ON THE VIBRATIONAL ANALYSIS OF FOUNDATION-STRUCTURE SYSTEM BY MULTI-DEGREE-OF-FREEDOM MODEL REPRESENTATION /IN JAPANESE/

A NEW MECHANICAL MODEL WITH MULTI-DEGREE-OF-FREEDOM IS PROPOSED. THIS MODEL IS BASED ON THE ASSUMPTION THAT THE SURFACE LAYER BE REPRESENTED BY THE ROWS AND COLUMNS OF A LUMPED-MASSES SYSTEM CONNECTED WITH EACH OTHER BY SPRINGS AND DASHPOTS HORIZONTALLY AND VERTICALLY. FIRST, AFTER THE APPROPRIATENESS OF THIS MODEL HAD BEEN CONFIRMED BY COMPARISON WITH THE SOLUTION FOR A CONTINUOUS SYSTEM, THE INFLUENCE OF THE NUMBER OF ROWS AND THE NUMBER OF COLUMNS FOR DYNAMIC CHARACTERISTICS HAS BEEN DISCUSSED. NEXT THIS MODEL HAS BEEN APPLIED TO THE ANALYSIS OF THE FOUNDATION-STRUCTURE SYSTEM, IN WHICH DISCUSSIONS WERE HELD ON THE BASIS OF SOME NUMERICAL RESULTS. THE CONSEQUENCES OF THE STUDY ARE SUMMARIZED. (1) IN THE PROPOSED MODEL, AS THE NUMBER OF THE ROWS IS INCREASED, THE NATURAL FREQUENCY OF IT GRADUALLY APPROACHES THE SOLUTION FOR A CONTINUOUS SYSTEM. THIS SHOWS THAT THE MODEL'S BEHAVIOR IS EQUIVALENT TO THAT OF A CONTINUOUS MEDIUM, WHEN THE NUMBER OF THE ROWS IS LARGE. (2) VIBRATIONAL PRESSURE ACTING ON A FIXED WALL EMBEDDED IN THE SURFACE LAYER RESEMBLES THE SOLUTION FOR A CONTINUOUS SYSTEM IN ITS DISTRIBUTION AND MAGNITUDE, WHEN THE NUMBER OF THE COLUMNS IS LARGE. THIS WOULD SHOW THAT THE PROPOSED DISCRETE MODEL IS FAIRLY REASONABLE. (3) AS THE SEMI-INFINITE SURFACE LAYER IS SUBSTITUTED FOR THE DISCRETE MODEL IT IS POSSIBLE THAT PECULIAR PHENOMENA OF THE MODEL MAY BE MANIFESTED. PARTICULARLY, WHEN THE EXCITING FREQUENCY IS LARGE, THE NUMBER OF THE ROWS AND OF THE COLUMNS HAVE TO BE CAREFULLY SELECTED. (4) IN GENERAL, STRUCTURAL FOUNDATIONS DEEPLY FOUNDED IN THE SURFACE LAYER VIBRATE IN COUPLING WITH SOIL IN ITS NEIGHBORHOOD. THE DOMAIN OF THE SURFACE LAYER IN WHICH THE COUPLING EFFECT IS PRESENT VARIES WITH THE FREQUENCY OF EXCITATION, THE NUMBER OF DEGREE OF FREEDOM OF THE MODEL, AND MOST LIKELY BY THE DIMENSION OF THE PORTION OF THE SURFACE LAYER CONSIDERED IN THE ANALYSIS. /RRL/A/

  • Supplemental Notes:
    • No 12a, pp 273-287
  • Corporate Authors:

    Kyoto University

    Disaster Prevention Research, Gokasho
    Uji City, Kyoto,   Japan 
  • Authors:
    • Goto, H
    • Toki, K
    • YOSHIHARA, S
  • Publication Date: 1969-3

Subject/Index Terms

Filing Info

  • Accession Number: 00234913
  • Record Type: Publication
  • Source Agency: Road Research Laboratory /UK
  • Files: TRIS
  • Created Date: Sep 28 1970 12:00AM