I-70 twin tunnels to be lined with concrete

The Colorado Department of Trasportation is going to line the I-70 twin tunnels, near Idaho Springs with concrete to enhance the tunnels' strength and longevity. Watch the video below explaining the details of the project and see pictures of the unlined tunnel's interior!

The CDOT construction crews are preparing to roll two large tunnel-form liner structures into the westbound tunnel entrance, on a rail, jacked up and concrete will be poured inside, aiming to cover the wire mesh which now serves as a temporary support measure. Then the forms will be moved by 40 feet each time to repeat the process. Lining works will begin from both sides of the tunnel, expected to complete the lining in 20 pours by this October, provided four pours are performed weekly. In the meantime, blasting works is in progress to remove dangerous parts of the rock face wall at the east end of the tunnel. Overall 30 more blasts are planned in that part of the project, which will continue through September.  

Additonal information and views from the twin tunnels are available in the following video: