Method of multiscale coincidence of pulses for measuring temporary loads from moving vehicles in bridges and overpasses

Abstract

Modern development of road transport is characterized by constant updating of the nomenclature of cars (including heavy-duty vehicles), by increasing of intensity and speed of their movement, especially in large metropolises and on roads of national and local significance. This complicates the operating conditions of spans of highway bridges to some extent, leads to their damage and early wear. The deterioration of the technical condition of the structures of the spans is largely due to the increased dynamic impact of the cars on the bridges. The purpose of this article is to measure the amplitude of oscillations of a bridge structure from temporary loads of rolling stock with non-periodic long-term loading by optical methods. In accordance with this goal, it is necessary to develop a technique and device for measuring the amplitude of oscillations of the bridge structure by converting the amplitude of oscillations in time intervals and their subsequent measurement by multi-scale pulse coincidence. In a number of works, digital deployment systems that use number systems with different bases, represented by a family of deployment functions, are considered in detail.
 Such digital systems in general, are described by the corresponding operating scheme. According to this operating scheme, a method of multiscale matching for measuring time intervals was developed, which formed the basis for measuring the vibration amplitude of the bridge structure. The given mathematical model of calculation of the number of measurement channels was used in the synthesis of velocity transducers and linear displacements based on optical (laser) deployment systems, information conversion devices of radar velocity sensors based on the Doppler effect. Similarly, a frequency comparison device, a digital frequency meter, a digital phase meter, and a number of other frequency-time group devices were synthesized.