11:30 a.m.–1 p.m. (ET)
Wednesday, Feb. 8, 2017
GSI members: $200 USD
Non-GSI members: $250 USD
An intrinsic property of all exposed geomembranes is that they expand and contract depending on the ambient temperature. During times of high temperature, this is evidenced by the appearance of waves (also called wrinkles) in installed geomembranes before they are backfilled or otherwise covered. The thicker and stiffer the geomembrane, the more the phenomenon is evidenced. This webinar will show that such waves when backfilled will not disappear. Laboratory and field exhumations indicate that the waves squash forming creases in the subsequent installed material.
The disadvantages of this situation are lack of intimate contact, increased potential seepage, tensile stresses at folds, mini-dam formation, and possible equipment damage to the tops of folds. That said, there are a number of methods that can be used by the contractor/installer to avoid the situation from occurring:
- fixing berms
- white sheet
- temporary tent
- backfill in early morning or night
This webinar advances in progressive stages of overview/background, fate of waves, implications of entombed waves, achieving intimate contact, and summary/recommendations.
Participants will learn the basic reason for the occurrence of geomembrane waves and the various reasons for not entombing them during backfilling. Entombed waves as small as 14mm (0.6in.) in height do not disappear after backfilling. While the methods used to avoid the situation are time consuming and tend to be somewhat expensive, they are necessary for a proper geomembrane installation.
- Understand the cause of field deployed geomembrane waves
- Understand the fate of waves upon backfilling
- Appreciate the negative implications of entombed waves
- Learn methods of achieving intimate contact without waves
- Appreciate the current status of the situation and how current practice must be improved
- Federal, state, and local governmental agencies dealing with geomembrane-lined solid waste facilities
- Private and public owners of such facilities
- Solid waste consultancies and testing laboratories
- Construction quality assurance inspectors of lined waste facilities
- Perhaps most of all, geomembrane installers and earthwork contractors for solid waste facilities
Specific topics covered
- Overview and background
- Fate of waves: A laboratory study
- Implications of entombed weaves
- Achieving “Intimate Contact”
- Summary and recommendation
Dr. Robert M. Koerner’s (professor emeritus, civil engineering, Drexel University; and director emeritus of the Geosynthetic Institute). Dr. Koerner’s interest in geosynthetics spans nearly 40 years of teaching, research, writing, and advising. His most widely used publication is the sixth edition of the textbook “Designing with Geosynthetics.” He is the founding director of the Geosynthetic Institute, a nonprofit research and development organization dedicated to the proper use of geosynthetics. The institute also provides laboratory accreditation and inspection certification programs.