Liquefaction Resistance Using CPT and Field Case Histories

Abstract

Relationships between cone penetration tip resistance and the liquefaction potential of sandy soils are presented to facilitate use of the cone penetration test (CPT) in liquefaction assessments. The relationships are based on 180 liquefaction and nonliquefaction field case histories where CPTs were performed and illustrate the importance of median grain size and fines content on liquefaction resistance. The proposed CPT-based relationships were developed to describe the field case histories where CPT data are available, and eliminate the need to rely on conversions of standard penetration test (SPT) blow counts to CPT tip resistance used by existing CPT liquefaction-potential relationships. A new conversion between CPT tip resistance and SPT blow count is also proposed using the liquefaction-potential relationships developed from CPT data and existing liquefaction-potential relationships developed from SPT data. Finally, tentative CPT based liquefaction-potential relationships are proposed for clean and silty gravel based on 18 liquefaction and nonliquefaction case histories.

Field Evaluation of the Cyclic Strength versus Cone Tip Resistance Correlation in Silty Sands

“…For tests on MLS withˆnes content, FC＝0 and 15z, CPTU was essentially drained. For drained CPTU in MLS, the CRR-qt1N correlations consistently fell to the left of those proposed by Stark and Olson (1995) and Robertson and Wride (1998) for clean sand.…”

“…The CRR-qt1N correlations proposed by Stark and Olson (1995) for clean sand (FCÃ5z), silty sand (5ºFCº35z) and sandy silt (FCAE35z) are included in Fig. 14 for reference.…”

“…vo ) n (2) where n＝exponent that varies with soil type The associated CRR-qt1N correlations for clean sands have been established according toˆeld observations. Although diŠerent in magnitude and/or format, it has been suggested that separate sets of CRR-qt1N correlations should be used for sands withˆnes (Stark and Olson, 1995). Alternatively, the qt1N should be adjusted to an equivalent clean sand value, (qt1N)cs before invoking the CRR-(q t1N ) cs correlation (Robertson and Wride, 1998).…”

CPT-Based Probabilistic and Deterministic Assessment of In Situ Seismic Soil Liquefaction Potential

“…The cone penetration test ͑CPT͒ is a reliable in situ index test that has found widespread use as a tool for assessing the liquefaction resistance of potentially liquefiable soils. A number of CPT-based liquefaction triggering resistance curves have been suggested by previous researchers ͑e.g., Seed et al 1983;Olsen 1984;Ishihara 1985;Jamiolkowski et al 1985;Robertson and Campanella 1985;Franklin 1986;Seed and De Alba 1986;Shibata and Teparaska 1988;Sugawara 1989;Mitchell and Tseng 1990;Olsen and Koester 1995;Stark and Olson 1995;Rongxiang and Zhaoji 1995;Robertson and Wride 1998;Toprak et al 1999;Juang et al 2003;Idriss and Boulanger 2004͒.…”

Probabilistic Liquefaction Triggering based on the Cone Penetration Test

“…The CPT is a reliable in situ index test that has found widespread use as a tool for measuring resistance of potentially liquefiable layers. CPT-based liquefaction triggering curves have been suggested by previous researchers (e.g., Shibata & Teparaska, 1988;Seed & De Alba, 1986;Mitchell & Tseng, 1990;Stark & Olson, 1995;Suzuki et al, 1995;Robertson & Campanella, 1985;Robertson & Wride, 1998;Toprak et al, 1999;and Juang et al, 2003). For use in performance-based engineering analysis the triggering correlations must be presented in a probabilistic manner.…”