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
• 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.
  
  
• Format:
  PDF
• Collection(s):
  University Transportation Centers US Transportation Collection
• Main Document Checksum:
  urn:sha256:ce06b055594af9e6ee3cbd588666510fbc18c8ec88a2b0700393521027720d51
• Download URL:
  https://rosap.ntl.bts.gov/view/dot/25106/dot_25106_DS1.pdf
• File Type:
  [PDF - 26.13 MB ]