MOBILE RIVER TUNNEL

COMPLETION OF THE MOBILE (ALA.) RIVER TUNNEL, SCHEDULED FOR LATE 1972, PROVIDES A VITAL LINK IN INTERSTATE-10. THE STEEL, TWIN-TUBE SECTIONS ARE APPROXIMATELY 40 FEET DEEP BY 80 FEET WIDE AND ARE 346 FEET LONG. TWIN CYLINDRICAL TUBES 36 FEET 9 INCHES IN DIAMETER PROVIDE SEPARATE WATERTIGHT ENCLOSURES FOR THE ROADWAY AND AIR DUCT FOR EACH TUBE. AN OUTER OPEN-TOPPED OCTAGONAL STEEL FORM PLATE RETAINS THE BALLAST CONCRETE WHICH IS POURED AROUND AND BETWEEN THE CYLINDRICAL TUBES TEMPORARY STEEL BULKHEADS CLOSE THE TUBE ENDS TO CONTROL BUOYANCY WHILE THE SECTIONS ARE AFLOAT AND DURING SINKING AND JOINING OPERATIONS. SEVEN TUBE SECTIONS ARE REQUIRED. THE TUNNEL LENGTH IS 3,000 FEET PORTAL TO PORTAL. CURVED RAMPS APPROXIMATELY 715 FEET LONG AT EACH END MAKE THE TOTAL LENGTH APPROXIMATELY 4,430 FEET. THE TUNNEL LENGTH COMPRISES (FROM WEST TO EAST) 200 FEET OF CAST-IN PLACE CONCRETE ARCH SECTION, 50 FEET OF VENTILATION STRUCTURE, 26.5 FEET OF TRANSITION SECTION, 2,422 FEET OF PREFABRICATED SECTIONS SUNK IN A TRENCH DREDGED TO PROFILE (SEVEN SECTIONS), 26.5 FEET OF TRANSITION SECTION, 50 FEET OF VENTILATION STRUCTURE, AND 225 FEET OF CAST-IN-PLACE CONCRETE ARCH SECTION. TANGENT GRADES OF 5.25 PERCENT (WEST) AND 5.05 PERCENT (EAST) ARE CONNECTED BY A VERTICAL SAG CURVE OF 900-FOOT LENGTH WITH THE STEEL TUBE SECTIONS FABRICATED TO FIT THE PROFILE. A MINIMUM COVER OF 5 FEET IS PROVIDED UNDER THE SHIP CHANNEL (600 FEET WIDE BY 40 FEET DEEP, ALLOWING 2 FEET FOR OVERDREDGING. AT THE LOW POINT, THE TOP OF THE TUNNEL AND THE ROADWAY ARE, RESPECTIVELY, 57 FEET AND 83.5 FEET BELOW THE RIVER SURFACE. DETAILS OF CONSTRUCTION ARE GIVEN.

  • Authors:
    • Roberson, B L
  • Publication Date: 1972-12

Media Info

  • Features: Photos;
  • Pagination: p. 424-8
  • Serial:
    • Military Engineer
    • Volume: 64
    • Issue Number: 422
    • Publisher: Society of Military Engineers

Subject/Index Terms

Filing Info

  • Accession Number: 00236463
  • Record Type: Publication
  • Files: TRIS
  • Created Date: May 15 1973 12:00AM