Utah State University DigitalCommons@USU All Graduate Theses and Dissertations Graduate Studies 5-2010 Internal Design of Mechanically Stabilized Earth (MSE) Retaining Walls Using Crimped Bars Bernardo A. Castellanos Utah State University Follow this and additional works at: https://digitalcommons.usu.edu/etd Part of the Civil Engineering Commons Recommended Citation Castellanos, Bernardo A., "Internal Design of Mechanically Stabilized Earth (MSE) Retaining Walls Using Crimped Bars" (2010). All Graduate Theses and Dissertations. 580. https://digitalcommons.usu.edu/etd/580 This Thesis is brought to you for free and open access by the Graduate Studies at DigitalCommons@USU. It has been accepted for inclusion in All Graduate Theses and Dissertations by an authorized administrator of DigitalCommons@USU. For more information, please contact [email protected]. INTERNAL DESIGN OF MECHANICALLY STABILIZED EARTH (MSE) RETAINING WALLS USING CRIMPED BARS by Bernardo A. Castellanos A thesis submitted in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE in Civil and Environmental Engineering Approved: _________________________ _________________________ James A. Bay John D. Rice Major Professor Committee Member _________________________ _________________________ Marvin W. Halling Byron R. Burnham Committee Member Dean of Graduate Studies UTAH STATE UNIVERSITY Logan, Utah 2010 ii ABSTRACT Internal Design of Mechanically Stabilized Earth (MSE) Retaining Walls Using Crimped Bars by Bernardo A. Castellanos, Master of Science Utah State University, 2010 Major Professor: Dr. James A. Bay Department: Civil and Environmental Engineering Current design codes of Mechanically Stabilized Earth (MSE) Walls allow the use lower lateral earth pressure coefficient (K value) for designing geosynthetics walls than those used to design steel walls. The reason of this is because geosynthetics walls are less rigid permitting the wall to deform enough to work under active pressures instead of at rest pressures as in steel walls. A new concept of crimped steel bars was recently introduced. This new type of bar was tested for tension and pullout behavior. Results on tests made on crimped bars show that putting those crimps in the steel bar will give us a better pullout behavior and a more flexible tensile behavior. This new type of steel bar will behave more like geosynthetics, allowing the wall to deform sufficiently to reach the necessary deflection to reach the active condition. iii The use of steel by current design codes is pushing MSE walls to be designed with more steel than needed. Measurements of the force in different walls showed that the steel is not being used even close to the maximum stress allowed by the code which is 50%. The proposed design methodology using crimped bars will help us save around 52% of steel volume compared to the actual design procedures. This means a huge improvement in the usage of steel versus actual designs. This improvement is obtained because of the efficient behavior of rounded bars under corrosion and because of the flexibility in the bars obtained with the crimps that will allow us to reach the active condition. (137 pages) iv DEDICATION This thesis is dedicated first to God for all the opportunities given and for being the guide of my life. To the Dominican government, for providing me the necessary funds to attend Utah State University. To my family, for their unconditional support all these years. To friends and all others that motivated me throughout this process. The gratitude I have for the inspiration and confidence conferred upon me by these people is indescribable. Bernardo A. Castellanos v ACKNOWLEDGMENTS I would like to thank my committee members, Drs. James Bay, for all his unconditional support and dedication to this project, Loren Anderson, John Rice, and Marv Halling, for their support and insight throughout this process. Finally, I would like to thank Hilkfiker Retaining Walls in the person of Bill Hilfiker for providing the funds and steel bars for the realization of this project. Bernardo A. Castellanos vi CONTENTS Page ABSTRACT .............................................................................................................................ii DEDICATION ........................................................................................................................ iv ACKNOWLEDGMENTS .......................................................................................................... v LIST OF TABLES .................................................................................................................. viii LIST OF FIGURES .................................................................................................................. xi CHAPTER 1 INTRODUCTION, OBJECTIVES AND ORGANIZATION ............................................... 1 1.1 Introduction ................................................................................................ 1 1.2 Objectives of the Research ......................................................................... 2 1.3 Report Organization .................................................................................... 3 2 LITERATURE REVIEW ............................................................................................... 4 2.1 Introduction ................................................................................................ 4 2.2 American Association of State Highway and Transportation Official (AASHTO) MSE Walls Design Code ............................................................ 4 2.2.1 General ......................................................................................... 4 2.2.2 Loads in the MSE walls ................................................................. 7 2.2.3 Overall stability .......................................................................... 10 2.2.4 Sliding ......................................................................................... 10 2.2.5 Bearing capacity ......................................................................... 11 2.2.6 Overturning ................................................................................ 16 2.2.7 Loads in the reinforcement ........................................................ 16 2.2.8 Load at the connection to the face of the wall. ......................... 19 2.2.9 Reinforcement strength ............................................................. 20 2.2.10 Pullout resistance ..................................................................... 27 2.3 K-Stiffness Method.................................................................................... 30 2.3.1 General ....................................................................................... 30 vii 2.3.2 Strength limit state design for internal stability for geosynthetic walls ........................................................................................... 39 2.3.3 Strength Limit state design for internal stability for steel walls 41 3 DESIGN METHODOLOGY ........................................................................................ 43 3.1 Concept ..................................................................................................... 43 3.2 Crimp Properties ....................................................................................... 44 3.2.1 Pullout resistance ....................................................................... 44 3.2.2 Crimp deflection ........................................................................ 46 3.3 Model Definition ....................................................................................... 55 3.3.1 Tensile design of the wall ........................................................... 62 3.3.2 Pullout design of the reinforcement .......................................... 64 3.3.3 Wall deflections ......................................................................... 67 4 DESIGN OF A 40 FT. HEIGHT MECHANICALLY STABILIZED EARTH (MSE) WALL USING THE PROPOSED METHODOLOGY ................................................................ 69 4.1 Introduction .............................................................................................. 69 4.2 Description of the Wall ............................................................................. 69 4.3 Wall Design ............................................................................................... 70 4.4 Designs Summary ...................................................................................... 74 5 COMPARISON BETWEEN DESIGN METHODOLOGIES ............................................ 79 5.1 Introduction .............................................................................................. 79 5.2 Other Design Methodologies .................................................................... 79 5.3 Designs Comparison .................................................................................. 80 6 CONCLUSIONS AND RECOMMENDATIONS ............................................................ 83 REFERENCES ...................................................................................................................... 85 APPENDICES ...................................................................................................................... 87 APPENDIX A. Visual Basic Scripts for Crimps Properties Calculation .............. 88 APPENDIX B. MSE Walls Complete Designs .................................................