Long-span tunnel overlapping carrying arch structure for upper-soft and lower-hard stratum and construction method thereof

Abstract

The invention relates to a long-span tunnel overlapping carrying arch structure for an upper-soft and lower-hard stratum and a construction method thereof. The arch structure comprises an outer layer of arch-shaped primary support, two layers of arch-shaped primary supports, two arch springing longitudinal beams and an arch-shaped wall rock reinforcement ring, wherein the two layers of arch-shaped primary supports, the outer layer of arch-shaped primary support and the arch-shaped wall rock reinforcement ring are sequentially overlapped on a tunnel vault part from inside to outside. The arch structure has the characteristics of simplicity in structure, strong carrying capacity, better stress and waterproof properties, convenience for construction organization and good usage functions, and is capable of providing a wide operating space during a construction period and creating a comfortably open and closed underground space during a usage period. The construction method has the characteristics of simplicity in process and convenience for operation, and is capable of reducing construction safety risks, controlling stratum settlement very well, realizing large mechanical operation, improving work efficiency, saving construction costs and the like.

Description

technical field [0001] The invention belongs to the technical field of design and construction of tunnels and underground engineering, and in particular relates to a superimposed load-bearing arch structure and a construction method for building large-scale underground structures such as long-span tunnels and subway stations in upper-soft and lower-hard composite strata. Background technique [0002] The 21st century is an era of great tunnel engineering and underground space development and utilization. With the acceleration of the urban construction process, more and more underground spaces with little impact on ground transportation and the environment are favored, especially large-section underground space structures that can meet different functions are more popular. [0003] When building long-span traffic tunnels in mountainous fault fracture zones and large underground structures such as subway stations in urban areas, affected by factors such as geological condition...

AI Technical Summary

Problems solved by technology

[0004] (1) Stress redistribution after excavation becomes unfavorable;

[0005] (2) The stress concentration at the foot of the foot is too large, requiring a large foundation bearing capacity;

[0006] (3) The vault is unstable;

[0007] (4) Large slack ground pressure; the buried depth is small, and the arching effect cannot be well exerted;

[0008] (5) The bearing capacity of the supporting structure is relatively small

[0011] For long-span tunnels in rocky strata, the traditional structural type and construction method adopt the method of step-by-step span reduction by setting up temporary supports. The temporary support is damaged by blasting, resulting in a safety accident

Images