A support device and support method for a loess tunnel

Abstract

The invention discloses a supporting device and method for a loess tunnel. The method includes the steps that first wood boards are arranged on the outmost layer of the supporting device, are tightly attached to the wall of the tunnel and surround the tunnel by one circle, so that a load-bearing arch is formed; a plurality of steel arch frames are arranged on the inner layers of the first wood boards at intervals, and the steel arch frames are tightly attached to the first wood boards; the space between every two adjacent steel arch frames is filled with a second wood board, and the second wood boards are flush with the surfaces of the steel arch frames; prefabricated steel reinforced concrete pipe pieces are tightly attached to the inner layers of the steel arch frames and the inner layers of the second wood boards and arranged on the innermost layer of the supporting device. The supporting device and method have the advantages that construction is convenient, supporting strength is high, safety and reliability are achieved, no water is needed in the whole process, the number and spacing of the steel arch frames can be adjusted according to on-site practical situations, the prefabricated steel reinforced concrete pipe pieces are adopted as a secondary lining so that construction quality can be better guaranteed compared with conventional anchor sprayed concrete, and the prefabricated steel reinforced concrete pipe pieces also make the tunnel more attractive.

Description

technical field [0001] The invention relates to the technical field of tunnel construction support, in particular to a collapsible loess tunnel support device and a support method. Background technique [0002] The collapsibility of loess is a special engineering geological property of loess. Loess has the property of rapid structural damage and sudden subsidence after being soaked by water under its own weight or external load. The cause of collapsibility is that the loess is mainly composed of silt and weakly hydrophilic minerals, has a macroporous structure, has a small natural water content, and has strong bonded water bonds of clay particles and cement bonds of salt, which can bear a certain amount of moisture when dry. The deformation is not large due to the load, but after soaking, the connection of soil particles is significantly weakened, causing the damage of the soil structure and collapsing deformation. [0003] Loess widely distributed in parts of Northeast, N...

AI Technical Summary

Problems solved by technology

However, tunnels generally adopt the support method of bolts and shotcrete. Since the shotcrete must contain water, the loess absorbs the water in the concrete and tends to become unstable. This makes it unsuitable for loess areas to use traditional bolts plus shotcrete. Concrete support method

The shield machine suitable for soft soil adopts the principle of mud-water balance, so there will also be water on the excavation surface, making the loess on the excavation surface easy to absorb water and become unstable.

In the existing methods, there is no support scheme in an anhydrous environment. Therefore, it is of great significance to study the tunnel construction method in a dry environment in the loess area

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