PH C2钢管组合桩因抗腐蚀、贯入性能好, 在高桩码头开始推广使用。但是其上部是PH C 管桩, 下部是钢管 桩, 两者桩径不同, 弹性模量和密度等差异很大, 荷载在桩体中的传递呈现出不同的作用机理, 传统计算方法无法直 接应用于其竖向承载力计算, 而且该桩型竖向荷载传递机理研究未见报道, 导致PH C2钢管组合桩竖向荷载设计缺 少机理依据。运用FLAC3D 软件并基于镇江扬中长江沿岸地区地质条件, 对PH C2钢管组合桩进行竖向静载数值计 算, 同时考虑土体软化特性、桩土接触特性及沉降大变形问题, 对/ 接桩部位埋深0 、/ 接桩部位面积0 问题进行研究。 分析其不同组合下对桩身极限承载力的影响以及桩身轴力、侧摩阻力分布规律。结果表明, 镇江扬中长江沿岸地区 打入的PH C2钢管组合桩是端承摩擦桩; 接桩部位埋深与面积会影响极限承载力和桩体失稳后沉降值大小; 桩身轴 力在接桩部位发生较大衰减; 桩侧摩阻力随深度变化较复杂; 整桩侧摩阻力极值出现在接桩部位。

PH C2steel composite pile, w ith cor rosion resistance and g oo d penet ratio n pr operties, has been po pularized in high2pile whar f. H ow ever, there are alway s some difference of t heir diameter, modulus of elast icity and density between PH C pipe pile in the upper part and steel pipe pile in the lower part , and the load tr ansfer o f com posite pile w as sig nificantly differ ent in its upper and low er part. The tr adit ional method can not be applied directly to calculate the vert ical bear ing ca pacity , thus the load tr ansfer mechanisms wer e no t investig ated. Therefor e, the desig n of compo site pile lacked mechanism basis. Based o n g eo lo gical condi2 t ions of the Yang tze River reg ion of Zhenjiang Yangzhong, and considering softening o f soil, the contact cha racteristics of pile2 soil and gr eat settlement deformation, simulation test of ver tical static loading of PH C2steel composite pile w as conducted by u2 sing FLAC3D softw are, then the effect of / depth o f jo int0, / area o f jo int0 on ult imate bearing capacit y and the ax ial force and pile later al f rictio n resistance w ere analy zed. The r esults indicated that the PH C2steel composit e pile which driven in Yang tze Riv er r egion of Zhenjiang Yangzhong is end2bear ing fr iction pile; t he area and depth o f joint affects the ult imate bearing capacity and settlement value o f unstable pile; the g reater attenuation of ax ial force occurs in the jo int ; the pile lateral friction resistance changes intr icately w ith incr easing depth; the ult imate pile lateral frict ion resistance o ccur s in the joint.

江苏省/ 3330工程人才项目( Rq415001) ; 江苏省交通运输科技项目( 2014T13) ; 南京水利科学研究院中央级公益性科研院所基本科 研业务费专项资金面上项目( Y415002)