Construction process for large-section soft rock large-deformation tunnel

Abstract

The invention relates to the field of tunnel engineering, in particular to a construction process for a large-section soft rock large-deformation tunnel. The adopted construction process comprises the steps that (1) an upper step is constructed; (2) a middle step is constructed; (3) a lower step is constructed; (4) reserve core soil is excavated; (5) an inverted arch is excavated, specifically, every time cycle excavation is conducted for 3 m, primary spraying is conducted immediately after the inverted arch part is excavated; (6) an inner layer steel frame is erected in time, HW200*200 profile steel is adopted, after closing ring formation, an inner layer is made, and concrete is sprayed to the designed thickness; (7) a concrete inner surface is sprayed on the inner layer, and a waterproof board is laid; (8) after tunnel deformation reaches designed reserved deformation, secondary lining is made; and (9) under supporting of advanced grouting small duct, the next cycle of construction is conducted till the tunnel is made through. The construction process meets the requirement of soft rock large deformation, limit intrusion is avoided, meanwhile, stress of a support structure can be reduced, and safety of the support structure is ensured.

Description

[0001] 1. Technical field: [0002] The invention relates to the field of tunnel engineering, in particular to a construction technique for a large-section soft rock large-deformation tunnel. [0003] 2. Background technology: [0004] In order to meet the development needs of national highways and high-speed railways, the excavation section of traffic tunnels is getting larger and larger, and it is inevitable to pass through complex strata such as soft rocks, which brings great challenges to tunnel construction. Due to the large amount of deformation of the surrounding rock after the excavation of the soft rock tunnel, the deformation rate is fast, and the duration is long. The protection structure is easily cracked, damaged, and invaded due to excessive force, resulting in frequent excavation and arch replacement, which not only makes it difficult to guarantee the quality of tunnel construction, but also leads to uncontrollable cost, unpredictable construction period, and ung...

AI Technical Summary

Problems solved by technology

[0004] In order to meet the development needs of national highways and high-speed railways, the excavation section of traffic tunnels is getting larger and larger, and it is inevitable to pass through complex strata such as soft rocks, which brings great challenges to tunnel construction

Due to the large amount of deformation of the surrounding rock after the excavation of the soft rock tunnel, the deformation rate is fast, and the duration is long. The protection structure is easily cracked, damaged, and invaded due to excessive force, resulting in frequent excavation and arch replacement, which not only makes it difficult to guarantee the quality of tunnel construction, but also leads to uncontrollable cost, unpredictable construction period, and unguaranteed construction safety. In addition, the section of the tunnel being built is getting larger and larger, and the above problems are even more difficult to solve

Images