Shallow-buried section reverse small pipe shed hole forming method

Abstract

The invention discloses a shallow-buried section reverse small pipe shed hole forming method in the technical field of tunnel construction. The method comprises the steps that firstly, an I-shaped steel arch frame is erected on a tunnel excavation face, and a pipe shed hole is drilled in the pipe shed fixing hole of the I-shaped steel arch frame in the obliquely upward direction; then a pipe shed steel pipe is inserted along the pipe shed hole, and the exposed part of the end of the pipe shed steel pipe and the arch top part of the I-shaped steel arch frame are welded together; then cement is used for grouting the interior of the pipe shed steel pipe till the designed grouting pressure or the designed grouting amount is reached; and finally, a cantilever tunneling machine is used for conducting operation face excavation, the short-excavation and short-support manner is adopted, and supporting is conducted every time excavation is conducted by 0.4-0.5m till shallow-buried section construction is completed and the shallow-buried section penetrates through the ground surface. According to the hole forming manner, the influence of excavation on ground surface deformation is effectively reduced, the stability of the shallow-buried section of an inlet hole section is guaranteed, the construction progress is accelerated, the construction technical problem that a hole cannot be formed in a forward inlet section of the shallow-buried section is solved, the tunnel construction safety is guaranteed, meanwhile, investment is saved, and economic benefits are increased.

Description

technical field [0001] The invention relates to the technical field of tunnel construction, in particular to a method for forming a hole in a shallow buried section with a reverse small pipe shed. Background technique [0002] At present, most of the construction of the shallow section of the tunnel uses mechanical cutting, drilling and blasting, mechanical slag removal, tunnel support and other methods. However, for the relatively steep slope at the entrance section, the terrain is dominated by gullies, vertical and horizontal valleys, and relatively complex terrain with large ups and downs, and the surrounding rock has no self-stabilization ability. Excavating tunnels in conventional ways is likely to lead to serious deformation and damage. Large-scale roof caving and landslides. At present, due to the unfavorable terrain, the entrance of the tunnel cannot be formed into a hole. There are also bridges, large excavation slopes and supports to enter the tunnel. However, thi...

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Problems solved by technology

However, for the relatively steep slope at the entrance section, the terrain is dominated by gullies, vertical and horizontal valleys, and relatively complex terrain with large ups and downs, and the surrounding rock has no self-stabilization ability. Excavating tunnels in conventional ways is likely to lead to serious deformation and damage. Large-scale roof caving and landslides

At present, due to the unfavorable terrain, the entrance of the tunnel cannot be formed into a hole. There are also bridges, large excavation slopes and supports to enter the tunnel. However, this type of method is not good for the project cost, and the safety of the construction cannot be obtained. ensure

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