Calculation of the stress-strain state of monolithic bridges on the action of real seismic impacts

Abstract

To improve the transport infrastructure of the Republic of Uzbekistan, there is a tendency to build monolithic structures of bridges and overpasses. The article presents the calculation of a monolithic bridge on the 1083rd km of the M-39 highway passing through the city of Samarkand. The results of the monolithic bridge calculation on dynamic loads are presented, based on the records of two real seismograms of two dangerous earthquakes registered for a system with a spectral composition: the Gazli (Uzbekistan) and Manjil (Iran) earthquakes. The results of calculations of longitudinal and vertical displacements, and normal stress in the upper and lower parts of the span along the length of the bridge were analyzed. The calculations performed, show that the span structure and bridge supports have an overestimated margin of safety for an 8-point earthquake according to MSK-64. To ensure the guaranteed seismic safety of bridge structures, it is required to conduct design calculations based on a set of records of earthquake events that are close in dominant frequencies to the characteristics of the construction site. This provision must be included in the relevant regulatory documents.