Three-truss main girder structure of highway and railway bi-purpose cable-stayed bridge and installation method thereof

Abstract

The invention relates to a three-truss main girder structure of a highway and railway bi-purpose cable-stayed bridge and an installation method thereof, relating to the technologies of designing and constructing a heavy load and long span highway and railway bi-purpose cable-stayed bridge. The structure of three main trusses comprises a middle truss piece and side truss pieces arranged on both sides of the middle truss piece, wherein an orthotropic slab and a transverse bracing truss are arranged between the upper edges of the middle truss piece and each side truss piece, and a railroad transverse girder, a railroad longitudinal girder and a horizontal bracing cross bridging are arranged between the lower edges of the middle truss piece and each side truss piece; and the invention provides the installation method adopting adaptive pre-splicing of multiple truss-sections, arrangement of temporary constructional rod pieces, integral lifting of each truss section and multi-node simultaneous alignment. The invention has the beneficial effects of: 1. pushing the highway and railway bi-purpose cable-stayed bridge to develop towards the direction of large span and heavy loading, 2. improving the installation efficiency and quality, 3. reducing the quantity of welding lines of construction sites, 4. innovatively practicing the multi-point simultaneous butt joint technology, 5. adopting the temporary rod pieces for solving the problems of unstability and large deformation in the processes of delivering and lifting the truss sections, 6. strengthening the adaptability of adjacent truss sections, and 7. solving the problems of inconsistent deformation of the middle and the side trusses and inconsistent centre-of-gravity positions of the truss sections.

Description

technical field [0001] The invention relates to the design and construction technology of a heavy-duty, long-span road-rail dual-purpose cable-stayed bridge, in particular to a three-truss main girder structure of a road-rail dual-purpose cable-stayed bridge and an installation method thereof. Background technique [0002] Road-rail dual-purpose bridge refers to the bridge that arranges railway traffic and road traffic at the same time. Because the dual-purpose bridge can effectively save resources, it has been used more and more. The steel truss bridge is convenient for arranging double-deck decks, so that road transportation and railway transportation can be separated, and it is the first choice for road-rail dual-purpose bridges. Cable-stayed bridges have greater spanning capacity than simply supported girder bridges and continuous girder bridges. Cable-stayed bridges with steel truss girders as the main girder are the development direction of long-span road-rail bridges...

AI Technical Summary

Problems solved by technology

[0004] 1) The installation speed is slow, and the installation is lifted one by one, and the operation cannot be synchronized, and the efficiency is low;

[0005] 2) The welding workload on the construction site is heavy, and the bridge deck and the main truss are connected by weld seam. Due to the limitation of operating conditions, the quality of the weld seam is difficult to control, and the shrinkage of the weld seam has a great influence on the alignment and internal force distribution of the bridge

[0013] 4) Under the action of self-weight load, the deformation of the middle girders and the girders on both sides of the girders is inconsistent, and the deformation of the middle girders is larger, resulting in the deviation between the positions of the girders to be installed and the installed main girders, and the smooth docking. The crane must have The ability to adjust the elevation of each girder individually;

[0014] 5) When the truss section is installed, it is multi-point synchronous docking. The difficulty of synchronously inserting each member into the gusset plate and synchronously positioning it in place is greatly increased. The butt joint process is easy to be blocked, stuck, and scratch the friction surface at the node

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