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
  • Floods
  • Hydraulic jetting
  • Evaluation
  • Compaction
  • Laboratory tests
  • Field tests
  • Slurry
  • Drainage
• 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.
  More +
• Format:
  PDF
• Funding:
  0092-11-03
• Download URL:
  https://rosap.ntl.bts.gov/view/dot/28932/dot_28932_DS1.pdf
• File Type:
  [PDF - 10.45 MB]
• Collection(s):
  US Transportation Collection
• Main Document Checksum:
  urn:sha256:c9dccfb3084eeadc5dff07234e1fc62cece850322ce31c7431a9b2d1c88ee151