IGS Award 2010 for HUESKER
Geosynthetic Reinforcement Using Innovative Polymers 

During the 9^th ICG in Guaruja, Brasil in May 2010 HUESKER Synthetic GmbH from Gescher, Germany received the 2010 IGS Award for the development and application of high-performance geosynthetics made from innovative polymers. The unanimous decision was taken by the IGS Award Committee based on the proven ability of using these geosynthetics to support soil layers over cavities, for reinforced piled embankments and numerous other geotechnical solutions. Demonstrations in the field by a significant number of constructed projects also validated these solutions and their use of geosynthetics. The IGS Committee also noted  that the properties, applications and performance of these geosynthetic reinforcements have been presented in many high-quality technical papers.
The development, production and engineering applications of these products were on the one hand initiated as a response to the increasing requirements on reinforcements due to more and more sophisticated, demanding and critical georeinforced systems; but on the other hand, they opened the door to a number of even more elaborate and seminal engineering solutions. Thus, it was and still is a process of interaction of engineering design, product development and application resulting in mostly pioneering work in this area. Typically, high-strength low-strain low-creep reinforcement helps to solve problems with bridging sinkholes, heavily loaded or sensitive piled embankments and similarly geostructures sensitive to deformations, such as some landfills or heavy embankments on very soft soils.
HUESKER Synthetic were the first manufacturer (in 1993) to develop, test and apply the use anywhere in the world of extremely high-strength low-strain low-creep geogrids from an Aramid polymer (AR). This was used for bridging a sinkhole in a case of reactivation on the German Federal Road B 180 near Eisleben with an ultimate tensile strength (UTS) of 1200 kN/m at less than 3% strain (Fortrac^® 1200/50-10A). HUESKER adopted this pioneering solution using Aramid because even the strongest reinforcement from Polyester (PET) was not able to meet the specific requirements resulting from the design analyses.In fact the sinkhole reactivated in 2001, the geogrids and system proved to be appropriate and successful in saving human life. The experience gained with the production of the Aramid geogrids for this first project was later on used to establish an entire HUESKER geogrid "family". The geosynthetic applications were then extended; e.g. in 1997 to geogrid-reinforced piled embankments for high-speed trains (300 km/h) at Rathenow (Körgraben) in Germany because of the stringent deformation limitations (UTS 800 kN/m at < 3% strain, Fortrac^® 800/100-20 A).
The applications were also extended to ensure local and global stability against sliding on landfill slopes (Landfill Böschistobel, Austria) providing reinforcements with very high tensile forces at low strains (UTS 550 kN/m & 1200 kN/m ).
The application field was enlarged still further on in 2000 – 2001 using Aramid geogrids again for bridging sinkholes like in the first application in 1993 (Highway B 180 at Eisleben, see above) but this time for a high-speed railroad, (300 km/h), at Gröbers in Germany.
For these selected projects mentioned a significant amount of pioneering work was done for the first time anywhere in the world. Geogrids from Aramid (AR) were developed and produced, their application for bridging sinkholes was tested and approved by "real life" monitored projects; applications for piled embankments for high-speed-trains and bridging sinkholes under a high-speed railroad and AR-reinforcements in landfills also followed.

Around the end of the nineties HUESKER developed and started production of high-strength Polyvinylalcohol (PVA) geogrids and later on wovens for these now typical high-strength low-strain applications for bridging sinkholes, piled embankments and similar applications cited above for Aramid reinforcements.

Over the years the product "families" of PVA geogrids Fortrac^®  "M" and PVA wovens Robutec^® were developed, tested, established and applied in the high-strength range of up to 1600 kN/m UTS.(Geogrids from PVA started in Japan in the beginning of the nineties. The development was strongly influenced by Professor Tatsuoka for a new system of retaining walls because of the very advantageous mechanical behavior (low strain, low creep) and chemical (high resistance) behavior. However, the strength was limited to typically ca. 100 kN/m UTS and the application was only to walls).

The first significant HUESKER high-strength-PVA-project was the landfill Einöd near Stuttgart, Germany in 1998. It had to be increased by up to 70 m to enlarge the capacity. The intermediate sealing layer on top of the old waste had to be reinforced to minimize deformation and to bridge an old gas dome. Only high strength geogrids from PVA were able to meet both the stringent stress-strain and chemical resistance requirements. HUESKER proposed  an optimized engineering solution, then developed and produced the biaxial PVA geogrids (UTS 150 kN/m in MD & CD at < 5 % strain, Fortrac^®  150/150-30 M) and uniaxial PVA geogrids (UTS 900 kN/m at < 5 % strain, Fortrac^® 900/50-20 M) for this project.

These product developments and applications were then expanded to an even higher range of strengths for both uniaxial and biaxial geogrids and for other georeinforced systems. For example, in 2002 for the piled highway embankment for the A63 Selby Bypass project in the UK the optimal solution demanded extremely high-strength low-strain geogrids because of the large pile to pile clear span distances and the lateral spreading forces involved. Based on a cost-benefit analyses HUESKER developed and produced PVA geogrids with UTS of 1600 kN/m at < 5 % strain to ensure bearing capacity and to control deformations.

In 2003 for a very flat piled embankment railroad project Büchen at the main rail link Berlin - Hamburg, Germany, a high-strength low strain geogrid in combination with a high alkaline resistance was required. The optimal solution was a PVA geogrid Fortrac^® 400/30-30 M with a UTS of 400 kN/m at < 5% strain. At approximately the same time for the piled embankment railroad project Paulinenaue at the same link Berlin – Hamburg, the (sophisticated) optimised solution required a biaxial low-strain geogrid. The biaxial geogrid Fortrac^® 200/200-30 M was developed and produced, (UTS of 200 kN/m in both MD and CD at < 5% strain), to meet the requirements.

A further step ahead was the combined use of reinforcements from different polymers resulting into an optimized system solution. E. g. both PVA and Polyester were successfully used together for the Selby Bypass, UK or PVA and Aramid were used together at Dolphingstone, UK.

 

The development and applications of high-strength PVA reinforcement continued further on; to ensure brevity we will focus on only one additional (recent) case:

In 2008 – 2009 a raw material stockyard for a steel plant of Thyssen Krupp (TKCSA) had to be constructed in soft soil lowlands near Sepetiba in Brazil. As an optimal solution for solving the crucial bearing capacity and deformation problems the intensive use of high-strength low-strain geosynthetic reinforcements was adopted. The best choice was found to be the application of customized PVA geogrids and PVA wovens. To meet the different requirements in different areas of the stockyard these PVA geogrids, (in the UTS range of 500 kN/m to 1600 kN/m and PVA wovens in the UTS range of 1000 kN/m to 1600 kN/m), were produced and installed. The total quantity of PVA geogrids (Fortrac^® M) and PVA wovens (Robutec^®) amounts to more than 600,000 m². The total installed geosynthetics strength (installed UTS x area) amounts to more than 630.10⁶ kN/m x m². It is the first application of PVA geogrids and wovens in such a high-strength range in such a quantity. On a final note it is believed to be the largest geotechnical/geosynthetic engineering project in terms of total installed reinforcement strength. HUESKER intends to continue with the tradition of innovation combining also in the future the integral process of interaction of engineering design and optimization, research, product development and applications.