VIBRATION TESTS OF A HIGH RISE BRIDGE PIER USING ROCKET PROPULSION METHOD

TWO METHODS OF VIBRATION TESTS WERE USED ON A HIGH RISE PIER OF STEEL FRAMED REINFORCED CONCRETE AT THE SOKOZAWA BRIDGE SITE. FORCED VIBRATION OF STRUCTURE OR STRUCTURAL ELEMENTS IS CAUSED BY A MECHANICAL EXCITOR WITH ROTATING ECCENTRIC MASS, A LARGE MASS PENDULUM OF ADJUSTABLE NATURAL PERIOD, OR ARTIFICIAL EXPLOSION OF SMALL MAGNITUDE. DAMPED FREE VIBRATION OF STRUCTURE IS CAUSED BY A SUDDEN RELEASE OF STATIC DISPLACEMENT BY PULLING WIRE OR ROCKET PROPULSION. THE CALCULATED VALUES AND TEST RESULTS ARE COMPARED. THE CONCLUSIONS FROM THE VIBRATION TESTS ARE: (1) THE OBTAINED VALUES OF NATURAL FREQUENCY WELL AGREE WITH THE CALCULATED ONES BASED ON THE ASSUMPTION THAT THE PIER IS A CANTILEVER FIXED AT THE BOTTOM; (2) THE OBTAINED VALUES OF DAMPING CONSTANT (RATIO TO THE CRITICAL DAMPING) ARE 0.006 TO 0.01; THEY ARE CONSIDERABLY SMALLER THAN THOSE USUALLY EXPECTED WITH THE STEEL FRAME REINFORCED CONCRETE; AND (3) IT HAS BEEN VERIFIED THAT ROCKET PROPULSION METHOD IS USEFUL IN CAUSING DAMPED FREE VIBRATION OF STRUCTURES AND THUS IN OBTAINING THE DYNAMIC CHARACTERISTICS OF STRUCTURES.

  • Supplemental Notes:
    • pp 44-50, 6 FIG, 4 TAB
  • Authors:
    • Okubo, T
    • IWASAKI, T
  • Publication Date: 1969

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  • Accession Number: 00209342
  • Record Type: Publication
  • Files: TRIS
  • Created Date: Dec 28 1970 12:00AM