1967 RIPPING AND BLASTING RESULTS IN SOUTHWESTERN U.S.A.

IMPROVEMENTS IN TRACTORS AND RIPPERS AND IN BLAST-HOLE DRILLS AND EXPLOSIVES HAVE INCREASED PRODUCTION AND DECREASED UNIT COST IN THE FRAGMENTATION OF EARTH-ROCK STRUCTURES. THESE METHODS ARE SUMMARIZED AND RESULTS CURRENTLY IN PRACTICE PRESENTED. PRACTICES ARE CORRELATED WITH THE SEISMIC SHOCK WAVE VELOCITIES OF THE STRUCTURES. SEISMOGRAPH STUDIES WERE MADE OF 300 JOB SITES AND 200 OF THE STUDIES CORRELATED WITH THE CONTRACTORS' AND THE MINERS' EXCAVATING METHODS AND PRODUCTION. THE ROCKS OF SOUTHWESTERN USA ARE GENERALLY WARPED, FOLDED, DIPPED, AND FAULTED BY EARTHQUAKES AND ARE OF IGNEOUS, SEDIMENTARY, AND METAMORPHIC TYPES. THE SEISMOGRAPH IS AN ACCEPTED MEANS OF MEASURING THE COST OF EXCAVATION OF ROCKS BY DERIVING: (1) RIPPING COSTS AND BLASTING COSTS WHICH ARE PROPORTIONAL TO THE DEGREE OF CONSOLIDATION OF THE MATERIAL, (2) CONSOLIDATION WHICH IS PROPORTIONAL TO THE SEISMIC SHOCK WAVE VELOCITY OF THE MATERIAL, AND (3) THE COST OF PREPARING THE MATERIAL FOR MOVEMENT WHICH IS PROPORTIONAL TO THE SHOCK WAVE VELOCITY OF THE EARTH-ROCK STRUCTURE. TRACTORS ARE INCREASING IN HORSEPOWER AND WEIGHT, AND THE PARALLELOGRAM TYPE RIPPER IS MORE EFFICIENT THAN THE SWING TYPE RIPPER. THESE FACTORS HAVE INCREASED THE PRODUCTION OF MEDIUM AND HEAVY-DUTY TRACTOR RIPPERS. THE PERFORMANCE AND OPERATION OF THESE RIPPERS ARE REVIEWED. AVERAGING PRODUCTION AND UNIT COST EQUATIONS FOR BOTH MEDIUM AND HEAVY-DUTY TRACTOR RIPPERS, PRODUCTION VARIES INVERSELY APPROXIMATELY AS THE 3.15 POWER OF THE SHOCK WAVE VELOCITY. THE UNIT COST VARIES APPROXIMATELY AS THE 3.18 POWER. PERCUSSION DRILLS AND BLASTING ARE ALSO DISCUSSED. THE SELECTION OF RIPPING OR BLASTING METHODS DEPENDS ON THE CONSOLIDATION FOUND IN THE EARTH-ROCK STRUCTURE. SECONDARY CONSIDERATIONS ARE METHOD OF HAULAGE, THICKNESS OF BEDDING OR STRATIFICATION OF THE ROCK

• Supplemental Notes:
  • Vol 110, No 9, PP 44-64, 5 FIG, 1 TAB, 3 PHOT
• Authors:
  • Church, H K
• Publication Date: 1967-9

Media Info

• Serial:
  • Roads and Streets
  • Publisher: Donnelley (Reuben H) Corporation

Subject/Index Terms

• TRT Terms: Consolidation; Construction; Construction equipment; Costs; Crushers; Drills; Earthwork; Elastic waves; Freight handling; Geological surveying; Igneous rocks; Metamorphic rocks; Physical properties; Presplitting (Blasting); Reviews; Rock excavation; Rocks; Sedimentary rocks; Seismographs; Seismometers; Shock waves; Soils; Stratification; Truck tractors
• Uncontrolled Terms: Construction costs; Fragmentation; Hauling; Soil consolidation
• Old TRIS Terms: Rippers; Rock properties; Seismographic methods (Soil surveys)
• Subject Areas: Construction; Finance; Freight Transportation; Geotechnology; Highways; Vehicles and Equipment;

Filing Info

• Accession Number: 00219296
• Record Type: Publication
• Files: TRIS
• Created Date: Jul 8 1994 12:00AM