SHEARING STRESSES AND SURFACE DEFLECTIONS DUE TO TRAPEZOIDAL LOADS
THE STRESSES AND SURFACE DEFLECTIONS OF A SEMI-INFINITE ELASTIC MEDIUM AND OF AN ELASTIC LAYER OF FINITE DEPTH ARE OBTAINED BY THE PRINCIPLE OF SUPERPOSITION. WHEN THESE EFFECTS ARE KNOWN FOR A CONCENTRATED SURFACE LOAD, THE CORRESPONDING RESULTS FOR DISTRIBUTED OR CONTINUOUS SURFACE LOADS MAY BE OBTAINED BY SUMMATION OR INTEGRATION METHODS. IN THE FIRST PART ALL THE STRESSES IN THE SUPPORTING MEDIUM ARE DETERMINED FOR SURFACE LOADS WHICH SIMULATE TRIANGULAR, SYMMETRICAL, AND UNSYMMETRICAL TRAPEZOIDAL SURFACE LOADS DUE TO ROAD FILLS, TOGETHER WITH THE MAXIMUM SHEARING STRESSES UNDER SUCH LOADS. IN PARTICULAR IT IS SHOWN THAT THE DEPTH AT WHICH THIS MAXIMUM SHEAR OCCURS UNDER A SYMMETRICAL TRAPEZOIDAL FILL IS AT A DEPTH APPROXIMATELY EQUAL TO ONE-HALF OF AN EQUIVALENT RECTANGULAR LOAD OF EQUAL INTENSITY. THIS MAXIMUM SHEAR VALUE DOES NOT EXCEED 0.318 P WHERE P IS THE MAXIMUM INTENSITY OF THE SURFACE LOADING. IN THE SECOND PART SUPERPOSITION METHODS ARE EMPLOYED TO DETERMINE THE STRESSES AND SURFACE DEFLECTION OF A FINITE ELASTIC LAYER SUPPORTED BY A ROUGH RIGID BASE, AND BEARING A TRAPEZOIDAL SURFACE LOAD. IT IS KNOWN THAT THE STRESSES ARE NO LONGER INDEPENDENT OF POISSON'S RATIO NU, AND THAT SHEARING FAILURE OCCURS WITHIN THE LAYER BEFORE IT OCCURS AT THE SUPPORTING BASE. THE SURFACE DEFLECTIONS ARE EVALUATED (USING NU=0.25) FOR SEVERAL TYPES OF SURFACE LOADING AND VARYING DEPTHS OF THE ELASTIC LAYER. IT IS ALSO SHOWN THAT THE RESULTS OF THE FIRST PART OF THE PAPER CAN BE DERIVED AS A LIMITING CASE BY ALLOWING THE DEPTH OF THE LAYER TO BECOME INFINITE. IT IS RECOGNIZED THAT THESE SOLUTIONS FURNISH BASIC PICTURES, DEPARTURES FROM WHICH IN THE IMPERFECTLY ELASTIC MATERIAL MUST BE EXAMINED AND JUDGED BY EXPERIMENTAL PROGRESS. /AUTHOR/
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Supplemental Notes:
- Vol 19, pp 409-423, 14 FIG, 2 TAB. 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.
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Authors:
- Holl, D L
- Palmer, L A
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Discussers:
- Terzaghi, K
- Publication Date: 1940
Media Info
- Media Type: Digital/other
- Monograph Title: Proceedings of the Nineteenth Annual Meeting of the Highway Research Board Held at Washington, D.C. December 5-8, 1939
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Serial:
- Highway Research Board Proceedings
- Volume: 19
- Publisher: Highway Research Board
Subject/Index Terms
- TRT Terms: Deflection; Elastic bodies; Elasticity (Mechanics); Pavement layers; Shear stress; Stresses
- Old TRIS Terms: Elastic solids; Elastic theory
- Subject Areas: Geotechnology; Highways; Pavements;
Filing Info
- Accession Number: 00207266
- Record Type: Publication
- Files: TRIS, TRB
- Created Date: Oct 3 1971 12:00AM