Safety and Performance of an Active Load Control System for Bridges

It has been estimated that about 20% of the 155,000 bridges in the UK have strength deficiencies in some form. These are partly due to various types of deterioration and partly because loading standards have increased over the years. If a bridge fails its assessment there are several alternative actions available to the bridge owner. These include: complete replacement; strengthening and repair; reduction of the number of loaded lanes; posting a load limit; or “do-nothing” on the basis of advanced assessment using bridge-specific loading, sophisticated analysis or probabilistic risk assessment. An additional alternative is to employ active control of the bridge loading by using live information from weigh-in-motion (WIM) equipment linked to signals on entry to the bridge. The objective of this paper is to assess the performance and safety implications of an active load control system.

• Introduction

• The Load Control System

• Analysis of Traffic and Load Data

• Operation of the Control System

• Type of Signal

• Performance of the System

• Conclusions

• Acknowledgements

• References