Asset Management for Retaining Walls Final report Submitted to Michigan Department of Transportation ORBP Number OR15-114 by Adda Athanasopoulos Zekkos, PhD (PI) Jerome Lynch, PhD (coPI) Dimitrios Zekkos, PhD, PE (coPI) Athena Grizi, PhD (PostDoc) Kidus Admassu (Graduate Student Researcher) Brahim Benhamida, PE (MSG) Rich J. Spino, PE (MSG) Matthew Mikolajczyk, PE (formerly MSG) Department of Civil & Environmental Engineering University of Michigan 2350 Hayward St Ann Arbor, MI 48109-2125 March 2020 TECHNICAL REPORT DOCUMENTATION PAGE 1. Report No. 2. Government Accession No. 3. MDOT Project Manager SPR­1676 Eric Burns 4. Title and Subtitle 5. Report Date Asset Management for Retaining Walls March 23, 2020 6. Performing Organization Code 7. Author(s) 8. Performing Organization Report No. Adda Athanasopoulos-Zekkos, Jerome Lynch, Dimitrios Zekkos, None Athina Grizi, Kidus Admassu, Brahim Benhamida, Rich J. Spino, Matthew Mikolajczyk 9. Performing Organization Name and Address 10. Work Unit No. (TRAIS) The Regents of the University of Michigan 3003 South State St. Ann Arbor, MI 48109 11. Contract or Grant No. 2016-0068 Z2 12. Sponsoring Agency Name and Address 13. Type of Report and Period Covered Michigan Department of Transportation Final Report Office of Research and Best Practices 10/01/2016 to 12/31/2019 8885 Ricks Road Lansing, MI 48917 14. Sponsoring Agency Code 15. Supplementary Notes 16. Abstract The work described here represents an attempt to develop a comprehensive risk management framework for the asset management of retaining wall structures. The work presented includes the development of a sensing strategy that can be used by structural inspectors to assess the coupled performance of the wall structure and the geotechnical system it supports. A reliability framework was developed using first-order reliability methods (FORM) to assess the reliability factor (β) for wall components and incorporates the consequences of failure with the estimated structural reliability factors to provide a basis for risk assessment of retaining walls. A new inspection manual was developed to reflect the instrumentation strategies and risk analyses developed. 17. Key Word 18. Distribution Statement Retaining Walls, Asset Management, Field No restrictions. This document is available Monitoring, Ground Settlement Thresholds. to the public through the Michigan Department of Transportation. 19. Security Classify. (of this report) 20. Security Classify. (of this page) 21. No. of Pages 22. Price Unclassified Unclassified 334 i TABLE OF CONTENTS Technical Report Documentation Page ............................................................................................ i Table of Contents ............................................................................................................................. ii List of Figures ...................................................................................................................................v List of Tables .................................................................................................................................. viii List of Symbols ................................................................................................................................ ix List of Abbreviations ....................................................................................................................... xi Acknowledgements ......................................................................................................................... xii Executive Summary ........................................................................................................................ xiii 1. Introduction ...........................................................................................................................1 1.1. Organization of report ..................................................................................................1 1.2. Objectives ....................................................................................................................1 1.3. Review of Existing Guidelines ....................................................................................3 1.3.1. Brutus and Tauber (2009) Synthesis Report and recommendations ...............16 1.3.2. Minnesota DOT Synthesis Report (2013).......................................................18 1.3.3. National Park Service (NPS) Wall Inventory and Condition Assessment Program (WIP) (2010) ....................................................................................19 1.3.4. North Carolina DOT (2015) ............................................................................25 1.3.5. Colorado DOT (2003) .....................................................................................33 1.3.6. Colorado DOT (2016) .....................................................................................37 1.3.7. Wisconsin DOT (2017) ...................................................................................47 1.3.8. Alaska DOT (2013) .........................................................................................52 1.3.9. Pennsylvania DOT (2010) ..............................................................................54 1.3.10. Nebraska DOR (2009) ....................................................................................58 1.3.11. British Columbia Ministry of Transportation - Canada (2013) ......................60 1.3.12. Victoria Highway Department - Australia (2014) ..........................................61 1.3.13. Kentucky Transportation Cabinet (1998) .......................................................66 1.3.14. City of Seattle (2014) ......................................................................................70 1.3.15. The City of Cincinnati (2015) .........................................................................75 1.4. MSE Wall Issues and Guidelines ................................................................................78 1.5. Retaining Wall Monitoring and Health Assessment Technologies ............................91 1.5.1. LiDAR Mapping and Assessment ..................................................................94 1.5.2. Photogrammetry for condition assessment of ERS ........................................96 1.5.3. Inspection of retaining walls using Ground Penetrating Radar (GPR) ...........98 1.5.4. Condition Assessment of Mechanically Stabilized Earth (MSE) Walls ........100 2. Design and Deployment of Wireless Monitoring Systems for the I-696 and M-10 Retaining Walls ...................................................................................................................103 2.1. Introduction ................................................................................................................103 2.2. Retaining Wall Systems .............................................................................................105 2.2.1. Overview of the I-696 and M-10 Retaining Wall Systems ............................105 ii 2.2.2. On-Site Visual Assessment ............................................................................105 2.3. Long-Term Monitoring System Design and Installation ...........................................106 2.3.1. Sensor Placement on the Wall Panels ............................................................107 2.3.2. Sensing Transducers ......................................................................................111 2.3.3. Wireless Sensing Node ..................................................................................113 2.3.4. Dual-Axis Tilt Calculation ............................................................................115 2.3.5. Packaging Wireless Sensor Nodes .................................................................116 2.3.6. Field Installation on the Wall Systems ..........................................................116 2.4. Data Acquisition Process ...........................................................................................117 3. Response Data Analysis of the I-696 and M-10 Retaining Wall Systems .........................122 3.1. Introduction ................................................................................................................122 3.2. Performance of the Wireless Sensor Units ................................................................123 3.3. Tall I-696 Retaining Wall Panel ................................................................................125 3.3.1. Description of the Wall System .....................................................................125 3.3.2. Daily Mean Responses ...................................................................................128 3.3.3. Response Scatter Plots ...................................................................................132 3.3.4. Wall Deflection Curves..................................................................................134 3.4. Short I-696 Retaining Wall System ...........................................................................146 3.5. M-10 Retaining Wall System....................................................................................1 51 3.5.1. Description of the Wall System .....................................................................151 3.5.2. Preliminary Observations from 2012 and 2013 .............................................153 3.5.3. Daily Mean Responses and Scatter Plots .......................................................155