Bridges: Gota Bridge Monitoring

Case study: DiTeSt System

Integrity monitoring
DiTeSt SMARTape used for bridge monitoring
Self-monitoring
Warning messaging system
World premiere

Project Description

Summary: The integrity monitoring of five main girders (total of 5 km) of the existing steel-concrete bridge using distributed DiTeSt SMARTape fiber optic strain sensor. Self-monitoring features and warning messaging system implemented.

Clients: Minova Bemek

Place: G?eborg (Sweden)

Period: 2005 - N/A

Installation: Minova Bemek

Structure's short description: G?a?vbron, the bridge over G?a river, was built in thirties and is now more than sixty years old. The bridge is nearly 1000 meters long and consists of concrete slab supported on nine steel continuous girders supported on nearly 54 columns. During the last maintenance works, number of cracks were found in steel girders, notable in zones above columns where the important negative bending moments are present. Two issues are in cause of steel cracking: fatigue and mediocre quality of the steel. The bridge authorities decided to keep the bridge in service for the next fifteen years, but in order to increase the safety and reduce uncertainties related to the bridge performance an integrity monitoring system have been mandatory.

Aim of monitoring: The aims of the monitoring system have been to detect and localize new cracks that may occur due to fatigue and to detect unusual structural behaviors. The warining messages are automatically sent to responsible engineers via e-mail and SMS. The main issue related to selection of the monitoring system has been the total length of the girders which is for all the nine girders more than 9 km. It was therefore decided to monitor the most loaded five girders (total length of 5 km approximately) and logically a fiber optic distributed sensing system have been selected. For the first time a truly distributed fiber optic sensing system is employed on such large scale to monitor bridge integrity.

Number of sensor: 64

Main Results: Results are not disclosed.

View to steel girders

View to testing SMARTapes installed on a girder

Bibliography:

Integrity monitoring of old steel bridge using fiber optic distributed sensors based on Brillouin scattering , Branko Glisic, Daniele Posenato, Daniele Inaudi, 14th SPIE Annual Symposium on Smart Structures and Materials & Nondestructive Evaluation and Health Monitoring, San Diego (CA), USA, 6531-25, 2007

Integrity Monitoring of Old Steel Bridge Using Fiber Optic Distributed Sensors Based on Brillouin Scattering , Branko Glisic, Daniele Posenato, Fredrik Persson, Frank Myrvoll, Merit Enckell, Daniele Inaudi, The 3rd International Conference on Structural Health Monitoring of Intelligent Infrastructure - SHMII-3, November 13-16, on conference CD, 2007

Structural Health Monitoring of Bridges in Sweden , M. Enckell, The 3rd International Conference on Structural Health Monitoring of Intelligent Infrastructure - SHMII-3, November 13-16, On Proceedings CD, 2007

Fibre Optic Methods for Structural Health Monitoring , Branko Glisic and Daniele Inaudi, Johh Wiley & Sons, Ltd, 2007

Fiber Optic Sensors For Structural Control , Andrea Del Grosso, Daniele Inaudi, The 14th World Conference on Earthquake Engineering, October 12-17, 2008, Beijing, China, 2008

Distributed sensors for damage detection and localization , Branko Glisic, Merit Enckell, Frank Myrvoll, Jan Tuvert, 4th International Conference on Structural Health Monitoring on Intelligent Infrastructure (SHMII-4) 2009, 22-24 July 2009, Zurich, Switzerland, 2009