Seismic assessment of storey isolation on tall buildings

Abstract

Isolation technique on tall buildings is becoming increasingly common in large urban centres in order to ensure structural integrity and performance. In this regard, while base isolation is able to decouple the structure from the ground (considering the entire structure as a unique block), storey isolation can separate upper levels from lower parts. Such technique consists of intentionally concentrating seismic energy dissipation in interfaces between selected parts of the structures in order to interrupt the flux of energy between stories. The possibility to separate levels of structures is important especially in multifunctional tall buildings where various parts have different functions and seismic performance requirements. Storey isolation aims at diffusing flexibility along the height of the building and thus reducing seismic forces by intentionally concentrating seismic energy dissipation in interfaces between selected parts of the structures. This paper aims at assessing its effects (in terms of reduction in seismic forces and evaluation of the displacements) by considering several configurations performed with OpenSees. Interfaces were introduced in several locations over the height of the building in order to assess the performance of the studied configurations.