Investigation of soil density and fabric effect on SPT and V_s measurements using a calibration chamber

Abstract

This paper presents experimental data of Standard Penetration Test (SPT) and shear wave velocity V_s measurements using a pressurized chamber. The influences of soil density and soil fabric were focused because they have been found to be the major factors to liquefaction resistance under similar stress states. Two sand specimens were prepared and consolidated to a mean effective stress of around 30 kPa. The specimens’ relative density was of about 80 %, and theV_s values measured were between 175 and 190 m/s, such that the small-strain stiffnessG₀ differed by 16 %. SPT was performed in constant stress conditions, and almost equal blow counts (N-value) were recorded in the two specimens. The results demonstrated that N-value could not reflect the discrepancy in soil fabric as indicated by the differentV_s(G₀) values at the given density.