ANALYSIS OF CONCRETE SLABS ON GROUND SUBJECTED TO WARPING AND MOVING LOADS

A THEORY HAS BEEN DEVELOPED WHEREBY STRESSES AND DEFLECTIONS COULD BE CALCULATED FOR A SERIES OF RECTANGULAR SLABS LYING ON A VISCOELASTIC FOUNDATION AND SUBJECTED TO A MOVING LOAD. THE STRESSES AND DEFLECTIONS ARE CAUSED BY THE WEIGHT OF THE SLAB, THE MOVING CONCENTRATED LOAD, AND THE LINEAR TEMPERATURE (OR MOISTURE) VARIATIONS THAT CAUSE SUFFICIENT WARPING SO THAT THE SLAB IS ONLY PARTIALLY SUPPORTED BY ITS FOUNDATION. THE SUPPORT CONDITIONS WERE SIMULATED BY A KELVIN VISCO-ELASTIC MODEL, AND ZONES (WHICH DEPENDED ON THE VALUE OF SUB-GRADE REACTION) WERE SET UP SO THAT THE SOLUTIONS TO THE GOVERNING DIFFERENTIAL EQUATIONS COULD BE REDUCED TO A SET OF SIMULTANEOUS ALGEBRAIC EQUATIONS. THE EQUATIONS WERE SOLVED WITH THE AID OF AN IBM 7090 DIGITAL COMPUTER USING A FORTRAN SOURCE PROGRAM. IT WAS FOUND THAT WHEN PARTIAL SUPPORT CAUSED BY WARPING EXISTS, THE TENSILE STRESS IN THE SLAB CAN INCREASE WITH INCREASING VELOCITY OF LOAD. MOREOVER, THE MAXIMUM DEFLECTION (DOWNWARD) NEED NOT OCCUR WHEN THE VELOCITY OF THE LOAD IS EQUAL TO ZERO. THE REDUCTION IN SUBGRADE SUPPORT OVER A NARROW REGION (8 FT. OR LESS) LEADS TO DEFLECTIONS AND STRESSES THAT ARE HIGHER THAN THOSE CALCULATED USING THE INITIAL VALUE OF SUBGRADE REACTION. THIS IS PARTICULARLY EVIDENT WHEN THE LOAD IS OVER THE REGION OF REDUCED SUBGRADE REACTION. /AUTHOR/

• Record URL:
  http://onlinepubs.trb.org/Onlinepubs/hrr/1969/291/291-017.pdf
• Supplemental Notes:
  • Paper sponsored by Committee on Theory of Pavement Design and presented at the 48th Annual Meeting.Distribution, posting, or copying of this PDF is strictly prohibited without written permission of the Transportation Research Board of the National Academy of Sciences. Unless otherwise indicated, all materials in this PDF are copyrighted by the National Academy of Sciences. Copyright © National Academy of Sciences. All rights reserved
• Authors:
  • LEWIS, K H
  • Harr, M E
• Publication Date: 1969

Media Info

• Media Type: Print
• Features: Figures; References; Tables;
• Pagination: pp 194-211
• Monograph Title: Design, evaluation, and performance of pavement systems
• Serial:
  • Highway Research Record
  • Issue Number: 291
  • Publisher: Highway Research Board

Subject/Index Terms

• TRT Terms: Coefficient of subgrade reaction; Computer programs; Deflection; Digital computers; Mathematical models; Motion; Motor vehicles; Slab on grade; Stresses; Theory; Viscoelasticity
• Identifier Terms: FORTRAN (Computer program language)
• Uncontrolled Terms: Moving vehicles
• Old TRIS Terms: Slab on ground construction
• Subject Areas: Highways; Pavements;

Filing Info

• Accession Number: 00207061
• Record Type: Publication
• Files: TRIS, TRB
• Created Date: Mar 9 1970 12:00AM