Seismic protection provided by a new diamond-shaped bracing system with a horizontally layered friction damper

Abstract

We present a new diamond-shaped bracing system with a horizontally layered friction damper (HLFD) that remedies the drawbacks of existing vibration control systems and is applicable to existing reinforced concrete (R/C) buildings. We investigated the material properties and energy dissipation of the HLFD. Pseudo-dynamic testing was performed on two-story full-size frame specimens based on an existing R/C building lacking seismic protection. We studied the hysteretic characteristics, energy dissipation, and ability to control the seismic response. The hysteretic characteristics were subjected to non-linear dynamic analysis, and the results were compared to those of the pseudo-dynamic test. Next, the effects of the new system on an existing R/C building lacking seismic protection were evaluated in terms of the non-linear dynamics. We derived the seismic response force, displacement characteristics, energy dissipation, and damper forces and displacements before and after seismic strengthening. Without protection, the building exhibited shear collapse at an earthquake ground acceleration of 200 cm/s2. However, damage was minimal when the new protective system was installed. At a maximum earthquake acceleration of 300 cm/s2, seismic damage remained low.