National Academies Press: OpenBook
Page i
Suggested Citation:"Front Matter." National Academies of Sciences, Engineering, and Medicine. 2019. Proposed Modifications to AASHTO Culvert Load Rating Specifications. Washington, DC: The National Academies Press. doi: 10.17226/25673.
×
Page R1
Page ii
Suggested Citation:"Front Matter." National Academies of Sciences, Engineering, and Medicine. 2019. Proposed Modifications to AASHTO Culvert Load Rating Specifications. Washington, DC: The National Academies Press. doi: 10.17226/25673.
×
Page R2
Page iii
Suggested Citation:"Front Matter." National Academies of Sciences, Engineering, and Medicine. 2019. Proposed Modifications to AASHTO Culvert Load Rating Specifications. Washington, DC: The National Academies Press. doi: 10.17226/25673.
×
Page R3
Page iv
Suggested Citation:"Front Matter." National Academies of Sciences, Engineering, and Medicine. 2019. Proposed Modifications to AASHTO Culvert Load Rating Specifications. Washington, DC: The National Academies Press. doi: 10.17226/25673.
×
Page R4
Page v
Suggested Citation:"Front Matter." National Academies of Sciences, Engineering, and Medicine. 2019. Proposed Modifications to AASHTO Culvert Load Rating Specifications. Washington, DC: The National Academies Press. doi: 10.17226/25673.
×
Page R5
Page vi
Suggested Citation:"Front Matter." National Academies of Sciences, Engineering, and Medicine. 2019. Proposed Modifications to AASHTO Culvert Load Rating Specifications. Washington, DC: The National Academies Press. doi: 10.17226/25673.
×
Page R6
Page vii
Suggested Citation:"Front Matter." National Academies of Sciences, Engineering, and Medicine. 2019. Proposed Modifications to AASHTO Culvert Load Rating Specifications. Washington, DC: The National Academies Press. doi: 10.17226/25673.
×
Page R7

Below is the uncorrected machine-read text of this chapter, intended to provide our own search engines and external engines with highly rich, chapter-representative searchable text of each book. Because it is UNCORRECTED material, please consider the following text as a useful but insufficient proxy for the authoritative book pages.

NCHRP Web-Only Document 268: Proposed Modifications to AASHTO Culvert Load Rating Specifications Mark Mlynarski Michael Baker International Moon Township, PA Chad Clancy Modjeski and Masters Mechanicsburg, PA Timothy J. McGrath Consultant Arlington, MA Michael G. Katona Consultant Gig Harbor, WA Contractor’s Final Report for NCHRP Project 15-54 Submitted July 2019 ACKNOWEDGMENT This work was sponsored by the American Association of State Highway and Transportation Officials (AASHTO), in cooperation with the Federal Highway Administration, and was conducted in the National Cooperative Highway Research Program (NCHRP), which is administered by the Transportation Research Board (TRB) of the National Academies of Sciences, Engineering, and Medicine. COPYRIGHT INFORMATION Authors herein are responsible for the authenticity of their materials and for obtaining written permissions from publishers or persons who own the copyright to any previously published or copyrighted material used herein. Cooperative Research Programs (CRP) grants permission to reproduce material in this publication for classroom and not-for-profit purposes. Permission is given with the understanding that none of the material will be used to imply TRB, AASHTO, FAA, FHWA, FMCSA, FRA, FTA, Office of the Assistant Secretary for Research and Technology, PHMSA, or TDC endorsement of a particular product, method, or practice. It is expected that those reproducing the material in this document for educational and not-for-profit uses will give appropriate acknowledgment of the source of any reprinted or reproduced material. For other uses of the material, request permission from CRP. DISCLAIMER The opinions and conclusions expressed or implied in this report are those of the researchers who performed the research. They are not necessarily those of the Transportation Research Board; the National Academies of Sciences, Engineering, and Medicine; or the program sponsors. The information contained in this document was taken directly from the submission of the author(s). This material has not been edited by TRB.

The National Academy of Sciences was established in 1863 by an Act of Congress, signed by President Lincoln, as a private, non- governmental institution to advise the nation on issues related to science and technology. Members are elected by their peers for outstanding contributions to research. Dr. Marcia McNutt is president. The National Academy of Engineering was established in 1964 under the charter of the National Academy of Sciences to bring the practices of engineering to advising the nation. Members are elected by their peers for extraordinary contributions to engineering. Dr. John L. Anderson is president. The National Academy of Medicine (formerly the Institute of Medicine) was established in 1970 under the charter of the National Academy of Sciences to advise the nation on medical and health issues. Members are elected by their peers for distinguished contributions to medicine and health. Dr. Victor J. Dzau is president. The three Academies work together as the National Academies of Sciences, Engineering, and Medicine to provide independent, objective analysis and advice to the nation and conduct other activities to solve complex problems and inform public policy decisions. The National Academies also encourage education and research, recognize outstanding contributions to knowledge, and increase public understanding in matters of science, engineering, and medicine. Learn more about the National Academies of Sciences, Engineering, and Medicine at www.national-academies.org. The Transportation Research Board is one of seven major programs of the National Academies of Sciences, Engineering, and Medicine. The mission of the Transportation Research Board is to increase the benefits that transportation contributes to society by providing leadership in transportation innovation and progress through research and information exchange, conducted within a setting that is objective, interdisciplinary, and multimodal. The Board’s varied committees, task forces, and panels annually engage about 7,000 engineers, scientists, and other transportation researchers and practitioners from the public and private sectors and academia, all of whom contribute their expertise in the public interest. The program is supported by state transportation departments, federal agencies including the component administrations of the U.S. Department of Transportation, and other organizations and individuals interested in the development of transportation. Learn more about the Transportation Research Board at www.TRB.org.

C O O P E R A T I V E  R E S E A R C H  P R O G R A M S  CRP STAFF FOR NCHRP Web-Only Document 268 Christopher J. Hedges, Director, Cooperative Research Programs Lori L. Sundstrom, Deputy Director, Cooperative Research Programs Waseem Dekelbab, Senior Program Officer Megan A. Chamberlain, Senior Program Assistant Eileen P. Delaney, Director of Publications Natalie Barnes, Associate Director of Publications Kathleen Mion, Senior Editorial Assistant NCHRP PROJECT 15-54 PANEL Field of Design—General Design Timothy A. Armbrecht, Illinois DOT, Springfield, IL (Chair) Thomas Kevin Koch, Garner, NC Yi Qiu, Texas DOT, Austin, TX Holly O'Neal Thomas, St.Tammany Parish Government, Covington, LA Bradley M. Wagner, Michigan DOT, Lansing, MI James L. Withiam, D'Appolonia Engineering Division of Ground Technology, Inc., Monroeville, PA Lubin Gao, FHWA Liaison Stephen F. Maher, TRB Liaison Author Acknowledgements The research reported herein was performed under NCHRP 15-54 by Michael Baker International, Modjeski & Masters, Inc., Timothy McGrath (consultant), and Michael Katona (consultant). Michael Baker International was the contractor for this study. The work undertaken by Modjeski & Masters, Inc, Timothy McGrath, and Michael Katona was under a subcontract with Michael Baker Jr., Inc. Mark Mlynarski, P.E, Project Manager, Michael Baker Jr., Inc., and Chad M. Clancy, P.E., Modjeski & Masters, Inc. were the Co-principal investigators. The other authors of this report and significant contributors to this research were Timothy J. McGrath, Ph.D., and Michael G. Katona, Ph.D. The work was performed under the general supervision of Mr. Mlynarski and Mr. Clancy. The software development and data extraction work at Michael Baker International was performed under the supervision of Mr. Mlynarski with the assistance of Krisha Kennelly, P.E., Technical Manager-Bridge Software. Field assistance, Michael Pichura, P.E., Aaron Colorito, P.E., and Jerry Jones P.E. The work at Modjeski & Masters was performed under the supervision of Mr. Clancy with the instrumentation assistance of Dave Barrett, P.E., the technical guidance of Tom Murphy, P.E. Ph.D., and the 3D modeling assistance of Reza Baie and Jesus M. Villanueva. Special thanks to the states of Massachusetts, Maryland, Ohio, and Pennsylvania for their willingness to provide structures to be tested, staff to assist in the field testing, traffic control and loaded trucks for use in the field testing. Also, thanks to the State Police of those states for their efforts in weighing to loaded vehicles. While no culverts were selected for their state, thanks also the state of Illinois for volunteering to offer the field testing of their culverts. Also, a special thanks to Jerry Silagyi, P.E. of Lane Enterprises, Joel Hahm, P.E from Big R Bridge, and Kevin Grant of Contech for assisting in locating culverts, models, and plans for this research.

v C O N T E N T S SUMMARY .............................................................................................................................................. VII  CHAPTER 1 ............................................................................................................................................... 1  Background.. ......................................................................................................................................... 1  Surveying / Soliciting Data.............................................................................................................. 1  CHAPTER 2 ............................................................................................................................................... 3  Research Approach .............................................................................................................................. 3  Development of Field Test Program ................................................................................................................... 4  Culverts Selected ...................................................................................................................................................... 4  Review and Selection Process ................................................................................................................................... 4  Selection Criteria .................................................................................................................................................. 4  Vendors ................................................................................................................................................................ 4  Pennsylvania (DOT and County) ........................................................................................................................... 5  Maryland DOT ...................................................................................................................................................... 5  Ohio DOT .............................................................................................................................................................. 5  Massachusetts DOT .............................................................................................................................................. 5  Illinois DOT ........................................................................................................................................................... 5  Executing the Field Testing Program ........................................................................................................................ 7  Culvert Instrumentation ........................................................................................................................................... 7  Model 1 – Field Test ‐ Reinforced Concrete Box – Single Cell (M1C1) .................................................................... 10  Model 2 – Field Test ‐ Reinforced Concrete Box –Twin Cell (M2C1) ...................................................................... 13  Model 3 – Field Test ‐ Reinforced Concrete Box – Single Cell – Precast (M3C1) .................................................... 16  Model 4 – Field Test ‐ Reinforced Concrete Arch (M4C1) ...................................................................................... 19  Model 5 – Field Test ‐ Metal Arch (M5C1) .............................................................................................................. 23  Model 6 – Field Test ‐ Metal Box Arch (M6C2) ....................................................................................................... 27  Model 7 – Field Test ‐ Metal Box Arch (M7C1) ....................................................................................................... 31  Development of Analysis Testing Plan ............................................................................................................... 35  Software Used for the Analysis/ Data Gathering .................................................................................................... 35  CANDE Toolbox/Development of the 2D CANDE Models .................................................................................. 35  Changes to the CANDE GUI and Steps for Creating CANDE Models .................................................................. 36  BrDR Regression Testing and Data Mining ......................................................................................................... 40  Development of the 3D Models ......................................................................................................................... 42 

vi CHAPTER 3 ............................................................................................................................................. 43  Findings and Applications ............................................................................................................... 43  Calibration of the 3D Models ............................................................................................................................. 43  Summary of Areas of Specification to Review .................................................................................................... 44  Effects of Subgrade on Rating ................................................................................................................................. 45  Design‐Analysis ....................................................................................................................................................... 55  Culvert Load Distribution ........................................................................................................................................ 63  Non‐Rectangular Culverts ....................................................................................................................................... 66  Pavement ................................................................................................................................................................ 66  Model 7 3D Analysis Review .............................................................................................................................. 67  Culvert Loading and Instrumentation ........................................................................................................... 67  Results Before and After Paving .................................................................................................................... 70  CANDE Models with and Without Pavement ..................................................................................................... 78  Model 7 ......................................................................................................................................................... 78  Recommendations ............................................................................................................................................. 79  Shear Capacity ........................................................................................................................................................ 80  Economic Impact ................................................................................................................................................ 81  Live Load Surcharge vs. Approaching Wheel Load ................................................................................................. 86  Background/Spec Change Proposal ................................................................................................................... 86  Economic Impact ................................................................................................................................................ 89  CHAPTER 4 ............................................................................................................................................. 92  Conclusions and Suggested Research .......................................................................................... 92  Proposed Revisions to the LRFD Specifications and the MBE .............................................................................. 93  Suggested Research ........................................................................................................................................ 110  Data Archiving ................................................................................................................................................ 110  Changes to the CANDE Software .......................................................................................................................... 110  CANDE Input Files ................................................................................................................................................. 110  AASHTOWare BrDR Export Files (XML) ................................................................................................................. 111  AASHTOWare BrDR Regression Data/Report ID Descriptions .............................................................................. 111  3D FEM Files .......................................................................................................................................................... 111  Field Testing Data ................................................................................................................................................. 112  List of Appendices ......................................................................................................................................... 113 

vii Summary This report highlights the work accomplished under the AASHTO-sponsored project entitled “Proposed Modifications to AASHTO Culvert Load Rating Specifications.” Administered by NCHRP as Project 15- 54, the research has provided proposals for changes to the AASHTO Manual for Bridge Evaluation (MBE) through the load testing of seven culverts and the review and data analysis of culvert models of varying types. The culverts were analyzed using 3D analysis, 2D analysis using Culvert ANalysis and Design (CANDE) (Mlynarski, M., M. G. Katona, and T. J. McGrath. NCHRP Report 619: Modernize and Upgrade CANDE for Analysis and LRFD Design of Buried Structures. Transportation Research Board of the National Academies, Washington, D.C., 2008.), AASHTOWare Bridge ® Design and Rating (BrDR), and BOXCAR (FHWA). Over the past decade, significant state and federal resources have been expended to develop a state‐of‐ the-art set of reliability‐based bridge design and load rating specifications, the LRFD and LRFR. In addition, states continue to load rate using the load factor (LFR) and allowable stress (ASR) rating methods according to the MBE. However, these design and rating methods were developed for larger bridge structures and can result in overly conservative ratings when applied to buried culverts. Of the 600,000+ records in the National Bridge Inventory (NBI), over 130,000 represent culverts, thus constituting a significant proportion of the nation’s bridge infrastructure and, since the NBI only records culverts spanning more than 20 feet, and most culverts have spans of less than 20 feet, the actual number of culverts is vastly higher. As stated in the Request for Proposals document, the choice of, or change in the load rating method may affect the transportation of goods and services over the nation’s highways by imposing load limits on routes that were previously unrestricted. Determining effective revisions to the existing specifications for culverts and the potential economic impact for possible changes in ratings due to the changes and/or rating method was critical to the success of this project. The objective of this research was to propose modifications to the culvert load rating specifications in the MBE and revise the AASHTO LRFD Bridge Design Specifications accordingly. The objective was accomplished by  Surveying the DOTs for current culvert practices and issues related to culvert rating.  Contacting states via telephone who agreed to talk to us.  Developing and executing full scale field tests on seven culverts with the aid of four different state agencies (Maryland, Massachusetts, Ohio, and Pennsylvania).  Developing and executing a full analysis of the subject culverts in both 3D and 2D analysis.  Identifying areas of the (MBE) and LRFD Specifications for improvement and recommendations for updates to those specifications based on the field testing and analysis results. The literature survey was conducted in the first phase of the project to ascertain the current state of the culvert rating specifications. This survey included an online survey with an optional follow-up interview at the agency’s request. Some of the results yielded by the survey and interviews were:  Concrete culverts are used extensively, followed by steel corrugated culverts. Only one state indicated that they rated thermoplastic culverts and they are not reporting rating issues for those types of structures.  Reinforced concrete culverts are not rating well but don’t show physical signs of distress.  Studies that included input files for culvert analysis that could be utilized by this study.  Other research efforts including those from California, Ohio, and Pennsylvania which were utilized in this research. Based on the literature survey and subsequent interaction with the project panel, a sample testing plan and target field testing matrix was developed. Upon approval by the project panel, the effort to locate target culverts was conducted by contacting the state DOTs. This process yielded a field testing plan that was developed in tandem with an analytical plan that would be used to evaluate the current processes and

viii specifications used for culvert rating and evaluation. In all, seven culverts were field tested and analyzed in 3D using a FEM software package and in 2D using the CANDE software updated under NCHRP Project 15-28.The seven culverts analyzed and their location were: Model 1 – Reinforced Concrete Box (Single Cell) Pennsylvania Model 2 – Reinforced Concrete Box (Twin Cell) Maryland Model 3 – Reinforced Concrete Box – (Single Cell-Precast) Pennsylvania Model 4 – Reinforced Concreted Arch Ohio Model 5 – Metal Arch Pennsylvania Model 6 – Metal Arch Pennsylvania Model 7 – Metal Arch (Long span) – Deep Corrugation Massachusetts In addition to the load testing, each of these models was analyzed in 3D and CANDE. In some cases, software was developed for this project (CANDE Tool Box and revisions to the CANDE analysis engine) to facilitate the research. These tools are delivered with this project so that others may use them as well. The reinforced concrete box models were also analyzed in BrDR. Upon review of the existing specifications, modifications were proposed and, where possible, testing the changes using the BrDR software through a process of regression testing by analytically comparing the current specification with the suggested changes. The results of those recommendations are provided as part of this research and include modifications to the MBE and LRFD Specifications including:  Recommendations for culvert live load distribution.  Recommendations for non-rectangular culverts.  A study on the effects of pavement in culvert rating and recommendations for the use of an analytical tool developed on this project (CANDE Tool Box and CANDE) for analyzing culverts with pavement elements. Recommendations were also made for implementing the effects of pavement in other culvert programs.  Changes to the shear capacity calculations for reinforced concrete box culverts.  Changes to the live load surcharge loads (now described as approaching wheel load).  The effects of fill depth on live load.  The effects of haunches on reinforced concrete culvert analysis.  Sections for concrete, metal, and plastic culverts.

Next: Chapter 1 »
Proposed Modifications to AASHTO Culvert Load Rating Specifications Get This Book
×
MyNAP members save 10% online.
Login or Register to save!
Download Free PDF

Over the past decade, significant state and federal resources have been expended to develop a state‐of-the-art set of reliability‐based bridge design and load rating specifications, including Load and Resistance Factor Design (LRFD) and Load and Resistance Factor Rating (LRFR). However, these design and rating methods were developed for larger bridge structures, and may result in overly conservative ratings when applied to buried culverts. Of the more than 600,000 records in the National Bridge Inventory, over 130,000 represent culverts, thus constituting a significant proportion of the nation’s bridge infrastructure.

The TRB National Cooperative Highway Research Program's Web-Only Document 268: Proposed Modifications to AASHTO Culvert Load Rating Specifications proposes modifications to the culvert load rating specifications in the Manual for Bridge Evaluation and revises the AASHTO LRFD Bridge Design Specifications accordingly.

  1. ×

    Welcome to OpenBook!

    You're looking at OpenBook, NAP.edu's online reading room since 1999. Based on feedback from you, our users, we've made some improvements that make it easier than ever to read thousands of publications on our website.

    Do you want to take a quick tour of the OpenBook's features?

    No Thanks Take a Tour »
  2. ×

    Show this book's table of contents, where you can jump to any chapter by name.

    « Back Next »
  3. ×

    ...or use these buttons to go back to the previous chapter or skip to the next one.

    « Back Next »
  4. ×

    Jump up to the previous page or down to the next one. Also, you can type in a page number and press Enter to go directly to that page in the book.

    « Back Next »
  5. ×

    To search the entire text of this book, type in your search term here and press Enter.

    « Back Next »
  6. ×

    Share a link to this book page on your preferred social network or via email.

    « Back Next »
  7. ×

    View our suggested citation for this chapter.

    « Back Next »
  8. ×

    Ready to take your reading offline? Click here to buy this book in print or download it as a free PDF, if available.

    « Back Next »
Stay Connected!