Control of Self-Adaptive Unstressed Configuration for Incrementally Launched Girder Bridges

Abstract

Abstract The configuration of the main girder not only affects the appearance of the bridge, but also directly relates to the mechanical performance of the bridge, which is one of the key objectives for construction control. This paper presents a new geometric-control method (the phase-transformation method) of the self-adaptive unstressed configuration for incrementally launched girder bridges. The phase change of the prefabricated girder (i.e., the relative change of the in-plane horizontal angle and displacement) and the geometric deviation of the assembled segment in the assembly platform are considered in the procedure. First, some basic concepts of the key control parameters are introduced, such as the theoretically unstressed configuration, the reference phase, and the current phase. Next, the coordinate transformations under both the reference and instantaneous phase are derived based on the translation and rotation of the girder's rigid motions. In order to gradually adjust the errors of the unst...