Excavation construction method for underwater foundation pits of deep water foundation adjacent to existing line large-span continuous beam

Abstract

The invention discloses an excavation construction method for underwater foundation pits of a deep water foundation adjacent to an existing line large-span continuous beam. The excavation construction method comprises the following steps: I, erecting an excavation platform which comprises an assembly type floating body and a floating body position regulating device; II, mounting impact drilling machines: mounting the plurality of impact drilling machines on the excavation platform, wherein the plurality of the impact drilling machines form impact crushing equipment; III, moving the excavation platform; IV, impacting for a first time and synchronously removing slag: carrying out impact crushing on integral underwater base rocks in a construction area where an underwater abutment lies and moving away rock blocks by adopting a long-arm excavator; and V, impacting for a second time and synchronously removing slag: carrying out impact crushing on underwater rocks at bottom mounting positions of a cofferdam, and moving away rock blocks by adopting the long-arm excavator. The excavation construction method disclosed by the invention is simple in step, is reasonable in design, is simple and convenient to construct, is good in using effect, and can simply, quickly and quickly complete an excavation construction process for the underwater foundation pits of the deep water foundation; and the excavation construction process is safe and reliable, and has relatively small influences on the outside world.

Description

technical field [0001] The invention belongs to the technical field of bridge construction, and in particular relates to an underwater foundation pit excavation construction method for a deep-water foundation adjacent to an existing line with a large-span continuous beam. 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 singl...

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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