Remote Monitoring of Bridges

The instrumented long-term continuous health-monitoring system installed on the Tech 21 Bridge during its fabrication is used to evaluate the performance of the instrumentation system itself. The bridge has been continuously monitored for nearly four years to demonstrate its performance. Field monitored results are studied to evaluate the behavior and durability of the bridge structure, components, and material. This evaluation is also studied to determine the level of long-term performance of the instrumented monitoring system in the harsh infrastructure environment. The measured readings of the bridge include the hidden additive of the system's performance. In addition to the structural behavior, results measured also demonstrate the ambient effects on the system. Time, temperature, and humidity dependence of the system are recorded and characterized.

2003

The Federal Highway Administration (FHWA) has concluded, on the basis of extensive research, that cathodic protection (CP), the technology used to mitigate corrosion of metals embedded in concrete, is the only rehabilitation technique that has proven to stop corrosion in salt-contaminated bridge decks regardless of the chloride content of the concrete. This technology is based on the principle of applying an external source of current to counteract the internal corrosion current produced in reinforced concrete components. During CP, current flows from an auxiliary anode material through the electrolyte (concrete) to the surface of the reinforcing steel. Various materials in various configurations are used as auxiliary anodes for CP, resulting in various types of CP systems. The selection of the anode material and its configuration is paramount to the success of the system. The primary objective of the 5-year study was to determine the effectiveness of various materials and configura...

The use of Cathodic protection (CP) in bridges took off in 1970's and since then attracted reasonable attention from practicing engineers and academia for protecting structural steel reinforcement in bridges against corrosion. The problem is further magnified when the bridge is exposed to high chloride contamination and humidity. CP is deemed to be a cost effective protection technique in such corrosive environment, thus reducing bridge deterioration and helping to uphold the structural integrity of the bridge for a longer period of time. In this article, several corrosion protection techniques are highlighted and a state-of-the-art on electrochemical corrosion protection techniques is presented, followed by an overview of a case study on state highway bridge 44 (also known as Brighton Road Bridge) located in Otago, New Zealand. The case study investigates the key factors involved in the selection of a corrosion protection technique along with a discussion of several aspects of the design process, the installation process and the performance monitoring of the selected solution. The project involves design, installation, and monitoring of an impressed current CP system for the bridge 44, where the installation has been completed to date within 32 weeks from the kick off date and well within budget equaling to one third of the cost estimated to replace the bridge.

Smart Structures and Materials 1995: Smart Systems for Bridges, Structures, and Highways, 1995

A comprehensive market survey and laboratory evaluation was conducted for the Ohio Department of Transportation and the Federal Highway Administration to identify the most promising sensors and data-acquisition systems for infrastructure application. A pilot system for highway bridge monitoring was implemented on a typical steel-stringer bridge in Cincinnati for high-speed traffic and long-term environmental monitoring. Static tests were performed with known truck loads to confirm monitoring results and to calibrate finite-element and section analysis models of the bridge. A complete and accurate characterization of the as-is structural condition has been related to the structural capacities and reliability. This multi-disciplinary research improves our understanding of the actual loading environment and the corresponding bridge responses. Instrumented monitoring is expected to complement inspection methods, provide an objective measure of the state-of-health, and alert officials to bridge deterioration or failure.

Bridge Structures, 2008

Structural health monitoring (SHM) is becoming increasingly popular with bridge owners and administrators for bridge evaluation and management. At the same time, bridge security is also emerging as an important consideration for all infrastructure owners. But the role of SHM for bridge security aspects is not well understood or studied. A workshop was held with representative members of bridge owners, researchers, consultants, and security personnel to evaluate several aspects of this issue. This paper summarises these deliberations, subsequent data analysis, and pertinent results associated with various SHM technologies, measurement methods, and interaction between stakeholders. These results will be helpful to the SHM and security communities in understanding the role of SHM in enhancing bridge security.

Bridge Structures, 2017

Delaware's Indian River Inlet Bridge opened to traffic in May of 2012. The cable-stayed bridge has a main span of 289 m and back spans of 121 m. It was constructed using a combination of cast-in-place and precast reinforced concrete. In an effort to enhance the long-term maintenance and management of this significant infrastructure, a comprehensive structural health monitoring (SHM) system was installed on the bridge. To the authors knowledge, this is the first long-span, cablesupported bridge in the U.S. to have a permanent long-term structural health monitoring system installed during initial construction. The fiber-optic SHM system that was installed has 144 sensors distributed throughout the structure. These sensors measure strain, acceleration, tilt, bearing displacement, temperature, wind speed and direction, and chloride ingress at key locations on the bridge. The SHM system provides valuable quantitative data which can be utilized by the bridge owner in their management and maintenance the bridge for years to come. This paper will review the design of the bridge and provide an overview of the SHM system, including the types and layout of the sensors, and the fiber-optic network.

2007

Sensors for infrastructure monitoring and evaluation utilizes different types of sensors which are placed at strategic locations to monitor the behavior of structures and provides valuable data such as strain, temperature, and vibration. A sensor network helps in identifying structural problems at early stages, prolonging the life of these structures, and improving public safety. This paper will discuss the experimental evaluation of two types of sensors commonly used in bridge applications.

key words: anode bridge cathodic protection chlorides corrosion maintenance Strategic Highway Research Program

2014

Current inspection procedures for suspension bridge main cables mainly consist of visually inspecting the exterior covering of the cable every 2 years. An in-depth inspection is usually scheduled as necessary to assess the condition of the interior wires by wedging the cable at selected locations along the cable. However, such approaches were found to be deficient in uncovering the most deteriorated and weakest regions in the cables of several bridges during their full cable rehabilitation projects. In this study, an integrated methodology was developed that uses state-of-the-art sensing capabilities and non-destructive evaluation (NDE) technologies to assess the cable condition. A smart sensor system integrated with NDE technologies is an approach that shows potential for assessing the condition of suspension bridge cables. NDE technologies for direct detection of the corrosion damage (i.e., main flux method, magnetostrictive technology, and acoustic emission technology) were imple...

2013

With the advancement of many off-the-shelf data acquisition systems readily available today and the availability of 3G and 4G highspeed wireless cellular networks, the potential for remote monitoring of critical bridges has never been better. Needs exist regarding scour and general structural response for long-term monitoring. However, short-term monitoring using quickly deployable, rugged systems are also desirable in cases where impact, fire, environmental effects, or other damage may occur. These robust systems can be deployed rapidly, and endure harsh elements, enabling DOTs to constantly assess and monitor a structure, or a network of structures. Hence, the objective of this project is to explore the feasibility and proof of concept of using a web-based bridge monitoring interface for use on selected INDOT bridges for both short-term and long-term applications. This report will focus on a single case study, the Virginia Ave Bridge over I-65 SB, a steel plate girder bridge that frequently falls victim to truck impact as a result of low clearance. This case study is uniquely different and provides insight into how targeted instrumentation systems can be used to probe specific parameters desired by owners for bridge condition assessment and monitoring. It will be shown how commercially available instrumentation systems can be tailored to fit any unique application required. Additionally, it will be demonstrated that INDOT benefited from this specific case of fielddeployed, short-term monitoring, which included automated notifications of critical onsite conditions.