Calibration of Region Specific Gates Pile Driving Formula for LRFD

This research project proposes new Louisiana Department of Transportation and Development (DOTD) pile driving formulas for pile capacity verification using pile driving blow counts obtained at either end-of-initial driving (EOID) or at the beginning-of-restrike (BOR). The pile driving formulas were developed using a regional database containing 252 static load tests and 934 dynamic load tests (DLT) collected from DOTD projects. The DLTs were conducted on blow counts taken at EOID (183 Case Pile Wave Analysis Program (CAPWAPs)) and BOR (751 CAPWAPs). The pile driving formulas were developed by conducting a nonlinear regression analysis of the generic Gates formula. The Load and Resistance Factor Design (LRFD) resistance factors (ɸ) were calibrated using the Monte Carlo Simulation (MCS) method for the Strength I limit state with a reliability index (βT) of 2.33 as recommended for pile groups in American Association of State Highway and Transportation Officials (AASHTO) specifications. The current LADOTD pile driving formula (Federal Highway Administration (FHWA) Gates Formula) used to evaluate blow counts taken at EOID was evaluated; results show a best fit ratio of 0.80 with a resistance factor of 0.67—higher than the AASHTO specifications resistance factor (ɸ) of 0.40 for the same pile driving formula. The new EOID LADOTD Modified pile driving formula has a best fit ratio 0.91 with a resistance factor of 0.59. This study recognizes pile capacity setup can significantly affect pile driving formulas ability to predict pile capacity when using blow counts obtained at BOR. Pile capacity setup was evaluated by computing the Skov-Denver pile setup factors (AQ) using total pile capacity (Q). A minimum of two pile setup categories (A and B) were identified in Louisiana. Pile setup category A is located in the coastal marshes along the gulf coast of Louisiana with setup factors (AQ) ranging from 0.135 to 0.428. Pile setup category B was assigned to the remainder of the state with AQ pile setup factors ranging from 0.021 to 0.108. An evaluation of the pile setup curves using the Skov-Denver model indicates that more than 90% of the long-term pile capacity (load test conducted at t = 14 days) can be obtained at t ≥ 6 days for pile setup category A and t ≥ 3 days for pile setup category B. A BOR pile driving formula was developed for setup category A with restrikes conducted at t ≥ 1 days with a best fit ratio of 0.93 and a corresponding resistance factor (ɸ) of 0.64. A different BOR pile driving formula was developed for pile setup category B with restrikes conducted at t ≥ 1 days with a best fit ratio of 0.92 and a corresponding resistance factor (ɸ) of 0.605. Recommendations on the implementation of these EOID and BOR pile driving formulas have been included in this study.

• Record URL:
  http://www.ltrc.lsu.edu/pdf/2016/FR_561.pdf
• Record URL:
  http://www.ltrc.lsu.edu/pdf/2016/FR_561_Appendix.pdf
• 
• Summary URL:
  http://www.ltrc.lsu.edu/pdf/2016/ts_561.pdf
• Corporate Authors:

  GeoStellar Engineering, LLC

  Baton Rouge, LA  United States 

  Louisiana Transportation Research Center

  Baton Rouge, LA  United States 

  Louisiana Department of Transportation and Development

  1201 Capitol Access Road, P.O. Box 94245
  Baton Rouge, LA  United States  70804-9245

  Federal Highway Administration

  1200 New Jersey Avenue, SE
  Washington, DC  United States  20590
• Authors:
  • Tavera, Eduardo A
  • Burnworth, Gabriel H
  • Rix, Glenn J
  • Jung, Jongwon
• Publication Date: 2016-5

Language

• English

Media Info

• Media Type: Digital/other
• Edition: Final Report
• Features: Appendices; Figures; Maps; References; Tables;
• Pagination: 566p

Subject/Index Terms

• TRT Terms: Calibration; Implementation; Load and resistance factor design; Load tests; Monte Carlo method; Pile driving; Recommendations; Regression analysis
• Identifier Terms: AASHTO LRFD Bridge Design Specifications; Louisiana Department of Transportation and Development
• Geographic Terms: Louisiana
• Subject Areas: Bridges and other structures; Construction; Highways;

Filing Info

• Accession Number: 01603577
• Record Type: Publication
• Report/Paper Numbers: FHWA/LA.16/561, LTRC Project Number: 14-1GT
• Files: TRIS, ATRI, USDOT, STATEDOT
• Created Date: Jun 28 2016 4:41PM