STUDY ON EARTHQUAKE RESPONSE CAHARACTERISTICS OF BASE-ISOLATED BUILDING USING THE FRICTION DAMPERS WITH CONED DISC SPRINGS

摘要

This report describes the static and dynamic characteristics of base-isolated building using friction dampers with coned disc springs and laminated natural rubber bearings. The friction damper uses coned disc springs to press down a sliding material vertically against a stainless steel plate installed on the foundation horizontally. When the friction damper is moved horizontally by earthquake or gale, then friction occurs between the sliding material and stainless steel plate, and vibration energy is absorbed. The present coned disc springs are designed to obtain non-linear characteristics, which always springs up a constant resilient force, without being affected by the height variations of the laminated rubber bearings. Static and shaking table tests of base-isolation model using the friction dampers and laminated rubber bearings were taken into practice to grasp basic characteristics and functions of the friction damper. From the results of tests and analyses, the following functions of the friction damper in base-isolation system were confirmed. (1) The friction damper with coned disc springs resists the horizontal load of gale and restrains base-isolation system to prevent the aggravation of dwelling ability by shake. (2) The friction damper has such a stable damping efficiency without undergoing influence by height fluctuations of the laminated rubber bearing caused by daily temperature expansion and contraction, creep and the rocking vibration in case of the earthquake. (3) The friction damper has a function of supporting load and securing the base-isolation system against emergent excessive earthquake input. The example of the friction damper with coned disc springs applied in the actual base-isolated building is presented in the end.