The Geosynthetic Institute (GSI) will sponsor a webinar, “Soil Consolidation Using Wick Drains, aka PVDs.” on October 28, from 11:30 a.m. to 1 p.m. EDT. Geosynthetic Materials Association (GMA) member companies and their employees receive discounted rates on all GSI webinar and short course registrations.
Wick drains, also called prefabricated vertical drains (PVDs), consist of a drainage core encapsulated by a geotextile which serves both as a filter and separator. They are typically 100 mm (4.0 in.) wide by 10 mm (3/8 in.) thick and are on spools of up to 300 m (1000 ft.) in length. Their use is to rapidly consolidate saturated fine-grained foundation soils. At this point in time, they have completely replaced sand drains for such purposes. Most ground modification contractors are fully aware of the technology. The webinar will begin with calculating the installation stresses during various parts of the procedure. The geotechnical design process insofar as calculating the time for 90% consolidation will be presented transitioning from Terzaghi to Barron to Hansbo methods. This is followed by four issues, which are somewhat tenuous and remain to be clarified.
Lastly, a completely new issue of recognizing that wick drains will reinforce foundation soils by virtue of their intrinsic tensile strength is presented. This is illustrated in the context of a major failure that used sand drains. While the increase in factor of safety value is quite small, there are options presented to enhance the value. The study was first published in 2017 and is extremely revealing.
Participants will learn how wick drains are installed along with the stress induced in doing so. They will then learn about consolidation design in three stages that have been developed over time leading to the current Hansbo method. Insight into four remaining issues and concerns will be daylighted with remedies for each. Lastly, a major case history failure using sand drains will be counterpointed against using wick drains, which would probably have avoided such a major incident from occurring.
- Understand the origin and geotechnical background of in situ consolidation of fine-grained foundation soils
- Understand why wick drains have gained universal acceptance using these geosynthetic materials
- Understand the various wick drain design methodologies
- Be exposed to the latest research needs that are available
- Appreciate the tensile strength that wick drains afford to reinforcing soft foundations soils and how this feature can be incorporated in design
This webinar will be beneficial to owners of saturated fine-grained foundation soil sites in both the public and private sectors; federal, state and regional geotechnical, transportation and environmental engineers; engineers from municipal districts and townships; private and municipal land developers, architectural and landscape designers; general civil consulting engineers; testing laboratories servicing these organizations; manufacturers and representatives of wick drain materials; ground modification contractors; academic and research groups; and others desiring technically related information on this important aspect of our constructed infrastructure.
George R. Koerner, Ph.D., P.E., and CQQ is the director of the Geosynthetic Institute. He is in charge of laboratory accreditation, field certification and continuing education at the institute. He also manages several research projects and has published more than 350 technical papers in his 35-year association with polymers used in below-ground construction. Koerner’s Ph.D. is from Drexel University in geotechnical engineering. He is a registered professional engineer and a certified quality auditor. Koerner has received many awards over the years. The most notable being IFAI’s Environmental Technologies Award of Excellence 1995, ASCE’s DVGI Geotechnical Engineer of the year in 2004, the title of ASTM Fellow in 2013 and GMA’s first Robert M. Koerner Lecture and Award in 2017.
Webinars cost $200.00 for GSI and GMA members, and $250.00 for nonmembers. Successful completion of a multiple-choice test after the webinar carries 1.5 professional development hours (PDH).
For more information or to register, visit http://www.geosynthetic-institute.org/webinar.htm.