PRE-SPLITTING DONE UNDER SAND BLANKET FOR SUBURBAN FREEWAY

A MOUND BARRIER OF SAND PLACED ATOP PRE-SPLITTING BLAST HOLES HELPED TO MUFFLE THE SOUND AND INSURE AGAINST FLYING ROCK IN CARVING OUT A 1,8000,000 CU. YD. AMPHITHEATER. THE PRE-SPLITTING WHICH REQUIRED 56,270 FT. OF HOLE WAS DONE ON 36-IN. CENTERS USING A TRACK DRILL WITH STEEL AND HARD ROCK BITS. THE EXTENDABLE BOOM DRILL AND SPECIAL SLOPE TEMPLATES HELPED TO LINE QUICKLY AND KEEP AN ACCURATE SLOPE LINE. PRE-SPLITTING WAS DONE ALONG 100 FEET OF LINE AT A TIME, OR FOR 33 OR 34 HOLES, TO SPLIT THE AREA THAT WOULD THEN BE DRILLED AND SHOT FOR ROCK REMOVAL. PRODUCTION DRILLING WAS AT LEAST 60 FT. AWAY FROM THE PRE-SPLIT LINE UNTIL THE LINE WAS SHOT, AND THE NEAREST PRODUCTION HOLE WAS KEPT 4 FT. FROM THE PRE SPLIT LINE TO PROVIDE AGAINST BACK BREAKS. PROCEDURAL DETAILS AND EQUIPMENT USED IN THE PRE-SPLIT METHOD ARE DESCRIBED. OVER 800 SHOTS WERE REQUIRED TO COMPLETE THE 1,000,000 CU. YD. ROCK PORTION OF THE 1. 8000,000 CU. YD. OF EXCAVATION. EQUIPMENT USED FOR MOVING FRAGMENTED ROCK AND DIRT, PUSHERS, RIPPERS, AND EQUIPMENT USED FOR SPREADING ON THE FILL AND TRIMMING EMBANKMENTS AND EARTH CUT SLOPES ARE DETAILED.

• Publication Date: 1973-2

Media Info

• Pagination: p. 31-3
• Serial:
  • Roads and Streets
  • Volume: 116
  • Issue Number: 2
  • Publisher: Donnelley (Reuben H) Corporation

Subject/Index Terms

• TRT Terms: Drills; Equipment; Mufflers; Presplitting (Blasting); Rock excavation; Sand; Sound; Sound absorption
• Old TRIS Terms: Blanketing; Presplitting
• Subject Areas: Construction; Highways;

Filing Info

• Accession Number: 00215631
• Record Type: Publication
• Files: TRIS
• Created Date: Oct 9 1973 12:00AM