桩基后压浆技术在地铁盖挖车站中的应用

结合无锡地铁大型盖挖车站工程,采用自平衡静载荷试验,对软黏土地基中大直径钻孔灌注桩桩端压浆前后承载力性能进行对比测试研究。结果表明:在硬塑黏土层桩端压浆效果明显,压浆后桩极限承载力增强比例达9.9%~54.6%,桩端阻力增强达30%以上。对压浆后桩承载力实测增值与现行规范理论计算增值比较,结果表明:实测结果能较好地符合规范,可为同类地区地铁桩基后压浆施工提供借鉴。

Pile Post Grouting Technology Application in the Large-scale Cover and Cut Subway Station

In the soft clay ground, we have tested and studied the bearing capacity performance of the large-diameter bored pile tip before and after grouting, combined with the project of the large cover excavation subway station in Wu xi, with the method of the self balanced static load test. The results show that: the effect of the pile tip grouting is obvious in hard plastic clay stratum, and the ultimate bearing capacity enhancement ratio of the large- diameter bored pile tip after grouting is up to 9.9%~54.6%, and the pile tip resistance enhancement is more than 30%. We also have compared the measured values of the bearing capacity of the bored piles after grouting to the theoretical calculation added values of the current specification, and then we know that the results of the current specifications can be well exactly in line with the measured results. The study provides a reference for the subway pile post grouting construction in the similar area.