Date:
18 May 2022,
5.00PM – 6.00PM
duration:
1 hr
Location:
Online
CPD hours:
1 hrs
Cost:
Free event
Register Add to Calendar 2022-05-18 17:00:00 2022-05-18 18:00:00 Pacific/Auckland [UNSA-001] Join the New Zealand Geotechnical Group for a presentation on unsaturated soil mechanics for rainfall-induced slope failures, presented by Prof. Harianto Rhahardjo (Nanyang Technological University, Singapore). Online Engineering New Zealand hello@engineeringnz.org

Join the New Zealand Geotechnical Group for a presentation on unsaturated soil mechanics for rainfall-induced slope failures, presented by Prof. Harianto Rhahardjo (Nanyang Technological University, Singapore).

Rainfall-induced slope failures are commonly observed in residual soils during rainy seasons. Numerous residual soil slopes are generally unsaturated because of the commonly deep groundwater table. Therefore, it is important to develop a slope susceptibility map to identify areas that are susceptible to slope failures during rainfall. Incorporating unsaturated soil properties in the development of slope susceptibility map will result in more realistic and sustainable assessments of regional stability of slopes under rainfall. The development of such a susceptibility map using the Transient rainfall infiltration and grid-based regional slope stability (TRIGRS) model and Scoops3D for three-dimensional slope stability assessment will be discussed at the presentation. Two-dimensional (2-D) seepage and slope stability analyses on the selected residual soil slopes with past failure history were carried out to evaluate the established slope susceptibility map. The minimum factors of safety from the numerical analyses of the investigated slopes were in good agreement with the minimum factors of safety obtained from the slope susceptibility map. In addition, several slope improvement methods using the principles of unsaturated soil mechanics such as Capillary Barrier System (CBS) and GeoBarrier System (GBS) will also be illustrated with some case studies.

About the speaker:
Professor Rahardjo is a registered Professional Engineer (PEng) in Saskatchewan, Canada and Singapore. He has served as a consultant on various projects for several engineering firms and government institutions in Southeast Asia, Hong Kong, China, Canada and Australia. He has conducted extensive research on unsaturated soil mechanics to solve geotechnical problems associated with tropical residual soils. His research focus has been on rainfall-induced landslides; one of the major natural disasters occurring in many parts of the world.  He has applied unsaturated soil mechanics principles to better understand the mechanisms of rainfall-induced slope failures especially in tropical residual soils. Professor Rahardjo is currently developing Advanced Moisture Sensing Technology for Urban Greenery and Monitoring of Slope Stability. Professor Rahardjo is the co-author of the first textbook on unsaturated soils “Soil Mechanics for Unsaturated Soils“, by D.G. Fredlund and H. Rahardjo, published by John Wiley in 1993, the second textbook “Unsaturated Soil Mechanics in Engineering Practice”, by D.G. Fredlund, H. Rahardjo and M.D. Fredlund, published by John Wiley in 2012 and over 400 technical publications.  He has also presented his research works in numerous keynote / invited lectures and short courses in various countries.