Combined foundation bed for immersed tube tunnels and construction method thereof

Abstract

The invention relates to the technical field of immersed tube tunnels and particularly discloses a combined foundation bed for immersed tube tunnels and a construction method thereof. The combined foundation bed comprises a block stone tier and a broken stone tier. The construction method includes: throw-filling an immersed tube foundation trench pre-excavated, with block stone to form the block stone tier, leveling and compacting the block stone tier by means of underwater leveling, and paving the broken stone tier on the block stone tier by a special unit to form the broken stone tier in a ridge-and-ditch structure. The non-uniformity caused by stratum distribution and foundation trench excavation is adjusted by throw-filling and leveling of the block stone tier, the broken stone tier in the ridge-and-ditch structure further coordinatively support a segment structure, the block stone tier and the broken stone tier in the ridge-and-ditch structure, both having the ability to accommodate bottom silt, allow the immersed tube tunnel foundation bed to form a smoothly coordinative support system of both hardness and softness, non-uniform excess differential settlement is under control, the structural stress of the immersed tube tunnel and joint openness are lowered, and the structural and waterstop safety is improved.

Description

technical field [0001] The invention relates to the technical field of immersed tube tunnels, in particular to a composite subgrade bed of an immersed tube tunnel and a construction method for the composite subgrade bed of the immersed tube tunnel. Background technique [0002] At present, the subgrade system of the immersed tube tunnels that have been completed is mainly divided into two types: the first laying method and the second laying method. As far as the first laying method is concerned, it includes laying the gravel layer first and then grouting and laying the gravel layer with ridges first. There are two options. [0003] The foundation bed of the immersed tunnel is paved with crushed stones first and then grouted. Usually, the submerged tunnel is fully paved. After the pipe joints are submerged, post-grouting is carried out in the pipe. This kind of subgrade has many procedures and high rigidity, and the subgrade does not have the function of readjustment. ; Firs...

AI Technical Summary

Problems solved by technology

[0006] The purpose of the present invention is to provide a composite subgrade bed for immersed tube tunnels, to overcome the rigidity of the subbed of the immersed tube tunnel subbeds in the prior art where crushed stones are laid first and then grouted. The foundation bed of the immersed tube tunnel in Shishi has poor adaptability to soft ground and cannot provide good rigidity support.

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