Mechanistic Development of CPT-Based Cyclic Strength Correlations for Clean Sand

Abstract

Mechanistic approaches for developing cone penetration test-based liquefaction triggering correlations are presented and evaluated with an application to Ottawa sand. The mechanistic approaches utilize combinations of data from: undrained cyclic direct simple shear tests, dynamic geotechnical centrifuge tests with in-flight cone penetration profiles, and cone penetration simulations. Cyclic direct simple shear tests on Ottawa sand characterize the relationship between cyclic resistance ratio ( ) and relative density ( ). Relationships between cone tip resistance ( ) and are developed from geotechnical centrifuge tests and cone penetration simulations. Penetration simulations using the MIT-S1 constitutive model with three different calibrations for Ottawa sand examine the role of critical state line shape and position on simulated values. The − relationship from laboratory tests is composed with measured and simulated − relationships via common values to develop − relationships. An alternative − relationship is developed from inverse analyses of centrifuge test sensor array data (i.e., arrays of accelerometers and pore pressure sensors). The results of these different approaches are compared to case history-based correlations for clean sand and their relative merits discussed.Recommendations are provided for future application of these mechanistic approaches for developing liquefaction triggering correlations of poorly characterized or unique soils.

Axisymmetric Simulations of Cone Penetration in Biocemented Sands

“…The interface coefficient of friction (the ratio of the interface friction angle and the soil's critical state friction angle) represents the friction along the cone face and ranges from 0 to 1 for a perfectly smooth and a perfectly rough cone, respectively. An interface coefficient of friction equal to 0.60 was used for these simulations, which is consistent with the value used for simulated cone penetration in sand by Moug et al (2019b). The soil zone sizes increase following a power distribution away from the cone.…”

“…Large deformations of the model geometry, which will concentrate near the cone tip and shoulder, can lead to numerical instability and hence were accommodated with an ALE algorithm, which performs grid rezoning and model property remapping throughout the penetration depth. Details of the ALE algorithm and the model's implementation have been given by Moug (2017) and Moug et al (2019b).…”

Revisiting the effect of relative density on cyclic liquefaction of clean and silty sands: the crossing effect

“…Note that Eq. 2 is not a new relationship and has been proposed in several other liquefaction studies as well (Idriss and Boulanger 2008;Moug et al 2019). The coefficient of determination (R 2 ) values for each curve in Figs.…”

Closure to “Axisymmetric Simulations of Cone Penetration in Saturated Clay” by Diane M. Moug, Ross W. Boulanger, Jason T. DeJong, and Robert A. Jaeger

“…As such, the writers rely on single element simulations under multiple loading conditions, including one-dimensional compression, direct simple shear, triaxial compression, and triaxial extension loading conditions to demonstrate that the calibrated soil behavior reasonably agrees with observed soil behavior (i.e., with lab data) and with typical soil behavior relationships. Additional discussion of MIT-S1 calibration is provided in Moug et al (2019) and Price (2018).…”