SOFT ROCK EXPLORATION WITH PRESSURE EQUIPMENT

A NEW INSTRUMENT, DEVELOPED FOR IN-SITU TESTING OF SOIL AND SOFT ROCK, PROMISES TO GIVE ACCURATE AND USEFUL INFORMATION ON STRESS-STRAIN CHARACTERISTICS AT ECONOMICAL COST. THE PRESSURE METER EQUIPMENT CONSISTS OF A COMBINATION VOLUMETER-MANOMETER CONNECTED TO A CYLINDRICAL BOREHOLE EXPANSION DEVICE. THIS PROBE IS CONSTRUCTED OF A STEEL TUBE SURROUNDED BY TWO FLEXIBLE RUBBER MEMBRANES, THE INTERIOR MEMBRANE FORMING THE MEASURING CELL AND THE EXTERIOR PROVIDING THE GUARD CELLS AT THE ENDS OF THE PROBE. THE GUARD CELL IS ACTIVATED BY GAS PRESSURE AND IS USED TO REDUCE END EFFECTS ON THE MEASURING CELL TO PROVIDE AN ESSENTIALLY TWO-DIMENSIONAL CONDITION. THE MEASURING CELL IS PRESSURIZED WITH WATER AND KEPT AT A SLIGHTLY HIGHER PRESSURE THAN THE GUARD CELL TO INSURE THAT IT IS ALWAYS PRESSING AGAINST THE BOREHOLE WALL. TWO CONCENTRIC TUBES CONNECT THE VOLUMETER TO THE PROBE. AFTER LOWERING THE PROBE TO THE DESIRED DEPTH, PRESSURE IS APPLIED TO THE BOREHOLE WALL BY INFLATING THE RUBBER MEMBRANES. TWO RECENT APPLICATIONS OF THIS EQUIPMENT ARE DESCRIBED - THE CASTAIC SURGE CHAMBER WITHIN THE CALIFORNIA AQUADUCT AND STOKES CANYON TUNNEL NEAR LOS ANGELES. /ASCE/

  • Availability:
  • Supplemental Notes:
    • Vol 38, No 10, PP 34-36, 4 FIG, 2 PHOT
  • Authors:
    • Dixon, S J
    • Jones, W V
  • Publication Date: 0

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  • Accession Number: 00229608
  • Record Type: Publication
  • Files: TRIS
  • Created Date: Aug 15 2004 2:39AM