Evaluation of scour potential of cohesive soils - phase 2.

Details

• Creators:
  Anderson, J. Brian ; Fang, Xing ; Walker, Melvin E. ; Wright, William H. ; Chen, Gang
• Corporate Creators:
  Auburn University. Highway Research Center
• Corporate Contributors:
  Alabama. Dept. of Transportation
• Subject/TRT Terms:
  • Bridge foundations
  • Scour
  • Cohesive soils
  • Depth
  • Erosion
  • Shear stress
• Publication/ Report Number:
  ALDOT 930-789-1
• Resource Type:
  Tech Report
• Geographical Coverage:
  Alabama
• Corporate Publisher:
  Auburn University. Highway Research Center
• Abstract:
  Determination of erosion parameters in order to predict scour depth is imperative to designing safe, ; economic, and efficient bridge foundations. Scour behavior of granular soils is generally understood, ; and design criteria have been established by the Federal Highway Administration. The same is not true ; for cohesive soils, and because of their complexity, a universal scour prediction method has not been ; established by the industry. The Erosion Function Apparatus (EFA) was created to determine the rate ; of scour of cohesive soils under known shear stresses, which can then be used to predict scour depths ; under similar conditions. During this study, ten cohesive soil formations were sampled with the ; assistance of the Alabama Department of Transportation. Specimens from these formations were scour ; tested in an updated EFA featuring an ultrasonic sensor for quantitative erosion measurements. EFA ; tests were performed to determine erosion functions and whether any formations demonstrated scour ; resistance. Geotechnical index tests were also performed on these formations to correlate scour to ; geotechnical properties. Results of testing verified the performance of the ultrasonic sensor and updated ; EFA. Three of the ten tested formations were scour resistant. Scour resistant formations has SPT N ; value 60 or more with moisture content less than 22% and mean grain size less than 0.008 mm. Velocity ; and shear stress based erosion functions were generated for the seven scourable formations with scour ; rates upwards of 15 mm per hour.
  More +
• Format:
  PDF
• Download URL:
  https://rosap.ntl.bts.gov/view/dot/29483/dot_29483_DS1.pdf
• File Type:
  [PDF - 4.63 MB]
• Collection(s):
  US Transportation Collection
• Main Document Checksum:
  urn:sha256:dcf3401061091a1ac972854cf4aea63b0de4d3e182a8fbba68ef1915d139a1ad