Study On Construction Control For Arch Rib Hoisting Of Long Span Arch Bridge

Arch bridge, which has a long history, is widely used in bridge engineering because of its beautiful shape and advantageous stress properties. In recent years, the larger span becomes the development direction of arch bridge, which led to the structural system becomes complex, at the same time, the corresponding difficulty of construction is also improved. Although the arch bridge construction methods varied, non-bracket cable-stayed suspension is common construction method being used to install Long-span box arched bridges in recent years. The construction control for the hoisting of the rib of the long-span arch bridge is very important because of the construction difficulty of cable-stayed suspension method complexity mechanics mechanism of the oblique-draw-buckle-hanged system.Based on the Pu wan sea-crossing arch bridge, this article emulates the hoisting of the rib and study on the static behavior and stable performance of the tower by using FEA software: Midas civil 2013.The prolegomenon part summarizes the development of steel structure arch bridge and introduces several forms of modern steel arch bridge. It analysis the mechanical characteristics of the half-through tie arch-bridge. The method and content of the construction control for the hoisting of the rib is also discussed in this paper.Based on the setting theory of fabrication camber, the fabrication camber of the arch bridge is calculated by combining the forward-calculation method and back-running method. Using the camber of the key nodes of the arch rib, the camber of the rest of the entire arch rib is obtained by polynomial fitting.Calculating the cable force and construction cambers of the arch rib is the key to the construction. In this paper,several calculation methods of cable force are divided into analytical method and numerical method. On the basis of previous studies, this paper adopts a kind of cable force calculation method,which is subjected to control objective based on bare arch alignments. The arch rib pre camber calculation error and the unreasonable deformation problem after the arch rib closure are solved reasonably because of the construction camber which is only set up for the closure segment.In this paper, the whole construction process of arch rib hoisting is simulated, and the simplified calculation method of the buckle tower and pile foundation is given. Two different kinds of bare arch alignments, which are respectively obtained by cable-stayed suspension method and floor support method, are compared and analyzed. In view of the problem of system transformation in the process of hoisting of the rib, two different methods are used to simulate the temporary hinge of arch rib in this paper. According to the actual situation, the monitoring scheme of the hoisting of the rib of Pu Wan arch bridge is established, and the source of the error in the hoisting process of arch rib is analyzed.The static performance of the tower and the calculation method of wind load on the tower are analyzed in this paper. Based on the research theory of the two kinds of stability problems, local stability and overall stability of the temporary tower are calculated in this article. In the construction process, the influence of wind cable on the tower during the construction is also s studied in this paper.