Vehicle effects on seismic response of a simple‐span bridge during shake tests

Abstract

Summary Presence of vehicles on a bridge has been observed many times during past earthquakes. Although in practice, the engineers may or may not include the live load contribution to seismic weight in design, current bridge design codes do not specify a certain guideline. A very limited research has been conducted to address this issue from design point of view. The focus of this research is to experimentally assess the effect of a vehicle on the seismic response of a bridge through a large‐scale model. In this scope, a 12‐meter long bridge, having a one lane deck with concrete slab on steel girders, has been shaken under five different ground motions obtained from recent earthquakes that occurred in Turkey, in its transverse direction, both with and without a vehicle on top of the deck. The measured results have indicated that top slab transverse acceleration and bearing displacements can reduce up to 18.7% in presence of a vehicle during seismic tests, which is an indication of reduction in substructure forces. The main reason for the reduction in seismic response of the bridge in the presence of live load can be ascribed to the increase in damping of the system due to mass damper‐like action induced by the vehicle. This beneficial effect cannot be observed in vertical seismic response. Copyright © 2014 John Wiley & Sons, Ltd.

Dynamic vehicle–bridge interaction under simultaneous vertical earthquake excitation

“…Priestley et al 1996;Kappos et al 2012Kappos et al , 2013and references therein). Characteristically, the existing seismic codes and guidelines worldwide (Japan Road Association 2002;CEN 1991;AASHTO 1996) account for the traffic action solely as an additional vertical live load/mass on the bridge.…”

“…The experiments showed that the presence of the stationary trucks had a beneficial effect on the performance of the examined bridge for small amplitude motions, but this improvement diminished with increasing amplitude of shaking. Shaban et al (2015) tested a 12-m long bridge of 20 tonnes, with and without, a stationary 1 ton urban motorcar. Again, the presence of the vehicle reduced the measured deck transverse acceleration and bearing displacements.…”

Mechanism study of vehicle‐bridge dynamic interaction under earthquake ground motion

“…The influence of highway motor vehicles on bridge seismic responses is still a subject of ongoing research. [3][4][5][6][7] The possibility of vehicles encountering an earthquake when crossing a viaduct or highway bridges was believed considerably low in the past. But nowadays with common traffic congestion occurring during rush hour in the busy urban areas 2 and with heavily trafficked highways be swollen with overweight trucks and special permit vehicles, 8 dynamic interaction between vehicle and bridge under earthquake should be considered.…”

“…A few shake-table experiments and numerical analyses conducted in recent years, for the purpose of investigating the effect of vehicle on seismic responses of specific highway bridges, suggest that vehicle will give a beneficial effect on bridge seismic responses and could reduce the extent of seismic damage of bridge at the end of earthquake. 3,4,[10][11][12] This kind of beneficial effect is generally attributed to be either the result of added vehicle mass which elongates the fundamental period of bridge to a favorable part of the seismic response spectrum, or the result of increased effective damping ratio caused by the tuned-mass-damper (TMD) effect of vehicle. However, none of these has been substantiated by rigorous theoretical analysis.…”

Seismological and Engineering Demand Misfits for Evaluating Simulated Ground Motion Records

“…Many researchers have studied the hazard and intensity proposed by large and destructive earthquakes (e.g., [1][2][3][4]). In most engineering applications, ground motion time histories are required in order to perform time history analyses of geotechnical or structural systems (e.g., [5][6][7][8][9]). In regions of sparse ground motion networks or lack of potential large earthquakes, simulated ground motion time histories have been increasingly recommended in earthquake engineering practice in recent years (e.g., [10,11]).…”