How can you inspect and maintain bridges to prevent failures?

1 Inspection methods

Bridges are inspected using different methods, depending on their type, condition, and location. Some of the common methods are visual inspection, non-destructive testing, and structural health monitoring. Visual inspection involves checking the bridge for signs of damage, such as cracks, spalling, rust, or deformation, using binoculars, cameras, or drones. Non-destructive testing uses techniques such as ultrasound, magnetic, or infrared to detect defects or anomalies inside the bridge materials or components. Structural health monitoring uses sensors, data loggers, and software to measure and analyze the bridge's behavior and performance over time.

2 Maintenance strategies

Bridges are maintained using different strategies, depending on their design, function, and service life. Some of the common strategies are preventive maintenance, corrective maintenance, and rehabilitation. Preventive maintenance aims to prevent or delay deterioration by applying protective coatings, lubricating moving parts, or cleaning drainage systems. Corrective maintenance aims to repair or replace damaged or defective parts, such as bearings, joints, or cables. Rehabilitation aims to restore or improve the bridge's capacity, functionality, or appearance by strengthening, widening, or upgrading the bridge.

3 Best practices

In order to inspect and maintain bridges efficiently, civil engineers should plan and schedule activities according to the bridge's priority, risk, and budget. Additionally, it is important to follow the standards and guidelines for bridge inspection and maintenance, such as the National Bridge Inspection Standards (NBIS) in the US or the European Standards for Bridge Management (EN 13306) in Europe. Furthermore, appropriate equipment and tools should be used for the inspection and maintenance tasks, such as ladders, scaffolds, harnesses, or robots. Additionally, it is important to document and report the inspection and maintenance findings, actions, and recommendations using forms, photos, videos, or software. Finally, engineers should evaluate and update the inspection and maintenance plans and procedures based on feedback and results.

4 Tools and resources

Civil engineers can make use of various tools and resources to help them inspect and maintain bridges, such as bridge management systems that store and analyze bridge data, bridge inspection manuals with instructions for conducting bridge inspections, bridge maintenance manuals with guidance for performing bridge maintenance, and bridge inspection and maintenance training courses to provide knowledge and skills. For example, in the US, the FHWA Bridge Inspector's Reference Manual (BIRM) and the AASHTO Bridge Preservation Guide (BPG) are used, while in the UK and Europe the CIRIA Bridge Inspection Manual (C574) and the CEDR Bridge Maintenance Handbook (BMH), as well as the NHI Bridge Inspection Training (FHWA-NHI-130055) and ECTS Bridge Engineering (BRE), are employed.

5 Benefits and challenges

Inspecting and maintaining bridges to prevent failures has many benefits and challenges for civil engineers and society. Enhancing safety and reliability, extending service life, improving functionality and aesthetics, and preserving historical and cultural value are just some of the benefits. Challenges include accessing and inspecting hard-to-reach or complex bridge structures, detecting hidden or emerging defects, implementing and coordinating activities with minimal disruption, and securing adequate resources and funding, especially for aging or deteriorating bridges.

6 Here’s what else to consider

This is a space to share examples, stories, or insights that don’t fit into any of the previous sections. What else would you like to add?