Liquefaction potential of sand deposits has recently been evaluated by Seed using converted Standard Penetration Test (SPT) "N" vaues, based upon the concept that factors tending to improve liquefaction resistance, likewise improve SPT resistance. The procedure compares SPT "N" values corrected to an overburden pressure of 1 TSF with stress ratio, tau/sigma, in the field. On this basis, the objective of this research was to evaluate the correction factor, C sub N, used to correct "N" values to an overburden pressure of 1 TSF for four different sands. Cyclic triaxial tests were also performed on these same sands. Using these laboratory data, extension of the data base from field observations was attempted. A series of laboratory SPT were conducted on four sands at various overburden pressures to develop relationships between overburden pressure, relative density, sand type, and "N" values. In addition, isotropically consolidated cyclic triaxial tests were conducted on these same four sands at comparable relative densities and overburden pressures to evaluate their liquefaction potential. Utilizing these data, correction factor, C sub N, values, where C sub N = N sub 1 over N and N sub 1 = N values at 1 TSF overburden pressure and N - N values at various overburden pressures, were obtained and compared with previously reported C sub N values. Similarly, cyclic triaxial results were converted to field response utilizing appropriate correction factor, C sub r, values and equivalent cycles for various earthquake magnitudes. Plots of tau/sigma vs N sub 1 were prepared based upon these data and compared with previously published field response. Conclusions concerning the magnitudes and acceptability of C sub N and C sub r values for comparing field response are drawn. In addition, the data base of field observations is extended by utilizing laboratory data. /Author/

Media Info

  • Features: Appendices; Figures; References; Tables;
  • Pagination: p. 976-990

Subject/Index Terms

Filing Info

  • Accession Number: 00179792
  • Record Type: Publication
  • Report/Paper Numbers: Proceeding
  • Files: TRIS
  • Created Date: Oct 12 1978 12:00AM