{"id":101860,"date":"2021-11-16T10:18:48","date_gmt":"2021-11-16T10:18:48","guid":{"rendered":"https:\/\/www.pbctoday.co.uk\/news\/?p=101860"},"modified":"2021-11-16T10:18:48","modified_gmt":"2021-11-16T10:18:48","slug":"hs2-colne-valley-viaduct","status":"publish","type":"post","link":"https:\/\/www.pbctoday.co.uk\/news\/planning-construction-news\/hs2-colne-valley-viaduct\/101860\/","title":{"rendered":"HS2 celebrates momentous carbon saving in Colne Valley Viaduct"},"content":{"rendered":"

HS2<\/a> confirmed that it is on track to cut the amount of embedded carbon in the Colne Valley Viaduct by at least 28.4%, as works continue for what will be the UK\u2019s longest railway bridge<\/h2>\n

The team has cut the amount of embedded carbon in the viaduct<\/a> by 63,300 tonnes CO2e \u2013 the equivalent of 234,500 flights from London to Edinburgh – through narrowing the viaduct.<\/p>\n

The Viaduct<\/h3>\n

The Colne Valley Viaduct will stretch for 3.4km across a series of lakes on the outskirts of London and will be one of the most high-profile structures on the new HS2 high-speed rail link under construction between London, the West Midlands, and Crewe<\/a>.<\/p>\n

HS2\u2019s main works contractor Align JV \u2013 a team made up of Bouygues Travaux Publics<\/a>, Sir Robert McAlpine, and VolkerFitzpatrick \u2013 worked for four years on the design with architects Grimshaw and design partners Jacobs and Ingerop-Rendel.<\/p>\n

The team refined the original design produced as part of the HS2 parliamentary process to make it more efficient by reducing the amount of steel and concrete in the structure.<\/a><\/p>\n

This included working closely with rail systems experts at HS2 to allow the structure to be narrowed by over 1m, while still allowing sufficient space for signalling and control equipment alongside the line.<\/p>\n

They also worked to bring the northbound and southbound tracks closer together further north, which in turn significantly reduced the amount of earthworks required for the approach embankment.<\/p>\n

Conscious of commitments made to the community about the appearance of the viaduct as it passed over the lakes, the team focused on creating arches over the water while reserving simpler, easier to construct, designs for the approaches.<\/p>\n

Inside the viaduct, the engineers opted for a \u2018post-tension’ design, with lightweight super-strong steel cables running the full length of structure.<\/p>\n

The cables will be monitored 24\/7 by a network of high-tech sensors and act to bind the viaduct together allowing it to handle the enormous forces produced by trains passing at speeds of up to 200mph (320km\/h).<\/p>\n

An extensive programme of test piling was also completed ahead of the start of construction with geological and structural data from these tests fed back into the design of the viaduct, which resulted in a 10-15% reduction in the depth of the piles and associated time, cost and carbon savings.<\/a><\/p>\n