Reduction of vertical acceleration bridge structure

Abstract

   The increase in the speed of trains is associated with the problem of increasing dynamic reactions of railway bridges and, consequently, the risk of resonant phenomena. The deployment of a high-speed railway network increases the need for innovative construction solutions for new bridges and cost-effective methods for upgrading existing routes, including the development of methods to reduce dynamic loads on bridge structures. One such method is to install dynamic vibration dampers on the bridge floor to reduce the vertical acceleration of the bridge beam or shock absorbers installed between the bridge span and the supports. A significant drawback of known designs of mass dampers of vibration dampers is reduction of efficiency of additional masses excited due to bridge oscillations at reduction of bridge oscillation amplitude to small values. In addition, as a rule, such a phenomenon as eccentricity arising when the bridge beam deforms from the movement of the train is not taken into account. During bridge deflection, this eccentricity can cause the edges of the bridge floor beam to rotate.
   In this work, it is proposed to use dampers of vibration dampers with dynamic compensators in the form of inertial masses installed coaxially with the supporting elastic elements and springs connected to the base and span structure of the bridge structure. The theoretical justification of the proposed technical solutions is presented, which make it possible to provide reliable protection against vibrations due to more complete compensation of periodic forces and moments transmitted by bearing elastic elements, forces and moments of the opposite direction from inertial masses oscillating in antiphase.