April 30, 2019

Kate Darby Coauthored a Paper on Changes in Liquefaction and Cone Penetration Resistance in the Journal of Geotechnical and Geoenvironmental Engineering

Kate Darby, Ph.D. (California) coauthored a paper entitled "Progressive Changes in Liquefaction and Cone Penetration Resistance across Multiple Shaking Events in Centrifuge Tests" that was published in the Journal of Geotechnical and Geoenvironmental Engineering in Volume 145, Issue 3 in March 2019.

Kate's co-authors are Ross W. Boulanger; Jason T. DeJong; and Jaclyn D. Bronner.

Kate is a Senior Staff Engineer based in California focused on geotechnical engineering, liquefaction triggering correlations, and physical modeling. She has been involved in geotechnical, infrastructure, and geoenvironmental projects. Her doctoral graduate studies at the University of California, Davis involved evaluating limitations in cone penetrometer testing (CPT)-based liquefaction triggering correlations. Kate has experience conducting safety reviews, evaluating CPT-based liquefaction, and conducting air quality research.

The Journal of Geotechnical and Geoenvironmental Engineering, published by the American Society of Civil Engineers (ASCE), covers the broad area of practice known as geotechnical engineering. Topics include foundations, retaining structures, soil dynamics, engineering behavior of soil and rock, site characterization, slope stability, dams, rock engineering, earthquake engineering, environmental geotechnics, geosynthetics, computer modeling, groundwater monitoring and restoration, and coastal and geotechnical ocean engineering.

ASCE represents more than 150,000 members of the civil engineering profession in 177 countries. Founded in 1852, ASCE is the nation's oldest engineering society. ASCE stands at the forefront of a profession that plans, designs, constructs, and operates society's economic and social engine – the built environment – while protecting and restoring the natural environment.

Abstract

The effects of shaking history on cone penetration test (CPT)–based liquefaction triggering correlations for clean saturated sand are examined by using cone penetration resistance and cyclic strength data pairs from dynamic centrifuge model tests. Three model tests on a 9-m-radius centrifuge examined the liquefaction responses of level profiles of saturated Ottawa F-65 sand subjected to multiple (17–29) shaking events that produced successive changes in density and model response characteristics. Inverse analysis of data from dense accelerometer arrays were used to define time series of cyclic stress ratios and shear strains throughout the profile. Cyclic resistance ratios against triggering of ∼100%∼100%excess pore pressure ratio in 15 equivalent uniform cycles were computed at multiple depths based on weighting of the cyclic stress ratio time series up to the time of triggering. Cone penetration tests performed at select times during each model test were used to define the variation in cone tip resistances with depth and shaking history. The resulting data pairs, with normalized cone tip resistances ranging from 20 to 340 and cyclic resistance ratios ranging from 0.1 to 2.0, show that both quantities progressively increase as a result of recurrent liquefaction events and generally follow the trends predicted by case history–based liquefaction triggering correlations. Three 1-m-radius centrifuge tests of similar configurations produced consistent results. Implications for the interpretation of case histories and engineering practice are discussed.

More Information

About the paper: https://ascelibrary.org/doi/abs/10.1061/%28ASCE%29GT.1943-5606.0001995
About the ASCE: https://www.asce.org/about_asce/
For consultation regarding liquefaction and cone penetration resistance, contact Kate Darby at This email address is being protected from spambots. You need JavaScript enabled to view it..

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