上海中心大厦桩基础变刚度调平设计

对于上海地区的超厚软弱土层,如何控制建筑沉降和差异沉降是设计的重点。变刚度调平设计是基于沉降控制的基础设计方法,对于群桩基础和软土地基的高层建筑沉降差异控制有显著的效果。介绍了上海中心大厦大直径后注浆钻孔灌注桩基础设计中按照变刚度调平概念,通过合理选择桩长和桩距,使得主楼底板中心和边缘的计算差异沉降控制在合理的范围,优化了底板的设计。经过试桩,认为后注浆的桩端注浆方法能有效提高单桩承载力和减小不同桩承载力间的变异值。

Variable rigidity design in the pile foundation of Shanghai Tower

How to control the settlement and differential settlements of buildings in Shanghai is important.Variable rigidity design is based on the settlement control and is efficient in differential-settlement control of high-rise buildings with piles group and soft bed.Large-diameter post-grouting bored piles are adopted in the foundation of Shanghai Tower.The foundation of Shanghai Tower was designed according to the variable rigidity conception.By selecting length and distance of piles properly,the differential settlements of plate at centre and edges were controlled within the reasonable range,which can optimize the plate design.Pile tests show that post-grouting technique can increase the bearing capacity of the single pile as well as decrease differences among bearing capacities of different piles.