SEISMIC REACTION OF FRAME BUILDINGS WITH A COMBINED SEISMIC PROTECTION SYSTEM

The aim of the study is to search for methods to improve the efficiency of the earthquake protection systems with rubber-metallic seismic insulating supports by combining them with dry friction and brittle uncoupling elements. The research is based on dynamic modelling methods. The computational dynamic model of the combined earthquake protection system and the system of differential equations of the seismic motion of a five-story frame building were compiled and an algorithm for estimating the efficiency and selection of the optimum parameters of the earthquake protection system was developed. Horizontal shifting seismic forces, maximum mass movements and maximum movements of rubber-metallic seismic insulating supports at different intensities and prevailing periods of seismic soil oscillations were determined. It is shown that, by using a combined earthquake protection system, seismic loads on frame buildings can be reduced by a factor of 1.5-2 and maximum mass movements – by 4-5 times. In addition, the area of rational application of seismic isolation systems with rubber-metallic supports in relation to the prevailing periods of seismic ground oscillations is expanding substantially.