Bridges: Versoix

Case study: SOFO System

More than 100 sensors installed
Concrete monitoring during setting
Old-new interaction evaluation
Bending / torsion evaluation
Curvature analysis
Long-term monitoring
Automatic and remote monitoring

Project Description

Summary: Concrete monitoring during setting, old-new interaction evaluation, bending / torsion measurement, curvature analysis, long-term monitoring, automatic and remote monitoring, load testing, more than 100 sensors installed

Clients: Geneva of Canton

Place: Geneva Canton (Switzerland)

Period: 1996 - 1999

Installation: IMAC - EPFL

Structure's short description: The Versoix bridge was refurbished and enlarged to accommodate an additional security lane. This required the strengthening of the supporting beams. The selected construction techniques was based on the creation of a new structure perfectly monolithic the existing one creating problems of differential shrinkage.

Aim of monitoring: To monitor the behavior of the bridge during the works and in the long term, it was decided to instrument it with more than 100 sensors allowing the measurement of the curvatures at 13 different sections and the calculation of the bridge's horizontal and vertical deformations by double integration of the curvatures. Sensors pairs were also used to verify the adherence between old and new concrete.

Number of sensor: 104

Main Results: The measurements in fresh concrete allowed the prediction of cracking long before the cracks became visible and the optimization of the concrete mix for successive pours. The sensor pairs confirmed the excellent adherence between the old and new concrete. The single sensors were used to follow the long-term shrinkage of concrete and the seasonal deformations due to temperature changes. Since more concrete was added on one side of the bridge that on the other, the differential shrinkage tends to bend the bridge horizontally. This behavior was actually observed in the first few months after pouring the new overhangs. The total lateral deformation was of about 5 mm for the first two spans. During a static load test, the vertical displacement was measured by double integration of the curvatures. Excellent agreement with the direct measurements performed with dial gages is found. The figure presents a comparison between the results of the dial gages (dots) and the deformation obtained with the SOFO? system with a load at the center of the second span. The precision in the vertical deformation was estimated to 0.1 mm over 100 m (first and second span).

Cross-section with sensor locations

Measured vertical deformation during load test and comparison with dial gauge readings

Bibliography:

SOFO?: Monitoraggio di opere del genio civile tramite sensori a fibre ottiche, G. Ballerini, D. Inaudi, S. Vurpillot, ARCHI, architettura e ingegneria, ed. Casagrande, Nr. 1, p 74 -80, 1998

Application of civil structural monitoring in Europe using fiber optic sensors, D. Inaudi, Progress in Structural Engineering and Materials, Vol 2, No 3, p 351-358, 2000

Monitoring of bridges and concrete structures with fiber optic sensors in Europe, A. Del Grosso, K. Bergmeister, D. Inaudi, U. Santa, IABSE conference on cable-supported bridges, Seoul, invited paper, 2001

Bridge spatial deformation monitoring with 100 fiber optic deformation sensors , S. Vurpillot, N. Casanova, D. Inaudi, P. Kronenberg, SPIE, Smart Structures and materials, San Diego, USA, Vol 3043, p 51 - 57, 1997

Verformungsmessungen mit optischen Glasfasersensoren , N. Casanova, Weiterbildungskurs ETH Z?ich, Feldmessungen und Beobachtungsmethode in der Geotechnik, Switzerland, p 1-10, 1997

Verformungsmessungen mit optischen Glasfasersensoren , N. Casanova, Messen in der Geotechnik 98, IGB-TUBS Braunschweig - Institut f? Grundbau und Bodenmechanik Fachseminar, Germany, p 1-14, 1998

SOFO?: Monitoring of concrete structures with fiber optic sensors, D. Inaudi, N. Casanova, P. Kronenberg, S. Vurpillot, 5th int. Workshop on Material Properties and Design, Weimar, Germany, Aedificatio Publishers, p 495 - 514, 1998

Long-term monitoring of a concrete bridge with 100+ fiberoptic long-gage sensors , D. Inaudi, P. Kronenberg, S. Vurpillot, B. Glisic, S. Lloret, SPIE, Conf. Nondestructive Evaluation Techniques for Aging Infrastructure & Manufacturing, Newport Beach, USA, Vol 3587, p 50-59, 1999

Bridge deformation monitoring with fiber optic sensors , D. Inaudi, N. Casanova, S. Vurpillot, B. Glisic, S. Lloret , IABSE Symposium, Structures of the future - The search for quality, Rio de Janeiro, Brazil, Vol 83, p 132, 1999

SOFO?: Structural monitoring with fiber optic sensors , D. Inaudi, S. Vurpillot, G. Martinola, G. Steinmann, Fib Commission Meeting, Institute or structural engineering, University of applied sciences, Vienna, Austria, Vol 40, 9, 1999

Deformationsmessungen mit glasfasersensoren , N. Casanova, D. Inaudi, TFB Veranstaltung 4371/72, Wildegg, Switzerland, Ref 5, p 1-22, 1999

Bridge spatial displacement monitoring with fiber optic deformation sensors , S. Vurpillot, P. Kronenberg, D. Inaudi, ACI/KCI 2000 International Conference Repair, Rehabilitation and Maintenance of Concrete, Seoul, Korea Structures, and Innovations in Design and Construction, SP193-54, 2000

Pont sur la Versoix - N1 - autoroute du L?an, Equippement de l'ouvrage en capteurs ?fibre optiques, S. Vurpillot, L. Pflug, P. Kronenberg, IMAC-DGC-EPFL, 24 Novembre 1997, ISS-IMAC IM-01-1997-FO-SV 001, 25.11.1997, p. 1-22 + appendix 1-6, 1997

Deformation monitoring during bridge refurbishment under traffic , D. Inaudi, N. Casanova, S. Vurpillot, B. Glisic, P. Kronenberg, S. Lloret, 16th Congress of IABSE, Luzern, Switzerland, on CD, 2000

Early Age and Long-term Monitoring of Concrete Structures Using Fibre Optic Sensors , Branko Glisic, Daniele Inaudi, Conspectus, Journal of HDB, Singapore, p 93-102, 2001

Structural Monitoring of Concrete Structures , B. Glisic, D. Inaudi, S. Vurpillot, Third World Conference on Structural Control, 7-12.4.2002, Como, Italy, Vol 2, p 729-238, 2002

Whole Lifespan Monitoring of Concrete Structures , Branko Glisic, Daniele Inaudi, Samuel Vurpillot, First International conference on Bridge Maintenance, Safety and Managment, IABMAS'02, CIMNE, Barcellona, 2002

Structural Monitoring of Concrete Bridges during Whole Lifespan , Branko Glisic, Daniele Inaudi, 82nd Annual Meeting of the Transportation Research Board (TRB), January 12-16, 2003, Washington DC, USA, On CD, paper number 03-3012, 2003

Long-gauge fiber optic sensors for global structural monitoring , B. Glisic, D. Inaudi, Structural Health Monitoring Workshop, ISIS Canada, 19-20 September 2002, Winnipeg, Canada, 2002

Long-gauge sensor topologies for strucutral monitoirng, D. Inaudi, B. Glisic, Fisrt fib world congress, 14-18 October 2002, Osaka Japan, 2002

Strain, deformation and crack monitoring in bended structural members using long-gauge fiber optic sensors, B. Glisic, D. Inaudi, Test 2003, 13-15 May 2003, Nurenberg, Germany, paper A3.4 on conference CD, 2003

Monitoring of Bridges and Concrete Structures with Fibre Optic Sensors in Europe , A. Del Grosso, K. Bergmeister, D. Inaudi, U. Santa, IABSE Conference, Seoul, Korea, August 2001, 2001

Components of structural monitoring process and selection of monitoring system, Branko Glisic, Daniele Inaudi, Daniele Inaudi, 6th International Symposium on Field Measurements in GeoMechanics (FMGM 2003), September 15-18, 2003, Oslo, Norway, pages 755-761, 2003

Nadzor betonskih mostov v njihovi zivljenjski dobi s pomocjo opticnih interferometrijskih senzorjev z dolgo merno osnovo , Branko Glisic, Daniele Inaudi, Miran Antauer, 7. Slovenski kongres o cestah in prometu (7th Slovenian congress on roads under the traffic), October 20-22, Portoroz, Slovenia, 2. del (Vol.2), pp. 195-204, 2004

Finite Element Structural Monitoring Concept , Glisic B., Inaudi D., The 2nd fib International Congress June 5-8, 2006, Naples, Italy, on conference CD, ID 17-18, 2006

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