Articles about CUR96

Colinton Dell is a steep-sided gorge and wildlife refuge on the Water of Leith, just north of the old village of Colinton on the outskirts of Edinburgh.
Today walkways and a cycle path take visitors to the ruined Redhall Mill and past Kate's Mill, where paper for the Bank of Scotland's first banknotes is said to have been made.
As a result of a Lifespan e news letter campaign in the autumn of last year we received an enquiry from the Mott MacDonald team in Edinburgh.

After several on line meetings and an on site visit we developed a solution for the Client Edinburgh City Council and introduced CRL Scotland to the project team as a specialist contractor that was capable of delivering the project.

Following a tender process in early 2023 CRL Scotland were awarded the project valued at circa £250,000 as reported in March of this year

The objective of the project was to provide a replacement deck for the existing Colinton Dell Rustic Footbridge with a design life of 120 years. The existing timber deck on the footbridge was in very poor condition and a new Lifespan Structures (FRP) deck was designed, manufactured & installed by CRL Scotland as a replacement so that the bridge can be re-opened in July of this year

Due to the very challenging location of the site the CRL team came up with a carefully thought out plan as to how they would remove the old bridge and be able to safely install the new Lifespan FRP deck sections.

Additional challenges for the team included a high pressure gas main adjacent to the existing bridge, the steepness of the Dell either side of the bridge location and that everything had to come through the famous Colinton Dell Tunnel.

The new Lifespan Structures FRP deck was designed in house to conform with a specification provided by Mott MacDonald. The new deck of approximately 28m span was supplied in 5 sections of 5.7m long x 2.5m wide and 65mm thick that are mechanically fixed onto the existing longitudinal steel beams, that are in good condition. A new 1.5m high galvanised steel parapet was also be installed.

Watch the video here of the completed bridge
https://youtu.be/7F7L-bdyUPE

Due to economic & climate considerations Clients demand ever more sustainable options when trying to repair or extend the life of their bridges rather than its complete replacement. Bridges often require repairs and eventually wholescale replacement of key structural elements during its service life & these can be very expensive and disruptive to the users of the bridge. Perhaps the most disruptive and costly is that of the deck replacement which could be steel, concrete or a timber deck for pedestrians, cyclists and vehicle trafficking.

Our first project of this kind in the UK has been sucessfully completed after extensive work by the Lifespan team with the Client, Forestry England the largest landowner in England. The Lifespan bridges provide a far more sustainable, cost effective and durable bridge deck solution than has been historically achieved using traditional building materials whilst also reducing the carbon footprint and energy embodiment in the bridge structures. The 2 new Lifespan resin infused FRP bridges were designed to BS EN 1991-2 [Ref 4.N] load model LM1 & LM2 which is also fully compliant with the latest DMRB standards and capable of withstanding trafficking by fully laden 44T logging HGV lorries.

Almost 7 years ago one of our Local Authority Clients issued a tender for a project that required a new simply supported 8m single span bridge of 1m width with a standard anti climb parapet. A variety of typical bridge construction types were permitted including steel, timber and an alternative using Lifespan resin infused FRP composites. With input from the Client additional considerations were made as to the likely cost and regularity of maintenance works for each of the possible bridge types in order to ascertain a whole life cost for each of the options.

EuCIA publishes update on future Eurocode for composites

The extent to which manufacturing-induced fibre mat misalignments compromise the structural integrity of pultruded GFRP road bridge decks is not properly understood. The problem is often critical at the web-flange junctions, which frequently contain the most severe misalignments and are subjected to high local moment-shear (M-V) combinations due to concentrated tyre load and also global vehicle load effects. Over the last 20 years, several GFRP decks have developed tyre load-induced damage of the top flange, due in large part to the prevalence of fibre misalignments.

Colinton Dell is a steep-sided gorge and wildlife refuge on the Water of Leith, just north of the old village of Colinton on the outskirts of Edinburgh. It extends from Colinton Parish Church towards Slateford along the Water of Leith Walkway and has an area of 10 ha (25 acres). The Dell includes mature and ancient mixed woodland and the protection afforded by the high banks and thick undergrowth makes it a natural habitat for wildlife, including numerous bird species and amphibians, voles, weasels, stoats and occasionally roe deer.

Bridge decks often require repairs and eventually replacement during the service life of a bridge. These can be steel, concrete or timber decks for pedestrian and vehicle access. At Lifespan we can design, supply, and if required install, lightweight FRP composite decks which can reduce the deck dead load by 50%. These decks reduce the environmental impact in terms of carbon and energy embodiment. They are also quicker and safer to install compared to traditional materials. The decks are delivered complete with surfacing and ready for installation onsite.

Bridge design is not just structural performance but also about how a bridge looks and the social benefits that a well-designed bridge can deliver in the context of the surrounding environment. Highways England have recently published a document entitled “Principles of Good Road Design” in an initiative to improve the design process which we fully support. There is an emphasis on innovation using long lasting quality materials which we can deliver with an FRP composite bridge. At Lifespan we work with leading bridge Architects to deliver a design concept based on the brief from the Client.

We are now in a position to offer vehicle bridges that carry traffic loads shall be designed for BS EN 1991-2 [Ref 4.N] load models (LM) LM1, LM2 and, if appropriate for pedestrians, LM4 which are fully compliant with the latest DMRB standards. We are currently in the design phase for two vehicle bridges to be supplied and installed later this year. We started the business in 2015 and without an established market for moulded FRP composite bridges in the UK we decided to target the local authority sector with footbridges, this has been very well received.