Design and Verification of Blast Densification for Highway Embankments of Liquefiable Sands

Details

• Alternative Title:
  Measuring the effect of occluded gas bubbles on stress-strain response of a loose to ; medium sand
• Creators:
  Finno, Richard ; Knai, Hilde B.
• Corporate Creators:
  Northwestern University (Evanston, Ill.). Infrastructure Technology Institute
• Corporate Contributors:
  United States. Department of Transportation. University Transportation Centers (UTC) Program
• Subject/TRT Terms:
  • Sand
  • Sand deposits
  • Soils
  • Sand
  • Sand deposits
  • Soils
• Resource Type:
  Tech Report
• Geographical Coverage:
  Illinois
• Edition:
  Final report.
• Corporate Publisher:
  Northwestern University (Evanston, Ill.). Infrastructure Technology Institute
• Abstract:
  As part of a larger effort to investigate the effects of blast densification on the properties and ; behavior of compacted sand deposits, this study presents a procedure for replicating in the ; laboratory the occluded gas bubbles believed to exist in the ground after blasting, and a ; preliminary evaluation of the effect of these bubbles on the stress-strain response of loose to ; medium samples of a fine sand. The procedure for creating gassy soil specimens relied on the ; exsolution of CO2 gas from carbonated water when the applied pressure was reduced. A system ; was developed for replacing the pore water in a sand sample with water saturated with CO2. ; After replacing the pore water, a given amount of bubbles could be produced in the sample by ; lowering the backpressure by a controlled increment. Using this setup, a series of drained and ; undrained triaxial compression tests were performed on sand samples with void ratios ranging ; from 0.62 to 0.82 and containing varying amounts of gas. It was concluded that the presence of ; free gas lowered the effective friction angle of the sand by 1.0 to 1.5 degrees compared to fully ; saturated samples at the same void ratio. This effect may explain the reduction in cone ; penetration resistance after blasting which is often observed in the field.
  More +
• Format:
  PDF
• Download URL:
  https://rosap.ntl.bts.gov/view/dot/25106/dot_25106_DS1.pdf
• File Type:
  [PDF - 26.13 MB]
• Collection(s):
  University Transportation Centers ; US Transportation Collection
• Main Document Checksum:
  urn:sha256:ce06b055594af9e6ee3cbd588666510fbc18c8ec88a2b0700393521027720d51