Interpretation of in situ test results from the CANLEX sites

Abstract

One of the primary objectives of the Canadian Liquefaction Experiment (CANLEX) project was to evaluate in situ testing techniques and existing interpretation methods as part of the overall goal to focus and coordinate Canadian geotechnical expertise on the topic of soil liquefaction. Six sites were selected by the CANLEX project in an attempt to characterize various deposits of loose sandy soil. The sites consisted of a variety of soil deposits, including hydraulically placed sand deposits associated with the oil sands industry, natural sand deposits in the Fraser River Delta, and hydraulically placed sand deposits associated with the hard-rock mining industry. At each site, a target zone was selected and various in situ tests were performed. These included standard penetration tests, cone penetration tests, seismic downhole cone penetration tests (giving shear wave velocity measurements), geophysical (gamma-gamma) logging, and pressuremeter testing. This paper describes the techniques used in the in situ testing program at each site and presents a summary and interpretation of the results.Key words: CANLEX, in situ testing, shear wave velocity, geophysical logging, pressuremeter.

A Critical Review of CPT-based Correlations for Shear Wave Velocity in North Sea Soils

“…The variations of the V s predictions with the different correlations are immediately apparent. As expected, the correlation by Hegazy and Mayne [10] leads to an overprediction of V s and the correlation of Wride et al [11] to a pronouced underprediction. The correlations by Andrus et al [12], Robertson and Cabal [14], McGann et al [15] and the new stress-dependent correlation show a good match with the measurents between 5m and 15m depth.…”

“…The variations of the V s predictions with the different correlations are again apparent and these variations exist in all layers. For the correlations by Hegazy and Mayne [10] and Wride et al [11] an over-and underprediction of V s is respectively noticed. In the sandy layers, correlations by Andrus et al [12] and Robertson and Cabal [14] show an overprediction of V s .…”

“…Out of the five selected correlations, the correlation by Robertson and Cabal [14] has the most neutral bias and a relatively small COV. The correlations by Wride et al [11] and McGann et al [15] have a tendency for underprediction of V s while the correlation of Hegazy and Mayne [10] shows a tendency for overprediction of V s . The accuracy metrics are summarised in Table 3.…”

“…When direct shear wave velocity measurements at the location under consideration are not available, a correlation between conventional CPT measurements and shear wave velocity (or small-strain stiffness) is generally used. Several authors have formulated correlations between CPT measurements and G max or V s [8][9][10][11][12][13][14][15][16], each based on a dataset containing both CPT measurements and direct measurement of V s . It should be noted that G max and V s are related through the fundamental relation G max = ρV 2 s , where ρ is the bulk density of the soil.…”

Cone penetration test (CPT)-based soil behaviour type (SBT) classification system — an update

“…Figure 10 shows SCPTu data to a depth of 40 m at the KIDD site near Vancouver, British Columbia, which was part of the CANLEX research project Wride et al 2000). The soils are essentially normally consolidated, uncemented Holocene-age natural (silica-based) deposits from the Fraser River delta and represent both sandlike and claylike soils in one profile.…”