Bridge dynamics and dynamic amplification factors — a review of analytical and experimental findings

Abstract

The dynamic amplification factor (DAF) is an important parameter in the design of highway bridges and yet no worldwide consensus has been reached so far as to its value. Some disagreement exists between provisions of various national bridge codes. This is because the DAF depends, in addition to the maximum span or the natural frequency, on many other parameters that are difficult to take into account with reasonable accuracy. Vehicle speed, weight, and dynamic characteristics, the state of the structure, roadway roughness, expansion joints, the type of bridge supports, soil–structure interaction, and influence of secondary elements are some aspects influencing the DAF. This study reviews the analytical and experimental findings on bridge dynamics and the evaluation of the DAF. Key words: bridges, vibrations, bridge testing, bridge design codes, dynamic amplification factor.

Measurement of the Bridge Surface Deflections Using Near-Field Amplitude of Secondary Radiators System

“…Consequently, all modern measuring technologies for bridge structures can be divided into three groups. The first group includes the use of radar systems of millimeter and optical ranges of electromagnetic waves [10][11][12][13][14][15] for estimation of deformations and deflections of bridge elements, including stay-cables which support the buildings. For this purpose, in particular, phase interferometers with a high-resolution range are used.…”

Dynamic amplification factors in cable-stayed structures

“…In 1992, P. Paultre et al [1,2,3] carried out a review of all the analytical and experimental studies that had previously been carried out. At the time, dynamic amplification factors were estimated on the basis of just one parameter, namely the span or the principal vibration frequency.…”

“…First of all, in order to determine the upper limit, let us assume that it is an undamped structure. In this case, the dynamic response of the structure to load q(x) applied instantaneously in t=0 is (1) and the static response of the structure to that same action is…”

Suspension bridge response due to extreme vehicle loads

“…Kim, Lynch, Lee & Lee, 2011;Lin & Yang, 2005;Mazurek & DeWolf, 1990;Paultre, Proulx & Talbot, 1995;Yin & Tang, 2011) . A review by Paultre, Chaalal and Proulx (1992) showed that the mechanical properties of the vehicle affects the dynamic response of the bridge, when the two interact from the roughness of the bridge surface. However, these excitation frequencies lie between 2-5Hz for the bounce of the vehicle's body, and would have limited effect on bridge modes with lower frequencies.…”