近海地基大直径PHC管桩竖向承载性状的试验研究

Experimental Study on the Axial Bearing Capacity Distribution of the Major Diameter PHC Pile in Coastal Foundation

对某跨海桥梁近海软土地基的2根大直径PHC桩进行静载试验,并通过预埋的应变式钢筋计测试桩身轴力分布,结果表明桩侧土层刚度越大,桩顶荷载传递给该土层承担的比例也越大,桩身轴力减小也越显著,反之则桩顶荷载更多向下部土层传递;桩身上部土层侧阻力先于下部土层发挥作用,且较大的荷载将使上部桩土发生较大相对位移,从而导致淤泥层侧摩阻力发生软化现象;尽管大直径PHC桩桩身刚度较大,但在设计工作荷载下桩顶实测沉降仍主要由桩身压缩引起。

Based on the pile test of the certain bridge, the static load tests with axial distribution test conducted by burying reinforcement meters in the reinforcement cages of the piles for 2 PHC piles are carried out. The results show that larger the stiffness of soil layer to be,more test load will be transferred to the certain soil layer. The excitation of resistance in the upper soil layer is ahead of that in the lower soil layer. The major relative displacement of upper pile body caused by major test load will make the resistance of mud lump soften. The compressions of the major diameter PHC piles are the main cause of the pile top settlements under the work load though to the major stiffness .