RESIDUAL STRENGTH AND LARGE-DEFORMATION POTENTIAL OF LOOSE SILTY SANDS

The authors of this paper summarize laboratory and field evidence on residual shear strength, density, and penetration resistance of very loose, water-deposited silty sands and sandy silts capable of liquefying and developing large shear deformations. A program of laboratory monotonic and cyclic undrained tests is performed on reconstituted, water-deposited, layered triaxial specimens of silty sand retrieved from the Lower San Fernando Dam. The results reveal that the soil acts contractively in shear, and both its density and steady-state strength increase quickly with consolidation pressure. These trends are confirmed for field conditions by comparison with available case histories of earthquake-induced flow failure and large lateral deformation of embankments, slopes, and mildly sloping ground. The 1971 flow slide in the Lower San Fernando Dam is reviewed in detail. The normalized Standard Penetration Index used to develop engineering charts is developed from the case histories. These charts can be applied in evaluating residual shear strength and to determine if a saturated silt-sand slope or site is likely to develop flow or large lateral deformations.

Language

  • English

Media Info

  • Features: Appendices; Figures; References; Tables;
  • Pagination: p. 896-906
  • Serial:

Subject/Index Terms

Filing Info

  • Accession Number: 00714632
  • Record Type: Publication
  • Files: TRIS
  • Created Date: Dec 18 1995 12:00AM