Effect of Construction Loads and Vibrations on New Concrete Bridge Decks

This paper presents an investigation on the effects of construction loads and vibrations on typical newly poured reinforced concrete bridge decks. The main objective of this paper was to perform dynamic finite-element analyses of concrete bridge decks under construction loads and vibrations. Two types of bridges were modeled by effectively simulating the loads encountered during construction. Separate analyses were performed to simulate one truck as well as two side-by-side trucks. Additional analyses were performed to simulate the loads during construction and pouring sequence. The loads imposed by concrete mixer trucks, including the full concrete load and the load imposed by a trailer unit carrying the pump, were taken into consideration during the modeling of the bridges. The results obtained consisted of vibration modes and frequencies for each structure in addition to top and bottom stresses in each principal direction. A separate analysis was performed that took into account the sequence of pour to determine the effect of moving loads from adjacent traffic and construction loads on fresh concrete. The time history and dynamic analysis indicated that the sequence of pour has a significant effect on the deformation of the concrete at early ages. As a result, the first three mode shapes obtained by the finite-element analysis will be used to optimize sensor locations for future dynamic field testing.