IMPLEMENTATION OF TOTAL ELECTRONIC INSPECTIONS FOR BRIDGES
INTERNATIONAL BRIDGE CONFERENCE, PITTSBURGH, PA
JUNE 1997
Albert Leung, Commonwealth of Massachusetts Highway Department (Boston, MA)
Sanjiv Nathwani, Trilon, Inc. (New Brunswick, NJ)
Avanti Shroff, Iffland Kavanagh Waterbury, PLLC (New York, NY)
INTRODUCTION:
The primary goal of a bridge inspection program is to ensure public safety. All structures are inspected biennially to detect and correct major deficiencies that may result in catastrophic failure. The secondary goal is to gather data for maintenance, rehabilitation and repair programs aimed at extending the useful life of our ailing structures. These goals can be a severe test of engineering skill and judgment.
Unfortunately, the biggest problem faced by bridge inspection programs has nothing to do with engineering. The task of collecting and managing the torrent of information that results from inspections often overwhelms agency bridge departments, taking precious time and resources away from engineering assessment and decision making.
If engineers are to continue to battle an aging infrastructure effectively, they must be freed from this information management burden and allowed to focus their attention on the engineering aspects of bridge management. One way to achieve this is to minimize the information management load with judicious application of intelligent automation.
The Massachusetts Highway Department (MHD) is moving towards complete electronic inspections for its bridges. MHD’s goal is to improve the quality and cost efficiency of the bridge inspection process by investing in several state-of-the-art technologies.
BACKGROUND:
Following is a brief review of the bridge inspection process at MHD prior to the introduction of new technology:
Organization: MHD’s bridge department consists of five geographically dispersed district offices, each supporting several inspection teams, and a central office in Boston. District offices are responsible for performing inspections and preliminary QC of field data, while the Boston office is responsible for all other functions.
Biennial Bridge Inspections: As per FHWA guidelines, MHD inspects approximately 7,000 bridges every two years. Bridges in poor condition are inspected every year.
Visual Inspections: The biennial inspections are largely visual, i.e. inspectors focus on detecting visual evidence of damage and/or deterioration. Such visual evidence is documented using numeric ratings, commentary, sketches and photographs. In the case of underwater inspections, visual evidence may be documented in full-motion video.
Inspections Using Special Equipment: Some portion of the biennial inspection may require special equipment, i.e. bridges over water are inspected for scour by taking depth soundings using fathometers to profile erosion. Such inspections may result in numeric ratings, sketches, commentary and data sets.
In Depth Inspections: Bridges in poor condition may be inspected in greater detail by taking core samples for analysis or using non-destructive techniques such as infra-red thermography and ultrasonic testing. Such inspections may result in documentation ranging from commentary and graphs to photographs and data sets.
Bridge Condition Ratings: MHD employs the National Bridge Inventory Standards (NBIS) and a rating scale of 0 to 9 for safety inspections. In addition, MHD is in the process of implementing the CoRe element rating system required by the Pontis Bridge Management System (BMS). Numeric ratings are first collected on paper forms and then transcribed to the NBI database and Pontis.
Repair Recommendations: Inspections may result in recommendations for immediate or eventual repair of the structure. Such recommendations are usually documented using simple commentary, but may require complex reporting to include supporting information in the form of sketches, plans, Computer Aided Design (CAD) files and photographs.
Load Ratings: Inspections are periodically supplemented with load rating analysis to verify the load carrying capacity of the structures. Such analyses result in data sets as well as commentary. In addition, all bridge ratings are accompanied by a BDS input file. These are stored so that different loading scenarios can be generated.
ISSUES:
There were several information management issues in the process described above. These issues fell into two broad categories, data collection and data management.
DATA COLLECTION:
Paper Based: At a minimum, the inspection of each bridge resulted in several paper forms with numeric ratings for NBI, and more recently Pontis. The paper forms were then transcribed to the NBI database and Pontis. Rating information was often supplemented with handwritten commentary, sketches, etc. that was never transcribed, and thus could only be referenced in paper format. This resulted in reliance on a paper based filing system with limited access, which proved frustrating to use especially in emergency situations.
Insufficient Visual Data: Although some of the more severe conditions were documented using 35 mm cameras, the majority of the inspections were performed without generating any visual documentation. Amongst other problems, it was felt that the use of 35 mm photography was prohibitively inefficient due to the high cost of media and film development, and the difficulties in managing access to large photo files. However, it was clear that capturing more visual data would greatly enhance assessment of field conditions.
NBI and Pontis Ratings: The field data collection procedures had to be modified to facilitate collection of Pontis ratings in addition to NBI ratings.
DATA MANAGEMENT:
Historical Data for the Field: It is important to supply inspectors with historical data for reference in the field because it provides them with a valuable perspective when examining a defect, especially when a progressive condition is encountered. However, since the historical information was largely in paper format, this required either maintaining a duplicate set of files, or risking loss or damage of original documents. In addition, there was no easy way to provide access to electronic data such as CAD files, data sets, videos, etc.
Limited Access to Field Information: Field information often needed to be accessed quickly and simultaneously by different groups, especially during emergency situations. Since a majority of field information was paper based, there was generally a time lag in routing the information, and the only way to facilitate simultaneous access was to create duplicate files or bring people together in one location for review.
NBI Database Outdated: Even though a database application existed to manage NBI and safety inspection data, it was outdated in its functionality. Additionally, it would be helpful to have the database re-engineered to be made usable by the districts and field teams. This would reduce the time lag for transcribing data and provide historical reference in the field.
Too Many Computing Environments: MHD had already invested in several forms of computer automation such as CAD, Geographic Information Systems (GIS), word processing, spreadsheets, etc. Unfortunately, most of these were deployed on diverse computing environments that made it impossible to access all information from a single point.
No Electronic Connection to District: The districts had some automation for administrative functions, but were essentially isolated as regards any electronic communication with the Boston office.
SOLUTION:
MHD selected several strategic technologies to address the problems discussed above and to complement the existing level of automation. Following is a complete list of automation envisioned for optimal information management:
New NBI and Safety Inspection Database: This application will enhance the functionality of the existing inventory database, and facilitate remote access from the field. The software will be expanded to house not only NBI and safety inspection data, but also to stage Pontis data - this duplication is considered necessary to create a central store for all rating information. The application will be designed for a user-friendly, mouse-driven, windowing environment to promote adoption by the districts and inspectors. It will also be designed using a cross-platform database development tool to ensure support for MHD’s mixed computing environment.
Multimedia Information Management System: This system will be the repository for all non-rating inspection information. Additionally, it will also house final copies of all other bridge information such as plans, CAD files, repair details, etc. The system will provide the means to convert all media to electronic format, e.g. scanners to convert papers documents and photographs to digital images; video digitizing equipment to convert full-motion video to digital video. It will also provide for high volume, scaleable storage to allow for conversion of historical information and for future growth of the information base. The system will be accessed over a Local Area Network (LAN) in the Boston office and a Wide Area Network (WAN) from the districts. Finally, the system will allow a subset of the database to be carried into the field by inspectors for historical review; detached viewing software running on portable computers will facilitate off-line access.
Electronic Photography: Inspectors will capture visual data using digital or still-video cameras and standard video camcorders. The video camcorders would also allow for capture of any relevant audio information including tap tests and verbal commentary. Such audio and visual information will be converted to digital files and stored on the multimedia information management system.
Personal Digital Assistant (PDA) Based Field Data Collection: Inspectors will capture all rating information, commentary and sketches using hand-held, pen-based computers known as PDAs that are ideal field data collection tools due to their small size, low weight, long battery life, sophisticated graphical user interface and handwriting recognition capabilities. The PDAs will share data with Pontis and the new NBI and safety inspection database.
ENVISIONED PROCESS: The automation will interact in the following way to describe a comprehensive information management process:
Figure I. Three tiers of information management
• Inspectors will be equipped with portable computers, digital/still-video cameras, video camcorders and PDAs. They will collect all NBI, safety inspection and Pontis rating information on the PDAs. They will also use the PDAs for short commentary and sketches. The portable computers will be used to review historical information, and to generate detailed commentary and sketches.
• Inspectors will transfer field information to workstations at the district offices during periodic visits. During these visits, they will also load pertinent historical information for the next set of bridges to be inspected onto the portable computers and PDAs.
• All field information will be QC reviewed at the district offices before being transferred to the multimedia information management system and the main NBI and safety inspection database. All audio and visual documentation will be digitized and any paper documents generated will be scanned prior to review.
• Once field information is transferred to the multimedia information management system and the main NBI and safety inspection database, it will be instantly available for review from any point on the WAN and Boston office LAN. Additional QC procedures may be instituted at the Boston office to review incoming field information prior to general release over the network.
• The Boston office will transfer CoRe element rating information to Pontis from the NBI and safety inspection database as necessary to develop deterioration modeling and recommendations for prioritizing projects for allocation of funds.
• Although all the input of field information will be performed at the district offices, the Boston office will be responsible for managing the network, the multimedia information management system and the NBI and safety inspection database. The Boston office will also be responsible for setting procedures for information use and distribution.
Figure II. Envisioned inspection information flow
• Other departments within MHD (maintenance, design and construction) will have complete access to the latest multimedia information management system and NBI and safety inspection database as necessary over the WAN and LAN. They will also submit information in final form over the network for archival to the multimedia information management system. Such information may be QCed prior to general release over the network.
Figure III. Envisioned bridge management information flow.
CURRENT STATUS:
MHD embarked on a plan to fulfill this vision in 1993. The plan is targeted for completion in 1998.
BUYING EXISTING TECHNOLOGIES: It was felt that procuring complete products as far as possible would be more cost-effective than developing all the automation in house. As a result considerable effort was invested in researching the market for existing technologies that would help meet MHD’s goals. This research and procurement cycle yielded the following results:
Multimedia Information Management System: After a year of research and reviewing potential developers and product vendors, a product was identified that met all the criteria set by the department for this technology. The system was capable of providing capture, storage and distribution for all information related to a bridge regardless of source and type - the system supported high speed black-and-white scanning, 24-bit color scanning, large format scanning for plans, video digitizing, scaleable high volume storage on optical media, industry standard LAN and WAN connectivity, high-speed black-and-white printing, photorealistic color printing, large format plotting and the ability to export subsets of the network database to laptop computers for detached viewing (Photo I).
The system has been implemented in four stages to date, and offers most of the required functionality. The Boston office now has complete LAN access to the system and the ability to enter and distribute all data types. Each district has been equipped with workstations to assemble and QC field data for transfer to the Boston office. The Boston office and all districts have been equipped with optical disk drives as a temporary solution for periodic information exchange until a WAN connection becomes available. All field teams have been equipped with detached viewing software to review historical information in the field on laptop computers.
Photo I. A multimedia information management system workstation
Electronic photography: The research in this area yielded a brand of full-motion video camcorders that were also capable of capturing still-video shots on the same tape (Photo II). This eliminated the need for two different types of cameras in the field. In addition, the camcorders were capable of being connected via standard RCA cables to video digitizing hardware and software supported by the multimedia information management system. All field teams have been equipped with these camcorders and necessary weather proofing gear. Note that even though Hi-8 format video produces images with considerably lower resolution than 35 mm photographs, the image quality is considered adequate for bridge inspection purposes (Photo III).
Photo II. A video camcorder field unit
Photo III. Dye Test Image
PDA Based Field Data Collection for Pontis Ratings: The research yielded a PDA based software specifically targeted for Pontis data collection. However, no corresponding product was found that could be adapted for NBI and safety inspection data collection. The Pontis data collection software and hardware has been procured and project completion is currently pending implementation and training by the vendor.
Photo IV. A PDA field unit
DEVELOPING NEW TECHNOLOGIES: Procuring the above products left two major automation items needing home-grown solutions:
New NBI and Safety Inspection Database: A database development tool was selected based on the following criteria: cross platform support, ease of development, strong graphical user interface, client-server architecture, compliance with MHD’s networking standards and ease of integration with the selected multimedia information management system. The software is nearing completion after a 18 month development cycle, and is being developed using in-house staff with some prior development experience. The application is designed for LAN access as well as remote access via modems. The application is also designed to be used over the World Wide Web - the database server communicates with a Web server that automatically converts user interface elements to Hyper Text Markup Language (HTML) pages that can be viewed using a standard Web browser. This allows all users to interact with the application in a uniform way from a cross-platform environment.
PDA Based Field Data Collection for NBI and Safety Inspection Ratings: This will require the development of software to be run on the PDAs utilized for Pontis data collection. The application will need to replicate a subset of the data entry capabilities of the NBI and safety inspection database. It will also need to provide a mechanism to transfer data between the PDA and the database. The development project may be undertaken by in-house staff or contractors.
CURRENT PROCESS: Since the plan is still not complete, the process that was originally envisioned has been modified to derive a maximum the benefit from technology already implemented. Following is a summary of the temporary process:
Field to Districts: Inspectors collect visual information using the video camcorders. Pontis rating information will soon be collected on PDAs, but the NBI and safety inspection information will continue to be collected on paper and transcribed to the database until a PDA based application becomes available. Commentary and sketches are largely generated using word processing and drawing software running on the laptop computers.
Districts to Boston Office: The inspectors periodically drop off paper forms and video tapes to their district office, and transfer any computer files to the district workstation. As the PDA based Pontis data collection software is implemented, inspectors will also transfer Pontis element rating data and commentary to the district workstations. The district offices scan the paper forms, transfer information to optical disks, QC all the information and ship the optical disks with the video tapes to the Boston office monthly. As the new NBI and safety inspection database is implemented fully, all its information will be transferred to the Boston office over the modem.
Boston Office: The Boston office QCs optical disks from the districts, digitizes relevant portions of the video tapes, and commits all the information to the multimedia information management system’s optical archive. At this point the inspection information is available to everyone on the network. CoRe element rating data is transferred to Pontis as necessary.
Boston Office to Districts: As yet there is no transfer of historical information back to the districts. Transfer from the multimedia information management system to the districts is awaiting backfiling of historical paper files to the system; transfer from Pontis and the NBI and safety inspection database is awaiting final implementation of the new database. In the interim some historical information may be made available to the districts via remote access using modem communications.
FHWA Tape: The annual tape to the FHWA is cut directly from the database.
Figure IV. Current inspection information flow
BENEFITS:
Despite the fact that some key portions of plan have yet to be executed, many benefits have already become apparent:
Improved Visual Documentation: Both the quantity and quality of visual documentation from the field has increased noticeably since video camcorders have been deployed. This is attributed to several factors: ease of use; the ability to review still-video shots as they are being taken using the camcorder’s color LCD screen; use of the zoom feature to get close up shots of specific conditions without using special equipment for access; the ability to add verbal commentary to still shots to explain location and context.
Cost Savings for Visual Documentation: It is estimated that the department saves some $80,000 a year on film and development costs alone by moving to electronic photography. All photographs are now taken as still-video shots using the video camcorder units. Each 120 minute tape allows inspectors to take up to 1,000 shots per tape; since video tape is erasable media, the tapes can even be reused if necessary.
Time Savings for Visual Documentation: As the inspectors gain confidence in using the camcorders, they are starting to rely increasingly on visual documentation combined with audio commentary to shorten the amount of time spent in generating written commentary. They are also finding that the adage ‘a picture is worth a thousand words’ applies to bridge inspection as well. This is greatly assisted by the fact that the inspectors and the districts have been freed from the burden of storing and managing the visual data - this is all handled by the multimedia information management system at the Boston office.
Video Adds an Important New Dimension to the Inspection Process: Full-motion video has made it possible to concisely capture conditions that were otherwise difficult to document using photographs and commentary. E.g. a relatively new bridge was found to have a concrete box beam that with a broken shear key, which resulted in it acting independently of the other members and showing visibly excessive deflections. As the previous sentence shows, the condition is difficult to describe. However, a short video clip showing the deflection of the beam as traffic passes over the bridge immediately conveys the severe nature of the condition; this provides a greater impact on the viewers and consequently a speedier response to the problem. The video was used to convince local officials of the town to close the bridge. Protests against closing the bridge were overcome by bringing out a portable computer to the meeting and showing the video from the computer.
Photo V. Concrete beam box showing excessive deflections
Eliminate Commentary Transcription: The inspectors have adapted very well to using laptop computers for commentary, which has eliminated the need to transcribe the commentary to electronic format.
Simplified QC: Having most of the field information delivered in electronic format has made the QC process at the districts much simpler. Preliminary feedback on the new NBI and safety inspection database shows that it is considered easier to use and much more powerful than the older application it replaces, which also contributes to making the QC process at the districts much easier.
Reduced Use of Paper: Virtually all paper traffic from the districts to the Boston office has been eliminated, even though the absence of a WAN requires transferring information via ‘mail net’ using optical disks. This decline in paper traffic has significantly reduced the records management burden at the Boston office.
Improved Response Time: Providing network access to all inspection information at the Boston office has dramatically reduced access time to pertinent information. This in turn has improved response time to emergency situations and improved the quality of recommendations and the confidence in decision making.
Empowered Staff: Perhaps most importantly, the introduction of the various technologies combined with the frequent training programs appears to have empowered district and field staff. This is showing up clearly in the increased quantity and improved quality of information, the level of feedback on all topics, and a new found enthusiasm which translates to overall productivity gains.
Finally, it is felt that a comprehensive database of inspection information that is easy to access will greatly improve the institutional memory of the department. This will mean less information is permanently lost as personnel leave or are transferred, and much steeper learning curve for incoming personnel.
COST: The total capital expenditure to date on this automation is estimated to be $2 million. This includes the cost of all hardware, software, installation and testing, training and annual maintenance contracts for the last four years. No significant increase in staffing was required to achieve the benefits listed above; the entire plan was executed by two staff engineers at the Boston office. Today the various systems continue to be managed with the addition of only one staff engineer at the Boston office to manage the QC and input process for the field information from the districts.
FUTURE PLANS:
The following items remain in the plan, which is targeted for completion by the end of calendar year 1998:
Complete Implementation of PDA Based Pontis Data Collection: This is awaiting the completion of user and system administrator training, and establishment of field procedures. The technology should be fully implemented by September 1997.
Complete Implementation of the New NBI and Safety Inspection Database: The development will be complete pending any final changes based on feedback from preliminary tests. Remote access to the central database from the districts needs to be configured and tested. The system should be put into full use after user training is completed by September 1997.
Backfiling: The backfiling of historical information to the multimedia information management system must be completed. All new information being created by the inspection program is stored to the optical archive in electronic format, however information generated prior to the implementation of the multimedia information management system must be brought on-line in order to complete the information base and eliminate reliance on paper. Completing the backfiling will also allow the department to initiate a transfer of historical information back to the districts, which will in turn allow the inspectors to take subsets of the historical information to the field for review using the detached viewing software provided by the multimedia information management system. A proposal for backfiling is currently under consideration; the project should begin in the next few months and finish by the middle of 1998.
Develop PDA Based Data Collection for the NBI and Safety Inspection Database: Since no product has been identified that will meet the requirements of the department, the software will have to be developed as a custom application. This application will allow for the collection of selected rating information and commentary and facilitate seamless exchange of data to and from the PDA and the new NBI and safety inspection database. It will allow inspectors to finally eliminate all paper in the field. The software development and user training will either be performed in house or by contractors. The project should be initiated early in 1998 for completion by the end of 1998.
Restructure Field Inspection and Management Procedures: Although procedures are being modified incrementally to incorporate each new technology, it is necessary to analyze the total impact of the technologies on the department’s workflow and identify any further efficiencies that can be derived. This function is best performed by a consultant familiar with bridge inspection procedures and the selected automation. A proposal for this project is currently under review and is slated to begin later in 1997. The project’s goal will be to produce a comprehensive procedures document that the department can use in its daily operations. This document will also set up guidelines for bridge inspections performed by consultants, including procedures to ensure that all information developed under contract is delivered in an electronic format compatible with MHD’s systems.
Establish WAN Connection Between Boston Office and Districts: This is the final step in creating an all electronic path for bridge inspection information at MHD. Once this is available, the optical disk transfers can be eliminated, video digitization can be performed at the districts, and a significant portion of the QC and archival burden can be transferred to the districts. In addition, districts can access the multimedia information management system, the new NBI and safety inspection database, and Pontis (if necessary) directly without having to rely on slow modem connections. No project has been identified to implement the WAN, however several alternatives are under consideration.
Integration With Other Departments: Finally, information in final form from other departments within MHD needs to be entered to the multimedia information system in order to realize the goal of making it comprehensive source for all non-rating information. It is hoped that as access to the system is made available to different departments, they will realize the benefits of having their information on line.
CONCLUSION:
In order to make the best use of limited resources, MHD has sought to improve the productivity and performance of its bridge inspection program through innovative automation. The results to date have shown how judicious use of technology can help shift the emphasis in bridge inspection programs from information gathering to information assessment, management and decision making. The goal is to free engineers from the administrative burden of records management to let them focus on more important tasks—engineering and infrastructure management.
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