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:
  BOR Calibration EOID FHWA Modified Gates Implementation Load Tests LRFD Monte Carlo Method Pile Driving Pile Driving Formula Recommendations Regression Analysis Reliability Analysis

  More +
• 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.
  
  
• Format:
  PDF
• Funding:
  State Project Number: SIO #30001424
• Collection(s):
  US Transportation Collection
• Main Document Checksum:
  urn:sha256:76a7476f7779d85cc1e006cc3b3718c9646cf69e3b00cca9df044f04ed34a200
• Download URL:
  https://rosap.ntl.bts.gov/view/dot/30895/dot_30895_DS1.pdf
• File Type:
  [PDF - 13.91 MB ]