2021 UF Ardaman-Wissa Lecture in Geotechnical Engineering

Date(s) - 04/15/2021
8:00 PM - 9:30 PM


Zoom Link: https://ufl.zoom.us/j/97808309701

Energy pile foundations

Charles W. W. Ng, Ph.D., FREng, FHKIE, FHKEng, FICE, FASCE

Department of Civil and Environmental Engineering, Hong Kong University of Science and Technology, HKSAR

It is evident that the demand for clean energy is increasing to support sustainable population growth and economic development worldwide. Shallow geothermal energy has been exploited by many to provide thermal comfort at a higher energy efficiency than traditional means. Energy pile is an example of green foundation to make use of shallow geothermal energy. Although end-bearing energy pile foundations have been investigated widely, the thermo-mechanical soil-pile interaction mechanisms of floating (i.e., mainly side resistance or friction) energy piles, elevated energy pile groups and piled rafts are complex and not yet fully understood. The operation of floating energy piles and groups may cause unwanted excessive heave/settlement and tilting on their supported structures. In this lecture, a series of carefully designed geotechnical centrifuge model tests will be presented to reveal the fundamental mechanisms of soil-energy pile interaction in saturated clay and sand. Moreover, elevated pile groups and piled rafts subjected to symmetrical and non-symmetrical cyclic thermal loading will be investigated and reported. Three-dimensional numerical back-analyses and parametric study will also be discussed. The differences between driven and bored floating energy piles will be illustrated. Furthermore, the effects of non-symmetrical cyclic thermal loading on a floating energy pile group and piled raft will be described. The observed fundamental different mechanisms between energy pile group and energy piled raft will be illustrated and explained. Design implications for different types of energy foundations subject to both symmetric and non-symmetrical cyclic thermal loading conditions will be discussed and revealed.

Professor Charles W. W. Ng is currently the Dean of HKUST Fok Ying Tung Graduate School, CLP Holdings Professor of Sustainability and Chair Professor in the Department of Civil and Environmental Engineering at the Hong Kong University of Science and Technology (HKUST). He is the President of the International Society for Soil Mechanics and Geotechnical Engineering (2017-2021). Professor Ng is a Chartered Civil Engineer (UK). He is also a Fellow of the Institution of Civil Engineers (FICE), the American Society of Civil Engineers (FASCE), and the Hong Kong Institution of Engineers (FHKIE). He was elected an Overseas Fellow by Churchill College, the University of Cambridge, a Fellow of the Royal Academy of Engineering (UK), and a Fellow of the Hong Kong Academy of Engineering Sciences. Professor Ng has supervised more than 55 Ph. D and 60 M. Phil students from over 20 countries to graduation since 1995. He has published some 350 SCI journal articles and 250 conference papers and delivered more than 80 keynotes and state-of-the-art reports across the six continents. He is the main author of three reference books: (i) A Short Course in Soil-structure Engineering of Deep Foundations, Excavations and Tunnels by Thomas Telford in 2004, and

(ii) Advanced Unsaturated Soil Mechanics and Engineering and (iii) Plant-Soil slope Interaction by CRC: Taylor & Francis in 2007 and 2019, respectively.