A MODEL STUDY OF THE SMALL BOY FOOTING BEHAVIOR

AS PART OF OPERATION SUNBEAM, EVENT SMALL BOY, A FOOTING- SUPPORTED FIELD-TEST STRUCTURE WAS TESTED. A SIMPLIFIED MODEL OF THE FIELD TEST STRUCTURE WAS DEVELOPED AND VERIFIED BY COMPARISON OF THE RESULTS OF TESTS OF A SMALL-SCALE MODEL WITH THE ACTUAL PROTOTYPE. EXPERIMENTAL AND ANALYTICAL INVESTIGATIONS WERE CONDUCTED USING THIS MODEL TO DETERMINE THE EFFECTS OF VARIATIONS IN THE MASS OF THE STRUCTURE AND IN THE POSITIVE PHASE DURATIONS OF THE TRANSIENT LOADING. THE SMALL STATIC PRELOAD OF THE SMALL BOY FOOTINGS DID NOT SIGNIFICANTLY INFLUENCE THEIR DYNAMIC REPONSE. THE STRUCTURAL INERTIA AFFECTED THE REPONSE OF THE FOOTINGS, BUT NOT THE DYNAMIC FOOTING LOAD-DISPLACEMENT RELATION. THE EFFECT OF INCREASING POSITIVE PHASE DURATION WAS TO INCREASE MAXIMUM DISPLACEMENT AND THE TIME TO ITS OCCURRENCE. THIS EFFECT WAS MORE SEVERE FOR HIGH INTENSITY LOADINGS. THE RESULTS OF THIS STUDY INDICATE THAT, IF THE LOAD DURATIONS APPLIED TO THE SMALL BOY STRUCTURE HAD BEEN THOSE ASSOCIATED WITH A HIGH WEAPON YIELD, COMPLETE COLLAPSE OF THE SYSTEM WOULD HAVE OCCURRED. A SINGLE DEGREE OF FREEDOM ANALYTICAL MODEL WAS FOUND TO BE USEFUL FOR PREDICTING THE FOUNDATION REPONSE OF PROTECTIVE STRUCTURES IN CASES WHERE A REASONABLE ESTIMATE OF THE DYNAMIC FOOTING LOAD DISPLACEMENT RELATION CAN BE MADE. A BRIEF OUTLINE OF A TENTATIVE DESIGN PROCEDURE FOR SINGLE DEGREE OF FREEDON STRUCTURE-FOOTING SYSTEMS SUBJECTED TO GIVEN TRANSIENT LOADINGS AND CHARACTERIZED BY A NONLINEAR SOIL-RESISTANCE FUNCTION WAS DEVELOPED. IT IS RECOMMENDED THAT THIS OUTLINE BE EXPANDED INTO A DETAILED DESIGN PROCEDURE. /AUTHOR/

  • Supplemental Notes:
    • No 3-793, 280 PP, 70 FIG, 10 TAB, 13 REF, 4 APP
  • Authors:
    • Hadala, P F
    • Jackson, J G
  • Publication Date: 1967-8

Media Info

Subject/Index Terms

Filing Info

  • Accession Number: 00234297
  • Record Type: Publication
  • Files: TRIS
  • Created Date: Mar 18 1994 12:00AM