Large-section tunnel excavation method based on double-side-wall pilot tunnel method

Abstract

The invention relates to the field of tunnel construction, in particular to a large-section tunnel excavation method based on a double-side-wall pilot tunnel method. The large-section tunnel excavation method comprises the steps that step 1, construction preparation is conducted and is characterized by further comprising the following steps that step 2, an upper step of a pilot tunnel is constructed; step 3, an upper step of the following pilot tunnel is constructed; step 4, an upper step of the middle pilot tunnel is constructed; step 5, a lower step of the pilot tunnel is constructed; step 6, a lower step of the following pilot tunnel is constructed; step 7, a lower step of the middle pilot tunnel is constructed; step 8, monitoring and measuring are performed; step 9, dismantling is performed; step 10, sealing is performed; step 11, inverted arch construction is conducted; and step 12, arch bridge construction is conducted. The large-section tunnel excavation method is convenient to construct and high in efficiency.

Description

technical field [0001] The invention relates to the field of tunnel construction, in particular to a large-section tunnel excavation method based on a double-side-wall pilot pit method. Background technique [0002] At present, according to field measurements, the ground subsidence caused by the double-side-wall pilot-pit method is only 1 / 2 that of the short-step method, and the excavation section is divided into many blocks, and each block is closed immediately after excavation. In the excavation of driving tunnels with poor surrounding rock conditions of grade V surrounding rocks, and in the excavation methods of large-span and ultra-long-span tunnels, the double-side-wall pilot-pit method is widely used. [0003] However, the traditional double-side-wall pilot tunnel method needs to use the lower part as the construction platform no matter when constructing the steps on the left pilot tunnel or the right pilot tunnel. The construction of the steps, and the left and right...

AI Technical Summary

Problems solved by technology

[0003] However, the traditional double-side-wall pilot tunnel method needs to use the lower part as the construction platform no matter when constructing the steps on the left pilot tunnel or the right pilot tunnel. The construction of the steps, and the left and right pilot tunnels cannot be constructed at the same time. It is not difficult to find that the heavy workload and slow construction progress are the main shortcomings of the traditional double-side wall pilot-pit method. In addition, the double-side wall temporary support system needs to run through the entire tunnel section. The one-time use and large-scale removal of the support is not conducive to cost control. When the tunnel is excavated to the rock entry stage, that is, although the geology is still V surrounding rock at this time, it already has certain self-stabilizing conditions. At this time, double sidewalls are used. Pilot method, obviously pays too much attention to safety, while ignoring progress control and cost control

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