超高层建筑桩筏基础中桩顶反力时变效应分析

超高层建筑地基-基础-上部结构共同作用体系中,材料、结构及荷载均具有时变性。随着超高层建筑的大量兴建及共同作用研究的不断深入,考虑时间效应的共同作用研究逐渐受到学术界及工程界的重视,并逐步应用到工程实践中。基于地基沉降及上部结构的时变性规律,以时间切片的方法综合考虑时变作用的耦合效应,分析得到超高层建筑共同作用结构系统中桩顶反力的分布及变化情况,同时对水浮力的取值问题进行了讨论。分析结果表明,桩筏基础是弹性体,并验证了变刚度调平设计的正确性与合理性;同时,对于软土地区超高层建筑,地下水浮力不可忽略。

Time-dependent Pile Reaction Force Analysis for Pile-raft Foundation of Super High-rise Buildings

In the interaction process of soil-foundation-superstructure for super high-rise buildings, materials, structures and loads all are time-dependent. With the substantial increase of super high-rise buildings and the in-depth study of interaction issues, the interaction study considering time effects has received more and more attention in the academic and engineering filed, and it is gradually applied to engineering practice. Based on the time-dependent features of settlement and superstructure, this paper considered the time-dependent coupling effects through using time-slicing approach. Then, this paper analyzed the distribution and changes of pile reaction force in super high-rise buildings and discussed the issue of water buoyant force. The analysis results show that pile-raft foundation in super high-rise buildings is elastic body, and it verifies the correctness and rationality of variable rigidity design. Besides, the analysis results show that the water buoyant force cannot be ignored for super high-rise buildings in soft clay areas.