Steel caisson enclosure structure at island-tunnel combination part

Abstract

The invention discloses a steel caisson enclosure structure at an island-tunnel combination part. The enclosure structure adopts a steel box body structure; water stop gates are arranged at the two ends of the box body; and the cavity part in the middle of the box body is a dock chamber of a tunnel to be built. The bottom plate and two side walls of the box body are in a hollow structure formed by welding a steel truss and a steel plate; and multiple grids are arranged and internally filled with underwater concrete. A steel box beam is arranged at the upper part of each water stop gate. The top of the box body also serves as a bidirectional back shore of a construction platform. The bottom plate of the box body is provided with a vertical foundation cast-in-place pile reserved sleeve penetrating through the bottom plate; and the reserved sleeve extends upwards and is connected with the bidirectional back shore at the top of the box body. The enclosure structure disclosed by the invention has a good water stop effect, reduces the construction difficulty, improves the construction efficiency, shortens the construction period, creates conditions for mounting the tunnel immersed tube as early as possible, and does not cause interference to the construction at the butt joint of an overwater tunnel immersed tube.

Description

Technical field: [0001] The invention belongs to a water-stop enclosure structure for construction on water of engineering structure buildings such as underwater tunnel-island junctions, that is, a steel caisson enclosure structure for island-sock junctions. Background technique: [0002] Before the technology of the present invention, two kinds of water-stop enclosure structures were mainly used in the construction of underwater tunnel-island junction: 1. lattice-type steel sheet pile cofferdam water-stop enclosure structure. ②The riprap cofferdam plus the underground diaphragm wall inside the cofferdam and the water-stop enclosure structure. [0003] Disadvantages of lattice-type steel sheet pile cofferdam water-stop enclosure structure: (1) The lattice-type steel sheet piles are backfilled with sand and gravel, and the water-stop effect is uncertain. After the excavation of the foundation pit, continuous precipitation is required for construction. (2) This process is sel...

AI Technical Summary

Problems solved by technology

[0003] Disadvantages of the water-stop enclosure structure of the lattice-type steel sheet pile cofferdam: (1) Sand and gravel are backfilled in the lattice-type steel sheet pile, and the water-stop effect is uncertain. After the excavation of the foundation pit, continuous precipitation is required for construction

(2) This process is rarely used in China, the steel sheet pile purchase cycle is long, the development cycle of the overall vibration sinking system is long, and equipment maintenance is difficult during the construction period, which affects the progress of the project

(3) The purchase cost of the vibrating hammer for overall vibrating sinking is high, and the number of times of use is limited, resulting in high construction cost of lattice steel sheet piles

[0004] Disadvantages of the riprap cofferdam plus the underground diaphragm wall inside the cofferdam: (1) The riprap cofferdam needs to excavate the foundation underwater, and the process of dredging and throwing mud will cause great pollution to the water body

(2) The riprap cofferdam needs to mine a large amount of stone, which has a great impact on the environment

(3) The backfilling sand in the cofferdam and the excavation of the foundation pit have a long period, which affects the progress of the project

(4) A row of ultra-long jet grouting piles needs to be added on the outside of the underground diaphragm wall, and the water-stop effect is uncertain

(5) Generally speaking, the riprap cofferdam plus the underground diaphragm wall in the cofferdam has a long construction period, high cost, heavy environmental pollution, and difficult quality assurance

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