Keynote Speaker

Prof. Mitsu Okamura

Ehime University (Japan)

Landslide and Erosion

Prediction and detection of backward erosion piping of river levees.

Biography

Academic Qualification

1988 Graduated from Civil Engineering department, Tokyo Institute of Technology
1990 Master of Engineering from Tokyo Institute of Technology
1993 Doctor of Engineering from Tokyo Institute of Technology

Awards

1998 Best paper by young researcher, Japanese Geotechnical Society
2007 Shamsher Prakash Research Award (Prakash Foundation, USA)
2009 Best Paper Award ISGI09, Singapore Geotechnical Society
2012 Best Paper Award, Japanese Geotechnical Society
2013 Best Article Award, Journal of Japanese Geotechnical Society
2014 Award for distinguished service, Japanese Geotechnical Society
2018 Best Paper Award of Advances in River Engineering, Japan Society of Civil Engineers

Professional Affiliations

Member, Japanese Geotechnical Society (JGS)
Member, International Society of Soil Mechanics and Geotechnical Engineering
Member, Japanese Society of Civil Engineers (JSCE)
Work Experiences
1993 – 1997 Research Associate, Tokyo Institute of Technology
1997 – 2004 Senior researcher, Public Works Research Institute, Ministry of Construction
2004 – 2009 Associate Professor, Graduate School of Science and Engineering, Ehime University
2009 – present Professor, Ehime University
Professional Services (Selected)
Vice President of Japanese Geotechnical Society (2019 – Present)
Chairman of ATC3 (Asian Technical Committee for Geotechnical Natural Hazards, International Society of Soil Mechanics and Foundation Engineering) (2018 -)
Chairman of Technical committee of River levee research, JSCE (2011 – 2017)
Chairman of Committee of Civil Engineering Education, JSCE (2014 – 2015)
Vice Dean of Institute of International Relation, Ehime University (2011 – 2014)
Chairman of Aseismic design manual for river levee, Public Works Research Institue
Associate Editor in Chief of Soils and Foundations, Japanese Geotechnical Society (2017 – )
Chairman of planning Committee Meeting, the Asian Civil Engineering Coordinating Council (2016 – 2019)
Member of 7 Technical Committees of Ministry of Land, Infrastructures, Transportation and Tourism.
Member of 8 Committees of Japanese Geotechnical Society
Member of 6 Committees of JSCE
Member of 2 Technical Committees of International Society of Soil Mechanics and Foundation Engineering

Abstract

Prediction and detection of backward erosion piping of river levees.

River levees occasionally breach during flooding in the mechanics of backward erosion piping and its impact is enormous. There is a critical need to develop a model to predict hydraulic gradient that cause backward erosion piping under river levee and a method to detect the piping in the field. This paper presents the results of 1g and centrifuge tests on backward erosion piping to facilitate better understanding the mechanism of sand transportation in the pipe. The 3D profile of the pile and flow rate of water in the pipe are observed using innovative testing techniques. A method to predict the hydraulic gradient is proposed. Next, there is a strong need for non-destructive techniques that can identify progression of the piping, and a practical piping detection method is developed in this study. Current inspection methods to river levees cannot detect the backward erosion piping until it manifests at the exterior surface. The developed method in this study, is capable of evaluating the length and location of the pipes based on deformation of levee slopes detected by UAV and Satellite. Centrifuge tests are conducted to confirm evolution of surface deformation as piping progressed.