Evaluation of bridge inspection and assessment in Illinois

Transportation Research Record, 2001

The congressionally mandated National Bridge Inspection Program requires states to inspect periodically all highway bridges on public roads, among other activities; visual inspection (VI) is the primary tool used to perform these inspections. A survey was conducted to help determine current policies and practices that may affect the accuracy and reliability of VI. The survey had three main objectives: to compile a "state of the practice" for bridge inspection, particularly as it pertains to VI; to gather information about bridge inspection management to study how inspection management may influence the reliability of inspections; and to gather data about the current use of nondestructive evaluation technologies and to identify current and future research needs. State departments of transportation, local departments of transportation, and select bridge inspection contractors participated in the survey. Conclusions drawn from this study indicate that the use of nondestructive evaluation has increased since 1993 and that the use of American Society of Nondestructive Testing Level III-certified personnel is increasing. VI was cited as the most frequently used nondestructive evaluation technique; however, vision testing for inspectors is almost nonexistent. Typically, professional engineers were not on site for inspections. State departments of transportation indicated a large demand for future research into the nondestructive evaluation of prestressed concrete superstructures and concrete decks. The congressionally mandated National Bridge Inspection Program requires states to periodically inventory, inspect, and rate all highway bridges on public roads. The research described in this paper, performed by the Federal Highway Administration's (FHWA's) Nondestructive Evaluation Validation Center (NDEVC), focuses on evaluating current policies and practices that may affect the reliability of visual inspection (VI) for highway bridges. This investigation had three main objectives. The first objective was to compile a "state of the practice" for bridge inspection, particularly as it pertains to VI. The second objective was to gather information about bridge inspection management and to assess how inspection management may influence the reliability of inspections. The final objective was to gather data about the current use of nondestructive evaluation (NDE) technologies and to attempt to identify current and future research needs. The target participants for the survey included state departments of transportation (DOTs), county DOTs from Iowa, and select bridge inspection contractors.

This project was conducted in cooperation with the Texas Department of Transportation and the Federal Highway Administration. The authors thank the members of TxDOT's Project Monitoring Committee-Tom Yarbrough (BRG), Adrian Janak (TSD), Alan Kowalik (BRG), and Joe Riba (BRG). Special thanks go to the Project Director Tom Yarbrough for his assistance and advice; Taylor Buckner (FTW) for providing the list of current and desired features for the Fort Worth District Bridge Inspection Reports System; Craig Cox (CST-MAP) for providing guidance in using the TxDOT MapZapper database application for mapping bridge inspection data; and district personnel in San Antonio, Fort Worth, Wichita Falls, Houston, Brownwood, and San Angelo who provided feedback to the researchers' presentations on a proposed BMIS. vii TABLE OF CONTENTS List of Figures .

Transportation Research Record, 2001

Routine inspection is the most common type of highway bridge inspection completed to satisfy the requirements of the National Bridge Inspection Standards. Routine inspections of highway bridges are typically completed using only visual inspection (VI) and rely heavily on subjective assessments made by bridge inspectors. Given this practice and the fact that VI may have limitations that affect its reliability, the Federal Highway Administration completed a comprehensive study to examine the reliability of VI as it is currently practiced in the United States. The accuracy and reliability of condition ratings generated through routine inspections of six in-service and decommissioned highway bridges were studied. These timed inspections were completed in normal summer weather conditions under direct observation. To ensure that results from this study would be applicable to normal bridge inspections, state department of transportation bridge inspectors made up the study sample, which included 49 inspectors from 25 states, representing a diverse cross section of the bridge inspector population. Results of the study indicate that routine inspections are completed with significant variability. Specifically, 95 percent of primary bridge element condition ratings will vary within two rating points of the average, and only 68 percent of these ratings will vary within one rating point. Additionally, the National Bridge Inspection Standards definitions of condition rating may not be sufficiently refined to allow for reliable routine inspection results.

2016

inspections must be detailed and reliable so that it can be used in INDOT's bridge management program to evaluate bridge condition, predict deterioration, and guide decision making. Findings • Data required by the Federal Highway Administration is sufficient for effective element level bridge inspections in the short term. This inspection program should be expanded over time to make it more useful to INDOT. Element level data is commonly used for fund allocation, deterioration modeling, and making preservation, repair, and replacement decisions. Element level data can also be used to predict upcoming maintenance or repair work. • Many states have long profited from the collection of element level inspection data. Most of the benefits are realized in the form of more reliable methods of

2001

Visual Inspection is the predominant nondestructive evaluation technique used in bridge inspections. However, since implementation of the National Bridge Inspection Standards in 1971, a comprehensive study of the reliability of Visual Inspection as it relates to highway bridge inspections has not been conducted. The goals of the study include: providing overall measures of the accuracy and reliability of Routine and In-Depth Visual Inspections, studying the influence of several key factors that affect Routine and In-Depth Inspections, and studying the differences between State inspection procedures and reports. Ten inspection tasks were performed at seven test bridges using State bridge inspectors. The sample of participating inspectors included 49 inspectors from 25 State agencies. Inspectors were provided with common information, instruction, and tools. Inspector characteristics were measured through self-report questionnaires, interviews, and direct measurements. Routine Inspections were completed with significant variability, and the Condition Ratings assigned varied over a range of up to five different ratings. It is predicted that only 68 percent of the Condition Ratings will vary within one rating point of the average, and 95 percent will vary within two points. Factors that appeared to correlate with Routine Inspection results include Fear of Traffic; Visual Acuity and Color Vision; Light Intensity; Inspector Rushed Level; and perceptions of Maintenance, Complexity, and Accessibility. In-Depth Inspections using Visual Inspection alone are not likely to detect or identify the specific types of defects for which the inspection is prescribed, and may not reveal deficiencies beyond those that could be noted during a Routine Inspection. The overall thoroughness with which inspectors completed one of the In-Depth tasks tended to have an impact on the likelihood of an inspector detecting weld crack indications. Other factors that may be related to In-Depth Inspection accuracy include: time to complete inspection, comfort with access equipment and heights, structure complexity and accessibility, viewing of welds, flashlight use, and number of annual inspections performed. The State procedural and reporting tasks indicated that most States follow similar procedural and reporting criteria. Several inconsistencies were noted with the use of the element-level inspection systems, but it is not known if these variations are the result of State practices or inspector use. Deck delamination surveys were found to have significant variability, with only a few teams performing a delamination survey as part of the Routine Inspection.

2007

Bridges constitute critical nodes of transportation systems, and therefore, ensuring their continuous operation is of the utmost importance for safe and efficient transportation. Currently, visual inspections and simplified analysis techniques are employed for condition assessment and for decision making about bridges. A novel approach to bridge condition assessment is Structural Health Monitoring (SHM), defined as the measurement of operating and loading environment through use of a system to track and evaluate incidents, anomalies, damage and deterioration. The objective of this project was to develop an SHM framework for integrative information system design. This framework is expected to improve bridge safety, enhance efficient operation and enable effective and low cost maintenance by taking advantage of new technological advances. Movable bridges are considered as the focus bridge type because these bridges exhibit various structural, maintenance and operational problems. In t...

Proceedings of the Institution of Civil Engineers – Bridge Engineering, 2022

Visual inspection remains key for assessing the condition of bridges and hence assisting with planning and maintenance activities. There have been many efforts to improve or supplement visual inspection processes using new sensing technologies and data capture methods to usher in an era of ‘smart bridges’ or ‘smart infrastructure’. One method to improve data capture is a ‘remote inspection’ where inspectors use digital photographs of a bridge to identify and grade structural defects to the standard of a ‘general inspection’. In this paper, survey data are presented to help formulate a preliminary assessment of the potential for engineers to implement this possible evolution of the visual inspection process. A potential schema for remote visual inspections is developed and presented as a conceptual web application. The focus on the development of the schema includes the need for ease of use by inspectors and integration of collected digital data into bridge management systems. The suggested platform is seen as a transitional method to aid in the long-term implementation of further automation of the inspection process. The system architecture is provided along with possible technologies that may support or enhance it, as well as a discussion of the potential barriers to implementation.

Proceedings of the ICE - Bridge Engineering, 2015

This paper discusses the role of visual inspections in the UK highways bridge inspection regime, and how current practice results in inspection data that are less reliable than they could, and should, be. Evidence that visual inspections in general are not totally reliable is discussed. Similar problems have been overcome in other areas, such as pavement inspection, by using technological aids during the data collection and inspection process. It is hoped that better bridge condition data could be obtained by making use of technology to assist the visual inspection process on bridges. Some of the ways in which images could be recorded to make the inspection process more reliable and reproducible are discussed, and a prototype system that has been developed with the aim of providing a full, highresolution image record of the visual condition of a bridge, which is suitable for use, is presented. Bridge Engineering Can technology improve routine visual bridge inspections? McRobbie, Wright and Chan

Transportation Research Record, 2001

In-depth inspection is one of the two most common types of bridge inspection. In contrast with routine inspection, in-depth inspection is a close-up, hands-on inspection that generally covers only a portion of a bridge. The Federal Highway Administration's Nondestructive Evaluation Validation Center recently completed a study of the reliability of visual inspection of highway bridges. Part of this study focused on the accuracy and reliability of in-depth inspections as completed by state bridge inspectors from across the United States. Three in-depth inspection tasks were completed, two focusing on the inspection of steel superstructures and one focusing on the inspection of concrete bridge decks. Visual inspection techniques were used, with the possible use of simple inspection tools. Results show that many in-depth inspections completed by state bridge inspectors do not accurately represent the condition of the structure. In-depth inspections of the steel superstructures revealed that certain deficiencies for which this type of inspection is frequently prescribed were rarely detected. Specifically, only a small minority of state bridge inspectors located the presence of any of the existing crack indications. The delamination survey of a concrete bridge deck indicated that the accuracy of this type of inspection is relatively poor. Very few state bridge inspection teams provided results that could be considered to portray the condition of the deck accurately. Publication of this paper sponsored by Committee on Structures Maintenance and Management. FIGURE 9 Areas of the deck indicated to contain delaminations by at least five teams compared with actual delaminated areas.

2014

Improving bridge safety, reliability, and the allocation of bridge inspection resources are the goals of the proposed risk-based bridge inspection practices. Currently, most bridges in the United States are inspected at a fixed calendar interval of 24 months, without regard to the condition of the bridge. Newer bridges with little or no damage are inspected with the same frequency as older, more deteriorated bridges thus creating inefficiency in the allocation of inspection resources. The proposed methodology incorporates reliability theory and expert elicitation from the Indiana Department of Transportation's Risk Assessment Panel, developed during this research, to rationally determine bridge inspection needs. Assessments are made based on the likelihood and consequence of failure for specific bridge components. The likelihood of failure is determined through attributes based on design, loading, and condition characteristics while the consequence of failure is based on expected structural capacity, public safety, and serviceability. By combining the expressions of likelihood and consequence for each component, an optimum inspection interval for the entire bridge can be determined through the use of risk matrices. The methodology was evaluated through case studies involving Indiana bridges. Over 30 years of historical inspection reports were utilized in the back-casting process to evaluate deterioration levels and assess the adequacy of the risk criteria. Results of the case studies conducted during the research indicated that the risk analysis procedures provided suitable inspection intervals ranging from 24 to 72 months for Indiana bridges.