黏性土层中后压浆桩承载性状的对比试验研究

基于无锡江海西路快速路工程开展的4个标段场地8根试桩静载试验,通过对比未压浆桩与压浆桩实测结果,研究黏性土层中桩端后压浆对桩基承载变形性状、桩端阻力及桩侧阻力发挥性状的影响。结果表明:桩端后压浆技术可显著提高桩基承载性能,并对提高桩基成桩质量的稳定性具有很好的效果;桩端压力浆液在桩端形成水泥结石体,有效地改善了桩端沉渣问题,显著增强了桩端承载变形性能与支承刚度;桩端后压浆可提高极限桩侧摩阻力发挥水平,使得压浆桩极限侧摩阻力要大于未压浆桩,从而提高桩基承载性能发挥的稳定性。

Experimental study on bearing behaviors of post-grouting bored piles in cohesive soils

Based on the load tests on eight field piles at four sites of Jianghai West Road in Wuxi City, the bearing and deformation characteristics of piles, bearing capacities at pile tip and friction behaviors of the grouted piles are studied by comparing the field test results of the ungrouted and grouted piles. The results show that the pile tip grouting technique can significantly improve the bearing capacity of pile foundation and has a good effect on improving the stability of pile quality. The cement-stabilized soil is formed at the pile tip by the pile tip pressurized grout, which the sediment at the pile tip is effectively improved, and the bearing performances of the pile tip and the bearing stiffness are significantly enhanced. Moreover, the side friction ultimate resistance is significantly improved by the pile tip post grouting, and the side friction ultimate resistance of the grouted piles is larger than that of the ungrouted ones. Consequently, the stability of the bearing capacity of the pile foundation is improved by the pile tip post grouting.