Regulation of dynamic characteristics of bridge spans in the conditions of the changing impact of the temporary moving load

Abstract

It is known that an unregulated structure is likened to an unadjusted musical instrument [7]. The adjusted dynamic stress-strain state of the bridge spans will be adequate to the parameters of the design and operational state as a result of the introduction of regulation and control of fl uctuations in the conditions of the changing impact of the temporary mobile load. Methods for regulating dynamic characteristics by changing the frequency of natural oscillations of the system, taking into account energy dissipation, as well as introducing into the oscillatory process a transformed form of intense oscillations in the process of artifi cial or selective resonance, in which the oscillations of the system either damp or cease to be dangerous, are especially carefully considered. Attention is focused on the infl uence of the defectiveness of the roadway with an increase in the mass and speed of a temporary moving load. For this purpose, a classifi er of bridge deck defects has been developed to clarify the boundaries of the eff ect of a defect on the dynamic operation of a structure [1, 3]. Analysis of the structural content and criteria for determining shows the insuffi ciency of the components assessing the eff ect of the temporary mobile load on the span under non-stationary oscillations, and also reveals contradictions in the assessment of the dynamic additive . The practical use of the research results is advisable by the Ministry of Transport Construction in the implementation of state national programs and projects for improving structures, calculation methods, design and operation of bridge structures