Serviceability verification of pedestrian bridges under pedestrian loading

Abstract

Subject reviewDue to their slenderness, pedestrian bridges may vibrate significantly under pedestrian traffic. Many researches in the past few decades deal with the problem of predicting the vibration response induced by human activity reliably. Most of the codes in the field of footbridge design define certain pedestrian comfort criteria which have to be satisfied to fulfil the serviceability in relation to vibration. The main disadvantage of the current European codes (Eurocodes) is lack of defined dynamic models of pedestrian loads for the serviceability state verification in relation with vibration. In this paper a design procedure (with load models recommendation) for verification of the serviceability limit state related to vibration due to pedestrians is proposed. According to the proposed procedure the serviceability verification on a model of a reinforced concrete pedestrian bridge in the Maksimir Park in Zagreb is conducted. Keywords: pedestrian bridge; pedestrian load models; serviceability verification Dokaz graničnog stanja uporabljivosti pješačkih mostova pod pješačkim opterećenjemPregledni članak Pješački promet može izazvati značajne vibracije vitkih pješačkih mostova. U proteklih nekoliko desetljeća mnogi se znanstvenici bave problemom pouzdanog predviđanja dinamičkog odgovora (vibriranja) mostova izazvanog ljudskim kretanjem. Većina normi za projektiranje mostova definira određene kriterije koje je potrebno zadovoljiti da bi bilo dokazano granično stanje uporabljivosti vezano uz vibriranje. Osnovni nedostatak važećih europskih normi (Eurokodova) je nedostatak definiranih modela pješačkih opterećenja za koja se provodi dokaz graničnog stanja uporabljivosti vezanog uz vibriranje. U radu je predložen postupak proračuna pješačkih mostova (s preporučenim modelima pješačkog opterećenja) u području graničnog stanja vibracija uzrokovanih pješačkim opterećenjem. Koristeći predloženi postupak proveden je dokaz graničnog stanja uporabljivosti na modelu armiranobetonskog pješačkog mosta u parku Maksimir u Zagrebu.

Relation Between Stationary and Moving Pedestrian Load Models

“…Dynamic force produced by a single person can be represented by three components in perpendicular directions: vertical, horizontal lateral and horizontal longitudinal components [1]. Horizontal longitudinal force is usually considered negligible.…”

“…Vertical pedestrian load, assuming to be perfectly periodical force, can be formulated by Fourier series in Equation (1). Numerous different approximations of such formulation were developed in the past years [1,4].…”

“…where: Various coefficients α i and ϕ i can be found in literature [1,4,5]. In general, it can be said that including more than three or four harmonic members has no effect on the final load due to low values of α i for higher components.…”

“…Many single pedestrian load models have been developed [1,2] but most of them assume the numerical analysis using moving forces or moving biodynamic models. Nevertheless, most of the commercial programs used for static design of bridges do not provide the option of calculation with force moving along the structure.…”

Dynamic Characterization and Vibration Serviceability Assessment of a Highly Trafficked, Lively Pedestrian Bridge

“…The main reason in conducting an extensive serviceability assessment analysis on pedestrian bridges, has to do more with human comfort than with the structural integrity of the bridge. Human comfort on footbridges has been studied by several researchers in light of existing codes and guidelines (Bacinskas et al, 2014;Caifeng & Linxiong, 2015;da Silva et al, 2007;Dey et al, 2015;El-robaa et al, 2015;Gudmundsson, 2008;Honda, 2007;Sadeghi & Kueh, 2015;Salgado et al, 2014;Grandić, 2015;Van Nimmen et al, 2010;Živanović et al, 2006). was also conducted to obtain modal parameters.…”