黄土地基超高层桩筏基础变刚度调平设计

Stiffness variation leveling design of piled raft foundation of super high-rise buildings on loess

西安飞机公司运营及研发设计中心为黄土地基上的大底盘超高层建筑,塔楼、裙房和地下室连为一体不设缝。针对工程土质地基、摩擦桩型、超高层带裙房等特点,桩筏基础设计时采用以控制沉降变形为目的、以共同工作分析为手段的变刚度调平设计方法,使反力与荷载分布相协调,有效地减小基础沉降差、降低筏板内力及上部结构次应力、减小筏板厚度及配筋;采用合理的基床刚度系数,使变形计算结果接近工程实际;钻孔灌注桩采用后注浆工艺,有利于提高单桩承载力及控制沉降。

The Business & Research Development Design Center of Xi’an Airplane Company is a super high-rise building on loess with multiple towers-huge bases.The tower,skirt building and basement are entirety without seam.According to the features of soil foundation,friction pile foundation and super high-rise with skirt building,the variable rigidity design method of coation is used to control the deformation in the design of piled raft foundation.The reaction force is to make the differential settlement of foundation,the inner force of raft slab,the secondary stress of reinforcement be reduced effectively.Reasonable stiffness coefficient of subgrade can make the calculation results be closer to the practices.Bearing capacity of single pile can be raised and settlement can be controlled by bored piles with post-grouting technique.