ABSTRACT
This paper develops a novel method for bridge damage detection using an influence line derived from bridge accelerations resulting from passing vehicles. The acceleration influence line, i.e., bridge acceleration caused by a passing unit load, is analysed to measure any change in the bridge condition. Conventional direct methods of bridge damage detection use bridge strain response which is not influenced by damage unless the sensor is located at or close to the damaged point. However, bridge accelerations at a point are sensitive to stiffness throughout the bridge and are therefore sensitive to damage at all points. Therefore, an acceleration influence line is used in this paper to detect damage at any location in the bridge. An iterative analysis using the Moses’ Weigh-in-Motion algorithm is proposed to calculate acceleration influence line using bridge accelerations. A mean influence line from a population of influence line responses is used to detect bridge damage. This approach detects bridge damage quite effectively from changes in the mean influence line properties.
