Construction method of super-large section tunnel in fork and intersection section

Abstract

The invention discloses a construction method for a super-large section tunnel in a fork and intersection section, and relates to the technical field of construction in tunnel engineering. The construction method of the super-large section tunnel in the fork and intersection section includes the steps that a longitudinal construction area is planned; a second lining construction area is planned; a left part is excavated in the first excavation direction; a right part is excavated in the first excavation direction; a middle part is laterally excavated; the middle part area is excavated in the reverse direction to a fork site; a side wall of the right part is excavated in the direction of the first excavation direction; the remaining part of a tunnel face of the middle part is constructed in the first excavation direction; when an initial support is constructed in the rear part area, pouring of the last second lining of a branch tunnel and a main tunnel is completed, then a plug end wall is poured, and a second lining trolley is assembled in a front part area and the second lining is constructed until the construction is completed. The construction method of the super-large section tunnel in the fork and intersection section solves the construction problem of a 'big belly' section, provides on-the-spot basis for modifying, supplementing and perfecting the editing and revision of specifications and regulations and the industry standards, and a way of thinking is provided for speeding up the research in the aspect.

Description

technical field [0001] The invention relates to the technical field of construction in tunnel engineering, in particular to a construction method for a super-large-section tunnel at a bifurcation intersection section. Background technique [0002] The underground intercommunication of the highway project is a tunnel. At the intersection of the two tunnels, there are 5 lanes (meeting section), which is a super-large section. The meeting lane is generally designed to be 70 meters long, and then becomes 4 lanes. It belongs to a structure with small sides and a large middle . Its characteristics are: small clear distance at the intersection of the branch tunnel and the main tunnel, no intermediate guide double arch, large difference in tunnel height with variable section, and large variation in tunnel section. The difficulty is: (1) The intersection is a multi-arch without intermediate guide, and the tunnel height varies greatly, which is the weakest construction site, especial...

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Problems solved by technology

The construction of this part is currently in the discussion stage in the world. There are no relevant construction methods, specifications and regulations, and there is no mature construction experience for reference.

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