The Geosynthetic Institute (GSI) will sponsor a webinar, “Soil Consolidation Using Wick Drains, aka PVDs,” on Nov. 27, from 11:30 a.m. to 1 p.m. EST. 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 or 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 inch) wide by 10 mm (3/8 inch) thick and are on spools of up to 90 m (300 feet) 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 which used sand drains. While the increase in FS-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 stressed induced in doing so. They will then learn about consolidation design in three-stages which 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 that would probably have avoided such a major incident from occurring.
The webinar is intended for 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.
The webinar’s instructor, Dr. Robert M. Koerner, is professor emeritus of civil engineering at Drexel University, and founder and director emeritus of the Geosynthetic Institute.
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.