Technical Report Documentation Page 1. Report No. 2. Government Accession No. 3. Recipient’s Catalog No. TX-00/0-3970-1 4. Title and Subtitle 5. Report Date REMOTE BRIDGE SCOUR MONITORING: May 1999 A PRIORITIZATION AND IMPLEMENTATION GUIDELINE 7. Author(s) 6. Performing Organization Code Carl Haas, José Weissmann, and Tom Groll 8. Performing Organization Report No. Research Report 7-3970-1 9. Performing Organization Name and Address 10. Work Unit No. (TRAIS) Center for Transportation Research Department of Civil Engineering The University of Texas at Austin University of Texas at San Antonio 11. Contract or Grant No. 3208 Red River, Suite 200 6900 N. Loop 1604 West Research Study 7-3970 Austin, TX 78705-2650 San Antonio, TX 78249 12. Sponsoring Agency Name and Address 13. Type of Report and Period Covered Texas Department of Transportation Research Report Research and Technology Transfer Section/Construction Division September 1997 – May 1999 P.O. Box 5080 14. Sponsoring Agency Code Austin, TX 78763-5080 15. Supplementary Notes Project conducted in cooperation with the Federal Highway Administration. 16. Abstract Having the largest bridge population in the nation, the state of Texas stands to gain much through the development of bridge scour-monitoring and evaluation practices. Because it has such a large bridge population to manage, the Texas Department of Transportation (TxDOT) needs a logical and low-cost method of prioritizing and monitoring bridges for scour damage. An algorithm based on code contained in the BRINSAP database can be used effectively to prioritize bridge sites for further consideration of scour countermeasure implementation. Remote mechanical monitoring is an emerging method for detecting and tracking bridge scour. Mechanical scour monitors equipped with data telemetry equipment can provide a safe and effective means of tracking scour at bridge piers and abutments. Because remote mechanical scour monitoring is a relatively new approach, TxDOT should support extensive research and planning regarding methods of system development and implementation. 17. Key Words 18. Distribution Statement No restrictions. This document is available to the public through Bridge scour, monitoring systems, prioritization the National Technical Information Service, Springfield, Virginia 22161. 19. Security Classif. (of report) 20. Security Classif. (of this page) 21. No. of pages 22. Price Unclassified Unclassified 194 Form DOT F 1700.7 (8-72) Reproduction of completed page authorized REMOTE BRIDGE SCOUR MONITORING: A PRIORITIZATION AND IMPLEMENTATION GUIDELINE by Carl Haas José Weissmann Tom Groll Research Report Number 3970-1 Research Project 7-3970 Project title: Develop a Remote Automatic Monitoring and Public Information System for Hazardous Conditions Conducted for the TEXAS DEPARTMENT OF TRANSPORTATION by the CENTER FOR TRANSPORTATION RESEARCH Bureau of Engineering Research THE UNIVERSITY OF TEXAS AT AUSTIN and the Department of Civil Engineering THE UNIVERSITY OF TEXAS AT SAN ANTONIO May 1999 iv ABSTRACT Having the largest bridge population in the nation, the state of Texas stands to gain much through the development of bridge scour-monitoring and evaluation practices. Because it has such a large bridge population to manage, the Texas Department of Transportation (TxDOT) needs a logical and low-cost method of prioritizing and monitoring bridges for scour damage. An algorithm based on code contained in the BRINSAP database can be used effectively to prioritize bridge sites for further consideration of scour countermeasure implementation. Remote mechanical monitoring is an emerging method for detecting and tracking bridge scour. Mechanical scour monitors equipped with data telemetry equipment can provide a safe and effective means of tracking scour at bridge piers and abutments. Because remote mechanical scour monitoring is a relatively new approach, TxDOT should support extensive research and planning regarding methods of system development and implementation. DISCLAIMERS The contents of this report reflect the views of the authors, who are responsible for the facts and the accuracy of the data presented herein. The contents do not necessarily reflect the official views or policies of the Texas Department of Transportation. This report does not constitute a standard, specification, or regulation. There was no invention or discovery conceived or first actually reduced to practice in the course of or under this contract, including any art, method, process, machine, manufacture, design or composition of matter, or any new and useful improvement thereof, or any variety of plant, which is or may be patentable under the patent laws of the United States of America or any foreign country. NOT INTENDED FOR CONSTRUCTION, BIDDING, OR PERMIT PURPOSES Carl Haas, P.E. (Texas No. 018753) Research Supervisor v ACKNOWLEDGMENTS The researchers thank Mr. Anthony Schneider (DES), TxDOT project director, and T. D. Ellis (PAR), TxDOT program coordinator, for their assistance with this project. Special thanks also go to Mr. Gerald Freytag of TxDOT’s Yoakum District for taking the time to provide thoughtful and meaningful responses to the many questions imposed on him during the course of this project. Research performed in cooperation with the Texas Department of Transportation. vi TABLE OF CONTENTS CHAPTER 1. INTRODUCTION ............................................................................................. 1 1.1 BACKGROUND..................................................................................................... 1 1.1.1 Remote Monitoring of Bridge Scour........................................................ 1 1.1.2 Motivation for Study................................................................................ 2 1.1.3 Applicable Regulations ............................................................................ 3 1.1.4 Description of the Scour Process ............................................................. 4 1.2 PURPOSE ............................................................................................................... 5 1.3 SCOPE .................................................................................................................... 6 1.4 ORGANIZATION .................................................................................................. 6 CHAPTER 2. BRIDGE SCOUR EVALUATION AND MONITORING PRACTICES ........ 9 2.1 COMPONENTS OF A SCOUR EVALUATION PROGRAM.............................. 9 2.2 BRIDGE SCOUR EVALUATION PRACTICES IN TEXAS............................... 9 2.2.1 The BRINSAP Database ........................................................................ 10 2.2.2 Inspection Procedures and Data Transmission....................................... 13 2.2.3 Initial Screening Method for Scour Evaluation (SVEAR)..................... 15 2.2.4 Texas Secondary Evaluation and Analysis for Scour ............................ 16 2.3 SCOUR MONITORING AND SITE PRIORITIZATION................................... 17 2.3.1 Estimation of the Number of Bridges to be Prioritized.......................... 20 2.3.2 Selection of Prioritization Parameters.................................................... 22 2.3.3 The Role of Monitoring in a Bridge Management System .................... 23 CHAPTER 3. DEVELOPMENT OF THE PRIORITIZATION MODEL ............................. 27 3.1 COMPONENTS OF THE PRIORITIZATION MODEL..................................... 27 3.1.1 Rank Ordering of the Prioritization Parameters..................................... 27 3.1.2 Assignment of Weights to the Parameters ............................................. 28 3.1.3 Assignment of Scores to the Parameters................................................ 30 3.2 PRIORITIZATION MODEL PERFORMANCE AND CALIBRATION ........... 35 3.2.1 The Initial Model Output........................................................................ 36 3.2.2 Bridge Lists Prioritized by District Engineers ....................................... 37 3.2.3 Prioritization Model Performance.......................................................... 38 3.2.4 Prioritization Model Calibration ............................................................ 39 3.3 COMPARISON BETWEEN PRIORITIZATION METHODS ........................... 40 3.3.1 The CAESAR Scour Evaluation for Prioritization Method................... 40 3.3.2 The HYRISK Prioritization Method ...................................................... 41 CHAPTER 4. REMOTE SCOUR-MONITORING SYSTEMS............................................. 45 4.1 REVIEW OF AVAILABLE SCOUR-MONITORING SYSTEMS..................... 45 4.1.1 Magnetic Sliding Collar Monitoring Systems........................................ 45 4.1.2 Low-Cost Sonic Fathometer Monitoring Systems................................. 46 4.1.3 Sounding Rod Scour-Monitoring Systems............................................. 47 4.1.4 Other Buried Devices for Scour Monitoring.......................................... 48 vii 4.1.5 Capabilities and Limitations of Scour-Monitoring Equipment.............. 49 4.2 SURVEY OF OTHER STATES' EXPERIENCE WITH SCOUR MONITORING.................................................................................... 52 4.3 DOCUMENTATION OF SCOUR-MONITORING INSTALLATIONS IN TEXAS......................................................................................................... 53 4.3.1 Magnetic Sliding Collar System Installation in the Abilene District..... 54 4.3.2 Sonar System Installation in the Houston