Jim Paul assesses the maturing of the international geosynthetics industry.
This article coincides with the international conference and exhibition sponsored by the International Geosynthetics Society. This conference and exhibition is organised every four years and the sixth event is being held this year in Atlanta, USA from 25 to 29 March.
More than 2,000 delegates are expected to meet to update themselves with developments in this constantly growing discipline. The main themes will be a mix of those which consider fundamental behaviours as well as examination of design methods, actual performance and important case studies. A series of practical workshops will be an important feature.
The IGS was founded in 1983 and has grown to about 1,500 individual members and more than 70 corporate members. Its aims are to collect and disseminate knowledge on, and promote the advancement of, all matters relevant to geotextiles, geomembranes and related products, and to improve communication and understanding about them between designers, manufacturers and users.
One of the major committees working within the IGS council is the education committee, which I chair. Its brief is to sift through the information available and to present it in such a way that it is useful to members, be their interest production, specification or installation. Current projects include the transfer of teaching lectures to CD-ROM format to allow the important features to be reviewed either individually or in groups in any country. Teaching aids are being prepared to help lecturers to teach the fundamentals of geosynthetics. Even today, most civil engineering students learn to design in steel or concrete but very few receive teaching in the design of reinforced soil structures using polymer materials.
The use of geosynthetics in major construction projects has grown dramatically during the last 10 years and it must now be very unusual for there not to be some type of geosynthetic on any medium- or large-scale project. In many cases the need is for a simple separator geotextile to avoid contamination of a road sub-base by the soft clay formation material. However, more often it is the reinforcement effect of geosynthetics which produce significant cost savings in a project. We are fortunate in the UK to have one of the first national design codes in BS8006 1995-Code of practice for strengthened/reinforced soils and other fills. This code sets out detailed design guidance for soil reinforcement geosynthetics in steep embankments, vertical retaining walls, embankments on soft foundations and embankments over piles. Designers are now therefore able to examine the potential applications for geosynthetics and create well-defined project specifications ensuring that the geosynthetics used meet the needs of the project.
Another major application area for geosynthetic products is in landfill containment and closure systems. The main product range is clearly the geomembrane liner itself and much effort continues to be applied in development of even more inert polymers, in welding systems and in testing methods to detect leaks and minor faults in large liner systems which often cover several hectares. Also important is the section of suitable geotextile protection layers which minimise damage to the installed liner, cushioning it from the installation of drainage systems and filling of the waste which takes place on top. Again, significant work is being undertaken to determine the optimum product structure, thickness and polymers to carry out this function, and debate on progress of this work will take place in Atlanta.
Similarly, development of composite liner systems, composite drainage systems and composite cover systems are being undertaken.
Very few applications for geo-synthetics are confided to one region and most of the products are available throughout the world. There are nevertheless variations in the mix of applications by region with roads and embankments being built on super-soft foundations in parts of Japan and other Asian countries, geotextiles used to provide formwork for roof support filling in deep mines in South Africa, deep vertical drains used extensively in Asia and roads and embankments built over potential voids due to shallow mine workings in the UK and Poland and in karst areas in several parts of the world.
This means that geosynthetics is a world-wide business with much to learn from manufacturers, designers and users all with their own sets of products or experiences.
I believe we have moved on from the 'black box' technology of many manufacturers and specialist consultants to a stage where the technology is now well understood. Recent research by Tensar International in the UK showed that in most major consultancies the use of soil reinforcement geogrids was now considered a traditional solution.
Jim Paul is managing director of Tensar International, part of the Netlon Group in Blackburn, Lancashire. He is a board member of the European Association of Geosynthetics Manufacturers and a council member of the International Geosynthetics Society.