Keogh, D.L.

Thumbnail Image
Preferred name
Keogh, D.L.
Official Name
Keogh, D.L.

Research Output

Filters

3
3
Reset filters

Settings

Now showing 1 - 3 of 3
  • Publication
    Upstand Finite Element Analysis of Slab Bridges
    (Elsevier, 1998-12)
    O'Brien, Eugene J. 
    ;
    Keogh, D.L. 
    For slab bridge decks with wide transverse edge cantilevers, the plane grillage analogy is shown to be an inaccurate method of linear elastic analysis due to variations in the vertical position of the neutral axis. The upstand grillage analogy is also shown to give inaccurate results, this time due to inappropriate modelling of in-plane distortions. An alternative method, known as upstand finite element analysis, is proposed which is sufficiently simple to be used on an everyday basis in the design office. The method is shown to give much better agreement than the others when compared with an elaborate three-dimensional solid finite element model. Single- and two-span bridge decks with solid and voided sections are considered for both longitudinal and transverse bending stresses.
      1215Scopus© Citations 14
  • Publication
    Recommendations on The Use of a 3-D Grillage Model for Bridge Deck Analysis
    (Elsevier Science, 1996)
    Keogh, D.L. 
    ;
    O'Brien, Eugene J. 
    This paper highlights areas of inaccuracy in current modelling techniques for bridge decks with wide cantilevers. A 3-D grilllage model known as the upstand grillage is assessed by comparing its behaviour with that of a three-dimensional, finite-element model. Recommendation are made for the implementation of such a technique. The paper concludes with a comparison of results from analyses of a bridge deck using the standard and upstand grillage analogies and a three-dimensional finite-element method.
      649
  • Publication
    Simplified Elastic Model for Restraining Effects of Backfill Soil on Integral bridges
    (Elsevier, 1999-10)
    Lehane, Barry M. 
    ;
    Keogh, D.L. 
    ;
    O'Brien, Eugene J. 
    This paper presents the formulation of a simple method for the prediction of the additional stresses induced in frame type integral bridges due to thermal expansion of the deck. These stresses are controlled to a large extent by the restraint provided to the deck by the backfill soil adjacent to the abutments. The first part of the paper develops a realistic means of assessing appropriate equivalent elastic stiffness values for the backfill using results from recent high quality laboratory soil testing. A boundary element type approach is then used to derive approximate general expressions, written in terms of the soil stiffness and the flexural rigidity of the abutment, for the lateral and rotational restraint provided by both the abutment and soil. These expressions are subsequently manipulated into a form that enables designers to make use of standard frame analysis computer programs for the prediction of thermal expansion effects. The proposed method is shown to compare well with predictions obtained using a finite element model of the soil and structure.
      1417Scopus© Citations 20