Laying method for large-aperture water draining pipeline parallel to upper part of existing metro tunnel structure

Abstract

The invention discloses a method for laying a large-diameter drainage pipe parallel to the upper part of an existing subway tunnel structure, which comprises the following steps: step 1, using a mixture of cement and water glass to reinforce the bottom of the trench through a layered grouting process Processing; step 2, construction and support of Larsen steel sheet piles; using Larsen steel sheet piles as enclosure piles; step 3, excavating and setting steel supports and steel purlins, steel supports are fixedly connected with Larsen steel sheet piles through section steel; steps 4. Dig to the bottom of the foundation pit and tamp the pipeline foundation; step 5. Lay glass fiber reinforced plastic sand-filled large-diameter pipelines on the pipeline foundation, and construct the main structure. After the main structure reaches the design strength, it will be backfilled from bottom to top until Backfill to the design ground level; step 6, pull out the Larsen steel sheet pile, and fill the gap after the Larsen steel sheet pile or steel purlin is pulled out. The invention has fast construction speed and can ensure that the displacement of the top of the surrounding protection pile and the settlement of the surrounding ground are within an acceptable range during the excavation of the foundation pit.

Description

technical field [0001] The invention relates to the technical field of building construction, in particular to a method for laying a large-diameter drainage pipe parallel to an existing subway tunnel structure. Background technique [0002] In order to improve the city's drainage and waterlogging prevention capabilities, it is generally necessary to install large-diameter drainage pipes. Laying large-diameter drainage pipes has become an important measure to solve road water accumulation in urban built-up areas. However, a large number of subway tunnel structures in urban built-up areas have already been implemented. If large-caliber drainage pipes need to be installed in the drainage system, they can only be implemented above the subway tunnel structures. [0003] At present, the large-diameter drainage pipes installed above the subway tunnel structure usually use reinforced concrete pipes. Formwork, pouring and maintenance time of reinforced concrete manhole; the excavati...

AI Technical Summary

Problems solved by technology

[0004] In addition, the currently laid drainage pipes are often supported by horizontal slabs or channel steel sheet piles. Due to the low rigidity of the enclosure measures, the surrounding land subsidence is relatively large, and it must be in accordance with the local groundwater treatment plan. Cooperate

When laying drainage pipes near structures, tree root piles with a diameter of 400mm and double rows of jet-spray piles with a diameter of 800mm are often used as the enclosure piles for the foundation pit of the drainage pipeline to reduce the impact on adjacent structures. Reinforced concrete purlins are required for the first horizontal support in the vertical direction of the piles. Both the retaining piles and the purlins need to be maintained, and the operation time is relatively long

[0005] However, if the above-mentioned large-diameter pipelines are repeatedly laid, for the large-diameter pipelines laid in parallel above the existing subway tunnel structure, since the subway tunnel structure is very sensitive to changes in the surrounding environment, especially the construction work above the tunnel will make the tunnel The structure is displaced and deformed, even causing the tunnel structure to crack and leak

Therefore, laying large-diameter drainage pipes parallel to the top of the existing subway tunnel structure has always been a restricted area for laying pipes, which has brought great challenges to the design of urban outdoor drainage.

Images