Construction and Load Tests of a Segmental Precast Box Girder Bridge Model.

摘要

The cantilever construction of the first segmental precast prestressed concrete box girder bridge in the United States has been recently completed on the John F. Kennedy Memorial Causeway,Corpus Christi,Texas. The segments were precast,transported to the site,and erected by the balanced cantilever method of post-tensioned construction,using epoxy resin as a jointing material. In order to check the applicability and accuracy of the design criteria,analytical methods,construction techniques,and the shear performance of the epoxy joints,an accurate one-sixth scale model of the three-span continuous bridge was built at the Civil Engineering Structures Research Laboratory of The University of Texas Balcones Research Center. This report documents the construction and load testing of the bridge. Experimental results are compared with analytical values for the various stages of construction,service loadings,ultimate proof loadings,and final failure tests. During the cantilever construction and under service level loadings after completion,experimental results generally agreed with the computerized theoretical analyses. Because of the general absence of warping, a beam theory analysis reasonably predicted behavior of the bridge during the cantilever construction and under uniform service level loading. However, a folded plate theory analysis was required to predict distribution for nonuniform loadings and transverse moment distribution for wheel loadings. Ultimate load theories correctly indicated the load capacity of the structure when all loading and structural configurations were considered.