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GSI to host webinar on geotextile filters

Events | October 20, 2021 | By:

Photograph courtesy of Ocean Non Woven Pvt. Ltd.

The Geosynthetic Institute (GSI) will sponsor a webinar, “Geotextile Filters: Concerns and Issues,” on Nov. 10, 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.

It is roughly estimated that geotextiles have been used in more than 500,000 filtration applications to date. Improper performance is extremely rare, and in GSI’s database of field problems, there are only 82 published or known cases (~0.016%). Yet, these are important to recognize in the context of “lessons learned” so as not to be repeated in the future.

The various case histories are categorized into the following groups:

  • Geotextile filter design problems
  • Problems involving atypical soils
  • Problems involving atypical permeants
  • Geotextile filter installation problems

The webinar is illustrated with cross sections of specific situations as well as photographs of significance.

Insofar as a summary and recommendations are concerned, it is felt that the state-of-the-practice in geotextile filter design is very good when dealing with water as the permeant flowing through typical soils. In this regard, atypical permeants and unique soils need special consideration. Certainly, high-suspended soils and biological contaminants are of concern. Unique soil types such as cohesionless fine sands and silt, dispersive clays and ocher should also be evaluated accordingly. Four different long-term laboratory equilibrium tests are described for such situations, and they are compared to one another. Lastly, graded geotextile filters are described and recommended for unique situations.

Learning objectives

Participants will learn the three concepts of geotextile filtration design using a series of gradually more-sophisticated methods. All 82 field case histories will be explained in this context. Not only causes of problems will be illustrated but also clear explanations will be given. Many situations become obvious after the situation has occurred. Also, several situations are still challenging at the present time, e.g., reversing flow conditions, ocher growth and installation practices.

Webinar benefits

  1. Understand current geotextile filter design methods
  2. Understand which specific soil types are problematic
  3. Understand which permeant types are problematic
  4. Understand which installation problems have occurred
  5. Learn about the four long-term laboratory tests that are available

Intended audiences

This webinar will be useful for transportation, geotechnical, geoenvironmental and hydraulic engineering designers working in the respective field of expertise; owners, regulators and permitters of systems that include the necessity of soil or geotextile filtration; contractors installing geotextile filters insofar as proper practices are concerned; and geotextile manufacturers from the perspective of past practice, including a correct and incorrect range of using their products.

Specific topics covered

  1. Background
  2. Geotextile design problem
  3. Problems involving atypical soils
  4. Problems involving atypical permeants
  5. Geotextile installation problems
  6. Summary and recommendation

Webinar instructor

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

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