doi:10.16186/j.cnki.1673-9787.2023040061

Received:2023-04-27

Revised:2023-08-10

Online Date:2023-11-30

Dynamic responses of a beam to moving loads on elastic foundation overlyingvoids（Online）

ZHANG Bingqiang1, LI Jiayao1, PAN Qinfeng1, HUANG Zhibin2

1.College of Civil Engineering， Fujian University of Technology， Fuzhou  350118， Fujian， China；2.Fujian Railway Construction Co.， Ltd. of China Railway 24th Bureau Group， Fuzhou  350013， Fujian， China

Abstract:Voids beneath the concrete pavement usually generate due to plastic deformation caused by traffic load or rainwater erosion. However， the influence of voids beneath the pavement on the dynamic responses of the pavements to moving load are ignored， thus causing the theoretical results is less than the true data. To address this problem， a pavement overlying voids is simplified as an elastic beam spanning a void， and the mode superposition method is used to solve the dynamic responses of a beam to moving loads overlying voids. The influences of the parameters on the dynamic response of the beam are studied， including the moving speed of the load， the width of voids underlying the beam， the elastic coefficient of the foundation， and the bending stiffness of the beam. The results indicate that the void underlying the beam has a significant influence on the dynamic responses of the beam directly above the void， while the influence on the beam outside the void is little. When the void width is 2/9 of the length of the beam， the maximum vibrating displacement at the midpoint of the beam is about 4 times of that without considering the void underlying the beam. Increasing the bending stiffness of the beam and the elastic coefficient of the foundation can reduce the vibrating displacement at the midpoint of the beam. However， the effect of improving the foundation elastic coefficient is little when the void width the underlying the beam is 1/3 of the length of the beam.

Key words:beams overlying voids;dynamic analysis;superposition method;moving load;viscous foundation

CLC：U416.01