Traffic induced vibration effects on pedestrians on steel bridges in Sri Lanka : a case study

Abstract

The construction of roadways has accelerated in Sri Lanka as it is an essential factor for the economic development of the country. Most of our existing steel bridges need to be rehabilitated to upgrade the transportation network. The volume of traffic has increased many folds and the loads also have increased. These have imparted serious stresses on bridges causing vibrations, and may lead to pedestrian discomfort. This type of vibration is accentuated on steel bridges with truss girders. To ascertain the vibration of the bridge at serviceability, site measurements need to be obtained with a view of developing a model of the existing structure, and to validate it Then, the model would be used to mitigate vibration. A case study was undertaken on the truss type steel girder bridge of three spans (each 33 m) over the Deduruoya on Padeniya - Anuradhapura road at Kuruneegala district This bridge has been provided with a pedestrian walk way. The Finite Element Model (FEM) was developed usingSAP2000. Field tests were conducted under controlled conditions with HA vehicle and vibration was measured using • very sensitive vibrometer. The measured field data was used to calibrate the FEM model and effects on pedestrian was studied with different vehicle speeds and the loads.