旋挖钻孔灌注桩后注浆在超高层建筑桩基工程中的应用

Application of the Post Grouting for Swivel-driven Cast-in-situ Pile in the Pile Foundation Engineering of the Super High-rise Buildings

通过深层平板载荷试验得到强风化粗粒花岗岩三个亚层的桩端阻力特征值,并考虑场地地质及周边环境条件,选用以强风化底、中风化面为桩端持力层的旋挖钻孔灌注桩,并在桩底和桩侧进行后注浆来有效提高单桩竖向极限承载能力,目前此类桩基形式在超高层桩基工程中应用实例较少,可供设计人员参考。

Through the deep-layer slab load test of the strongly-weathered coarse granite,we obtain the characteristic value of the pile tip resistance of the three sublayer of the strongly-weathered coarse granite.And to consider adequately the site geological conditions and peripheral ambient conditions,we select the swivel-driven cast-in-situ pile as the pile foundation of the project which pile tip situates at the bottom of the strongly-weathered coarse granite and the top of the intermediately-weathered coarse granite,and simultaneously adapts post grouting in pile skin and pile tip to effectively improve the ultimate vertical bearing capacity of a single pile.Presently,there is fewer project experiences in this type of the pile foundation in the super high-rise buildings.The paper can give a reference for the designers.