A kind of deep water cofferdam construction method

Abstract

A deep-water cofferdam construction method, relating to the technical field of bridge construction, comprising the following steps: S1: building a drilling platform on the water surface, inserting and driving a steel casing, and constructing bored piles and auxiliary piles; S2: connecting high cofferdams for positioning The steel casing of the pile, and the lifting equipment is installed on the top of the steel casing; S3: the drilling platform is lifted to the top of the steel casing by the lifting equipment and fixed, and the drilling cycle construction is carried out for multiple cofferdam positioning piles; Install side plates and bulkheads of a certain height above the platform to form a cofferdam; S5: While connecting the high cofferdam side plates, lower the cofferdam, and always keep the top of the cofferdam above the water surface until the cofferdam is lowered to the bottom of the water. Start the cofferdam bottom sealing construction. In the construction method of the present invention, the drilling platform is directly used as a part of the cofferdam structure to carry out cofferdam construction, which saves construction costs and improves construction efficiency; when the cofferdam bottom is sealed, concrete is poured in different areas to ensure the bonding of the poured concrete force.

Description

technical field [0001] The invention relates to the technical field of bridge construction, in particular to a deep-water cofferdam construction method. Background technique [0002] At present, in the construction process of deep water cofferdams, the drilling platform is generally constructed first, and then the drilling platform is used to complete the construction of the bored piles, and then the drilling platform is removed, and then the construction of the cofferdam begins. During the construction of the cofferdam, due to the large drop in the surrounding water level, the back cover concrete is often required to be thicker. In actual construction, the concrete is often poured at one time to complete the back cover construction. During this process, the lifting system generally uses fine-rolled threaded steel bars to hang the cofferdam bottom keel. There are following three defects in the above-mentioned process: [0003] 1. The construction of the drilling platform a...

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Problems solved by technology

[0003] 1. The construction of the drilling platform and the cofferdam are completely separated. The steel after the drilling platform is removed cannot be fully utilized in the cofferdam construction, resulting in a lot of waste of steel. At the same time, the process of dismantling the drilling platform consumes more More manpower and material resources increase the construction cost

[0004] 2. In the process of back sealing, the supply speed of concrete is often not enough to meet the requirement of one-time pouring of the concrete back cover within the initial setting time, and often some concrete continues to be poured after the end of the initial setting until the back cover is completed; this will lead to the back cover concrete The displacement between the steel casing of the cofferdam increases and the cohesive force decreases, which may cause water leakage at the bottom of the cofferdam or even cause the cofferdam to float

[0005] 3. There are problems such as difficulty in lengthening, slow lifting speed, low strength and large consumption of fine-rolled threaded steel bars

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