Assessment of bridge response using weigh-in-motion data

Weigh-in-motion data gathered on highways provides statistics on gross vehicle mass (GVM), axle mass distribution, type of truck, speed, etc. It can be used to monitor freight volume and trends, and to detect illegally loaded trucks. The data is used in conjunction with vehicle mass limits to develop “design vehicles” such as SM1600 for bridge loading to be used for assessing performance against the limit states of ultimate strength, serviceability, fatigue, etc. A system has been developed for applying the individual trucks as loads to specific bridges or to a class of bridge of given span and influence function to see how they perform under current traffic. This replaces the use of “design vehicles” with the actual historical traffic. The load effects are a function of the span and the shape of the influence line or surface. The system provides valuable insights into the performance of actual ageing bridges and it enables the direct probabilistic structural risk assessment of existing bridges. (a) For the covering entry of this conference, please see ITRD abstract no. E211602.