Method for designing thickness of underwater tunnel subsurface excavated construction grouting reinforcement ring

Abstract

The invention discloses a method for designing the thickness of an underwater tunnel subsurface excavated construction grouting reinforcement ring. The method is characterized by comprising the following steps of: 1, selecting a group of reinforcement ring thickness parameters, and calculating the stability factors of a tunnel construction working surface under different reinforcement ring thickness conditions; 2, obtaining a reinforcement ring thickness-stability factor regression curve according to a least squares method based on different reinforcement ring thicknesses and corresponding stability factors; and 3, obtaining a reinforcement ring thickness required by a tunnel under a certain designed stability factor condition according to the reinforcement ring thickness-stability factor regression curve. A reinforcement ring thickness is obtained with the method for designing the thickness of the underwater tunnel subsurface excavated construction grouting reinforcement ring, so the field engineering construction requirements can be met, the construction safety of the tunnel can be ensured, and the engineering cost can be reduced.

Description

technical field [0001] The invention relates to a design method for the thickness of a grouting reinforcement ring in underground excavation construction of an underwater tunnel. Background technique [0002] When underwater tunnels are constructed using the mining method, in order to prevent engineering accidents such as water inrush and collapse on the excavation surface, advance grouting is usually used for pre-reinforcement during construction, and then the tunnel is excavated under the protection of the grouting reinforcement ring to ensure Construction safety of underwater tunnels. However, at present, the design of advanced grouting reinforcement parameters for underwater tunnels at home and abroad is mainly carried out on the basis of experience and according to the engineering analogy method. The relevant highway and railway tunnel design codes have no idea how to determine the thickness of the underwater tunnel grouting reinforcement ring. involves. In the actual...

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Problems solved by technology

However, at present, the design of advanced grouting reinforcement parameters for underwater tunnels at home and abroad is mainly carried out on the basis of experience and according to the engineering analogy method. The relevant highway and railway tunnel design codes have no idea how to determine the thickness of the underwater tunnel grouting reinforcement ring. involve

In the actual engineering design of underwater tunnels, the determination of grouting reinforcement parameters is often judged according to the personal experience of the design engineer. Whether the adopted grouting design parameters can fully meet the needs of safe tunnel construction, or whether the determined grouting parameters are too conservative , how big is its safety factor, even the design engineers themselves cannot determine

Therefore, on the one hand, in order to ensure safety in the design, design engineers often blindly increase the thickness of the grouting reinforcement ring to ensure the construction safety of the tunnel, thereby increasing the engineering cost of the tunnel; on the other hand, due to the lack of effective analysis and design method, it is impossible to carry out targeted design according to the geological conditions of the tunnel, and the entire tunnel often adopts exactly the same grouting reinforcement design parameters, which makes the construction risk of underwater tunnels in weak geological positions such as fault fracture zones

[0003] Generally speaking, the design of the thickness of the grouting reinforcement ring for underwater tunnels is still based on experience and cannot meet the needs of the rapid development of underwater tunnel construction in my country.

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