Holed excavation supporting structure for light and dark junction section of tunnel in bias pressure state and construction method

Abstract

The invention relates to a holed excavation supporting structure for a light and dark junction section of a tunnel in a bias pressure state and a construction method. In a supporting mode combining a bias pressure earth retaining wall and a cover arch, the unilateral bias pressure of the tunnel is balanced, thus ensuring the safety of a tunnel structure and safe holed excavation of the tunnel. With the adoption of the holed excavation supporting structure and the construction method, a slope is prevented from being destroyed in large area due to open cut tunnel excavation, and original ecological vegetation is protected to keep the slope intact and avoid landslip due to heavy excavation, so that neither engineering construction or environmental protection is neglected, and the engineering cost is also greatly lowered. The holed excavation supporting structure and the construction method can be widely applied to tunnel building in a mountainous hilly area.

Description

technical field [0001] The invention relates to a support structure and a tunnel excavation method in the tunnel excavation process, in particular to a support structure and a construction method in the tunnel excavation at the junction of light and dark mountain bodies under a bias state. Background technique [0002] With the rapid development of my country's economy and society, the construction of expressways has also been developed rapidly. Tunnels play an irreplaceable role in highway construction, especially in mountainous and hilly areas. Whether the tunnel can be entered quickly, safely and smoothly is one of the key links in tunnel construction. It is limited by conditions such as alignment, topography, and geology. Usually, when the surrounding rock at the entrance section is grade I-II and the ground conditions are good, it is generally possible to Directly excavate the entire section into the hole, and for the excavation of the initial 10m-20m section, the bla...

AI Technical Summary

Problems solved by technology

In the case of serious bias pressure at the tunnel entrance section, the above method has a large excavation area on the side slope, which seriously damages the surrounding vegetation environment, and a large amount of excavation. It is also necessary to construct water intercepting ditches, expressway isolation fences, etc., and the land acquisition area is relatively large; the project investment cost is high, and the large project volume will inevitably result in high investment costs and unnecessary waste; it is necessary to excavate large-scale holes However, there are problems such as poor construction safety and easy damage to the original environment.

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