EFFECT OF GRAVEL ON PUMPING BEHAVIOR OF COMPACTED SOIL. TECHNICAL NOTE

When clay is compacted wet of optimum, pumping or the softening and squeezing out of clay from beneath the compaction equipment occurs. Adding gravel to the clayey soil creates a granular skeleton that increases the undrained shear strength. Findings from a study to investigate the effect of gravel on the pumping behavior of a highly plastic soil reveals that even a partial gravel skeleton can prevent pumping of a clayey soil. In the study, pumping occurred during the modified Proctor compaction test when the undrained shear strength was less than 14 kPa (290 psf) and the initial tangent modulus was less than 1,600 kPa. To prevent this phenomenon, the clayey soil had to contain at least 63 percent rounded gravel or 54 percent angular gravel. A lower percentage of angular gravel was necessary to prevent pumping as the angular gravel more effectively interlocked and created the necessary gravel skeleton.

Language

  • English

Media Info

  • Features: Appendices; Figures; References; Tables;
  • Pagination: p. 863-866
  • Serial:

Subject/Index Terms

Filing Info

  • Accession Number: 00730008
  • Record Type: Publication
  • Files: TRIS
  • Created Date: Dec 29 1997 12:00AM