Bridge Structural Health Monitoring Systems
Bridges are complex structures which are made of multiple elements and components that become stressed and interact with one another when exposed to external phenomena. A successful bridge monitoring program requires appropriate planning, design and execution. To fully meet the objectives of such a program, special attention must be given to the specificities of each bridge throughout this process. Structural Health Monitoring allows rapid assessment of a bridge’s health, and this approach is recognized as one of the best means available to increase general safety and optimize operational and maintenance activities for bridges.
The primary functions of monitoring are to ensure the longevity and safety of bridges, as well as to optimize their management. In fact, malfunctioning bridges can often have serious consequences, and in some cases, result in the loss of human life. Even when there is no loss of life, populations suffer if the structure is partially or completely out of service. The economic impact of structural deficiency is not only reflected by costs of reconstruction, but also by losses in the other branches of the economy.
The monitoring program plays a fundamental role during the construction phase, enabling the verification of design hypotheses and construction process. This timely information, in some cases, can speed construction rates, and also increase a bridge's overall quality. Learning how a bridge performs under real conditions, in its natural environment, will help designers create better structures in the future. Most defects are introduced at the time of construction, and the detection of ongoing damages can be used to identify deviations from the design performance.
Furthermore, the data resulting from a monitoring program can be used to improve the operation, maintenance, repair and replacement of a structure based on reliable and objective data. To implement corrective measures and maintenance actions, monitoring must enable the timely detection of conditions or behaviours that could deteriorate the bridge, make it unsafe, or potentially result in its failure.
Monitoring also gives a precise performance evaluation of new materials and technologies used in bridge construction and rehabilitation. This objective is easily achieved with fiber optic sensors, since these sensors effectively integrate in new materials such as fiber-reinforced polymer composites. Furthermore, fiber optic sensors adapt perfectly to long-term monitoring of bridges behaviour, as well as short-term monitoring of the bridges dynamic behaviour under traffic load.
Finally, monitoring can be used as a tool for the “supervised lifetime extension” of bridges approaching the end of their life or in need of major repair. It ensures that such bridges can be operated safely, while allowing the postponement of major investments and traffic disruptions.
Structural monitoring using the Testindo Group solutions represents a reliable method to enlarge base knowledge on a structure, and to properly assess their structural performance and integrity.
Why is it important to monitor a bridge?
- To ensure bridge safety
- To safely extend the lifetime of a deficient bridge
- To improve knowledge and understanding of a structure
- To optimize operations and maintenance costs
Benefits of the Testindo Group's Integrated Bridge Structural Health Monitoring System
- Integrated solutions The Testindo Group provides Integrated Structural Health Monitoring Solutions for bridges, based on advanced fiber optic technologies and conventional sensors. The Testindo Group also integrates local corrosion sensors and other third party transducers for additional information. All sensing technologies are seamlessly integrated into a single database and user interface.
- SHMLive Through the SHMLive service, the Testindo Group offers a comprehensive solution for bridge monitoring. This includes the design of the system, its delivery and installation, maintenance and operation, web access to the data and data analysis by experienced engineering partners, all for a fixed monthly fee.
- Ensure security, assessing real conditions of the bridge Structural Health Monitoring aims to provide more reliable data on the real condition of the structure, observe its evolution and detect the appearance of new degradations. Furthermore, it provides a comparison between design and real (monitored) behavior and confirms or denies design performances. A structural monitoring system installed on a bridge is able to greatly improve the security for the structure itself and for the users as well
- Extend the lifetime of ageing bridges Many structures are in much better condition than expected or observed by visual inspection alone. In such cases, monitoring will allow the owner of a bridge to increase the safety margins without any intervention on the structure. Owners can take advantage of better material properties, over design and synergetic effects, to extend the lifetime or load-bearing capacity of structures. If repairs are really needed, the monitoring data will help designing an optimal repair strategy.
- Quality assurance A monitoring system provides information on the quality of the material used in the construction as well as on the structural design calculus during and after the construction.
- Improve knowledge of complex bridges Improve and increase knowledge on structural behavior of complex or novel bridges on the long-term and when new materials, new construction technologies and new structural systems are used. For bridges made of unusual material, monitoring is an effective way to understand the real behavior and to refine behavioral theories. Monitoring helps creation, knowledge’s improvement and accurate recalibration of numerical models.
- Assessing bridge safety immediately after a major event Understand and assess possible damages and failures caused by extraordinary events such as earthquakes, impacts, strong winds, storms or explosions. This ability allows a bridge manager or consultant to make a preliminary assessment of whether the safety of the bridge has been seriously compromised.
- The Testindo Group: a dependable partner for instrumentation project management The Testindo Group will support the owners in all phases of a project, from system design to installation, commissioning and training. Through the experience and commitment of the Testindo Group, any monitoring needs will be met. The Testindo Group has been instrumenting critical structures, including dams and nuclear power plants, for more than 60 years. Its worldwide network of system integrators provides a competent local support for any project. All the systems come with a 10 year warranty on the availability of spare parts.
The following packages are the most widely used for bridge monitoring. However, each project has specific requirements and needs that can be addressed by a tailored system. The Testindo Group has developed a 7-step methodology to design and implement an optimal SHM system for any bridge.
Local Strain: Local strain analysis, compare to finite element methods (FEM), vibration strain
Average Strain: Macrostrain analysis, compare to FEM, vibration deformations
Displacement: Joint openings, existing crack opening
Settlement: Differential settlement between columns or foundations
Tilt: Global or local tilt
3D Movement: Differential settlement, roof deflection
Vibration: Modal analysis, wind / seismic induced vibration
Load: Cable / Stay forces, reaction forces
Temperature: Steel / Concrete temperature
Rebar Corrosion: Concrete corrosion & humidity
Environment: Wind, air temperature, precipitation
Images: Building images, construction progress