The Orthotropic Spline Finite Strip Technique in the Linear Analysis of Ribbed Bridge Decks

  • Laith Khalid Al-hadithy Asst. Prof. Dr. Civil Engrng. Dpt. /Al-Nahrain University, Baghdad, Iraq
  • Imad Abdulwahid ali State Company for Grain Board, Baghdad, Iraq
Keywords: Spline Finite Strip Method (SFSM), Geometrical Orthotropy, Ribbed Bridge Decks, Plate-Bending action, B3-Spline Function.


This study presents an efficient simplification on the utility of the spline finite strip method SFSM in the analysis of orthotropic and ribbed bridge decks by conducting two stages of analogy. The actual ribbed bridge deck (practically subjected to combined plate-bending and plane stress actions) is, first, converted into and equivalent orthotropic plate, which is subsequently divided into orthotropic finite strips submitted to plate-bending action only with the use of B3-spline function to express the displacement function in the longitudinal direction of strips. A programming code using MATLAB computer package is constructed for the analysis of orthotropic plates by the spline finite strip method, where the fewest admissible number of longitudinal sections and local B3-spline functions has been employed to check its efficiency. When applied to a ribbed RC bridge deck of four transverse diaphragms, the present orthotropic spline finite strip technique has proved its reliability in the analysis of such decking system where very high degrees of coincidence of its results with those of the finely meshed sophisticated finite element method attaining 98.4, 86.9 and 95.6 for midspan deflection and longitudinal and transvers bending moments, respectively, have been obtained.


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