Method of Constructing Variable-height Steel Beams Using Lifting and Pushing Brackets

Abstract

The invention discloses a method of constructing a variable height steel girder by using a lifting and pushing support. The method comprises the following steps of: step 1. prefabricating a steel girder; step 2. installing a lifting and pushing support on piers, and meanwhile erecting an assembly platform; step 3. splicing a steel nose girder and the first segment of steel girder on the assembly platform, then connecting I-shaped steel to the top flanges of the steel girder and the steel nose girder by screws, arranging the I-shaped steel in a steel channel slideway of the lifting and pushing support, realizing the periodic lifting and pushing of the steel girder through the alternative matching of a fixed lifting machine and a movable lifting machine, thereby enabling the steel girder to continuously advance; step 4. before the steel nose girder reaches the third pier, assembling the next segment of steel girder at the tail of the upper segment of steel girder, and continuously lifting and pushing the steel girder according to the method of the step 3; step 5. repeating the step 4 until completing the erection of the integrated bridge; and step 6. dismantling the steel nose girder, the assembly platform and the lifting and pushing support, thereby completing the construction of the steel girder. The method can simplify the construction of the variable height steel girder, shortens the construction period and reduces the construction cost.

Description

technical field [0001] The invention relates to the technical field of steel girder construction, in particular to a method for constructing variable-height steel girders by using lifting and pushing brackets. Background technique [0002] At present, steel beams are erected mainly through the cantilever assembly construction method, the whole hole frame method, and the jacking construction method in China. Each method has its own characteristics and scope of application. The more common one is the jacking process, but it is applied to variable When the height of the beam is high, the construction process is more cumbersome. The specific construction steps are as follows: ①Prefabricated steel beams in the factory; ②Transport to the construction site and assemble them on the brackets. After assembling a segment, push them up. The cantilever outrigger adjusts the elevation of the jacking equipment in real time, or adjusts the elevation of the beam bottom by manually increasin...

AI Technical Summary

Problems solved by technology

This construction method has the following disadvantages: 1. The heavy segmental steel girders are greatly affected by the terrain conditions, and the hoisting and transportation of the steel girders cannot be carried out on the construction site where the water and land alternate and the elevation changes greatly; 2. The construction of the jacking process The steel girders need to use thicker steel plates or need to add stiffeners, which increases the total amount of steel girders and project cost, and the economy is poor; device and vertical elevation adjustment device, it is difficult to ensure the elevation of the beam body and reduce the construction efficiency, and at the same time it cannot meet the technical requirements of the bridge; 4. Adjust the beam by manually increasing or decreasing the steel backing plate or placing a jack Bottom elevation, this method is cumbersome to operate, low in precision, slow in construction speed, varies in height, and low in reuse rate of steel plates; 5. The traditional construction method has the problem of local instability at the push point or bottom support point

[0003] It can be seen that the construction of variable cross-section steel-concrete composite girder bridges using the jacking method has technical problems such as complex on-site operation procedures, low construction safety factor, discontinuous construction, and the need for auxiliary processes, which affects the promotion of variable cross-section steel-concrete composite girder bridges. application

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