Summary In this study, the long‐term differential foundation settlement and vertical shortening of super‐tall buildings are investigated considering the coupling effect. At first, a time‐dependent settlement model is proposed to predict the foundation settlement based on the construction sequence method, in which both soil compression and pile shortening are considered. The pile shortening including the elasticity, shrinkage, and creep contributes to the most settlement of a single pile. The distribution of foundation settlement of piled raft is pot shaped with a large value in the core while small values in the surroundings. A time‐dependent soil‐foundation‐structure system is then developed using a series of equivalent springs to represent the distributed foundation settlements, by which the vertical shortenings of shear wall and mega column are predicted considering the coupling effect and moisture distribution. The pot‐shaped distribution of foundation settlement of piled raft leads to the decrease of vertical shortening for shear wall while the increase of vertical shortening for mega column, especially in the low stories. Finally, some health monitoring records of the Shanghai Tower are applied to validate the proposed time‐dependent settlement model and soil‐foundation‐structure system. The predicted foundation settlements show reasonable agreement with the monitoring records. The predicted vertical shortenings with considering the differential foundation settlement agree better with measurements than those without considering the differential foundation settlement.

Due to the time-dependent properties of materials, structures, and loads, accurate time-dependent effects analysis and precise construction controls are very significant for rational analysis and design and saving project cost. Elevation control is an important part of the time-dependent construction control in supertall structures. Since supertall structures have numerous floors, heavy loads, long construction times, demanding processes, and are typically located in the soft coastal soil areas, both the time-dependent features of superstructure and settlement are very obvious. By using the time-dependent coupling effect analysis method, this paper compares Shanghai Tower's vertical deformation calculation and elevation control scheme, considering foundation differential settlement. The results show that the foundation differential settlement cannot be ignored in vertical deformation calculations and elevation control for supertall structures. The impact of foundation differential settlement for elevation compensation and pre-adjustment length can be divided into direct and indirect effects. Meanwhile, in the engineering practice of elevation control for supertall structures, it is recommended to adopt the multi-level elevation control method with relative elevation control and design elevation control, without considering the overall settlement in the construction process.

<p>In the interaction process of superstructure and foundation for super tall buildings, materials, structures and loads all are time-dependent. With the substantially increasing of super tall buildings and the rapid development of computer technology, the time-dependent interaction study also has made great progress, and this issue has received more and more attention in the engineering filed. By considering the time-dependent features of settlement and superstructure, the interaction of super tall buildings and foundation is analyzed through using time-slicing approach in this paper. Comprehensively taking into account the coupling effects of time- dependent actions, this paper discussed the time-dependent effect for raft bending moment considering construction process in super tall buildings. The analysis results show that the bending moment differences in super tall buildings raft caused by the time-dependent effect are within permissible range of engineering practice. That is to say, the traditional lumped analysis method can be able to meet the calculation accuracy requirements of the raft bending moment.</p>

<p> The settlement of foundation includes initial settlement, consolidation settlement and secondary consolidation settlement. By considering the mechanism of foundation settlement and the upper structural properties of time-dependent materials, time-dependent loads and time-dependent structures, the time-dependent rules of foundation settlement in soft clay are investigated in this study. Existing settlement prediction models are further developed, and a stepped loading time- dependent settlement model for the super high-rise buildings in soft clay is proposed. Numerical simulation of a super high-rise building project illustrates the effectiveness of the proposed time- dependent settlement model. The time-dependent settlement model developed in this study provides a foundation for further studies on the time-dependent effects due to the upper structure-foundation- subgrade interaction.</p>