The City of Fort Collins (Colorado) recently completed construction of a tunnel underneath BNSF Railway tracks to connect more than 30 miles of trails. The prospect of tunneling under an active rail line is a pretty big deal, and the railroad had strict requirements. The original concept of the tunnel was modified by the contractor and their engineer to utilize secant pile retaining walls to allow the construction of the portals closer to the rail line and decreasing the overall tunnel length. The tunnel was constructed by BT Construction and Lithos Engineering was their design engineer. Yenter construction was responsible for the retaining walls, including segments of sheet pile wall used to start things off. Anderson Drilling constructed the shafts for the secant pile wall and for the thrust wall. Read more about the project at TBM.
Today, Tuesday, February 26, 2008, the Svalbard Global Seed Vault is scheduled to start operating on the remote island of Spitsbergen, Norway in the Svalbard Archipelago. The location is only about 1000km (625 miles) from the North Pole. The Global Seed Vault will house duplicates of seeds from known species of plants from all over the world in case a natural or other disaster destroys the original species. [Editor] Read on for more details. Photo by Mari Tefre/Svalbard Global Seed Vault [/Editor]