SEISMIC RESPONSE OF BASE ISOLATED BUILDINGS WITH RUBBER BUMPERS CONSIDERING POUNDING TO MOAT WALLS
Carolina Jauregui1, John Sanchez2, Gilberto Mosqueda1.
1University of California, San Diego, La Jolla, CA, 2University of California, Irvine, Irvine, CA.
Base isolation, also known as seismic isolation, is a simple and effective method used to reduce the damage to buildings and other structures. A base isolation system decouples the superstructure from the ground, which results in a longer period and a reduction in the acceleration transferred to the superstructure during a seismic event. For this decoupling to occur, there needs to be empty space, known as the moat, so that the superstructure can move sideways without hitting the surrounding moat wall. Structural design codes regulate moat wall gap distances so that the building will not hit the moat wall, but despite this there have still been cases of pounding on moat walls during earthquakes. The goal of this project is to verify whether rubber bumpers will serve to reduce the seismic response of a building when pounding occurs. This project builds off of prior research that involved shake table tests using medium rubber, stiff rubber, and no rubber bumpers around a three-story base isolated intermediate moment resistant frame (IMRF) model. The base-isolated IMRF model was chosen due to the simplicity of fabrication and the facility of acquiring the necessary members. This project uses the data from the accelerometers and string potentiometers placed at each story to calculate the acceleration and drift ratio of each story. It is expected that the rubber bumpers will decrease the acceleration and drift ratio.