Lateral Load Performance of Partially Bonded Scrap Tire Rubber Pad Base Isolators

Abstract Scrap Tire Rubber Pad (STRP) isolators are a cost-effective alternative to steel-reinforced elastomeric isolators that have comparable seismic performance. Installing an STRP isolator between the superstructure and foundation without connecting them together reduces the cost of end plates and bonding expenses required for SREIs. Therefore, an unbonded STRP isolator displays rollover deformation that decreases effective lateral stiffness and tension stress within elastomer, enhancing the effectiveness of isolation and allowing adaptive design. The unbonded application is needed for a rollover deformation, but it may slip under an extreme earthquake. A fully bonded isolator is costly and easy to break due to high tension. A partially bonded STRP (PB-STRP) isolator combines the benefits of unbonded and bonded isolators. Therefore, this paper focused on the performance of the PB-STRP isolator with 25%, 50%, 75%, and 100% bonded regions evaluated using a validated STRP isolator finite element model. The FE analysis results show that an increase of bonded area increases lateral stability and stiffness while lowering the damping ratio. The stress condition is greatly affected by the bonded area. This study will help engineers and researchers build stronger buildings and develop cost-effective, environmentally friendly earthquake protection utilizing used tires.