PRESPLIT BLASTING PROCEDURES, BULL RUN STEAM PLANT, CLINTON, TENNESSEE

GEOLOGIC CONDITIONS AND DESIGN REQUIREMENTS AT THE BULL RUN STEAM PLANT PRESENTLY UNDER CONSTRUCTION BY THE TVA, 13 MILES WEST OF KNOXVILLE, TENN., DICTATED CLOSE CONTROL OF BLASTING PROCEDURES TO OBTAIN SAFE AND ECONOMICAL EXCAVATIONS. VARIOUS TECHNIQUES OF PRESPLIT BLASTING WERE USED IN THE INITIAL STAGE OF ALL MAJOR EXCAVATIONS AND OTHER SPECIALIZED LOADING AND DETONATION PATTERNS WERE USED IN LATER STAGES. HOLE DIAMETERS FOR PRESPLITTING VARIED FROM 1 1/2 TO 9 IN., AND HOLE SPACING RANGED FROM 12 TO 33 IN. ON CENTERS. CHARGES VARIED FROM 1/2 LB TO 175 GR PER LIN FT OF HOLE. FOR BOTH 9-IN. DIAMETER HOLES AND THE 2 3/4-IN. DIAMETER HOLES, THE COST OF MATERIALS WAS LESS THAN $0.10 PSF OF FACE DEVELOPED, HOWEVER, DRILLING AND LABOR COSTS WERE CONSIDERABLY HIGHER FOR DRILLING AND LOADING THE LARGER DIAMETER HOLES. USING THE PRESPLIT METHOD, CLEAN VERTICAL WALLS UP TO 70 FT IN HEIGHT WERE OBTAINED IN MODERATELY DIPPING, THOUGH COMPLEXLY SHEARED AND JOINTED ARGILLACEOUS LIMESTONE. AS THE WORK PROGRESSED, THE PRESPLIT PROGRAM WAS MODIFIED TO MEET THE VARYING GEOLOGIC CONDITIONS AND JOB REQUIREMENTS. THIS WORK WAS DONE ON A PRODUCTION BASIS. THEREFORE, REFINEMENTS AND EXPERIMENTATION NORMALLY CARRIED ON IN A RESEARCH PROGRAM COULD NOT BE FULLY UTILIZED. IT IS FELT, HOWEVER, THAT THE METHODS DEVELOPED ON THIS PROJECT COULD HAVE USEFUL APPLICATIONS ON OTHER MAJOR PROJECTS AND IN HIGHWAY CONSTRUCTION. /AUTHOR/

Media Info

  • Media Type: Print
  • Features: Figures;
  • Pagination: pp 53-59
  • Monograph Title: Construction on marsh deposits; Tunnel site geologic research; Ground water control; Presplit blasting
  • Serial:

Subject/Index Terms

Filing Info

  • Accession Number: 00214414
  • Record Type: Publication
  • Files: TRIS, TRB
  • Created Date: Dec 12 1994 12:00AM