A method of tunnel exit from steep cliffs

Abstract

The invention relates to a steep cliff tunnel hole excavation construction method. A one-way tunneling scheme is used. The method comprises the steps that S1, the hole body is excavated through a central cross diagram method, excavation is performed by dividing the hole body into upper right, upper left, lower right and lower left guide holes, and temporary supporting and primary supporting are performed; S2, an upper middle small guide hole is excavated on the tunnel face at the position 7m to 9m away from an exit finished hole, a primary support of the arch portion and temporary supports of the two sides of the upper middle small guide hole are mounted, and after the hole is excavated, hole opening cutting and supporting are performed; S3, the temporary supports are dismounted, and excavation is expanded to the hole body upper half section till the hole opening from the upper middle small guide hole towards the two sides of the hole body; S4, the lower half section is excavated till the hole opening. By the aid of the construction method, one-way tunneling is performed, hole excavation is performed through the upper middle small guide hole from the inside to the outside, the hole opening can be extended to the largest extent, the tunnel construction safety is guaranteed, and the problems that lots of time and expenditures are cost due to erection of auxiliary bridges through front hole tunneling in the traditional mode are solved; meanwhile, blind slope cutting of front hole tunneling is prevented, and original landforms are protected to the largest degree.

Description

technical field [0001] The invention relates to the technical field of tunnel excavation, in particular to a method for exiting steep cliff tunnels. Background technique [0002] In the prior art, the penetration of the tunnel adopts the method of two-way excavation, and the penetration position is set in the surrounding rock section above grade IV. The front of the cave enters the cave, and the entrance of the cave needs to be protected by the side of the road and the slope before the construction of the cave can be carried out. Before the construction, a temporary temporary bridge must be erected as a construction platform. , The construction of the slope is difficult, and it is necessary to carry out a large slope brushing, which will damage the topography and landslides, and is prone to disasters such as landslides. Contents of the invention [0003] The purpose of the present invention is to overcome above-mentioned shortcoming, provide a kind of tunnel exit construc...

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Problems solved by technology

[0002] In the prior art, the penetration of the tunnel adopts the method of two-way excavation, and the penetration position is set in the surrounding rock section above grade IV. The front of the cave is entered into the cave. The entrance of the cave needs to be protected by the side of the road and the slope before the construction of the cave can be carried out. Before the construction, a temporary temporary bridge must be erected as a construction platform. , the construction of the side slope is difficult, and a large slope must be carried out, which will destroy the topography and landform, and it is prone to disasters such as landslides

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