SOME CONSIDERATIONS OF SUBMERGED TUNNELLING

THE TRENCH AND PRECAST TUNNEL IS THE USUAL CONSTRUCTION METHOD OF UNDERWATER TUNNELING. THE LENGTH OF THE ELEMENTS HAS INCREASED TO MORE THAN 100 M, THE WIDTH TO MORE THAN 40 M, AND THE WEIGHT TO ABOUT 50,000 TONS. THERE IS A MORE OR LESS HISTORICAL DIFFERENCE IN SUBMERGED TUNNELING METHODS IN THE US AND THE REST OF THE WORLD, ALTHOUGH THERE IS A TENDENCY FOR BOTH METHODS TO GROW TOWARDS ONE ANOTHER, PARTICULARLY WITH REGARD TO EXECUTION. THE AMERICAN TUNNEL IS BASED ON THE CYLINDRICAL CROSS SECTION WITH TWO TRAFFIC LANES; THE EUROPEAN TUNNEL HAS A RECTANGULAR CROSS SECTION WHICH CAN EASILY BE ADAPTED TO THE REQUIRED NUMBER OF TRAFFIC LANES (2X3 OR 3X2 FOR INSTANCE). BECAUSE OF THE FINANCING SYSTEM AND RIGOROUS PREFABICATION, THE CONSTRUCTION TIME OF THE CYLINDRICAL TUNNEL IS MUCH LESS THAN THAT OF THE RECTANGULAR TUNNEL. THE JOINT CONNECTION OF RECTANGULAR TUNNELS HAS BEEN MUCH SIMPLIFIED BY THE APPLICATION OF A RUBBER GASKET, WHICH HAS BEEN USED ALSO FOR RECENT AMERICAN TUNNELS. THE FOUNDATION OF THE TUNNEL ELEMENTS IS GENERALLY DIRECTLY ONTO THE SUBSOIL, BUT SOMETIMES THE SOIL CONDITIONS ARE SO BAD THAT A PILE FOUNDATION HAS TO BE USED. SOME IDEAS ARE GIVEN ABOUT POSSIBLE DEVELOPMENTS OF LONG TUNNEL CROSSINGS AND BRIDGE- TUNNEL COMBINATIONS. /AUTHOR/

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Filing Info

  • Accession Number: 00215421
  • Record Type: Publication
  • Files: TRIS
  • Created Date: Aug 1 1971 12:00AM