桩底后注浆超长灌注桩在东方之门工程中的应用

Application of Super Length Bored Cast-in-place Pile Post Grouting in"Gate to the east"

超高层建筑由于高度大,基底桩底的附加应力大,需选择较深较好的土层作为桩基持力层,对于软土地基需穿越较厚砂层的情况下,通常会选用钻孔灌注桩。超深钻孔灌注桩的实际单桩承载力及施工中桩底清淤效果是设计中必须考虑的问题。本文通过苏州东方之门桩基持力层的选择及是否采用后注浆工艺的试验比较,表明适合的桩基持力层及施工工艺对超高层建筑桩基设计的重要性,以供其它同类工程参考。

Because of the high additional pressure at the end of pile in high-rise building,we must choose the better bearing stratum for the pile.Usually we choose the bored cast-in-place pile at the situation of driving through thick sand.In the design process,the actual vertical bearing capacity of super length bored cast-in-place pile,and the effect of clearing away the sediments at the end of pile during construction must be considered.For the project of'Gate to the east',through the determining of the pile bearing stratum and the comparison of in-site static loading test of a single pile whether post grouting is adopted,,the significance of the choice of pile bearing stratum and the proper method of construction in the design process of pile in high-rise building is proved.