PERFORMANCE OF SOILS UNDER TRACK LOADS REPT 2

A FIRST-GENERATION, QUANTITATIVE DESCRIPTION OF STRAIGHT-LINE TRACK PULL PERFORMANCE IN A DESERT SAND WAS SOUGHT BY LABORATORY TESTS OF A MODEL TRACK. OF 16 VARIABLES SELECTED TO PROVIDE A COMPREHENSIVE DESCRIPTION OF THE TRACK-SAND SYSTEM, ANALYSIS OF THREE PLACKETT-BURMAN (STATISTICAL) TEST DESIGNS SHOWED FOUR TO MERIT INITIAL STUDY--SOIL STRENGTH G, TRACK WIDTH B, TRACK CONTACT LENGTH L, AND LOAD W. PRINCIPLES OF SIMILITUDE WERE USED TO DEVELOP THREE DIMENSIONLESS, INDEPENDENT TERMS--P SUB 20/W, B/L, AND G(L CUBED)/W--TO EXPRESS THE FUNCTIONAL RELATION AMONG THESE VARIABLES AND P SUB 20 (PULL AT 20 PERCENT SLIP, I.E. NEAR-MAXIMUM PULL). DATA ANALYSIS DEMONSTRATED THAT THE LAST TWO TERMS CAN BE COMBINED TO G (BL) EXP 1.5/W. A SIMPLE LINEAR REGRESSION DETERMINED THE LEAST-SQUARES FIT OF P SUB 20/W TO LOG (G (BL) EXP 1.5/W) AS P SUB 20/W EQUALS O.204482 PLUS 0.161470 LOG (G (BL) EXP 1.5/W). VALUES OF A SUB 0 AND A SUB 1 IN P SUB 20/W EQUALS A SUB 0 PLUS A SUB 1 LOG (G (BL) EXP 1.5/W) WERE RELATIVELY STABLE IN REGRESSION OF DATA SUBGROUPS SEPARATED BY THE LEVELS AT WHICH G. B, L, AND W WERE TESTED. THE EQUATION FROM A MULTIPLE LINEAR REGRESSION OF P SUB 20/W ON LOG G, LOG V, LOG L, LOG W DID NOT DESCRIBE THE TEST DATA SIGNIFICANTLY BETTER THAN DID THE SIMPLE LINEAR REGRESSION. FROM EQUATION P SUB 20/W EQUALS A SUB 0 PLUS A SUB 1 LOG (G (BL) EXP 1.5W). EXPRESSIONS WERE OBTAINED FOR P SUB 20, W, AND P SUB 20/W IN TERMS OF A SUB 0, A SUB 1, K, AND E, WHERE K EQUALS G (BL) EXP 1.5, FOR TWO PERFORMANCE LEVELS OF PARTICULAR INTEREST, THE MAXIMUM-PULL AND ZERO-PULL CONDITIONS. /AUTHOR/

  • Supplemental Notes:
    • RPT NO TR M-71-5 1 APP
  • Authors:
    • Turnage, G W
  • Publication Date: 1971-11

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Filing Info

  • Accession Number: 00236676
  • Record Type: Publication
  • Report/Paper Numbers: Tech Rept
  • Files: TRIS
  • Created Date: Jun 5 1974 12:00AM