CONTINUOUS CONCRETING: SLIPFORM PAVING ON THE MOVE

THE REPORT DESCRIBES ANCHORING MODIFICATIONS THAT KEEP A MOLE ON-COURSE AND SLIPFREE AS IT TUNNELS ON SLOPES WHICH ARE 56 PERCENT STEEP. IN CONVENTIONAL HORIZONTAL TUNNELING FOUR STANDARD HYDRAULIC BRACES HOLD THE MOLE AS IT ADVANCES IN 2.5 FT CYCLES WITH ITS CUTTING HEAD AND 26 ROLLER BITS OPERATING AT A MAXIMUM OF 10 RPM. FOR THE INCLINED TUNNEL, HOWEVER, FOUR BRACES ARE ADDED IN OPPOSING PAIRS. COMBINED WITH THE ORIGINAL EXISTING BRACES, THE ADDED UNITS EXERT A 1,212-TON PRESSURE AGAINST THE ROCK, KEEPING THE MOLE STEADFAST IN A COMPLETED TUNNEL SECTION WHILE ITS CUTTING HEAD BORES FORWARD. TWO 12-MAN SHIFTS EXCAVATE APPROXIMATELY 7,062 CU FT. TO ADVANCE THE TUNNEL ABOUT 33 FT DAILY.

• Authors:
  • Donnelly, C W
• Publication Date: 1973-8

Media Info

• Features: Photos;
• Pagination: p. 63-70
• Serial:
  • Construction Methods and Equipment
  • Volume: 55n8
  • Publisher: McGraw-Hill, Incorporated

Subject/Index Terms

• TRT Terms: Boring; Braces; Mountains; Slopes; Tunneling
• Uncontrolled Terms: Grades
• Old TRIS Terms: Moles
• Subject Areas: Bridges and other structures; Construction; Highways;

Filing Info

• Accession Number: 00215681
• Record Type: Publication
• Files: TRIS
• Created Date: Jul 16 1974 12:00AM