Construction method of middle-and-small-scale steel truss tied-arch bridge

Abstract

The invention provides a construction method of a middle-and-small-scale steel truss tied-arch bridge. The construction method comprises the steps that steel beams on the upper portion of a main bridge are installed from supporting points on the two side edges to the midspan; all components of a main structure of side spans are installed firstly, then steel truss arches of a middle span are installed, lifting levers are installed after midspans of the steel truss arches are combined, and finally middle span tie bars and a bridge deck system of the middle span are installed through a crane; hoisting towers are symmetrically installed in the positions, corresponding to the two ends of the middle span, of the ground, and the steel truss arches of the middle span are hoisted through the cooperative construction of the two hoisting towers; hoisting arms of the two hoisting towers can cover the whole construction area specific to the middle-and-small-scale steel truss tied-arch bridge, and construction is conducted on the two sides at the same time, so that the hoisting speed is increased, and application of other hoisting equipment is reduced; during the installation of steel truss arch cantilevers of the middle span, the capsizing moment at the cantilever ends are balanced by adopting a ballast counterweight mode on the side spans, and the effect that the anti-capsizing stabilizing coefficient is larger than 1.3 is guaranteed; and when a combined section of the middle span is installed, jacks are arranged through pier tops of side piers, the combination error is adjusted in the mode that caving is conducted through the side piers and main piers are fixed, and the effect that the combined section can be installed smoothly is guaranteed.

Description

technical field [0001] The invention relates to a construction method of a small and medium-sized steel truss tied arch bridge, which belongs to the technical field of bridge construction. Background technique [0002] At present, the installation and construction methods of domestic steel truss tied arch bridges all take the construction of large-scale steel truss arch bridges as the research object. Generally, the buckle back cables, temporary buttresses, the combination of buckle back cables and temporary buttresses are used, and the climbing crane is used to cooperate. Installation: For small and medium-sized steel truss tied arch bridges with a mid-span length of less than 160m, the above-mentioned construction method has many temporary structures on site, a large workload, high construction costs, high risks, and low construction efficiency. [0003] Considering the problem of overturning moment in the cantilever installation method, the existing steel truss tied arch ...

AI Technical Summary

Problems solved by technology

[0003] Considering the problem of overturning moment in the cantilever installation method, the existing steel truss tied arch bridge construction method installs hoisting equipment on the bridge deck within the coverage of the mid-span, and the entire bridge deck needs to be completed before the mid-span steel truss arch is hoisted. Since the later installation of the mid-span steel truss arch will seriously affect the structural strength of the bridge deck rod system, and even cause the bridge deck rod system to bend and deform, this method puts forward higher requirements for the installation of the bridge deck rod system; or The hoisting equipment is installed on the ground within the coverage of the mid-span. Since the mid-span is generally covered on the river or ravine, the difficulty and stability of the hoisting equipment are greatly increased.

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