Final Report FDOT Contract No.: BDV31-977-05 UF Contract No.: 108380 Evaluation of Static Resistance of Deep Foundations Principal Investigators: Michael C. McVay, Ph.D. (PI) Jae, Chung, Ph.D. (Co-PI) Researchers: Thai Nguyen, M.S., P.E. Sudheesh Thiyyakkandi, Ph.D. Weina Lyu, M.S. John L. Schwartz III, M.S. Lin Huang, M.S. Vinh Le, M.S. Department of Civil and Coastal Engineering Engineering School of Sustainable Infrastructure and Environment University of Florida P.O. Box 116580 Gainesville, Florida 32611-6580 Developed for the Project Manager: Rodrigo Herrera, P.E., Florida Department of Transportation Structures Office May 2017 DISCLAIMER The opinions, findings, and conclusions expressed in this publication are those of the authors and not necessarily those of the Florida Department of Transportation or the U.S. Department of Transportation. Prepared in cooperation with the State of Florida Department of Transportation and the U.S. Department of Transportation. ii SI (MODERN METRIC) CONVERSION FACTORS (from FHWA) APPROXIMATE CONVERSIONS TO SI UNITS SYMBOL WHEN YOU KNOW MULTIPLY BY TO FIND SYMBOL LENGTH in inches 25.4 millimeters mm ft feet 0.305 meters m yd yards 0.914 meters m mi miles 1.61 kilometers km SYMBOL WHEN YOU KNOW MULTIPLY BY TO FIND SYMBOL AREA in2 square inches 645.2 square millimeters mm2 ft2 square feet 0.093 square meters m2 yd2 square yard 0.836 square meters m2 ac acres 0.405 hectares ha mi2 square miles 2.59 square kilometers km2 SYMBOL WHEN YOU KNOW MULTIPLY BY TO FIND SYMBOL VOLUME fl oz fluid ounces 29.57 milliliters mL gal gallons 3.785 liters L ft3 cubic feet 0.028 cubic meters m3 yd3 cubic yards 0.765 cubic meters m3 NOTE: volumes greater than 1000 L shall be shown in m3 SYMBOL WHEN YOU KNOW MULTIPLY BY TO FIND SYMBOL MASS oz ounces 28.35 grams g lb pounds 0.454 kilograms kg T short tons (2000 lb) 0.907 megagrams (or "metric ton") Mg (or "t") SYMBOL WHEN YOU KNOW MULTIPLY BY TO FIND SYMBOL TEMPERATURE (exact degrees) °F Fahrenheit 5 (F-32)/9 Celsius °C or (F-32)/1.8 SYMBOL WHEN YOU KNOW MULTIPLY BY TO FIND SYMBOL ILLUMINATION fc foot-candles 10.76 lux lx fl foot-Lamberts 3.426 candela/m2 cd/m2 SYMBOL WHEN YOU KNOW MULTIPLY BY TO FIND SYMBOL FORCE and PRESSURE or STRESS Lbf * poundforce 4.45 newtons N kip kip force 1000 pounds lbf lbf/in2 (psi) poundforce per square inch 6.89 kilopascals kPa ksf kips per square foot 0.04788 Megapascals Mpa tsf tons per square foot 0.09576 Megapascals Mpa iii APPROXIMATE CONVERSIONS TO SI UNITS SYMBOL WHEN YOU KNOW MULTIPLY BY TO FIND SYMBOL LENGTH mm millimeters 0.039 inches in m meters 3.28 feet ft m meters 1.09 yards yd km kilometers 0.621 miles mi SYMBOL WHEN YOU KNOW MULTIPLY BY TO FIND SYMBOL AREA mm2 square millimeters 0.0016 square inches in2 m2 square meters 10.764 square feet ft2 m2 square meters 1.195 square yards yd2 ha hectares 2.47 acres ac km2 square kilometers 0.386 square miles mi2 SYMBOL WHEN YOU KNOW MULTIPLY BY TO FIND SYMBOL VOLUME mL milliliters 0.034 fluid ounces fl oz L liters 0.264 gallons gal m3 cubic meters 35.314 cubic feet ft3 m3 cubic meters 1.307 cubic yards yd3 SYMBOL WHEN YOU KNOW MULTIPLY BY TO FIND SYMBOL MASS g grams 0.035 ounces oz kg kilograms 2.202 pounds lb Mg (or "t") megagrams (or "metric ton") 1.103 short tons (2000 lb) T SYMBOL WHEN YOU KNOW MULTIPLY BY TO FIND SYMBOL TEMPERATURE (exact degrees) °C Celsius 1.8C+32 Fahrenheit °F SYMBOL WHEN YOU KNOW MULTIPLY BY TO FIND SYMBOL ILLUMINATION lx lux 0.0929 foot-candles fc cd/m2 candela/m2 0.2919 foot-Lamberts fl SYMBOL WHEN YOU KNOW MULTIPLY BY TO FIND SYMBOL FORCE and PRESSURE or STRESS N newtons 0.225 poundforce lbf kPa kilopascals 0.145 poundforce per square lbf/in2 inch *SI is the symbol for International System of Units. Appropriate rounding should be made to comply with Section 4 of ASTM E380. (Revised March 2003) iv TECHNICAL REPORT DOCUMENTATION PAGE 1. Report No. 2. Government Accession No. 3. Recipient's Catalog No. 4. Title and Subtitle 5. Report Date Evaluation of Static Resistance of Deep Foundation: Phase I May 2017 6. Performing Organization Code 7. Author(s) 8. Performing Organization Report No. Michael McVay, Jae Chung, Thai Nguyen, Sudheesh Thiyyakkandi, Weina Lyu, John Schwartz III, Lin Huang, and Vinh Le 9. Performing Organization Name and Address 10. Work Unit No. (TRAIS) University of Florida – Dept. of Civil and Coastal Engineering Engineering School of Sustainable Infrastructure and Environment 11. Contract or Grant No. 365 Weil Hall – P.O. Box 116580 BDV31-977-05 Gainesville, FL 32611-6580 12. Sponsoring Agency Name and Address 13. Type of Report and Period Covered Florida Department of Transportation Final Report 605 Suwannee Street, MS 30 5/20/13 – 5/30/17 Tallahassee, FL 32399 14. Sponsoring Agency Code 15. Supplementary Notes 16. Abstract: The focus of this research was to evaluate and improve Florida Department of Transportation (FDOT) FB-Deep software prediction of nominal resistance of H-piles, prestressed concrete piles in limestone, large diameter (> 36”) open steel and concrete piles, as well as estimation of unit side friction on permanent steel casing for drilled shafts in Florida limestone. To accomplish this the following data was collected, (1) 642 dynamic load tests (DLT) and 33 static load tests on H-piles, (2) 100 DLT tests for prestressed concrete piles in Florida limestone, (3) 50 open-ended steel and concrete piles (22 piles larger than 36-in) from coastal areas in the U.S. and Asia, and (4) 17 cased drilled shafts embedded in Florida limestone. Evaluation of the H-piles revealed that generally, the piles undergo both setup and plugging after driving that is lost after a few restrikes; in addition, long piles undergo skin friction unloading. Recommendations to improve FB- Deep H-pile prediction include averaging Standard Penetration Test (SPT) N values only beneath the pile tip and increasing the limiting N values to 100 for strong limestone layers. In the case of prestressed concrete piles embedded in limestone, (1) weak limestone which for the purposes of this report was classified as N < 45 blows per foot, exhibit unit skin friction values more representative of soil than rock/shelly sand, (2) for competent limestone (N>45) the limiting SPT N value for estimating side and tip resistance should be increased to 100, and (3) the nominal tip resistance should be estimated by averaging the SPT N values within four diameters (or pile width) “B” below the pile tip. For all limestone (weak and competent), a revised unit tip resistance for 4B SPT N averaging is recommended. For all open-ended steel and concrete cylinder piles, it was found that many piles behaved plugged per the static load test results. It was established for both FB-Deep (2015) program and American Petroleum Institute (API - 2011) method that the end bearing was the minimum of inside side friction or unit end bearing acting over the bottom soil plug; in addition, the limiting N value should be increased to 100. Finally, for a permanent cased drilled shaft, the unit skin friction in load tested shafts was found to increase with rock strength to a limiting value of 1.2 tsf; an equation of nominal resistance as well as mobilized resistance as a function of displacement is presented. The contribution of casing in drilled shafts that derive most of their side resistance from the rock socket interface should not be implemented in design, due to strain incompatibility between the cased and uncased portions of the embedded length. 17. Key Words 18. Distribution Statement H-piles, prestressed concrete piles, open-ended steel and concrete piles, cased drilled shafts embedded in limestone, No restrictions. Static and Dynamic Load Tests, and FB-Deep 19. Security Classif. (of this report) 20. Security Classif. (of this page) 21. No. of Pages 22. Price Unclassified Unclassified 212 Form DOT F 1700.7 (8-72) Reproduction of completed page authorized v ACKNOWLEDGMENTS The researchers would like to thank the Florida Department of Transportation (FDOT) for the financial support to carry out this research and the State Materials Office in Gainesville, Florida, for providing access and assisting with many of the field tests (SPT) on H-pile sites. In addition, the assistance of district geotechnical engineers in obtaining project plans, geotechnical reports, driving logs, as well dynamic load tests (DLT) and signal matching (e.g., CAPWAP) assessments is appreciated. vi EXECUTIVE SUMMARY The focus of this research was to evaluate and improve Florida Department of Transportation (FDOT) FB-Deep software prediction of nominal resistance of H-piles, prestressed concrete piles in Florida limestone, large diameter (> 36”) open steel and concrete piles, as well as estimation of unit side friction on permanent steel casing for drilled shafts in Florida limestone. To accomplish this the following data was collected, (1) 642 dynamic load tests (DLT) and 33 static load tests along with site data for H-piles, (2) DLT test and site data for more than 100 prestressed concrete piles, (3) site data and static load tests or over 50 open-ended pipe piles (steel and concrete) with diameters ranging from 30” to 54” in coastal areas of the U.S. and Asia, and (4) load tests (Osterberg and Statnamic) from seven sites for 16 cased drilled shafts embedded in Florida limestone.