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N a t i o N a l c o o p e r a t i v e H i g H w a y r e s e a r c H p r o g r a m NcHrp RepoRt 676 Intelligent Soil Compaction Systems Michael A. Mooney Robert V. Rinehart Norman W. Facas Odon M. Musimbi Colorado SChool of MineS Golden, CO David J. White Pavana K. R. Vennapusa iowa State UniverSity Ames, IA TranSporTaT Ion reSearCh Board Washington, D.C. 2010 www.tRB.org Subscriber Categories Construction â¢ geotechnology â¢ Pavements Research sponsored by the American Association of State Highway and Transportation Officials in cooperation with the Federal Highway Administration
naTIonal CooperaTIve hIghway reSearCh program Systematic, well-designed research provides the most effective approach to the solution of many problems facing highway administrators and engineers. Often, highway problems are of local interest and can best be studied by highway departments individually or in cooperation with their state universities and others. However, the accelerating growth of highway transportation develops increasingly complex problems of wide interest to highway authorities. These problems are best studied through a coordinated program of cooperative research. In recognition of these needs, the highway administrators of the American Association of State Highway and Transportation Officials initiated in 1962 an objective national highway research program employing modern scientific techniques. This program is supported on a continuing basis by funds from participating member states of the Association and it receives the full cooperation and support of the Federal Highway Administration, United States Department of Transportation. The Transportation Research Board of the National Academies was requested by the Association to administer the research program because of the Boardâs recognized objectivity and understanding of modern research practices. The Board is uniquely suited for this purpose as it maintains an extensive committee structure from which authorities on any highway transportation subject may be drawn; it possesses avenues of communications and cooperation with federal, state and local governmental agencies, universities, and industry; its relationship to the National Research Council is an insurance of objectivity; it maintains a full-time research correlation staff of specialists in highway transportation matters to bring the findings of research directly to those who are in a position to use them. The program is developed on the basis of research needs identified by chief administrators of the highway and transportation departments and by committees of AASHTO. Each year, specific areas of research needs to be included in the program are proposed to the National Research Council and the Board by the American Association of State Highway and Transportation Officials. Research projects to fulfill these needs are defined by the Board, and qualified research agencies are selected from those that have submitted proposals. Administration and surveillance of research contracts are the responsibilities of the National Research Council and the Transportation Research Board. The needs for highway research are many, and the National Cooperative Highway Research Program can make significant contributions to the solution of highway transportation problems of mutual concern to many responsible groups. The program, however, is intended to complement rather than to substitute for or duplicate other highway research programs. Published reports of the naTIonal CooperaTIve hIghway reSearCh program are available from: Transportation Research Board Business Office 500 Fifth Street, NW Washington, DC 20001 and can be ordered through the Internet at: http://www.national-academies.org/trb/bookstore Printed in the United States of America nChrp reporT 676 Project 21-09 ISSN 0077-5614 ISBN 978-0-309-15519-9 Library of Congress Control Number 2010939000 Â© 2010 National Academy of Sciences. All rights reserved. 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, FTA, or Transit Development Corporation 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. noTICe The project that is the subject of this report was a part of the National Cooperative Highway Research Program, conducted by the Transportation Research Board with the approval of the Governing Board of the National Research Council. The members of the technical panel selected to monitor this project and to review this report were chosen for their special competencies and with regard for appropriate balance. The report was reviewed by the technical panel and accepted for publication according to procedures established and overseen by the Transportation Research Board and approved by the Governing Board of the National Research Council. The opinions and conclusions expressed or implied in this report are those of the researchers who performed the research and are not necessarily those of the Transportation Research Board, the National Research Council, or the program sponsors. The Transportation Research Board of the National Academies, the National Research Council, and the sponsors of the National Cooperative Highway Research Program do not endorse products or manufacturers. Trade or manufacturersâ names appear herein solely because they are considered essential to the object of the report.
Crp STaff for nChrp reporT 676 Christopher W. Jenks, Director, Cooperative Research Programs Crawford F. Jencks, Deputy Director, Cooperative Research Programs David A. Reynaud, Senior Program Officer Megan A. Chamberlain, Senior Program Assistant Eileen P. Delaney, Director of Publications Ellen M. Chafee, Editor nChrp proJeCT 21-09 panel Field of Soils and GeologyâArea of testing and Implementation Ahmad A. Ardani, FHWA Turner-Fairbank, McLean, VA (Chair) Steve W. Perkins, Montana State University, Bozeman, MT Sastry P. Putcha, Florida DOT, Tallahassee, FL Danesh Sajedi, Maryland State Highway Administration, Hanover, MD David P. Shiells, Virginia DOT, Chantilly, VA John A. Siekmeier, Minnesota DOT, Maplewood, MN Chun-Kun Su, North Carolina DOT, Raleigh, NC Michael Adams, FHWA Liaison G. P. Jayaprakash, TRB Liaison 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
aUThor aCKnowledgmenTS The authors are grateful to the NCHRP for funding the study and to the technical review panel members: Mr. Ahmad Ardani (chair), FHWA Turner-Fairbank; Mr. John Siekmeier, Minnesota Department of Transportation; Dr. Steve Perkins, Montana State University; Dr. Sastry Putcha, Florida Department of Transportation; Mr. Dan Sajedi, Maryland State Highway Administra- tion; Mr. David Shiells, Virginia Department of Transportation; and Mr. Chun-Kun Su, North Carolina Department of Transportation. The authors wish to thank a number of individuals who provided invaluable assistance throughout the project, including Geoffrey Bee and Kyle Jackson, Colorado School of Mines; Heath Gieselman, Mike Kruse, Amy Heurung, Eddy Blahut, and Allison Moyer, Iowa State Uni- versity; Dr. Reinhard Furrer, University of Zurich; Dr. Nils Ryden, Peab AB Sweden and Lund University; Patrick Miller, Olson Engineering, Inc.; Dr. Mark Thompson, CH2MHill; Dr. Dietmar Adam, Technical University of Vienna; and Dr. Gerhard BrÃ¤u, Technical University of Munich. The authors are grateful for the assistance and cooperation of the state departments of trans- portation/highway authorities and project contractors at the five field sites where testing was conducted: â¢ John Siekmeier of the Minnesota Department of Transportation; Tim Clyne, Ruth Roberson, and Jack Herndon at the Minnesota ROAD Research Facility; Hard Drives of Minnesota â¢ Aziz Khan, Naser Abu-Hejleh, Jake Kononov, and Chris Boespflug of the Colorado Depart- ment of Transportation; Flatiron Constructors, Inc., Intermountain Division â¢ Dan Sajedi of the Maryland State Highway Administration; Devin Miller and colleagues at Dewey Jordan Construction of Maryland â¢ Sastry Putcha of the Florida Department of Transportation; Tom Woods and colleagues at JEA Construction Engineering Services; Wade Henderson and colleagues at Keith & Schnars, P.A. â¢ C. K. Su and Brian Smith of the North Carolina Department of Transportation, David Teal and colleagues at Blythe Construction of North Carolina The authors are very grateful to Ammann, Bomag, Caterpillar, Case, Dynapac, and Sakai for providing rollers and to the representatives from these roller manufacturers for providing infor- mation about their current continuous compaction control and intelligent control equipment. The authors also thank Bob Horan for assisting in coordinating field project sites. Equipment and expertise provided by Arthur Taylor, Jeff Drake, and Geoffrey Kirk of Trimble Navigation Limited (3D Machine Control Construction Division) greatly increased the effectiveness of the research team and improved the quality of results and is very much appreciated. In addition, equipment provided by Olson Engineering, Inc., allowed for more efficient field testing and is appreciated.
This report describes intelligent compaction, a new method of achieving and document- ing compaction requirements through continuous compaction-roller vibration monitoring to assess mechanistic soil properties (e.g., stiffness, modulus), continuous modification/ adaptation of roller vibration amplitude and frequency to ensure optimum compaction, and full-time monitoring by an integrated global positioning system (GPS) to provide a complete GPS-based record of the compacted area. This report will interest state and local highway agency construction managers and geotechnical engineers and contractors, particularly excavation superintendants. Implementation of this system has the potential to improve infrastructure performance, reduce costs, reduce construction duration, and improve safety. Compaction of embankment, subgrade, and base materials is a significant portion of state highway construction budgets and is critical to the performance of highway pave- ments. Heterogeneity of earth materials, variability in equipment and operators, and dif- ficulty in maintaining uniform lift thickness and prescribed moisture content combine to make desired earthwork compaction difficult to achieve. Current quality-control and quality-assurance testing devices are typically used to assess less than 1% of the actual com- pacted area. Research findings in Europe and in the United States have shown that soil stiffness and modulus can be assessed through monitoring vibration of the compaction roller drum and that continuous monitoring, feedback, and automatic adjustment of the compaction equip- ment can significantly improve the quality of the compaction process. Standard specifica- tions for intelligent compaction systems in the United States are needed, much as they exist overseas. Under NCHRP Project 21-09, the Colorado School of Mines and Iowa State University conducted research to determine the reliability of intelligent compaction systems and to develop recommended construction specifications for the application of intelligent com- paction systems in soils and aggregate base materials. For the purposes of this project, intel- ligent compaction is defined as involving the use of vibratory rollers that are equipped with a control system that can automatically adjust compactive effort in response to real-time feedback of changes in material modulus during the compaction process. To achieve the project objectives, the researchers conducted a review of domestic and international literature and determined the current state of practice of intelligent com- paction. Interviews with compaction equipment manufacturers and European researchers provided information on equipment capabilities and the current state of practice abroad. The investigators identified five active state department of transportation construction F o r e W o r D By David a. Reynaud staff officer transportation Research Board
projects for the collection and comparison of intelligent and traditional compaction data. They formulated a data collection plan for roller data (from a minimum of three different manufacturers), instrumentation data, and in situ testing data. The researchersâ analysis of the data allowed validation of the roller data with the instrumentation data and correlation of the roller data with the in situ data. Additional analysis confirmed the importance of determining moisture, layer depth, and the foundation layer in the accuracy of intelligent compaction systems. Based on further analysis of the acquired data, target values for the modulus of different soil types have also been provided. Preliminary recommended con- struction specifications are included for the application of intelligent compaction systems in soils and aggregate base materials. The final report addresses the reliability and effective- ness of intelligent compaction technology in different soil types. Appendixes A through D, which provide supplemental information, are available on the TRB website (www.trb.org) at http://www.trb.org/Main/Blurbs/164279.aspx.
c o n t e n t s 1 summary 7 Chapter 1 introduction 7 1.1 Impetus and Objectives 7 1.2 Work Plan Overview 13 1.3 Summary of Report 14 Chapter 2 state of Practice 14 2.1 Continuous Compaction Control and Intelligent Compaction 22 2.2 State of Current and Emerging IC Equipment 30 2.3 Existing CCC Specifications 38 Chapter 3 Fundamentals of Roller Measurement Values 38 3.1 Roller MV Reporting Characteristics 40 3.2 Roller MV Position Reporting Error 42 3.3 Repeatability of Roller Measurement Values 44 3.4 Comparison of Roller Measurement Values 47 3.5 Measurement Value Dependence on Machine Parameters 50 3.6 Influence of Transverse Soil Heterogeneity on Roller Measurement Values 51 3.7 Conclusions and Recommendations 53 Chapter 4 Relationship Between Roller-Based stiffness and in situ Response 53 4.1 Roller-Induced Stress Paths and Levels 55 4.2 Measurement Depth in Vertically Homogeneous Embankments 58 4.3 Relating Roller-Based Stiffness to In Situ Response 63 4.4 Sensitivity of Roller-Based Stiffness to Thin Lifts 66 4.5 Conclusions 67 Chapter 5 analysis of intelligent soil Compaction 67 5.1 Operational Evaluation of AFC-Based IC 71 5.2 Influence of AFC on Compaction 76 5.3 Conclusions 79 Chapter 6 Relationships Between Roller Measurement Values and Point Measurements 80 6.1 Materials and Testing 81 6.2 Simple Linear Regression Relationships 89 6.3 Multiple Linear Regression Analysis 96 6.4 Relationships Between Roller MV and Resilient Modulus 101 6.5 Summary and Conclusions
104 Chapter 7 Quality Assurance of Pavement Earthwork Using Roller-Integrated Continuous Compaction Control (Recommended Specification Options) 106 7.1 Scope 106 7.2 Definitions 108 7.3 Notation 108 7.4 Important Considerations 110 7.5 Instrumented Roller Requirements 112 7.6 QA Option 1: Spot Testing of Roller-Informed Weakest Area(s) 113 7.7 QA Option 2: Limiting Percentage Change in Roller MV 114 7.8 QA Option 3: Comparison of Roller MV Data to Target MV 117 7.9 Uniformity Criteria 119 Chapter 8 Case Study Evaluation of Specification Options 119 8.1 Case Study IâGranular Subbase (Tb CO34) 126 8.2 Case Study IIâStabilized Granular Subgrade (Tb FL15) 129 8.3 Case Study IIIâFL19 Aggregate base 134 8.4 Case Study IVâTb FL23 Granular Subgrade 143 8.5 Case Study VâGranular Subgrade (Tb NC20) 146 8.6 Case Study VIâMN10 Nongranular Subgrade 147 8.7 Conclusions 150 Chapter 9 Conclusions 150 9.1 Overview 150 9.2 Review of Literature and European CCC Specifications 151 9.3 Fundamentals of Roller-based Measurement Systems 152 9.4 Relationship between Roller-Measured Stiffness and In-Ground Response 153 9.5 Evaluation of Automatic Feedback Controlâbased Intelligent Compaction 154 9.6 Relationship between Roller Measurement Values and Spot-Test Measurements 155 9.7 Recommended Specification Options for Earthwork Compaction QA Using Roller-Integrated Continuous Compaction Control 156 9.8 Implementation of Specification Options: Case Studies 159 References 162 Glossary 165 Appendixes A Through D Note: Many of the figures in this report have been converted from color to grayscale for printing. The electronic version of the report (posted on the Web at www.trb.org) retains the color versions.