Print ISSN: 1681-6900

Online ISSN: 2412-0758

Keywords : orthotropic


Evaluation of Elastic Deflections and Bending Moments for Orthotropically Reinforced Concrete Rectangular slabs Supported on Three Edges Only

Hisham M. AL-Hassani; Husain M. Husain; Aama; a Ali Ahmad

Engineering and Technology Journal, 2009, Volume 27, Issue 7, Pages 1247-1259

This paper deals with the evaluation of the elastic deflections and bending moments
for orthotropically reinforced concrete rectangular slabs supported on three variously
restrained edges with the fourth edge free and subjected to uniformly distributed load.
Six cases are considered for such slabs to cover all possible restraining conditions at the
three supported edges. Based on the finite difference approach, equations are derived to
calculate the maximum values of the positive and negative bending moments as well as
the maximum deflection in any of these six slab cases caused by the applied uniform
load.

Experimental Tests on Orthotropically RC Rectangular Slabs Having Various Restrained Edges and Subjected to Uniform Load

Husain M. Husain; Hisham M.AL-Hassani; Sarmad S. Abdul-Qader AL-Badri

Engineering and Technology Journal, 2009, Volume 27, Issue 5, Pages 913-929

In this research, nine orthotropically reinforced concrete (RC) rectangular slabs
having various boundary restraints at the edges are tested under uniformly distributed
load. The main aim of these tests is to show that when some or all edges of a slab are
restrained against rotation and horizontal translation the ultimate load carrying capacity
of the slab will be enhanced greatly above that suggested by the simple Johansen ,s yield
line theory(1). For this purpose, a specially designed rig is constructed and used for
providing slabs with various boundary restraints along their edges.
The results of tests, which are presented in the form of load-deflection curves plotted
non-dimensionally, show that for restrained slabs the enhancement in load above
Johansen ,s load ranges between 50% and 100% depending on the number and positions
of the slab restrained edges. These results are also used to examine the accuracy of a
recently submitted elastic-plastic theoretical model(2).

Analysis of Composite Bridge Superstructures Using Modified Grillage Method

Sabeeh Z. Al-Sarraf; Ammar A. Ali; Rana A. Al-Dujaili

Engineering and Technology Journal, 2009, Volume 27, Issue 5, Pages 942-953

The analysis principle was used to analyze anisotropic plates (having different
elastic properties and geometries in different directions), the model consists of four side
beams with flexural rigidity and torsional rigidity and two diagonal beams with only flexural
rigidity .
The substitute grid framework is analyzed to give the same deformations and
deflections of the orthotropic plate elements of the modeled bridge. Applicability of the
suggested procedure in the analysis of actual bridge decks is investigated using STAAD
Pro.2006 program. The results show that the suggested procedure is an acceptable procedure
which can be adopted to analyze this type of bridge deck. It is found that the modified
grillage method gives simpler method and adequate results when compared with the Finite
Element Method or orthotropic plate theory solved using Finite Difference Method for this
type of bridges.