The effect of the type of rubber-metal bearings on the vibrations of continuous reinforced concrete bridges was calculated based on real earthquake records. To solve problems, the finite element method and finite difference method were used. The results of the calculation of normal maximum stresses, and longitudinal and vertical displacements of a monolithic overpass under dynamic load, based on the records of two real seismograms, are presented. The calculations performed, show that the span structure and supports of the overpass have a sufficient margin of safety in the event of strong and very strong earthquakes according to MSK-64. To ensure the guaranteed seismic safety of bridge structures, it is required to conduct design calculations based on sets of records of past earthquakes that are close in dominant frequencies to the characteristics of the construction site.

Seismic isolation of a road bridge in the seismic region of Uzbekistan with a design seismicity of 9 degrees on the MSK-scale is considered. A special feature of the bridge is the large mass of the spans, which is almost 50 times greater than the reduced pier mass. At a first glance, this rules out tuning the isolation to mass dynamic regime. The rigidity of seismic isolation is determined basing on the condition of limiting the mutual displacement of spans. Even at this limitation, seismic loads were reduced by approximately two times, i.e. by one intensity number. A more effective isolation method has been proposed, that is, when one span is rigidly fixed to the pier and the other is seismically isolated, and then the isolation can be tuned, ensuring the operation of the isolated span as the mass damper. In this case, the load on one of the piers is reduced by more than two times and that on the adjacent pier by more than four times.