Forward construction method for oblique crossing bias tunnel

Abstract

The invention relates to a forward construction method for an oblique crossing bias tunnel. The method comprises the following steps of (1) surveying and setting out to determine a relation between atunnel body and a slope; (2) carrying out net hanging and anchor spraying protection on the slope, and carrying out triangular core soil backfilling; (3) constructing a cover arch foundation, mountinga steel plate embedded part on the top surface, and then erecting a cover arch frame; (4) determining an offset distance Li from BC to AC one by one according to a distance L between primary supportarch frames of a hidden tunnel; and performing whole truss dividing according to the offset distance Li to correspondingly form a side wall arch frame I and a side wall arch frame II, and correspondingly numbering the trusses one by one; (5) according to the numbers, performing mounting with two trusses as one cycle; (6) concrete spraying construction; (7) constructing to form a fan-shaped primarysupport tunnel body of which a tunnel body BC section is positioned outside the slope; (8) performing fixing to form a fan-shaped pipe shed; (9) performing remaining construction processes of a guidewall; and (10) conducting bottoming construction on the side wall arch frame II truss by truss in the BC direction of the tunnel body, then conducting radial grouting construction, and mounting radial pipes. According to the method, safe tunnel entering can be achieved under the condition of minimum damage to the tunnel side and face upward slope.

Description

technical field [0001] The invention relates to the technical field of oblique tunnel entry, in particular to a construction method for oblique bias tunnel forward advancement. Background technique [0002] With the continuous extension of highway construction in the western mountainous area, due to the limitation of the mountainous terrain and the overall layout of the line in the process of line selection along the river and the mountain, it is inevitable that the tunnel axis will obliquely intersect with the mountain contour line, or during the construction After the design was completed, human production activities destroyed the original topography of the tunnel entrance, resulting in changes in the working conditions of the tunnel entrance. One side of the tunnel fell to the bottom and the side slope was tens of meters high with loose surrounding rock, making it impossible to construct the tunnel orthogonally. Contents of the invention [0003] The technical problem t...

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Problems solved by technology

[0002] With the continuous extension of highway construction in the western mountainous area, due to the limitation of the mountainous terrain and the overall layout of the line in the process of line selection along the river and the mountain, it is inevitable that the tunnel axis will obliquely intersect with the mountain contour line, or during the construction After the design was completed, human production activities destroyed the original landform of the tunnel entrance, resulting in changes in the tunnel entry conditions. One side of the tunnel fell to the bottom and the side slope was tens of meters high.

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