Effect of verification cores on tip capacity of drilled shafts.

Details

• Creators:
  Tonon, Fulvio ; Youn, Heejung ; Raibagkar, Anay P.
• Corporate Creators:
  University of Texas at Austin. Center for Transportation Research
• Corporate Contributors:
  Texas. Dept. of Transportation ; United States. Federal Highway Administration
• Subject/TRT Terms:
  • Drilling
  • Boring
  • Rotary drilling
  • Drills
  • Drill bits
  • Test holes
  • Boreholes
  • Drilling and boring--Standards
  • Drill core analysis
  • Soil mechanics
• Publication/ Report Number:
  FHWA/TX-09/0-5825-1
• Resource Type:
  Tech Report
• Geographical Coverage:
  Texas
• Edition:
  Technical report; Sept. 2006-Aug. 2008.
• Corporate Publisher:
  University of Texas at Austin. Center for Transportation Research
• Abstract:
  This research addressed two key issues: ; 1) Will verification cores holes fill during concrete backfilling? If so, what are the mechanical properties of the ; filling material? In dry conditions, verification core holes always completely fill with concrete whose ; compressive strength is of equal strength to the concrete in the drilled shaft column. In wet conditions, the ; bottom half of the verification core hole fills with non-cemented gravel-sand mixture (φ = 52°), while the upper ; half of the verification core hole filled with weakly cemented material (Vp = 2000 fps). ; 2) When drilling in materials, such as shales, susceptible to degradation: does this degradation specifically around ; shaft verification core holes affect point bearing capacity? The shear strength of Del Rio Clay and Eagle Ford ; Shale is not affected by drying-duration, but is related to water content; the shear strength of Taylor Marl and ; Navarro Shale decreases considerably as drying-duration increases. The elastic modulus of all four clay shales ; drops significantly when clay shales are dried and then wetted. ; When shales are first dried and then rewetted and concrete is poured in the wet, the verification core hole reduces tip ; capacity by a maximum of 10% (14% for Taylor Marl). In all other cases, the verification core does not decrease the ; tip capacity.
  More +
• Format:
  PDF
• Funding:
  0-5825
• Download URL:
  https://rosap.ntl.bts.gov/view/dot/17941/dot_17941_DS1.pdf
• File Type:
  [PDF - 8.70 MB]
• Collection(s):
  US Transportation Collection
• Main Document Checksum:
  urn:sha256:955e009bcb68a8b22a804e87a21a84f6a4e31518e6bfcc5d75bd8e324393511a