Anti-silting system and method for subgrade geotextile compartment covering subgrade of immersed tunnel tunnel

Abstract

The invention relates to a block-type covering and anti-silting system of subgrade geotextiles for submerged tube tunnels, which includes a compartment geotextile desilting device and a special ship, and the compartment geotextile desilting device includes compartments, steel wire ropes, steel pipes The steel pipes are arranged at both ends of the geotextile, the two steel pipes are connected by steel wire ropes, the geotextile is arranged above the steel wire rope, and the four sides and the middle of the geotextile are respectively connected with the steel wire rope and the steel pipe through locks; the special ships include two The laying boat is connected with the silt removal device through a lifting wire rope. The anti-silting scheme of geotextile compartment covering the foundation bed of immersed tube tunnels in blocks can avoid excessive silting and affect the construction, completely isolate the silting and the foundation bed, and ensure that the dredging will not damage the already leveled bedding.

Description

technical field [0001] The invention relates to a system and a method used in the construction of a subsea tunnel, in particular to a system and a method for anti-silting the foundation bed of an immersed tube tunnel. Background technique [0002] The underwater tunnel often adopts the immersed tube method. The entire tunnel immersed tube is composed of multiple pipe joints. The general standard pipe joint is 180m long and 37.95m wide. , the width of the ditch is 1.05m, the width of the gravel strip is 1.8m, the bed area of ​​each standard immersed tube reaches (42m×180 m) 7560㎡, and the exposure time of the gravel bed from the beginning of leveling to the installation of the immersed tube is about 12 days , due to the high average sediment content in seawater in some sea areas, and the fact that there is about 2m of silt on the original mud surface at the top of the foundation trench, the sediment content changes during the flood season, the dredging and sand mining operati...

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Problems solved by technology

[0003] The adverse effects of sedimentation on immersed tube tunnels mainly include: changing the mechanical characteristics of the crushed stone bed and affecting the force transmission effect of the bed structure; Changing the bulk density of seawater will affect the anti-floating safety of the immersed pipe joint; if there is a mud layer in the gravel cushion foundation, after the tunnel is in operation, the settlement of the immersed pipe will be too large and unsatisfactory due to the consolidation deformation of the mud. The uniform settlement exceeds the standard, and a large bending moment is generated in the pipe section, which may lead to cracking of the pipe section in severe cases

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