Liquefaction susceptibility determination using cone penetration tests

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Canada is vulnerable to destructive earthquakes. One of the leading mechanisms of earthquake damage is by soil liquefaction. When the ground shakes, loose sandy materials saturated with water behave like a liquid. Liquefaction hazard and the associated damage can be reduced by identifying and stabilizing loose sandy soils. Because of the difficulty and large expenses in obtaining undisturbed samples of cohesionless sandy or silty soils, engineers rely on in-situ field techniques to determine soil density and thus loose liquefiable soil conditions. Cone penetration testing (CPT) is one of the most commonly used field testing probes in Canada to characterize the underlying soil, evaluate its in-situ density, and liquefaction potential. Although CPT is relatively easy to do in the field, it requires considerable care for interpreting soil properties. The current state of knowledge is lacking complete understanding of the effects of particle crushing, soil mineralogy, compressibility and in-situ horizontal stress conditions on CPT measurement. Advances in CPT will develop more reliable estimates of in-situ soil state, whether it is susceptible to liquefaction or not, and predicting more advanced soil parameters. In this research collaboration project, Western's miniature cone penetration test will be used to develop an enhanced method for estimating in-situ liquefaction susceptibility of cohesionless soils. The effects of fines content, sand mineralogy and horizontal stress will be also studied. More accurate CPT testing and interpretation resulting from this research will markedly improve the current precision in inferring soil density in practical situations, and thus more accurate and reliable geotechnical investigation and design involving CPT in Canada. With an improved understanding, construction could be avoided on these potentially liquefiable soils or improved soil strengthening techniques could be employed for reducing liquefaction damage.