INSTRUMENTATION FOR MEASUREMENT OF AXIAL LOAD IN DRILLED SHAFTS

DEFINING THE LOAD DISTRIBUTION ALONG THE LENGTH OF DRILLED SHAFTS IN THE FULL-SCALE LOAD TEST REQUIRES LOAD MEASUREMENT AT VARIOUS POINTS ALONG THE SHAFT'S LENGTH. ONE PHRASE OF THE DRILLED SHAFT TEST INVOLVES DEVELOPING A SUITABLE INSTRUMENTATION SYSTEM FOR MEASUREMENT OF LOAD IN DRILLED SHAFTS. THE SYSTEMS USED FOR AXIAL LOAD MEASUREMENTS IN THE FOUR DRILLED SHAFTS TESTED TO DATE CONSISTED OF ONE INDIRECT-MECHANICAL (TELLTALES), ONE DIRECT-MECHANICAL (GLOETZL), ONE DIRECT-ELECTRICAL (BOTTOMHOLE CELL), AND TWO INDIRECT-ELECTRICAL (EMBEDMENT GAGES, AND MUSTRAN CELLS). OTHER INSTRUMENTATION USED IN CONNECTION WITH THE TESTS INCLUDED LATERAL PRESSURE CELLS TO MEASURE THE LATERAL EARTH PRESSURE AGAINST THE SHAFT, THERMOCOUPLES FOR MEASURING THE IN-SHAFT TEMPERATURE, AN IN SITU DEVICE FOR MEASURING SHEAR STRENGTH OF SOIL, AND A NUCLEAR METHOD OF SOIL-MOISTURE DETERMINATION. THREE OF THE FIVE SYSTEMS WERE DESIGNED AND CONSTRUCTED AT THE UNIVERSITY OF TEXAS AT AUSTIN (UTA). THE RESULTS OF THE INSTRUMENTATION AND TESTING OF THE FOUR SHAFTS DEMONSTRATED THAT THE MOST DESIRABLE SYSTEM FOR THE PURPOSES OF THE PROJECT IS A UTA-STRAIN-MEASURING TRANSDUCER, THE MUSTRAN CELL. UTA- DESIGNED AND CONSTRUCTED. THE SYSTEM WAS FOUND TO BE RELIABLE, SENSITIVE, AND STABLE. THE ACCURACY OF THE SYSTEM WAS FOUND TO DEPEND MAINLY ON UNIFORMITY IN THE CROSS SECTIONAL DIMENSIONS OF THE SHAFT. ON THE BASIS OF THE RESULTS OBTAINED FROM THE TESTING OF THESE FOUR SHAFTS, THE MUSTRAN INSTRUMENTATION SYSTEM WAS ADAPTED FOR THE INSTRUMENTATION OF OTHER SHAFTS IN THE PROJECT REMAINING TO BE TESTED AXIALLY. /AUTHOR/

  • Supplemental Notes:
    • Res Rpt 89-6, 104 PP, 18 FIG, 1 TAB, 12 PHOT, 14 REF
  • Corporate Authors:

    University of Texas, Austin

    Center for Highway Research, 200 West 21st Street
    Austin, TX  USA  78712
  • Authors:
    • Barker, W R
    • Reese, L C
  • Publication Date: 1969-11

Subject/Index Terms

Filing Info

  • Accession Number: 00233005
  • Record Type: Publication
  • Files: TRIS
  • Created Date: May 16 1971 12:00AM