东江大桥嵌岩桩承载性能试验研究

报道了东莞东江大桥两根大直径嵌岩桩桩基承载力试验,探讨了嵌岩桩荷载传递规律,分析了桩端阻力和桩侧摩阻力随荷载的变化规律和桩底注浆对桩端附近侧阻力和端阻力的影响,得到了桩端附近侧摩阻力与相对位移的关系。结果表明,两桩桩底存在沉碴,Q–s曲线呈双折线型;桩端压浆对提高嵌岩桩的极限承载力效果显著,对减小桩基沉降有作用,不是明显;桩端附近侧摩阻力与相对位移的关系为加工软化型或抛物线型,桩底注浆对侧摩阻力与相对位移的关系有影响。

Load transfer mechanism of rock-socketed piles of Dongjiang Rive Bridge

The bearing capacity tests on two single large-diameter rock-socketed piles were carried out on Dongjiang River Bridge in Dongguan City.The load transfer behaviors of the piles implanted into soft rock layers were analyzed,the effect on the shaft resistance and the tip resistance of pile were analyzed after grouting into the tip of piles,and the relationship between the shaft resistance and the relative displacement was obtained.It was indicated that there were dregs in the tip of two piles and the curve of Q-s was a double broken line,the ultimate bearing capacity of the piles increased and the relevant settlement decreased remarkably after grouting,and the relationship between the shaft resistance near the tip and the relative displacement might be the type of working softening or parabola which was also influenced by grouting.