Evaluating the methodology and performance of jetting and flooding of granular backfill materials.

Details

• Creators:
  Fratta, Dante ; Newgard, Jeff
• Corporate Creators:
  University of Wisconsin--Madison
• Corporate Contributors:
  United States. Federal Highway Administration
• Subject/TRT Terms:
  Backfill Soils Compaction Drainage Evaluation Field Tests Floods Hydraulic Jetting Laboratory Tests Slurry
• Publication/ Report Number:
  WisDOT ID no. 0092-11-03
• Resource Type:
  Tech Report
• Geographical Coverage:
  Wisconsin
• Corporate Publisher:
  Wisconsin. Dept. of Transportation. Research and Library Unit
• Abstract:
  Compaction of backfill in confined spaces on highway projects is often performed with small vibratory plates, based
  
  solely on the experience of the contractor, leading to inadequate compaction. As a result, the backfill is prone to
  
  erosion and often exhibits excessive settlements, causing loss of support beneath pavements. The scope of this project
  
  includes developing standard specifications for two alternative hydraulic compaction methods, flooding and jetting,
  
  which additionally are suitable in confined spaces. During flooding, or compaction by drainage, the backfill layer is
  
  saturated with water from the surface and allowed to drain. During jetting, a probe emitting a high pressure jet of
  
  water is inserted into the layer, and the backfill is allowed to drain. In slurry flooding, a slurry mix is flood into place
  
  and it is allowed to drain so the lift gains strength. In these cases the energy of the flowing water and residual suction
  
  upon drainage increase the effective stress and move the grains into a denser arrangement. The results in the lab
  
  indicate that for compaction by drainage applications, uniform, rounded soils achieve the highest relative density due
  
  to their minimal particle interlocking upon deposition and subsequent high drainage capacity. Meanwhile during
  
  jetting applications, soils liquefy locally around the jet of water, and their compactness upon drainage is highly
  
  dependent on the hydraulic gradient, or the energy with which water drains from the pore space. Greater hydraulic
  
  gradient during the drainage phase of jetting has been observed to produce more compact soil structure.
  
  
• Format:
  PDF
• Funding:
  0092-11-03
• Collection(s):
  US Transportation Collection
• Main Document Checksum:
  urn:sha256:c9dccfb3084eeadc5dff07234e1fc62cece850322ce31c7431a9b2d1c88ee151
• Download URL:
  https://rosap.ntl.bts.gov/view/dot/28932/dot_28932_DS1.pdf
• File Type:
  [PDF - 10.45 MB ]