pipe pile total skin friction can be established for pipe piles which have only pile head load values and pile head settlement values, and the pile total skin friction and pile tip resistance can be obtained, then the bearing behaviors of pipe piles can be analyzed and acquired. However, the investigation is still preliminary because of the complexity, more field test data are required to improve and deepen the distribution function of pile total skin friction for pipe piles.