Method for restraining deformation of small-clear-distance tunnel in argillaceous sandstone stratum

Abstract

The invention discloses a method for restraining deformation of a small-clear-distance tunnel in an argillaceous sandstone stratum. The method comprises the steps that 1, a deformation monitoring module is installed, and an arch foot of an upper supporting steel frame is reinforced; 2, a primary supporting structure is reinforced for the first time; 3, middle clamping rock is reinforced; 4, the primary supporting structure is reinforced for the second time; and 5, the primary supporting structure is reinforced for the third time. According to the method, deformation of surrounding rock of the small-clear-distance tunnel is restrained by reinforcing the primary supporting structure, construction operation is easy, and the reinforced primary supporting structure is reliable and stable; and by reinforcing, monitoring and measuring multiple parts of the primary supporting structure, the stability and structural rigidity of the primary supporting structure are enhanced, cracking of the primary supporting structure is avoided, and therefore settlement convergence deformation of the surrounding rock of the tunnel is reduced, reinforcing and stability maintaining in the initial excavation stage of the tunnel are achieved, and the overall stability and construction safety of the tunnel are guaranteed.

Description

technical field [0001] The invention belongs to the field of reinforcement construction of small clear distance tunnels, and in particular relates to a method for suppressing deformation of small clear distance tunnels in argillaceous sandstone formations. Background technique [0002] The small clear distance tunnel refers to the special tunnel layout form in which the thickness of the interlayer rock in the tunnel is less than the minimum clear distance of the separated independent double tunnel. Destruction of the ecological environment and other issues. During construction, the construction is divided into the first hole and the second hole in sequence. Among them, the excavation of the second hole will cause the stress redistribution of the surrounding rock supported by the first hole, and the excavation of the first hole itself will also cause tunnel damage. Stress redistribution in surrounding rock, especially in expansive argillaceous siltstone geological conditions,...

AI Technical Summary

Problems solved by technology

[0002] The small clear distance tunnel refers to the special tunnel layout form in which the thickness of the interlayer rock in the tunnel is less than the minimum clear distance of the separated independent double tunnel. Destruction of the ecological environment and other issues. During construction, the construction is divided into the first hole and the second hole in sequence. Among them, the excavation of the second hole will cause the stress redistribution of the surrounding rock supported by the first hole, and the excavation of the first hole itself will also cause tunnel damage. Stress redistribution in surrounding rock, especially in expansive argillaceous siltstone geological conditions, due to the characteristics of soft rock, fragility, easy softening and disintegration when exposed to water, and loose structure, the self-stability of surrounding rock is poor. The deformation of the surrounding rock in the early stage converges greatly and the unevenness is obvious. The support structure needs to bear the secondary stress distribution of the surrounding rock. A little carelessness may cause damage to the support structure, excessive deformation, and ...

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