This presentation outlines the development of a new 'Unified' CPT-based method for estimating the axial capacity of driven piles in clay. The new method was calibrated with the Unified database of pile load tests developed as part of a joint industry project (JIP) under the management of the Norwegian Geotechnical Institute (NGI).
First, a rational basis for the CPT-based formulation is described, using trends from instrumented pile tests; the description facilitates an understanding of the approach and illustrates its empirical nature and limitations. The unified database was used to calibrate the formulation and it led to good predictions for an independent database of pile load tests and for measured distributions of shaft friction. Reliability analyses show that the calculated annual failure probability for a pile designed using the new Unified CPT-based method is comparable to that calculated with the API-method.
Dr. Zhongqiang Liu is Principal Geotechnical Engineer at Norwegian Geotechnical Institute (NGI), Oslo, Norway, with expertise in offshore foundation engineering, geohazards, statistical and machine learning methods and general geotechnical risk assessment.
He initiated and is now Chair of Technical Committee 309 of ISSMGE: "Machine Learning and Big Data in Geotechnics". He is Chair-Elect of "Geotechnical Safety Network (GEOSNet)" since 2022. Dr Liu is Guest lecturer at Norwegian University of Science and Technology (NTNU) and at University of Oslo (UiO). He is Technical Lead of Research Group – Risk and Reliability at NGI. His research has earned several international recognitions, including Best Paper Award of Journal Georisk in 2015, OTC ASCE Best Paper Award in 2019, GEOSNet Young Researcher Award in 2019 and Best Paper Award of JZUSA in 2023.