1st Croatian Conference on Earthquake Engineering 1CroCEE 2021

In the Institute of Earthquake Engineering and Engineering Seismology (IZIIS), Ss. Cyril and Methodius University in Skopje, extensive experimental and analytical research have been performed led by the third author, in the frame of the innovative NATO Science for Peace Project “Seismic Upgrading of Bridges in South-East Europe by Innovative Technologies (SFP: 983828)”. The specific project part included development of the innovative USI-VF system representing advanced technology for seismic isolation and seismic protection of bridges. By integrating the newly uniform VF energy dissipation devices, important advances of the USI-VF system have been achieved. The response of the isolated segment of the structure becomes controlled by simultaneous effects of the present isolation system and the new advanced added damping system. Initially, in the paper are presented the original research idea, device creation process, production of the first model prototypes, as well as, the original experimental laboratory tests of the main components of the integral prototypes of the developed new uniform VF energy dissipation devices. The innovative concept of the adaptive vertical energy dissipation device, VF device, has created important improvements and advanced seismic response features. The new VF devices provide added "adaptive" damping to the common seismically isolated system which generally does not possess sufficient damping capacity. In the second part of the paper, briefly are discussed unique and original observations resulting from conducted complex shaking table tests of large-scale bridge model. The extensive experimental research program is realized on a bridge model constructed by using the seismically isolated system upgraded with vertical fixed energy dissipation devices (USI-VF). The installed adaptable system for seismic protection of bridges utilizes double spherical rolling seismic bearings (DSRSB) as seismic isolators, while the qualitative improvement of seismic performances is achieved through the use of novel adjustable multi-directional vertical fixed energy dissipation (VF-ED) devices.