Plastic sheet piles have been available in this country for over five years and have been used in other parts of Europe for over 20 years. So with the dramatic rise in the cost of steel, why is there such a reluctance to try an ‘innovative’ alternative to steel sheet piles.
From discussions with various organisations within the UK, there have, unfortunately, been instances where companies undertaking the installation have been unable to drive the piles to the required depth, have broken the piles during the installation process or have failed the design capability. However, there are companies in the UK who have successful experience of the supply and installation of plastic sheet piles. It is not realistic to say that plastic sheet piles can be used in all instances where steel sheet piles can, but there are a great many times where they could be used and are not.
The main problems facing plastic sheet piles are:
- Failed projects travel round the industry far quicker and far more reaching than the successful ones.
- Regulatory bodies are nervous about using innovative materials until they have been tried and tested.
- Some consultants are unaware of the products and their design capacities.
- Contractors prefer to use the ‘old faithful’ as they have experience with the products, the sub-contractors or installing them themselves.
The key areas where plastic sheet piles could be used to both cost and other advantages within the railway are:
- Retaining walls/coffer dams – some plastic sheet piles have design parameters. They can therefore be used as a specifically designed steel sheet pile would be. With their lighter weight, non conductivity and corrosion resistance there are many areas where these would be superior to a steel sheet pile.
- Embankments – To stabilise the toe of an embankment in inaccessible areas and where there are limitations on the size of plant.
- Temporary works – the plastic sheet piles to be used as steel would be to retain temporary excavations and be propped where necessary. The pile can be retracted depending on the soil conditions. Especially useful where electrical arcs are could be an issue.
- Formwork – using plastic sheet piles are cheaper than the standard wood formwork, easy to install and lightweight.
Why should the railway industry be using plastic sheet piles?
Key advantages are:
- Lightweight materials – manually handled
- Lightweight plant – alleviates stresses on embankments and allows for easier accessibility
- Up to 30% cheaper than steel
- Manufactured from recycled plastics
(This article comes from railtechnologymagazine.com editor released)