Construction method of double arch tunnel auxiliary middle wall without middle pilot tunnel

Abstract

The invention discloses a construction method of a double arch tunnel auxiliary middle wall without a middle pilot tunnel. According to the technical points, firstly, an upper step of a left side tunnel is constructed, then a primary support is constructed, and a lower step of the left side tunnel is excavated; the auxiliary middle wall is conducted, specifically, a vertical steel frame is constructed in the corresponding position of an inverted arch, after concrete of the inverted arch is constructed, an inclined strut on the right side of the steel frame is constructed, and a horizontal transverse-strut steel frame is constructed; rebars are fixed on the steel frame in a quincuncial mode; meanwhile, double layers of reinforcement fabrics are hung on the horizontal transverse-strut steel frame; then sprayed concrete is constructed on the steel frame, and a secondary lining of the left side tunnel is constructed on the left side of the concrete; and a right side tunnel is constructed, specifically, an upper step is excavated, then a primary support is constructed, a middle step is excavated, a primary support of the middle step is constructed, a lower step is excavated, the primary support and the inclined strut on the right side of the middle wall are dismantled, an inverted arch of the right side tunnel is constructed, and finally a secondary lining of the right side tunnel is constructed . Middle pilot tunnel construction is omitted, the construction safety of a main tunnel is guaranteed, an existing construction method is fully utilized, construction efficiency is improved, and the construction period is shortened.

Description

technical field [0001] The invention belongs to the construction method of a multi-arch tunnel in the field of tunnel engineering of civil engineering, and in particular relates to a construction method for an auxiliary middle wall of a multi-arch tunnel without a central pilot tunnel. Background technique [0002] In tunnel engineering, due to site and line constraints, multi-arch tunnels are often used (multi-arch tunnels refer to left and right parallel tunnels sharing a middle wall). At present, the common construction method is to construct the pilot tunnel first, and then construct the main tunnel. The construction process of this method is complicated, and the slag is inconvenient. The existence of the main tunnel will affect the excavation efficiency of the main tunnel; during the initial support construction process of the main tunnel, construction workers are prone to stepping into the air accident; at the same time, there are weak points in the connection between ...

AI Technical Summary

Problems solved by technology

At present, the common construction method is to construct the pilot tunnel first, and then construct the main tunnel. The construction process of this method is complicated, and the slag is inconvenient. The existence of the main tunnel will affect the excavation efficiency of the main tunnel; during the initial support construction process of the main tunnel, construction workers are prone to stepping into the air accident; at the same time, there are weak points in the connection between the support of the main tunnel and the middle wall of the pilot tunnel For example, in the construction of the initial branch of the main tunnel, the waterproof process of the connection point is complicated and difficult; if the vault of the intermediate pilot tunnel is not filled densely, it is easy to cause a large bias at the primary branch of the main tunnel, etc.

Images