A Construction Method for Underground Excavation Tunnel with Variable Cross-section Stress Transformation

Abstract

The invention relates to a bored tunnel variable cross-section stress conversion construction method and belongs to the technical field of tunnel engineering. A profile steel grille local strengthening and transition area grille dense arrangement method is used, profile grilles are used at the cross-section position, the transition section grilles are vertical to the cross section axis and arranged densely and in welding connection with the profile grilles. One profile steel grille is arranged when the 4-4 section is constructed to the crosswire position, 5-5 section grilles are perpendicular to the section axis, the transition area grilles are arranged densely, and the grilles and the profile steel grilles are in welding connection. The 4-4 section profile steel grilles are in welding connection through strengthening plates, and 5-5 section reinforcement grilles and the 4-4 section profile steel grilles are in welding connection. The grilles and sprayed concrete can be attached tightly to surrounding rock, and the sprayed concrete can fill the grilles and space between the grilles and the surrounding rock and can be connected integrally with anchorage rods and forepoling structures, so that the support effect is good.

Description

technical field [0001] The invention relates to a construction method of variable cross-section stress conversion for an underground excavation tunnel, which belongs to the technical field of tunnel engineering. Background technique [0002] At present, with the extension of urban development space underground, urban underground engineering projects will gradually increase, especially in the current environment of domestic infrastructure construction, Beijing, Shanghai, Tianjin, Nanjing, Guangzhou, Shenzhen, Xi'an and other cities have planned There are a large number of underground tunnel projects, so the construction of tunnels with special-shaped variable cross-sections will be inevitable. [0003] During the reconstruction and construction of a certain station of Beijing Metro Line 4, the newly added transfer channel at the northwest entrance and exit is a representative variable-section construction channel. The conversion position of section 4-4 and section 5-5 of the...

AI Technical Summary

Problems solved by technology

In general, the grids are densely arranged at one end and the grid step is enlarged at the other end. This technology is convenient to realize the conversion of large and small sections, but there are certain construction risks at the enlarged end of the grid step, and the control of the axis of the bending position is prone to deviation.

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