CONSTRUCTIONAL DEFORMATION IN ROCKFILL DAM (DISCUSSION)

IN A DISCUSSION OF THIS PAPER, THE STRESSES IN THE CORES OF ROCKFILL DAMS, PARTICULARLY WHERE THE POSSIBILITY OF HYDRAULIC FRACTURING EXISTS, IS REVIEWED IN DETAIL. THE DISCUSSER HAS DEVELOPED A TRAPEZOIDAL ELEMENT TO FIT SLOPING INTERFACES BETWEEN THE CORE AND ADJACENT ZONES OF A DAM. THIS ELEMENT ALSO EMPLOYS A LINEARLY VARYING STRAIN PATTERN AND, ALTHOUGH THE DEFORMATIONS ARE NON-CONFORMING ALONG THE SLOPING SIDES, FOR SOILS PROBLEMS IT APPEARS TO BE ACCURATE ENOUGH PROVIDING THE SLOPING SIDES DO NOT DEVIATE TOO FAR FROM THE VERTICAL. TO COMPARE SOLUTIONS USING DIFFERENT ELEMENTS IN A PROBLEM WHERE STEEP GRADIENTS AND NONUNIFORM STRAINS ARE PRESENT, A NARROW WEDGE UNDER A UNIFORM HORIZONTAL LOAD HAS BEEN ANALYZED. AN APPROXIMATE ANALYTICAL SOLUTION FOR THE HORIZONTAL DEFLECTION CONSIDERING BENDING AND SHEAR COMPONENTS HAS ALSO BEEN DEDUCED. FINITE ELEMENT SECTIONS OF THE WEDGE ANALYZED IN PLANE STRAIN USING THREE DIFFERENT GRIDS CONSISTING OF TRIANGLES BASED ON CONSTANT STRAIN, AND RECTANGLES AND TAPEZOIDS BASED ON LINEARLY VARYING STRAIN ARE SHOWN. STUDIES INDICATE THAT WHERE NONUNIFORM STRAIN CONDITIONS ARISE AND WHERE POISSON'S RATIO APPROACHES THE CRITICAL VALUE OF 0.5, THE USE OF TRIANGULAR ELEMENTS LEADS TO LARGE ERRORS. ELEMENTS WITH STIFFNESS MATRICES BASED ON LINEARLY VARYING STRAIN PATTERNS YIELD BETTER RESULTS, AND WHERE THE GEOMETRY OF THE PROBLEM PRECLUDES THE USE OF RECTANGLES, TRAPEZOIDS ARE USEFUL. COMBINATIONS OF TRIANGLES AND RECTANGLES COULD BE USED, BUT IF VERY THIN TRIANGLES ARE INCORPORATED, THE SOLUTION IN THE TRIANGLES WOULD DETERIORATE. IN SUCH CASES, TRAPEZOIDS ARE MORE DESIRABLE, SINCE THE STEEPER THE INCLINE FACES OF THE ELEMENT, THE LESS THE CONDITION OF COMPARIBILITY OF DEFLECTION BETWEEN ELEMENTS IS VIOLATED.

  • Authors:
    • PENMAN, A
    • Charles, A
    • Skermer, N A
  • Publication Date: 1973-8

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Filing Info

  • Accession Number: 00236719
  • Record Type: Publication
  • Report/Paper Numbers: Proc Paper
  • Files: TRIS
  • Created Date: May 24 1974 12:00AM