NEVADA'S TWIN HIGHWAY TUNNELS

THE TUNNELS WHICH WILL CARRY EAST AND WESTBOUND TRAFFIC 1,426 AND 1,361 FT. RESPECTIVELY, WILL BE FINISHED TO 33 FT. WIDTH AND 25 FT. TO THE CROWN. A TOP-HEADING METHOD OF EXCAVATION HAS BEEN EMPLOYED TO ATTACK THE MASSIVE FACES. THERE WAS CAREFUL COORDINATION OF THE DRILLING AND MUCKING OPERATIONS. THE SEQUENCE IS AS FOLLOWS: BLASTING HOLES ARE DRIVEN; THE JUMBO RETREATS; THE ROUND IS PULLED; AND MUCK COLLECTED. WHILE MUCKING IS TAKING PLACE, THE JUMBO IS DRILLING IN THE OTHER TUNNEL. WHEN MUCKING AND PLACING OF STEEL SETS HAS BEEN COMPLETED IN THE FIRST TUNNEL, THE JUMBO MOVES BACK TO PLACE THE LAGGING AND DRILL IN THE NEXT ROUND. MUCKING OPERATIONS WERE HANDLED BY A CATERPILLAR 966 FRONT-END RUBBER TIRED LOADER AND A TRACK-MOUNTED CAT 977 WITH A SIDE-DUMP BUCKET LOADING INTO THREE 17 CU. YD. ATHEY ROCK WAGONS. THE STEEL RIB SETS FOR THE HEADING ARE 8WF67. THE TWO BEAMS FOR THE SET WERE BROUGHT TO THE SITE AND SET UP BY A 12.5 TON PETTIBONE HYDRAULIC CRANE. HEADINGS WERE DRIVEN WEST TO EAST AND BENCHING ACTIVITIES BEGAN EAST TO WEST FOR APPROXIMATELY 400 FT. SO THAT CONCRETING COULD GET UNDER WAY AT THE EAST PORTALS. THE REMAINING 1000 FT. IS EXCAVATED WEST TO EAST. THREE MILLION POUNDS OF REBAR WILL BE USED. THE THREE- LEVEL HINGED-WING ERECTION PLATFORM USED TO INSTALL THE NO. 10 BAR FOR THE TUNNEL ARCHES IS A CONVERTED 1937 EUCLID DUMP TRUCK. TEN-FOOT PLYWOOD PANELS BOLTED TOGETHER IN 80 FT. POUR SECTIONS ARE USED AS FORMS FOR ARCH FOOTINGS.

  • Publication Date: 1973-8

Media Info

  • Features: Photos;
  • Pagination: p. 33-5
  • Serial:

Subject/Index Terms

Filing Info

  • Accession Number: 00236693
  • Record Type: Publication
  • Files: TRIS
  • Created Date: Sep 17 1973 12:00AM