Construction method for three-dimensional intersection concave-convex fulcrums

Abstract

The invention relates to a construction method for three-dimensional intersection concave-convex fulcrums. The construction method for the three-dimensional intersection concave-convex fulcrums comprises the following steps of constructing a guard post, namely enabling the external side of a secondary lining structure of an air channel to be a first post side line and sequentially arranged towards the external side; constructing a bottom longitudinal beam, namely firstly pre-burring grids inside a pilot tunnel, enabling the tops of the grids to be connected with through-wall reinforcing bars of the pilot tunnel and then pouring the bottom longitudinal beam; constructing an air channel preliminary support ring beam, namely pre-burring reinforcing bars on the lateral side of the support ring beam, welding the grids after pouring of the support ring beam is finished and constructing a preliminary support; back filling concrete materials into the pilot tunnel; constructing a secondary lining of an arch portion of the air channel, namely enabling a groove to be a temporary support above the air channel and a PBA and arranging reinforcing bars according to a supporting beam; and constructing a secondary lining of an arc portion of the PBA, namely exploding a section and performing lining on a section by performing lining through a lining vehicle. The construction method for the three-dimensional intersection concave-convex fulcrums has the advantages of solving the problem that a three-dimensional intersection position reverse building arc portion is free of support, high in concrete exploding cost, large in dust and labor and time wasting; being simple in technology process, labor and material saving and rapid in progressing; enabling the quality of the fulcrums to be good; and bringing large economic benefits for enterprises.

Description

technical field [0001] The invention relates to the technical field of reverse construction of tunnels, in particular to a construction method for concave-convex fulcrums at three-dimensional intersections. Background technique [0002] The PBA construction method is a kind of underground excavation and reverse construction method evolved from the "hole pile method". The second lining arch is located on the surrounding piles as the premise, and then the reverse method is used for construction; at the intersection of the PBA and the air duct, in order to prevent To keep the clearance of the air passageway structure, a large number of retaining pile supports need to be discarded, which adds a lot of risk to the structural force transfer; this construction method will have many shortcomings when encountering large-span and small vector distance working conditions , the Beijing Subway Art Museum station constructed by China Railway 16th Bureau adopts the PBA construction method ...

AI Technical Summary

Problems solved by technology

[0002] The PBA construction method is a kind of underground excavation and reverse construction method evolved from the "hole pile method". The second lining arch is located on the surrounding piles as the premise, and then the reverse method is used for construction; at the intersection of the PBA and the air duct, in order to prevent To keep the clearance of the air passageway structure, a large number of retaining pile supports need to be discarded, which adds a lot of risk to the structural force transfer; this construction method will have many shortcomings when encountering large-span and small vector distance working conditions , the Beijing Subway Art Museum station constructed by China Railway 16th Bureau adopts the PBA construction method due to the dense underground pipelines. At the road interface, the arch structure with intersecting clear spans of two holes (6.0m, 5.5m) is very bad. The reverse method is that the main arch of the second lining of the station is 18.65m long, and there is no support on the side close to the air duct, which is extremely risky. In addition, the traditional construction method has a large amount of reinforced concrete demolition, high construction cost, large dust, long construction period and low benefit

Images