Construction method for double-wall steel cofferdam without bottom sealing concrete in deepwater bare rock geology

Abstract

The invention discloses a construction method for a double-wall steel cofferdam without bottom sealing concrete in deepwater bare rock geology. The construction method comprises the following steps that the prefabricated steel cofferdam is transported to a bridge pier position; in the water flow direction, the end, close to the upstream, of the steel cofferdam is fixed by a winch through a steel wire rope, the end, close to the downstream, of the steel cofferdam is fixed through a positioning tail anchor and a positioning ground anchor, the two side faces of the steel cofferdam are pushed in an ejecting mode through a tugboat for comprehensive positioning; a positioning groove is excavated in the position, below the steel cofferdam, of the bridge pier position in advance, and then the steel cofferdam sinks to the designed elevation, positioning groove concrete is poured, and the positioning groove concrete and an impervious layer jointly form a water-resisting layer so as to stop and isolate water. The steel cofferdam is positioned through grooving, large-range blasting does not need to be conducted, bottom sealing concrete with large thickness is not poured, excavation of a riverbed is reduced, the influence on the surrounding environment is reduced to the maximum degree, and the requirement for environmental protection is met.

Description

technical field [0001] The invention relates to the field of construction methods of double-wall steel cofferdams. More specifically, the present invention relates to a construction method for unsealed concrete double-wall steel cofferdams in deep-water bare rock geology. Background technique [0002] At present, the construction of bridge caps requires the use of cofferdams to form a dry construction environment, especially for deep-water bare rock geology where the caps need to be deeply buried in rock formations. Generally, the construction method of underwater blasting of bedrock is used. The number of bridges is increasing day by day, the topographical, geological and hydrological conditions at the cap foundation are becoming more and more complex, and the requirements for environmental protection in underwater construction are also getting higher and higher, which makes underwater blasting restricted in many underwater projects. At the same time, it is necessary to po...

AI Technical Summary

Problems solved by technology

[0002] At present, the construction of bridge caps requires the use of cofferdams to form a dry construction environment, especially for deep-water bare rock geology where the caps need to be deeply buried in rock formations. Generally, the construction method of underwater blasting of bedrock is used. The number of bridges is increasing day by day, the terrain, geology and hydrological conditions at the cap foundation are becoming more and more complex, and the requirements for environmental protection in underwater construction are also getting higher and higher, so that underwater blasting is restricted in many underwater projects

At the same time, it is necessary to pour back-sealing concrete in the construction of traditional caps. The bottom-sealing concrete layer can resist buoyancy, prevent water influx, and serve as the construction work area of ​​the cap. However, for deep water conditions, the thickness of the back-sealing concrete is often large, resulting in The amount of construction work has increased significantly, resulting in difficulties in construction, increased construction period, and increased construction costs

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