Dynamic Soil Structure Interaction of a High-Rise Building Resting over a Finned Pile Mat

Abstract

High-rise building safety is generally supported by pile-mat systems. They must be sturdy enough to withstand potential lateral loads brought on by earthquakes, wind, dredging, and machine vibrations, in addition to increased axial loads. An innovative piled-mat foundation system is required to deal with these impacts because standard pile foundation systems only have lateral capacities that are 10% of their axial capacities. This study aims to reduce the damage caused by seismic impacts on high-rise buildings using shear walls supported by piled mats, thereby minimizing vibrations within the structure. Compared with conventional pile systems, the finned-pile foundation is a proven method that can withstand a 65% to 80% higher lateral load; hence, a series of SSI analyses were performed on a 25-story high-rise building, with the shear wall resting on a finned-pile mat (FP-Mat), under a far-field earthquake excitation, using ABAQUS software. The seismic responses were studied by performing a time–history analysis on the FP-Mat, with varying fin-lengths (Lf) of 0.2Lp, 0.4Lp, 0.6Lp, and 0.8Lp, which was compared with an analysis of a conventional piled-mat (RP-Mat). The seismic responses for RP-Mat and FP-Mats were studied with peak-acceleration, maximum horizontal displacement, and inter-story drifts acting as the damage parameters. The provision of FP-Mats significantly reduced the vibrations and seismic effects on the building, and as the fin-length increased, the vibrations and seismic effects reduced further. The drifting bound was also reduced as the fin-length increased. The optimum fin-length for FP-Mats is suggested to be 0.6Lp in terms of seismic performance and construction efficiency. This study helps one understand the seismic behaviors of high-rise buildings resting on finned pile mats.