Bracket Cast-in-place Cable-stayed Bridge Construction Monitoring Technology

Larger span, more various types and construction methods of the cable-stayed bridges, has brought some new subjects to construction control. Cantilever placing cast method and cantilever placing installation method are often used in the cable-stayed bridge construction. In some special cases, such as the span of the bridge is not very large, the head room under the bridge is not very high and the bed river of the bridge is more gentle, the construction by the supports with fully paved steel tubes is also a good method considering the factors of manufacturing cost and the degree of difficulty of construction. Dezhou Chahe Bridge is an example.Some issues in the process of construction and the manners to solve these issues was analyzed in this paper. On the base of generalization of the existing experiences of construction control of the cable-stayed bridge, the construction control principle and method was put forward according the Chahe Bridge, that is take deformation, strain and cable tension as the measuring of "Three factors", take "two times stretch" for cable as control method of cable force and design corresponding construction procedure according to the specific requirements of each construction stage. Plane finite element fundamental analysis about establishing model of construction emulating calculation was introduced and some problems about construction control calculation was discussed. Besides, each construction stage of the bridge by making use of the model is analyzed and checking calculated in this paper. At the same time, the necessity and feasibility of "two times stretch" was approved. Finally, taking the Chahe Bridge as an example, the influence of the beam stress, elevation and cable tension caused by some important factors was analyzed and the main contents and manners of analyzing and identifying the sensibility of parameters was discussed in this paper.The research of the construction control of the cable-stayed bridge constructed by the supports with fully paved steel tubes not only improves theory and technical level of cable-stayed bridge construction control, but also solves difficult issues of the construction of the cable-stayed bridge constructed by the supports with fully paved steel tubes, and it also offers valuable experience for similar bridge construction in future.