Deep-water foundation construction method for large-span continuous beam adjacent to existing railway line

Abstract

The invention discloses a deep-water foundation construction method for a large-span continuous beam adjacent to an existing railway line. A deep-water foundation for construction comprises an underwater abutment and a plurality of drilled piles, wherein the underwater abutment is positioned on an underwater base rock on one side of the existing operating railway line, and the drilled piles are used for supporting the underwater abutment. The deep-water foundation construction method includes the steps: firstly, excavating an underwater foundation pit mounted at the bottom of a cofferdam by setting up an excavation platform, mounting an impact drill, moving the excavation platform and performing first impact, synchronous slag removal, second impact and synchronous slag removal; secondly, constructing the drilled piles and the underwater abutment by surveying and setting out, lowering a cofferdam, mounting a steel casing, sealing the bottom of the cofferdam, constructing the drilled piles, drawing water in the cofferdam, cutting off the steel casing and constructing the abutment. The steps are simple, the method is reasonable in design, simple and convenient in construction, good in use effect, safe and reliable in construction process and less in external influence, and the deep-water foundation construction process can be simply, conveniently and rapidly finished.

Description

technical field [0001] The invention belongs to the technical field of bridge construction, and in particular relates to a deep-water foundation construction method of a long-span continuous beam adjacent to an existing line. Background technique [0002] At present, my country's railway bridge construction is in a period of rapid development. The use of advanced design and construction technology to achieve the goal of saving investment, shortening the construction period and ensuring safety has always been the result pursued by the engineering community. Among them, in the construction of long-span and deep-water bridges, the design theory, construction technology and equipment have reached or approached the world's advanced level. For example, in the continuous girder construction of the new second-line new Yongjiang Bridge in Nanning Railway Hub, the main span of the bridge reaches 168m, which is the largest span among single-line railway bridges in China. The construct...

AI Technical Summary

Problems solved by technology

When the underwater blasting method is used to excavate the underwater foundation pit of the above-mentioned deep-water foundation of the bridge near the existing line, since the Yongjiang River is currently a Class III navigable channel, and the excavated foundation pit is relatively close to the existing bridge, if the underwater foundation pit is selected For excavation by blasting method, firstly, it is necessary to temporarily block the waterway, and secondly, it is necessary to go through the construction procedures near the existing line, and carry out blasting operations in the "blockade point". At the same time, it is also necessary to consider the impact of blasting on existing bridges, and the The selection of post-slag cleaning equipment requires a large cost investment, and more importantly, the construction procedures are very complicated

However, at present, when using the mechanical crushing method to excavate the underwater foundation pit of the bridge deep water foundation near the existing line, there is no unified, standard and standardized construction method to follow. During the construction process, the construction operation is inevitably relatively random, Problems such as low construction efficiency and poor construction effect

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