BEHAVIOR OF ONTARIO-TYPE BRIDGE DECK ON STEEL GIRDERS (ARCHING ACTION, COMPRESSIVE-MEMBRANE ACTION, PRECAST PANEL).

摘要

An experimental and analytical investigation was conducted regarding the behavior of reinforced concrete bridge decks designed in accordance with the Ontario Highway Bridge Deck Design Code.;The bridge was first loaded at four points statically to 60 kips per ram to study its response under service and overload conditions. It was then subjected to sinusoidal fatigue loading to a maximum of 26 kips per ram. During the fatigue cycling, the bridge was tested statically at intervals of about 1 million cycles to assess possible deterioration of the deck due to fatigue. After 5 million cycles of fatigue loading, the bridge was loaded statically to a maximum of 40 kips per ram to study its behavior after fatigue cracking.;To check to experimental results and permit their extension to bridge decks other than the one studied experimentally, two finite element models were developed using SAPIV to model the two types of bridge deck. Analytical prediction and experimental results agreed closely.;The bridge deck performed satisfactorily under current AASHTO design load levels and overload conditions, with respect to overall observed behavior, local stiffness of the deck at the loaded point, crack widths, local stresses, and bending moments in the deck. Fatigue loading did not significantly change the behavior of the deck under service load nor under overloads. Compressive membrane forces did not significantly affect the performance of the bridge at loads below cracking.;In the experimental part of the investigation, a 20- by 50- ft full-scale composite bridge (concrete deck on steel beams) was built and tested in the Ferguson Structural Engineering Laboratory of The University of Texas at Austin. Half of the bridge deck was cast-in-place topping, the other half was precast prestressed panel.