The structure and construction technology of super large cofferdam based on marine environment

Abstract

The invention discloses a construction process of a super-large cofferdam based on marine environment, which is characterized in that the cofferdam uses a sand washing film bag and a trapezoidal section structure. The width of the top of the cofferdam is about 15 meters, graded slope setting is carried out according to the height, and the slope of a upstream face is 1:3-1:4, the slope of a downstream face is 1:4, a steel plate pile water stop curtain is arranged on the top of the cofferdam, and a steel plate pile water stop curtain is arranged on the slope foot of the downstream face. The sandwashing film bag and the steel plate pile are combined in the process, and the process has the advantages that: the construction speed is fast, and the construction period can be shortened; the stability and durability are good, washing and flood can be resistant; due to the addition of the steel plate pile water stop curtain, the steel plate pile water stop curtain has higher rigidity and betteranti-seepage performance, and can achieve a good water-blocking effect; meanwhile, the cofferdam is convenient and fast to disassemble; and the steel plate pile can be used in a turnover way, so thatthe construction cost is reduced. The construction process of the super-large cofferdam based on the marine environment can provide reference basis and experience guidance for similar projects such as a water tunnel, a wharf cofferdam, a river-crossing bridge and the like.

Description

technical field [0001] The invention relates to a cofferdam construction technology, in particular to a super large cofferdam construction technology based on the marine environment. Background technique [0002] At present, tunnels in the marine environment are generally constructed using the shield method, shallow buried and underground excavation method, immersed tube method, and open cut method. Among them, the open-cut cofferdam can also adopt earth-rock cofferdam, soil bag cofferdam, steel sheet pile cofferdam, reinforced concrete sheet pile cofferdam, steel casing cofferdam, etc. [0003] The shield tunneling method, shallow buried underground excavation method, immersed tube method, etc. have a long construction period and a small working surface; they cannot be segmented and constructed at the same time. Earth-rock cofferdams and soil bag cofferdams for open-cut tunnels have poor waterproof and seepage effects. Steel sheet pile cofferdams for open-cut tunnels have...

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Problems solved by technology

[0004] The geology of the tunnel in the marine environment is generally silty silty clay, medium-coarse sand layer within 1-17 meters below the seabed, and the fully weathered and strongly weathered granite layer is distributed below the silty clay, and the geological structure is relatively complex; Typhoons are frequent in the construction environment, floods are prone to occur due to typhoons, and the cofferdam is also a place vulnerable to typhoons; the water depth in the construction area is very deep, and the underwater environment is very complicated and difficult to control

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