Calibration of region-specific gates pile driving formula for LRFD : final report 561.

Details

• Creators:
  Tavera, Eduardo A. ; Burnworth, Gabriel H. ; Rix, Glenn J. ; Jung, Jongwon
• Corporate Creators:
  GeoStellar Engineering, LLC ; GeoSyntec Consultants ; Louisiana State University (Baton Rouge, La.)
• Corporate Contributors:
  Louisiana. Dept. of Transportation and Development ; United States. Federal Highway Administration
• Subject/TRT Terms:
  • Calibration
  • Implementation
  • Load tests
  • Monte Carlo method
  • Pile driving
  • Recommendations
  • Regression analysis
  • LRFD
  • reliability analysis
  • pile driving formula
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• Publication/ Report Number:
  FHWA/LA.16/561 ; LTRC Project Number: 14-1GT
• Resource Type:
  Tech Report
• Geographical Coverage:
  United States ; Louisiana
• Edition:
  Final Report, January 2014 - February 2016
• Corporate Publisher:
  Louisiana Transportation Research Center
• Abstract:
  This research project proposes new 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 CAPWAPs) and BOR ; (751 CAPWAPs). The pile driving formulas were developed by conducting a nonlinear regression analysis of the ; generic Gates formula. The 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 AASHTO ; specifications. The current LADOTD pile driving formula (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.
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• Format:
  PDF
• Funding:
  State Project Number: SIO #30001424
• Download URL:
  https://rosap.ntl.bts.gov/view/dot/30895/dot_30895_DS1.pdf
• File Type:
  [PDF - 13.91 MB]
• Collection(s):
  US Transportation Collection
• Main Document Checksum:
  urn:sha256:76a7476f7779d85cc1e006cc3b3718c9646cf69e3b00cca9df044f04ed34a200