Composite supporting method used for ultra-deep comprehensive pipe rack foundation ditch in water crossing riverway

Abstract

The invention discloses a composite supporting method used for an ultra-deep comprehensive pipe rack foundation ditch in a water crossing riverway, and belongs to the technical field of underground urban comprehensive pipe rack deep foundation pit supporting. The method comprises the steps that firstly, a riverway cofferdam is constructed, and a drainage tube is mounted; secondly, riverway dredging within the construction range is carried out; thirdly, slope excavation to the top of a cast-in-place pile is carried out; fourthly, slope surface soil nails are put, and jet-anchor execution is carried out; fifthly, cast-in-situ bored pile construction is carried out; sixthly, a crown beam is constructed; seventhly, a pile back side high-pressure rotary jet grouting waterstop curtain is constructed; ninthly, excavation of foundation pit and construction of a crossed pipe rack main structure are carried out, after the lower foundation pit supporting and maintaining period is finished, earthwork on the foundation pit on the lower portion begins to be excavated and constructed, the earthwork is dug to the bottom at a time, and crossed main body structure is constructed. The currently-conventional supporting method is combined, supporting structure reliability is improved, construction cost is reduced, the construction proceed is quickened, and the influence on the environment and watercan be reduced.

Description

technical field [0001] The invention relates to the technical field of deep foundation pit support of an underground urban comprehensive pipe gallery, and more specifically relates to a composite support method for foundation grooves of an ultra-deep comprehensive pipe gallery in a water-passing channel. Background technique [0002] At present, in domestic comprehensive pipe gallery projects, there are few cases of passing under the river. In similar projects, shield tunneling and pipe jacking are mainly used to pass under the river to reduce the impact on the river and the surrounding environment. However, the construction cost of the shield tunneling method or the pipe jacking method is extremely high, and in order to prevent the top from collapsing during shield tunneling, the penetration depth is generally deeper under the river channel, which has caused certain problems for the excavation and support of the pipe gallery interface on both sides of the river channel. dif...

AI Technical Summary

Problems solved by technology

However, the top surface of the pipe gallery structure is at least 1m away from the bottom of the river channel, and the distance is generally more than 2m. The maximum relative depth of the pipe gallery excavation is more than 14m. The support of the river dams on both sides puts forward higher requirements, and this problem has not been solved at present

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