Date of Post: 01/12/2015
Category: Geotechnical Engineering Type: Articles
The use of Geosynthetic products for the reinforcement of base structures, in support of railway tracks and roads (paved or unpaved) is well known. Innumerous academic researches, laboratory tests and field trials have been performed over the last 20 years or so. Indeed, following our experience of implementing such solutions for more than 1,000Km of railway tracks in the last 5 years, we can add also actual deployment to this list of supportive evidence. The Geosynthetic products most often used for this purpose are Geotextile, Geogrid, and Geocell (a 3-dimensional version of Geogrid):
“Geosynthetics have exhibited successful applications across the globe in the areas of roads and pavement stabilization, embankment protection, ground stabilization, soil erosion control, landfills and waste management, etc. … One of the major drivers for conducting this study was the fact that India is yet to leverage the economic, environmental and safety benefits that are made possible by the usage of Geosynthetics. Geosynthetics provide better performance and longevity of infrastructure projects such as increasing the life of roads by 10-15 years.”
Following our experience in implementing soil stabilization solutions for railways and roads, and based on the data that was collected in these projects, several important advantages can be demonstrated :
1. Cost Reduction
Life cycle cost reduction can be shown as a result of two factors.
a) Reduction in construction costs: Offsetting the cost of Geosynthetic products is the fact that improved support for the base structure enables the use of thinner layers and/or less expensive filling materials. Often, this result in lower cost of construction.
b) Reduction in maintenance costs: Maintenance is required when track or road condition deteriorate. A more stable base structure can lead to significantly slower deterioration, lower maintenance costs and longer life cycle. In some railway projects maintenance costs were reduced by as much as 75%.
2. Higher Speed
High-speed railway tracks are designed and built with very expensive structures to support extremely high speeds in the range of 300-400 Km/hour or even more. However, the great majority of regular passenger and freight railway lines can only support considerable lower speeds. In those cases, the speed limit is directly related to the stability of the base structure. We have seen many cases where the allowed speed could be significantly improved (by as much as 30-40%) as a result of soil stabilization using Geosynthetics.
3. Increased Capacity
Another benefit of improved structure is higher load and bearing capacity. This can lead to increase in freight capacity due to combination of factors:
a) Improvement in the speed of freight trains and as a result higher frequency of freight trains over the same given section.
b) Increase in Axle load from up to 27-32 tons/axle.
4. Improved Safety
Track deterioration creates geometric distortions that may develop into serious faults. Faults are defined as misplacement of tracks in either vertical or horizontal directions, or cracks in roads, and can become serious risk that requires costly maintenance. It was demonstrated that stable base structures significantly reduce and delay the appearance of infrastructure faults.
We are highly thankful to Mr. Miki Granski (from Israel ) for contributing this valuable article.
Miki Granski has over 30 years of experience with telecommunications, networking and consumer electronics companies. He has worked with start-ups and multinational corporations to deploy new technologies for global markets. He leads Strategic Project Group and is instrumental in deploying innovative solutions in large organizations.
He started his career in semiconductors at Zoran, and then handled business development and management in senior positions at Zoran, NeoMagic and LSI Logic. Miki transitioned to the venture capital industry in 2002, where he worked with early-stage companies in Europe and Israel.
He holdsBSc. and MSc. degrees in electrical engineering and computer science from the Technion, Israel Institute of Technology, and an M.B.A. from the Kellogg School of Management at Northwestern University.