Novel enclosing structure applicable to connection change between new pipes and old pipes and construction method thereof

Abstract

The invention provides a novel enclosing structure applicable to connection change between new pipes and old pipes and a construction method thereof. Since the construction method which is used for reinforcing soil bodies under a pipeline under the condition that the enclosing structure can not be closed since the large-diameter pipeline penetrates through the enclosing structure of a foundation pit. By utilizing the combined enclosing structure with an SMW (Soil Mixing Wall) construction method, an MJS (Multiple Jet Solidification) construction method and a double-pipe rotary jetting construction method, the old sewage pipe is protected, and simultaneously, the excavation safety of the outer-covering foundation pit is guaranteed. Due to large pile diameter and good quality of a pile body in the MJS construction method, the influence on the old sewage pipe is less, the closure of the combined enclosing structure at the old sewage pipeline is ensured; double-pipe rotary jet is adopted from the part above 70cm of the pipe top of the old sewage pipe to the ground, the construction cost is greatly saved; after cutting, the old sewage pipe is chiseled off, so that the need for reutilizing the integrity of the structure of the old sewage pipe is ensured; after the water is stopped, the old sewage pie is cut and removed, then the space for construction of the foundation pit is increased, and the entering of the top pipe of the new sewage pipe into a hole is convenient, so that the construction size of the combined enclosing structure is reduced.

Description

technical field [0001] The invention relates to a construction method of a novel combined enclosure structure, in particular to an enclosure construction process for reconnecting large-diameter old and new pipes to a foundation pit. Background technique [0002] Due to the large-diameter old sewage pipe (or rainwater pipe), the foundation pit cannot be closed, and the depth of the bottom of the foundation pit is 11.2m, the outer diameter of the old sewage pipe reaches 2420mm, and the depth of the top of the old sewage pipe is 7.59m. Oblique, with a gap of 4.7m*3.6m in the form of a single enclosure, and a pile diameter of 800-2000mm using conventional rotary spraying (triple pipe rotary spraying), there are two technical obstacles to the bottom reinforcement of large-diameter sewage pipes: the first The scope of reinforcement does not meet the requirements, and the disturbance of the second pair of old sewage pipes is too large. Contents of the invention [0003] Aiming a...

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Problems solved by technology

[0003] Aiming at the deficiencies of the prior art, the present invention provides a method for reinforcing the soil below the pipeline when the large-diameter pipeline (which cannot be cut off during the construction of the enclosure and needs to be protected) passes through the enclosure structure of the foundation pit and the enclosure structure cannot be closed. The construction method firstly solves the problem that the existing technology disturbs the pipeline too much when the soil in the lower part of the pipeline is reinforced. The reinforcement range of the high pressure method cannot meet the design requirements and the reinforcement diameter is 3.1m.

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