Interactive horizontal load model for pedestrians crossing footbridges

Abstract

In recent years several theories have been put forward in relation to lateral forces imparted on bridges from crowd movements. It is now widely accepted that the interaction between the crowd and the structure, particularly when the crowd pacing frequency is close to the lateral natural frequency, is the major factor determining the lateral response. However, very little work has been done with individual pedestrians in order to determine the relationship between the lateral force induced by a single pedestrian and the structural response. Equally, most literature concerning lateral forces induced from walking is based on results from fixed force plate tests and hence no assessment of any interaction is made.This paper examines the lateral response of a GRP (glass-fibre reinforced polymer) cable-stayed footbridge to individual pedestrian crossings at a range of pacing frequencies. Two lateral load modelling approaches are considered. The first approach, derived from back analysis of the measured bridge response, was found to be ineffective in predicting the measured response accurately. A second modelling approach, incorporating a spring-damper to represent a moving pedestrian, which thereby accounts for the interaction between the structural response and the mass, stiffness and damping characteristics of the body of the traversing pedestrian, is demonstrated to be more effective in simulating the bridge response.

Experimental validation of moving spring-mass-damper model for human-structure interaction in the presence of vertical vibration

“…These parameters have been much-investigated in biomechanical engineering applications using measurements of rigid surface walking forces and accelerations of the human body centre of mass ( [25], [26], [27], [28], [29],[30], [31]). For structural vibration, Archbold [32], Caprani et al [33], Archbold et al [34], and Ahmadi et al [13] adopted the MSMD model parameters from the biomechanics literature. Hashim et al [35] determined dynamic properties of the standing (stationary) human body.…”

Reliability analysis of footbridge serviceability considering crowd loading

“…This GRF can be represented as a Fourier series (Bachmann & Ammann 1987;Rainer et al, 1988). However, in this work, each pedestrian is described by a moving force with just the first harmonic of the Fourier series (Archbold 2004) and is thus given by the following:…”

Damping and frequency of human-structure interaction system

“…Therefore, a human can be modelled as a moving springmass-damper (MSMD) to account for human mass, stiffness, and damping effects on the structural system. The MSMD was introduced by Archbold [10] and [11] into the HSI area. Archbold [11] also found that the MF model is conservative as it does not consider interaction between the pedestrian and the moving bridge, while Clemente et al (2010) [12] showed that if the interaction between the pedestrian and the bridge is to be considered, the pedestrians should be modelled as SMD oscillators.…”