DOCSLIB.ORG

A Qljarter Century of Geotechnical Researcll

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
A Qljarter Century of Geotechnical Researcll A QlJarter Century of Geotechnical Researcll PUBLICATION NO. FHWA-RD-98-139 FEBRUARY 1999 1111111111111111111111111111111 PB99-147365 \c-c.J/t).:.. L~.i' . u.s. D~~~~~~~Co~~~~~erce~ Natronal_Tec~nical Information Service u.s. DepartillCi"li of Transportation Spnngfleld, Virginia 22161 Research, Development & Technology Turner-Fairbank Highway Research Center 6300 Georgetown Pike McLean, VA 22101-2296 FOREWORD This report summarizes Federal Highway Administration (FHW!\) geotechnical research and development activities during the past 25 years. The report incl!Jde~: significant accomplishments in the areas of bridge foundations, ground improvenl::::nt, and soil and rock behavior. A fourth category included important miscellaneous efrorts tl'12t did not fit the areas mentioned. The report vlill be useful to re~earchers and praGtitior,c:;rs in geotechnology. --------:"--; /~ /1 I~t(./l- /-~~:r\ .. T. Paul Teng (j Director, Office of Infrastructure Research, Development. and Technologv NOTiCE This document is disseminated under the sponsorship of the Department of Transportation in the interest of information exchange. The United States G~)\fernm8nt assumes no liahillty for its contt?!nts or use thereof. Thir. report dor~s not constiil)tl":: a standard, specification, or regu!p,tion. The; United States Government does not endorse products or n18;1ufaGturers, Traderrlc,rks or nianufacturers' narl1es appear in thi;-, report only bec:8'I)Se they arc considered essential to tile object of the document. Technical Report Documentation Page 1. Report No. 2. Government Accession No. 3. Recipient's Catalog No. FHWA-RD-98-139 4. Title and Subtitle 5. Report Date A Quarter Century of Geotechnical Research February 1999 6. Performing Organization Code ). 7. Author(s) 1111111111111111111111111111111 Albert F. DiMillio PB99-147365 9. Performing Organization Name and Address 10. Work Unit No. (TRAIS) Office of Engineering R&D 2E3A0119 Federal Highway Administration 11. Contract or Grant No. 6300 Georgetown Pike McLean VA 22101 13. Type of Report and Period Covered ~~----~~--~~--~~~--------------------------------~ 12. Sponsoring Agency Name and Address Office of Engineering R&D Final Report Federal Highway Administration December 1997-December 1998 6300 Georgetown Pike 14. Sponsoring Agency Code McLean, VA 22101 15. Supplementary Notes 16. Abstract The Federal Highway's Geotechnical Research Program was formally initiated in the 1970's. During the early 1970's, FHWA field personnel and the State Highway Agencies (SHA) recognized the need for more definitive technology for solving various soil and foundation problems. This fact, along with the stimulus of sympathetic management and funds for research, permitted the establishment of the geotechnical research program. The purpose of this report is to synopsize the program, highlighting some of the more significant findings and contributions. This report gives an overview and summarizes the results of three geotechnical research programs. The project or program areas were: soil and rock behavior, bridge foundations, and ground improvement techniques. A fourth program area, tunneling, is outside of the research reported here and is covered elsewhere. A fifth category, summarized here, included important miscellaneous studies that did not fit categories given above. The report presents narratives and a comprehensive reference list for the various research categories. Items covered, for example in foundation engineering, include pile foundations, pile groups, drilled shafts, spread footings, and foundation load testing. Ground improvement efforts and soil and rock behavior are also given in appropriate detail. Outputs, including guidelines and implement:,ltion items, are given for the various topics covered. Finally, an outline of future geotechnical research needs is presented. 17. Key Words 18. Distribution Statement Geotechnical, piles, spread footings, ground improvement, No restrictions. This document is available to the public through soil and rock behavior. the National Technical Information Service, Springfield, Virginia 22161. 19. Security Classif. (ofthis report) 20. Security Classif. (of this page) 21. No. of Pages 22. Price Unclassified Unclassified 160 Form DOT F 1700.7 (8-72) Reproduction of completed page authorized This form was electronically produced by Elite Federal Forms, Inc. ACKNOWLEDGMENTS The author greatly appreciates the opportunity provided by the Federal Highway Administration (FHWA) to manage the Geotechnology Research Program described in this report. The program has benefitted from the efforts of a wide range of FHWA personnel who contributed to the success of this program. In the beginning, the guidance and support of Dr. Charles Scheffey and Richard E. Hay were very helpful in establishing the program and got it going in the right direction. I am especially grateful to Carl Ealy, who has been with me from the beginning to the present, and deserves most of the credit for managing the deep foundations research project. I also appreciate the contributions of Mike Adams, who has managed the shallow foundations project and many of the ground improvement studies during the second half of this program .. Special thanks are extended to other FHWA personnel who have also contributed to the success of this program. There are too many to mention them all by name, but a few stand out above the rest. In the Headquarters office, Jerry DiMaggio and Dick Cheney have provided advice concerning which topics needed to be researched, and critiqued the work on many of the studies from start to finish. They have used many of the results to prepare design and construction guideline manuals, technical advisories, and engineering circulars that have been distributed to FHWAand State Highway practitioners all over the United States and many foreign countries. Special credit is due John Hooks and Chien Tan Chang for their efforts to promote the technology transfer and implementation of the R&D products from this program. They provided the resources to enable Cheney and DiMaggio to accomplish their goals to bring the research results to fruition. The author is also indebted to all of the Regional Geotechnical Engineers who actively supported the program, especially Barry Berkovitz (Atlanta), Ron Chassie (Portland), Andy Munoz (Dallas), and Barry Siel (Denver). There is considerable satisfaction in knowing that these outstanding field engineers have taken our research products and used them to help make roads better in their regions. The single most important person in the success of this program was Don Fohs, who, like Chuck Scheffey and Dick Hay, is now retired from FHWA. The author is very grateful for his support and guidance throughout the entire period of performance. Sincere appreciation is also extended to all of the contract researchers and organizations that participated in this program. It would be nice to list them all by name; however, FHWA report processing requirements prohibit the mention of contractors' names in the report. This research program was blessed with many good contract personnel. Finally, many thanks to Raghu Satyanarayana, Clay Ormsby, Nanda Sen, and Robin Collins for helping to prepare the manuscript. ii Symbol When You Know Multiply By To Find Symbol Symbol When You Know Multiply By To Find Symbol LENGTH LENGTH in inches 25.4 millimeters mm mm millimeters 0.039 inches in ft feet 0.305 meters m m meters 3.28 feet ft yd yards 0.914 meters m m meters 1.09 yards yd mi miles 1.61 kilometers km km kilometers 0.621 miles mi AREA AREA 2 2 in square inches 645.2 square millimeters mm2 mm square millimeters 0.0016 square inches in2 2 ft2 square feet 0.093 square meters m2 m square meters 10.764 square feet ft2 2 yd2 square yards 0.836 square meters m2 m square meters 1.195 square yards yd2 ac aaes 0.405 hectares ha ha hectares 2.47 acres ac 2 2 mi square miles 2.59 square kilometers km2 km square kilometers 0.386 square miles mi2 VOLUME VOLUME ~.....I. w. ft oz ftuid ounces 29.57 milliliters mL mL milliliters 0.034 fluid ounces ft oz 1-" III gal gallons 3.785 liters L L liters 0.264 gallons gal ft3 cubic feet 0.028 cubic meters m3 m3 cubic meters 35.71 cubic feet ft3 yd3 cubic yards 0.765 cubic meters m3 m3 cubic meters 1.307 cubic yards yd3 NOTE: Volumes greater than 1000 I shall be shown in m3• MASS MASS oz ounces 28.35 grams g g grams 0.035 ounces oz Ib pounds 0.454 kilograms kg kg kilograms 2.202 pounds Ib T short tons (2Ooolb) 0.907 megagrams Mg Mg megagrams 1.103 short tons (2000 Ib) T (or "metric ton") (or "to) (or "to) (or "metric ton") TEMPERATURE (exact) TEMPERATURE (exact) OF Fahrenheit 5(F-32)/9 Celcius °C °C Celcius 1.8C + 32 Fahrenheit OF temperature or (F-32)/1.8 temperature temperature temperature ILLUMINATION ILLUMINATION fc foot-candles 10.76 lux Ix Ix lux 0.0929 foot-candles fc 2 2 ft foot-Lamberts 3.426 candelalm cdlm2 cdlm2 candelalm 0.2919 foot-Lamberts fl FORCE and PRESSURE or STRESS FORCE and PRESSURE or STRESS Ibf poundtorce 4.45 newtons N N newtons 0.225 poundforce Ibf 2 Ibflin2 poundforce per 6.89 kilopascals kPa kPa kilo pascals 0.145 poundforce per Ibflin square inch square inch • 51 is the symbol tor the International System of Units. Appropriate PROTECTED UNDER INTERNATIONAL COPYRIGHT levi sed September 1993) rounding should be made to comply with Section 4 of ASTM E380. ALL RIGHTS RESERVED. NATIONAL TECHNICAL INFORMATION SERVICE U.S. DEPARTMENT OF COMMERCE TABLE OF CONTENTS 1 INTRODUCTION ................................................................................................
Load more

Recommended publications
  • Post Grouting Drilled Shaft Tips Phase I
    Post Grouting Drilled Shaft Tips Phase I Principal Investigator: Gray Mullins Graduate Students: S. Dapp, E. Frederick, V. Wagner Department of Civil and Environmental Engineering December 2001 DISCLAIMER The opinions, findings and conclusions expressed in this publication are those of the authors and not necessarily those of the State of Florida Department of Transportation. ii CONVERSION FACTORS, US CUSTOMARY TO METRIC UNITS Multiply by to obtain inch 25.4 mm foot 0.3048 meter square inches 645 square mm cubic yard 0.765 cubic meter pound (lb) 4.448 Newtons kip (1000 lb) 4.448 kiloNewton (kN) Newton 0.2248 pound kip/ft 14.59 kN/meter pound/in2 0.0069 MPa kip/in2 6.895 MPa MPa 0.145 ksi kip-ft 1.356 kN-m kip-in 0.113 kN-m kN-m .7375 kip-ft iii PREFACE The investigation reported was funded by a contract awarded to the University of South Florida, Tampa by the Florida Department of Transportation. Mr. Peter Lai was the Project Manager. It is a pleasure to acknowledge his contribution to this study. The full-scale tests required by this study were carried out in part at Coastal Caisson’s Clearwater location. We are indebted to Mr. Bud Khouri, Mr Richard Walsh, and staff for providing this site and also for making available lifting, moving, and excavating equipment that was essential for this study. We thank Mr. Ron Broderick, Earth Tech, Tampa for donating his time, equipment and grout materials necessary for grouting shafts at Site I and II. We are indebted to Mr.
    [Show full text]
  • An Experimental Study of a Nailed Soil Slope: Effects of Surcharge Loading and Nails Characteristics
    applied sciences Article An Experimental Study of a Nailed Soil Slope: Effects of Surcharge Loading and Nails Characteristics Mahmoud H. Mohamed 1 , Mohd Ahmed 1,*, Javed Mallick 1 and Pham V. Hoa 2 1 Civil Engineeg Department, College of Engineering, K. K. University, Abha 61421, Saudi Arabia; [email protected] (M.H.M.); [email protected] (J.M.) 2 Ho Chi Minh City Institute, Vietnam Academy of Science and Technology, Ho Chi Minh City 008428, Vietnam; [email protected] * Correspondence: [email protected]; Tel.: +966-172-418-439 Abstract: The earth nailing system is a ground improvement technique used to stabilize earth slopes. The behavior of the earth nailing system is dependent on soil and nailing characteristics, such as the spacing between nails, the orientation, length, and method of installation of nails, soil properties, slope height and angle, and surcharge loading, among others. In the present study, a three-dimensional physical model was built to simulate a soil nailed slope with a model scale of 1:10 with various soil nail characteristics. The simulated models consist of Perspex strips as facing and steel bars as a reinforcing system to stabilize the soil slope. Sand beds in the model were formed, using a sand raining system. The performance of nailed soil slope models under three important nails characteristics, i.e., length, spacing and orientation, with varying surcharge loading were studied. It was observed that there is a reduction in the lateral movement of slope and footing settlements with an increase in length. It was found that the slope face horizontal pressure is non-linear with different nail characteristics.
    [Show full text]
  • NCHRP Report 461: Static and Dynamic Lateral Loading of Pile Groups
    NATIONAL COOPERATIVE HIGHWAY RESEARCH NCHRP PROGRAM REPORT 461 Static and Dynamic Lateral Loading of Pile Groups TRANSPORTATION RESEARCH BOARD NATIONAL RESEARCH COUNCIL TRANSPORTATION RESEARCH BOARD EXECUTIVE COMMITTEE 2001 OFFICERS Chair: John M. Samuels, Senior Vice President-Operations Planning & Support, Norfolk Southern Corporation, Norfolk, VA Vice Chair: E. Dean Carlson, Secretary of Transportation, Kansas DOT Executive Director: Robert E. Skinner, Jr., Transportation Research Board MEMBERS WILLIAM D. ANKNER, Director, Rhode Island DOT THOMAS F. BARRY, JR., Secretary of Transportation, Florida DOT JACK E. BUFFINGTON, Associate Director and Research Professor, Mack-Blackwell National Rural Transportation Study Center, University of Arkansas SARAH C. CAMPBELL, President, TransManagement, Inc., Washington, DC JOANNE F. CASEY, President, Intermodal Association of North America JAMES C. CODELL III, Secretary, Kentucky Transportation Cabinet JOHN L. CRAIG, Director, Nebraska Department of Roads ROBERT A. FROSCH, Senior Research Fellow, John F. Kennedy School of Government, Harvard University GORMAN GILBERT, Director, Oklahoma Transportation Center, Oklahoma State University GENEVIEVE GIULIANO, Professor, School of Policy, Planning, and Development, University of Southern California, Los Angeles LESTER A. HOEL, L. A. Lacy Distinguished Professor, Department of Civil Engineering, University of Virginia H. THOMAS KORNEGAY, Executive Director, Port of Houston Authority BRADLEY L. MALLORY, Secretary of Transportation, Pennsylvania DOT MICHAEL
    [Show full text]
  • Soils and Foundation Handbook”, a Minimum Core Barrel Size of 61 Mm (2.4”) I.D
    Soils and Foundations Handbook April 2004 State Materials Office Gainesville, Florida This page is intentionally blank. i Table of Contents Table of Contents ......................................................................................................... ii List of Figures ............................................................................................................. xi List of Tables.............................................................................................................xiii Chapter 1 ......................................................................................................................... 1 1 Introduction ............................................................................................................... 1 1.1 Geotechnical Tasks in Typical Highway Projects.................................................. 2 1.1.1 Planning, Development, and Engineering Phase ...................................... 2 1.1.2 Project Design Phase................................................................................. 2 1.1.3 Construction Phase.................................................................................... 2 1.1.4 Post-Construction Phase............................................................................ 3 Chapter 2 ......................................................................................................................... 4 2 Subsurface Investigation Procedures ........................................................................ 4 2.1
    [Show full text]
  • Stability Analysis of Slope Under Different Soil Nailing Parameters Based on the Geostudio
    International Journal of IJGE 2015 1(2): 88-92 Geohazards and Environmen t http://ijge.camdemia.ca, [email protected] Available at http://ojs.library.dal.ca/ijge Technical Notes Stability Analysis of Slope under Different Soil Nailing Parameters Based on the GeoStudio Ou-Ling Tang* and Qing-Ming Jiang Chengdu University of Technology, Chengdu 610059, P.R. China Abstract: In order to investigate the influence of different soil nailing parameters on the safety factor of a slope, the slope stability is analyzed by the GeoStudio software with different analysis methods. Soil nailing parameters (such as nail inclination, nail horizontal space, nail diameter and length) that influence the slope stability are analyzed by the Morgenstern-Price method. As the results show, the slope has the highest safety factor when the obliquity of soil nailing is about 15°, the safety factor decreases with the increase of soil-nail horizontal space with an evident acceptable space range of 2 m or less and increases linearly with the increase of soil-nail diameter and length. However when the soil- nail length equals approximately the height of the slope, the safety factor increases slowly. These results can provide a design base for field engineers. Keywords : soil nailing, retaining parameter, safety factor, Morgenstern-Price method 1 Introduction used the FLAC to simulate the change of nail’s Soil nailing is a technique of in-situ ground length, inclination, assigned the way and soil reinforcement which is widely used in the layer parameter to the influence of the horizontal foundations, pit excavations and permanent displacement of foundation pit and the greatest Sun (2007) discussed slopes.
    [Show full text]
  • LOADTEST Dynamic Load Testing (DLT)
    LOADTEST Dynamic Load Testing (DLT) INTRODUCTION RESULTS Dynamic load testing can be an attractive cost The measured pile head signals are analysed in effective alternative to traditional full scale static real time to provide: load testing. Instead of costly, time consuming • an estimate of the soil resistance proof loading using kentledge or anchor piles, mobilised during the test. the technique uses a heavy falling weight such • determination of maximum stresses in as a piling hammer to impart a short duration the pile and shaft integrity. impact to the pile head, whilst monitoring the • measurement of the overall operating pile response using attached transducers. The efficiency of the hammer and its test generates data required by the foundation coupling to the pile head. designer to provide assurance on the relative Additional analysis of each set of dynamic test capacity of the foundation and can usually data can be performed using the CAPWAP or provide additional information that can be DLTWAVE pile driving simulation computer difficult to obtain via static load testing. programs. These programs uses an iterative solution technique to optimise the parameters DESCRIPTION defining the soil resistance supporting the pile. The test is performed by striking the pile head This is done by matching forces at the pile head with a piling hammer or other suitable drop computed using stress wave theory with those weight whilst monitoring pile soil response in actually measured during the test. The terms of pile head force and velocity using programs output many parameters valuable to specially developed bolt-on reusable the experienced piling engineer.
    [Show full text]
  • Influence of Peripheral Velocity on Measurements of Undrained Shear Strength for an Artificial Soil
    Estimated Time to Failure, t (minutes) f 104 1000 100 10 1 0.1 2.0 u0 /s Rate Effect Model u β = 0.10 β s /s = (v /v ) u u0 p p0 1.5 0.05 1.0 Typical 0.5 Typical Range of Range of Interest for Wave Interest for Reference Rate & Storm Loading Earthquake ~ 3.4 mm/min Loading Norm. Undrained Shear Strength, s Strength, Shear Undrained Norm. 0.0 0.0100 0.100 1.00 10.0 100 103 Peripheral Velocity, v (mm/min) p Symbol Reference Soil This Work Bentonite-Kaolinite Mix Perlow & Richards, 1977 San Diego Clay Wiesel, 1973 Ska Edeby Tortensson, 1977 Backebol Tortensson, 1977 Askim Schapery & Dunlap, 1978 Gulf Mexico INFLUENCE OF PERIPHERAL VELOCITY ON UNDRAINED SHEAR STRENGTH AND DEFORMABILITY CHARACTERISTICS OF A BENTONITE- KAOLINITE MIXTURE by Giovanna Biscontin and Juan M. Pestana Geotechnical Engineering Report No UCB/GT/99-19 November 1999 Revised in December 2000 GEOTECHNICAL ENGINEERING. Department of Civil and Environmental Engineering University of California, Berkeley ii TABLE OF CONTENTS LIST OF TABLES......................................................................................................................................................II LIST OF FIGURES....................................................................................................................................................II INFLUENCE OF PERIPHERAL VELOCITY ON MEASUREMENTS OF UNDRAINED SHEAR STRENGTH FOR AN ARTIFICIAL SOIL..............................................................................................................1 ABSTRACT .............................................................................................................................................................1
    [Show full text]
  • Coming Full Circle 32 30 Years of Launched Soil Nails 48 Ground Stabilization for Underground Construc
    20 Ground Improvement 32 30 years of 48 Ground stabilization for 72 The Rise of UAVs – Coming Full Circle Launched Soil Nails Underground Construction in Geotechnics SEPTEMBER // OCTOBER 2016 Ground Improvement Proudly published by the Geo-Institute of ASCE SEPT/OCT GROUND 2016 IMPROVEMENT THE EVOLUTION OF LAUNCHED SOIL NAILS A 30-Year Retrospective By Colby Barrett, JD, PE, M.ASCE, and Graeme Quickfall Fiberglass launched soil nails used for bluff stabilization in Northern California. 32 GEOSTRATA SEPTEMBER/OCTOBER 2016 aunched soil nails are a unique remedial technology in the geotechnical construction Ltoolbox. These 20-ft-long, 1.5-in.-diameter nails are installed in a single shot using a compressed air “cannon” at velocities of up to 250 miles/hour, and at rates approaching 250 nails/day. The nails reinforce an unstable or potentially unstable soil mass by transferring the nail’s tensile and shear capacity into the sliding soil. However, at least as interesting as the tool itself, is the story behind the development of launched soil nail technology over the past 30 years. This story is not just one of technological innovation, advance- ment, and refinement of a specific piece of construction equipment. It stands as a testament of the innovative, bold, and resourceful char- acter of engineers and practitioners in the geotechnical construction industry. It’s also an insight into how engineers from three continents — often working independently — responded to challenges as diverse as national tragedy, shrinking infrastructure budgets, and the challenges posed by geohazards across the globe, to create a powerful new tool that continues to be refined, updated, and improved to the present day.
    [Show full text]
  • Downloaded from the Online Library of the International Society for Soil Mechanics and Geotechnical Engineering (ISSMGE)
    INTERNATIONAL SOCIETY FOR SOIL MECHANICS AND GEOTECHNICAL ENGINEERING This paper was downloaded from the Online Library of the International Society for Soil Mechanics and Geotechnical Engineering (ISSMGE). The library is available here: https://www.issmge.org/publications/online-library This is an open-access database that archives thousands of papers published under the Auspices of the ISSMGE and maintained by the Innovation and Development Committee of ISSMGE. Reliability of statnamic load testing of rock socketed end bearing bored piles Fiabilité d’un essai de charge Statnamic sur un pieu résistant à la pointe foré dans de la roche H. S. Thilakasiri Department of Civil Engineering, University of Moratuwa, Sri Lanka. ABSTRACT The pile load testing methods could be broadly classified into three categories: static, rapid and dynamic depending on the rate of loading. In this paper, the rapid load testing method referred to as the Statnamic test is discussed. The commonly used analysis method of the statnamic testing referred to as the Unloading Point (UP) method is used successfully for the floating piles but validity of some of the assumptions of the unloading point method to end bearing bored piles is questionable. Due to this problem, other analytical methods such as: Modified Unloading Point (MUP) method, Segmental Unloading Point (SUP) method and other signal matching techniques are introduced by some researches. Therefore, the validity of the unloading point method to rock socketed end bearing bored piles in Sri Lanka is investigated in this paper. This investigation is carried out using the commonly used wave number. Furthermore, the wave equation method, commonly used numerical procedure to model dynamic behavior of piles, is used by the author to investigate the validity of the assumptions associated with the unloading point method to rock socketed end bearing bored piles.
    [Show full text]
  • Appendix a Procedures & Commentary for Shaft 1-2-3
    APPENDIX A PROCEDURES & COMMENTARY FOR SHAFT 1-2-3 Nomenclature %R = percent recovery of rock coring (%) a = adhesion factor applied to Su (DIM) b = coefficient relating the vertical stress and the unit skin friction of a drilled shaft (DIM) bm = SPT N corrected coefficient relating the vertical stress and the unit skin friction of a drilled shaft (DIM) D = diameter of drilled shaft (FT) Db = depth of embedment of drilled shaft into a bearing stratum (FT) Dp = diameter of the tip of a drilled shaft (FT) f, ff = angle of internal friction of soil (DEG) fss , q = nominal unit shear resistance (TSF) g = unit weight (pcf) k = empirical bearing capacity coefficient (DIM) K = load transfer factor N = average (uncorrected) Standard Penetration Test blow count, SPT N (Blows/FT) Nc = bearing capacity factor (DIM) Ncorr = corrected SPT blow count qs = average splitting tensile strength of the rock core (TSF) qu = average unconfined compressive strength of the rock core (TSF) Su = undrained shear strength (TSF) s'v = vertical effective stress (TSF) A-1 Appendix A (continued) Procedures Commentary SECURITY NOTE: Microsoft XP users must set Security Level in Macro Security to Medium. This is done in Tools - Options - Macro Security - Security Level. General Worksheet Enter Job Name Job Name must be entered before analysis is run. Enter Job Location Job Location is optional. Enter Engineer Engineer is optional. Enter Boring Log Information The Boring Log worksheet can be displayed by clicking the Boring Log button or clicking on the Boring Log sheet tab at the bottom of Excel (see Procedures & Commentary for Boring Log Worksheet below).
    [Show full text]
  • Slope Stabilization and Repair Solutions for Local Government Engineers
    Slope Stabilization and Repair Solutions for Local Government Engineers David Saftner, Principal Investigator Department of Civil Engineering University of Minnesota Duluth June 2017 Research Project Final Report 2017-17 • mndot.gov/research To request this document in an alternative format, such as braille or large print, call 651-366-4718 or 1- 800-657-3774 (Greater Minnesota) or email your request to [email protected]. Please request at least one week in advance. Technical Report Documentation Page 1. Report No. 2. 3. Recipients Accession No. MN/RC 2017-17 4. Title and Subtitle 5. Report Date Slope Stabilization and Repair Solutions for Local Government June 2017 Engineers 6. 7. Author(s) 8. Performing Organization Report No. David Saftner, Carlos Carranza-Torres, and Mitchell Nelson 9. Performing Organization Name and Address 10. Project/Task/Work Unit No. Department of Civil Engineering CTS #2016011 University of Minnesota Duluth 11. Contract (C) or Grant (G) No. 1405 University Dr. (c) 99008 (wo) 190 Duluth, MN 55812 12. Sponsoring Organization Name and Address 13. Type of Report and Period Covered Minnesota Local Road Research Board Final Report Minnesota Department of Transportation Research Services & Library 14. Sponsoring Agency Code 395 John Ireland Boulevard, MS 330 St. Paul, Minnesota 55155-1899 15. Supplementary Notes http:// mndot.gov/research/reports/2017/201717.pdf 16. Abstract (Limit: 250 words) The purpose of this project is to create a user-friendly guide focusing on locally maintained slopes requiring reoccurring maintenance in Minnesota. This study addresses the need to provide a consistent, logical approach to slope stabilization that is founded in geotechnical research and experience and applies to common slope failures.
    [Show full text]
  • Mechanically Stabilized Earth (MSE)
    Mechanically Stabilized Earth Mechanically Stabilized Earth (MSE) • Mechanically stabilized earth walls and slopes are constructed with “reinforced soil” and consist of horizontal soil reinforcing elements including such things as steel strips, steel or polymeric grids, and geotextile sheets and a facing to prevent erosion. Mechanically Stabilized Earth (MSE) • Placement of horizontal reinforcing elements of this type significantly strengthens the soil and allows construction of very steep slopes. Even vertical walls can be constructed without support from a massive structural system at the face. CONCEPT OF REINFORCED SOIL without soil reinforcement with soil reinforcement TYPES OF SOIL REINFORCEMENTS Steel strip Geostrip Various types Geogrids (extruded, bonded, woven etc) Woven geotextiles Major applications of Soil Reinforcement as per design codes – Retaining Walls & Bridge Abutments – Retaining Slopes – Soil Nailing – Embankments • On soft soil (like Sabkha in gulf countries) • Over piles • Over areas prone to subsidence TYPICAL CROSS-SECTION OF A HIGHWAY RETAINING WALL Crashbarrier FrictionSlab Pavement Drainage Pipe Facing Panel Structural Fill Backfill Soil Reinforcement Embedment Depth Transverse Drainage Pipe Levelling Pad Geotextile Foundation Soil Mechanically Stabilized Slope Abutment Center for Potential Surcharge Geosynthetic Rotational Failure Plane Reinforcement Failure xH Plane 1V Reinforced Zone 4’vertical spacing Movement and Tension Develop Along Plane of Failure Miragrid Geogrid • Laguna Beach Area, CA How Steep Can a MSE Slope Go? • > 70 deg. is a retaining wall Design of Soil Reinforced Retaining Wall Stability Checks : 1. External Stability is addressed to check against over-turning, sliding and foundation failure 2. Internal Stability is addressed to determine soil reinforcement spacing, strength & length External Stability checks PET / HS Woven Polyester •Low creep behavior for long term structural stability and more economical design.
    [Show full text]