Effect of Low-Cost Base Isolator on Performance of Moderate-Story Buildings

The base isolator is an effective innovation to mitigate earthquake effects on buildings. It can reduce the risk of damage caused by earthquakes. In 2021, research took place on the application of a high-damping rubber bearing (HDRB) base isolator in four-story, eight-story, and twelve-story structures. The study resulted in 91.4, 93.1, and 94.6 mm displacements for four-story, eight-story, and twelve-story buildings, respectively. In this study, the Natural Rubber Bearing (NRB) type was used as the base isolator for the buildings. This particular kind of base isolator is made of natural rubber and is free from chemical substances or metals. The NRB appears to be less expensive, adjusting the preliminary factor could result in a reduced displacement value, which ranges from 52 to 60 mm depending on the building design parameters used. This research modeled the 6th floor of the building by using SAP 2000. In this study, five models with different parameters were performed. The changed factors are the effective damping and shear stiffness values. The interstory drift in the fixed-based design is 37.78 mm in the X direction and 38.81 mm in the Y direction. In the meantime, implementing a base isolator, the X and Y interstory drifts are 21.15 mm and 21.78 mm, respectively. Drift between the fixed base and the base insulator decreases by 5.6%.