Nonlinear dynamically automated excursions for rubber-steel bearing isolation in multi-storey construction

Conventional building design includes the concept of providing more stiff structural solution to withstand the lateral seismic loading. Introduction of flexible elements at the base of a structure and at the same time ensuring enough damping is the evocative alternate option to mitigate seismic hazard. The device that is capable to meet such criteria is known as isolator. This paper covers design of base isolators for multi-storey buildings in medium risk seismicity region and the structural response evaluation. Automated nonlinear models for dynamic response investigation have been configured. Finite element method (FEM) has been incorporated to envisage the structural response behaviors. Lead rubber bearing (LRB) and high damping rubber bearing (HDRB) have been chosen for inserting isolator link element in structural base. The nonlinearities of rubber-steel bearing have been duly considered. Linear static, linear dynamic and nonlinear dynamic analyses due to site-specific earthquake accelerogram are performed for both fixed based (FB) and base isolated (BI) buildings. Both time domain and frequency domain approaches have been carried out for dynamic solution. It was found that for multi-storey buildings, base isolation diminishes muscular amount of structural responses compared to the conventional fixed base (non-isolated) structures. Allowable higher horizontal displacement induces structural flexibility. The suggested isolation technique is competent to mitigate the structural hazard even under strong seismic vulnerability in optimum manner.

► Introduction of flexible elements at the base of structure
► Automated nonlinear models for dynamic response investigation using FEM
► Lead rubber bearing, high damping rubber bearing and rubber-steel bearing
► Fixed based and base isolated construction