REDUCING THE LATERAL DISPLACEMENT OF LEAD RUBBER BEARING ISOLATORS UNDER THE NEAR FIELD EARTHQUAKES BY CROSSWISE DISSIPATERS CONNECTED TO RIGID SUPPORT STRUCTURE

Abstract

The purpose of base isolation is to absorb earthquake energy, prolong the life of the structure, and enable the structure to be similar to a rigid body. However, since resonance can occur due to the closeness of the period of structures to the long period and large velocity pulses of the near field earthquakes, the stability of these buildings greatly reduces, and with the large displacement above isolation level, sometimes, tendency of overturning is created in isolators leading to their destruction. The main objective of this study is to significantly reduce the lateral displacement of base isolation subjected to near field earthquakes. In this research, seismic response calculation has been carried out for five steel moment frame structure with the 3, 5, 8, 11, and 14 stories in two states of with and without stiff core structure and energy dissipaters. The analyses has been done under fourteen scaled records of seven near- source and seven far-source earthquakes. It has been shown that the lateral displacement of base isolation system can be reduced by 87% for low-rise buildings, and 77% for high-rise buildings.