SKEW EFFECTS IN GIRDER BRIDGE DECKS

Abstract

Girder bridges have been found to eminently suit the small and medium span coverages both from the point of view of structural efficiency of the constituent members as well as ease of construction and economy. Girders monolithically interconnected through diaphragms and top-slab provide a general form of girder bridges which may span at right angle or some other inclination (skew) to the normal ( peipendicular) to the abutment. Over one third of the recently constructed short span bridges have been found to have significant skew .( A = 200). Bridges with skew angles up to 200 have traditionally been designed as right bridges presu-ming that such small skew angles do not materially alter the structural behaviour of the deck. This aspect is considered pertinent herein and hence has been chosen for some investigative study as to how small skew bridge decks behave structurally vis-a-vis the right deck. A part from this, another study has also been conducted to ascertain the nature of imposed load distribution (structural efficiency) amongst the girders as the top-slab material is progressively redistributed in the form of diaphragms (intermediate cross-beams).