(中南大学土木工程学院， 长沙 410075)

［摘要］为研究增强型预应力管桩的竖向承载特性，将其纵向凸肋按截面积计入桩体刚度，而环向凸肋对桩侧土的作用通过桩肋侧阻提高系数来反映；基于双曲线模型的荷载传递法，对外径相同的普通光圆型预应力管桩与增强型预应力管桩的模拟计算结果和现场静载荷试验结果进行对比分析，并采用该方法分析了环向凸肋部外径、环向凸肋间距和环向凸肋下部宽度等桩型参数对增强型预应力管桩荷载沉降曲线的影响。结果表明：计算得到的增强型预应力管桩的极限承载力值和沉降值与实测值均比较接近，普通光圆型预应力管桩计算的极限承载力值较接近实测值，但沉降值较实测值偏小。为获得较好的承载性能，环向凸肋厚t与桩体外径Dp的比值应控制在0.15～0.2；环向凸肋间距Lw应不大于1.5m；环向凸肋下部宽度L3w应不大于4t。

［关键词］增强型预应力管桩; 荷载传递法; 荷载-沉降曲线; 承载性能; 桩型参数

中图分类号：TU473      文献标识码：A      文章编号：1002-848X(2014)01-0077-05

Load-settlement behavior and simulation analysis of enhanced prestressed pipe piles

Guo Zhiguang, Wei Limin, Feng Shengyang, He Qun

(School of Civil Engineering, Central South University, Changsha 410075, China)

Abstract: To investigate vertical bearing characteristics of enhanced prestressed pipe piles, longitudinal ribs were considered to improve pile stiffness by including the cross-sectional area of the pile and the effect of circumferential ribs on soil can be reflected by friction improving coefficient. Based on the hyperbolic model load transfer method, the comparison between the in-situ static load test of the enhanced prestressed pipe pile with rib and the common circular pipe pile with the same outer diameter was made and the influence of the pile parameters (including the diameter of the rib, the spacing between ribs and the width of rib lower side) on the load-settlement curve of enhanced prestressed pipe piles was studied. The results show that calculated ultimate bearing capacity and settlement of enhanced prestressed pipe piles are close to that measured. Calculated ultimate bearing capacity of the circular pipe pile is close to that measured but settlement is a little smaller. For greater bearing capacity and smaller settlement, it is suggested that the ratio of rib thickness t to outer diameter Dp should be controlled between 0.15 and 0.2 and rib spacing Lw should not exceed 1.5m. Moreover, ribbed bottom width L3w should not be larger than 4t.

Keywords: enhanced prestressed pipe pile; load transfer method; load-settlement curve; bearing capacity; pile parameter

*铁道部科技研究开发计划重点课题(2009G008-B，2010G018-E-3)。

作者简介：郭志广，博士研究生，Email：guo009@foxmail.com。

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