Investigation of Closure Pour Elimination for Phased Construction of Steel Girder Bridges.

摘要

Phased construction is a common practice used by State DOTs during the replacement of a bridge. This method allows for the traffic flow to be maintained on half of the bridge while a new deck is constructed on the other half. For steel girder bridges there is often an issue with differential elevation between the phases. This difference in elevation often prevents the second half of the deck from being poured in one step. Instead, a portion of the second half of the deck is poured and then a third phase, closure pour is used to connect the first two poured slabs. This closure pour can significantly extend the construction time and increase the cost of the deck. The enclosed investigation assesses the deflection of a phased constructed steel girder bridge in Bellevue, Nebraska. The camber and deflection data, of the phases, from the design specs was compared to a numerical model and tilt sensor readings. The finite element model was analyzed the CSI Bridge structural analysis software. The numerical results were on trend with the design specs, although the values were slightly larger. Therefore, calibration is needed for the finite element model. Six weeks of daily deflection data was captured by the EL-tilt sensor. However, due to several issues the further data mining is required before comparisons can be made to the design plans and numerical results.