Gravelly soils have liquefied at multiple sites in at least 27 earthquakes over the past 130 years. These gravels typically contain more than 25% sand which lowers the permeability and makes them susceptible to liquefaction. Developing a reliable, cost-effective liquefaction triggering procedure for gravelly soils has been a challenge for geotechnical engineers. Typical SPT- or CPT-based correlations can be affected by large-size gravel particles and can lead to erroneous results. To deal with these problems, we have developed liquefaction triggering curves for gravelly soils based on (1) shear wave velocity (Vs) and (2) a large diameter cone penetrometer. With a cone diameter of 74 mm, the Chinese Dynamic Cone Penetration Test (DPT) is superior to smaller penetrometers and can be economically performed with conventional drilling equipment. Using logistic regression analysis, the DPT has been directly correlated to liquefaction resistance at sites where gravels did and did not liquefy in past earthquakes. Probabilistic liquefaction resistance curves were developed based on 137 data points from 10 different earthquakes in seven countries. Using a similar data set, probabilistic liquefaction triggering curves were also developed based on Vs measurements in gravelly soils.
May 20, 2025 - 3:30pm-4:30pm
The seminar will take place only in presence at the Room Caveau, Faculty of Engineering, via Eudossiana 18, Rome.
For the seminars supplied by the PhD Program of the DISG credits are not provided. Also certificates of attendance will not be produced for seminars.