Investigating the Performance of LRB Insulators against Near-field Earthquakes in Concrete Buildings

The purpose of the seismic isolator system is to isolate the upper structure from the ground motions so that the earthquake destructive forces do not act on the building or they are reduced substantially. Seismic isolator is a robust seismic design method that is based on the concept of seismic demand reduction rather than increasing the seismic capacity of the structure. Due to severe earthquakes, it is necessary to use seismic isolator methods to reduce the force applied to the structures and the damage the structural and non-structural components. This study investigates the performance of LRB insulators in concrete buildings against the near-field earthquakes. The analysis of buildings under earthquake loads was performed using dynamic time history analysis with direct integration method. After analyzing the buildings, parameters such as period, damping, earthquake energy absorption and roof acceleration were studied in these models. The results showed that the applied seismic isolators were highly efficient in the horizontal component and were able to perform well in most earthquakes. In the vertical component, they caused the earthquake waves passing through them became weaker and the seismic behavior of the isolated buildings was better than the ones without seismic isolates. However, the effect of the designed base isolators on the vertical component was evaluated much less than the horizontal component.