The Official Lecture of the International Geosynthetics Society (IGS)
"The use of geomembranes for lining canals"
Prof. Dr. Eng. J.P. GIROUD
Member of the US National Academy of Engineering
Dr. Giroud, Chevalier in the Order of the Légion d’Honneur and a former professor of geotechnical engineering, is a consulting engineer, member of the US National Academy of Engineering, Doctor Honoris Causa of the Technical University of Bucharest, Past President of the International Geosynthetics Society (IGS), Chairman Emeritus and founder of Geosyntec Consultants, and Chairman of the Editorial Board of Geosynthetics International. Dr. Giroud has authored over 400 publications. He coined the terms “geotextile” and “geomembrane” in 1977. He has developed many of the design methods used in geosynthetics engineering and has originated a number of geosynthetics applications. In 1994, the IGS named its highest award “The Giroud Lecture”, “in recognition of the invaluable contributions of Dr. J.P. Giroud to the technical advancement of the geosynthetics discipline”; a Giroud Lecture is presented at the opening of each International Conference on Geosynthetics. In 2002, Dr. Giroud became Honorary Member of the IGS with the citation “Dr. Giroud is truly the father of the International Geosynthetics Society and the geosynthetics discipline”. In 2005, Dr. Giroud has been awarded the status of “hero” of the Geo-Institute of the American Society of Civil Engineers (ASCE) and has delivered the prestigious Vienna Terzaghi Lecture. In 2005-2006 he presented the Mercer Lectures, a prestigious lecture series endorsed jointly by the IGS and the International Society for Soil Mechanics and Geotechnical Engineering (ISSMGE). In 2008, J.P. Giroud delivered the prestigious Terzaghi Lecture of the ASCE. In 2016, Dr. Giroud delivered the prestigious Victor de Mello Lecture of the ISSMGE and, in 2017, the prestigious Széchy Lecture, in Budapest. Dr. Giroud has 56 years of experience in geotechnical engineering, including 48 years on geosynthetics.
The use of geomembranes for lining canals
This keynote lecture will present the state of the art on the use of geomembranes (often associated with other geosynthetics) for canal lining. Numerous case histories of geomembrane-lined canals from various parts of the world, in particular the Middle East, will be presented. These cases, spanning four decades from the 1970s to date, include large canals as well as small canals, which play an important role in irrigation schemes. Also, the case histories will include the rehabilitation of old concrete-lined canals. The focus will be on irrigation canals; however, examples of hydroelectric canals lined with geomembranes will be mentioned, because the considerable experience gained on hydroelectric canals is likely to be beneficial to the design and construction of irrigation canals. The case histories will show that flexible linings with very low permeability are the only viable option in some climatic conditions (e.g. freeze and thaw) and soil conditions (soluble soils containing gypsum, collapsible soils such as loess, and swelling clays). The case histories presented illustrate the use of a variety of geomembranes in canals (e.g. PVC geomembranes, HDPE geomembranes, EPDM geomembranes, bituminous geomembranes, geotextile-geomembrane composites). Design methods related to the use of geomembranes in canals will be discussed, in particular: drag forces exerted by flowing water on geomembrane liners, uplift of geomembranes by dynamic pressure of the flowing water, bridging of cracks by geomembranes, stability of protective layers on the side slopes. The need for protection of geomembrane liners will be addressed and the following protection techniques will be discussed: concrete slabs, cast-in-situ concrete, soil layers, cobbles, gabions, fabric-formed concrete panels, geocells, articulated concrete blocks, etc. Finally, the performance of geomembranes in canals will be addressed and compared with the performance of traditional concrete linings.