苏通大桥超长桩桩底后压浆试验及效果

Test of Pile Bottom Post Grouting for Super Long Pile in Sutong Bridge and the Effect

在苏通大桥松散软弱的地层条件,实施超长(>100 m)、超大(2.5 m)摩擦桩桩底后压浆工程,在我国是首次运用。结合工程实践,就压浆工程的设计、施工的技术要点进行全面介绍。通过对钻孔取样分析,指出浆液初凝时间地表实验与地下实际存在较大差异;通过施工体验,结合取样显示的浆液扩散渗透状况,提出可渗透地层以注浆量为控制参数,压力不列为控制参数的思路。

Pile bottom post grouting for friction pile with super long（100m） and super large（2.5m）was first applied in loose and soft formation in Sutong Bridge construction in China.Based on the engineering practice,the design and key technical points were introduced.By the analysis on the samples,the obvious difference of slurry initial setting time between ground experiment and underground situation was found.According to the slurry diffusion and permeation conditions by sampling,the grouting amount,not the pressure,is taken as control parameter in permeable formation.