ROWE LECTURE
Selection of long-term shear strength parameters for geosynthetic interfaces
The complexity of strain-softening interfaces that can lead to progressive failures along geosynthetic interfaces in lined containment facilities has been a source of confusion for performing slope stability evaluations for over 30 years. The present paper provides a review of the relevant historical literature on this subject, examines significant mining and landfill stability failures that occurred over a period spanning 25 years that are symptomatic of this issue, and presents new quantifications of shear strength variability that can be caused by manufacturing, installation and construction practices that may increase the tendency towards progressive failure mechanisms. Practical guidance and recommendations are given, applicable to numerical as well as limit-equilibrium approaches, that are intended to lend confidence to practitioners tasked with selecting appropriately conservative geosynthetic shear strength parameters for waste containment and mining facilities.
BIO
Richard Thiel, P.E., president of Thiel Engineering
Richard Thiel is a practicing civil and geotechnical engineer with 37 years experience specializing in containment design and construction for geotechnical projects. He has been the president of his own small company in California for 28 years. He has been a member of the IGS since 1991, and of the American Society of Civil Engineers since 1982. He is a veteran of geosynthetic conferences and committees around the world, was an instructor for the ASCE seminars on containment liner and cover systems design, educator for the California State Water Board, presented numerous short courses related to geosynthetics and liner system design, and is author of over 90 publications related to geosynthetics.
