Construction method of inner excavated abutment

Abstract

The invention relates to a construction method of an inner excavated abutment in tunnel construction. The method mainly solves the problems of sliding slope caused by big excavation height and loose slope of the inner abutment at the tunnel outlet at present. The method includes steps of removing collapse rocks at heading slope of outside of a tunnel, performing anchor-plate retaining on the outside slope of the tunnel from top to bottom; applying lock pin anchor pipes at two lining parts of both sides of the abutment and the front abutment beam groove; arranging temporary supports to left and right side walls of two liners of the tunnel, and excavating the abutment construction in the tunnel step by step, and excavating left part and then right part; applying the excavation scheme of concrete protecting wall to a hole excavating pipe, and excavating segmentally, and excavating one segment and supporting the segment; after excavating to a design elevation, placing a reinforcement cage, and pouring concrete; pouring a cushion cap concrete once, arranging face protecting ribs at four sides of the cushion cap; pouring the abutment body concrete twice, wherein the first pouring height is bottom height of a cushion, and the second pouring height is the designed elevation. The method is small in construction site, and segmental construction is free from slide collapse.

Description

[0001] Technical field: [0002] The invention relates to an excavated inner abutment construction method in tunnel construction. [0003] Background technique: [0004] At present, the construction of the abutment at the exit of the tunnel is to excavate the abutment to the bottom of the tunnel at one time. The excavation height is large, and the construction site is large. If the side slope is loose, it will cause slipping and collapse, which poses a safety hazard. [0005] Invention content: [0006] The technical problem to be solved by the present invention is to provide an excavated inner abutment construction method with small construction site, no sliding and collapse phenomenon, and safe construction. [0007] The above purpose is achieved in this way: the construction method of excavating the inner abutment first manually removes the dangerous rocks on the outer side slope of the tunnel, temporarily supports the side slope (back pressure, filling joints and anchor sp...

AI Technical Summary

Problems solved by technology

[0004] At present, the construction of the abutment at the exit of the tunnel is to excavate the abutment to the bottom of the tunnel at one time. The excavation height is large and the construction site is large. If the side slope is loose, it will cause slipping and collapse, which poses a safety hazard.