Performance analysis of a complex superstructure-foundation-subsoil interaction system due to variable pile spacing

Reasonably evaluating the behavior of building structures gives rise to concerns associated with the design method considering interaction between superstructure and foundation. The pile plays a dominant role in the foundation, and varying pile spacing is an effective method for optimizing the pile group foundation. However, the interaction between the superstructure, foundation and subsoil is a complex physical process involving multiple objects. Quantitative assessment of the effects of varying pile spacing on the entire interaction system remains challenging. This study was aimed to accurately assess the effect of different pile spacing on the internal force redistribution of complex superstructures. Based on a case study of a high-rise building with a frame-core tube structure and pile-raft foundation, four cases with different pile spacing were considered. Special attention was given to the relationships of the load-transfer effects between the frame column and the core tube. Subsequently, using a series of numerical simulations, the whole construction process was modeled and calculated. The results confirmed that different pile spacings could affect the performance of the foundation-subsoil, and increasing the pile spacing outside the core tube is an economical and feasible method, which is more suitable for the mechanical characteristics of the frame-core tube structure.