Constructed in 1931 by the Illinois Terminal Railroad, the Tucker Tunnel is located underneath Terminal Boulevard in downtown St. Louis. Over the years, the tunnel condition has deteriorated and the concern is that the failure of the tunnel would have a severe impact on the roadway above as well as adjacent buildings. Expanded Polystyrene manufacturer and fabricator Versa-Tech was awarded the contract for providing the Geotechnical Fill in the form of EPS Geofoam Blocks that will be used to fill the void. Some 3,300 blocks totaling over 675,000 cubic ft will be utilized for the first phase. The blocks have a unit weight between 1 and 2 pcf and unlike conventional backfill, should reduce the lateral pressures on the inside of the tunnel to prevent the walls from failing outwards and adversely affecting buildings and other infrastructure. [Source: Versa-Tech. Image: Versa-Tech]
