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Downtown Tunnel Repairs and Standpipe Replacement

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Modjeski and Masters is assisting Metro Transit with repairs for the Downtown Tunnel. The project was coordinated with the FTA to obtain a Categorical Exclusion for this historic structure. M&M also coordinated with the City of St. Louis and the St. Louis Fire Department.

M&M designed and detailed a new manual dry standpipe system in accordance with current NFPA codes and standards. M&M’s reconfigured design includes support brackets and acceptable attachment to the historic structure, as well as staging details for the removal and replacement. The sequence of construction required takes into account life safety concerns during construction.

Additional tunnel repair services included drainage system assessment and improvements; isolated load capacity ratings; steel grating removal and ceiling inspection at the Old Post Office; and miscellaneous shotcrete, sandstone, brick masonry, and concrete repairs.

M&M is currently providing bidding assistance and will provide construction services once the contract is awarded.

Bridge Geometry
Total Project Length 4,460 feet
Tracks Serviced 2