Embedded data collector (EDC) phase II load and resistance factor design (LRFD).

Details

• Creators:
  McVay, Michael C. ; Wasman, Scott J.
• Corporate Creators:
  University of Florida. Dept. of Civil and Coastal Engineering
• Corporate Contributors:
  United States. Dept. of Transportation
• Subject/TRT Terms:
  • Piles (Supports)
  • Design load
  • Load tests
  • Static tests
  • Instrumentation
  • Bridge foundations
  • Skin resistance
  • Data collection
• Publication/ Report Number:
  BDV31-977-13
• Resource Type:
  Tech Report
• Geographical Coverage:
  Florida
• Corporate Publisher:
  Florida. Dept. of Transportation
• Abstract:
  A total of 16 static load test results was collected in Florida and Louisiana. New static load tests on five test piles ; in Florida (four of which were voided) were monitored with Embedded Data Collector (EDC) instrumentation and ; contributed to the total of 16. For the voided test piles, EDC instrumentation was placed in the piles at different locations ; relative to the void to compare the estimated resistances. In the four test piles, the measured top compressive stresses ; measured in the solid section of the pile were typically about 25% smaller than the measured values in the voided section of ; the pile. However, when the top stresses were adjusted by area (i.e., divide by 645 in2 ; / 900 in2 ; = 0.72), then the stresses ; were very comparable. Two methods were used to estimate the pile capacities: The UF method and the Tran et al. methods. ; The UF method (employed in SmartPile Review) uses the Case capacity equation with variable case damping, Jc, to assess ; total capacity and the Unloading Point Method for tip resistance, (i.e., skin friction = total – tip resistance). The Tran et al. ; method computes side friction using a segmental approach and tip resistance using conservation of force and energy. The ; Tran et al. method for side friction showed a smaller difference (6%) in predicted capacities between top solid and voided ; gauge sets than the UF method (23%) using the Case Equation for the four voided test piles. ; Load and Resistance Factor Design (LRFD) resistance factors () for piles with EDC were calculated for a ; reliability, , of 2.33 using the First Order Second Moment (FOSM) method and the First Order Reliability Method ; (FORM). For the UF method, a total of 42 pairs (measured vs. predicted; bias,  = 0.998, standard deviation,  = 0.212, and ; CV = 0.212) were analyzed for the cases of EDC in both the solid and voided sections (four new test piles supported in ; present project)). The FORM = 0.75 and FOSM = 0.64. A smaller data set of 34 pairs (measured vs. predicted; bias,  = ; 0.918, standard deviation,  = 0.172, and CV = 0.188) were analyzed for the cases of EDC only in the solid sections. The ; FORM = 0.73 and FOSM = 0.62. For the Tran et al. method, a total of 39 pairs (measured vs. predicted; bias,  = 0.991, ; standard deviation,  = 0.169, and CV = 0.17) were analyzed for the cases of EDC in both the solid and voided sections. ; The FORM = 0.81 and FOSM = 0.68. A smaller data set of 33 pairs (measured vs. predicted; bias,  = 0.979, standard ; deviation,  = 0.182, and CV = 0.186) were analyzed for the cases of EDC only in the solid sections. The FORM = 0.78 and ; FOSM = 0.66. For the Fixed Jc method, FORM and FOSM were calculated for limited data sets (solid/voided and only solid ; sections). The listed resistance factors should be used with caution due to the limited data set and the conditions they were ; obtained (e.g., limited soil types tested, time between BOR and static load test, lack of fully instrumented tests piles).
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• Format:
  PDF
• Download URL:
  https://rosap.ntl.bts.gov/view/dot/29547/dot_29547_DS1.pdf
• File Type:
  [PDF - 1.56 MB]
• Collection(s):
  US Transportation Collection
• Main Document Checksum:
  urn:sha256:6f007fac5c21ca2e43e7430de419d6a5e1d39d1a951ebf0b3f68497875cde444