Face reinforcing device for soft rock tunnel and construction method thereof

Abstract

The invention discloses a face reinforcing device for a soft rock tunnel and a construction method thereof. The face reinforcing device comprises a protective layer arranged along a tunnel face and further comprises multiple hollow-structure anchor rods inserted into the soft rock tunnel by being perpendicular to the tunnel face. Multiple grout vent holes are formed in the surfaces of the anchor rods, and concrete grout in the anchor rods can flow out through the grout vent holes. Wooden wedges are arranged at the tail ends of the anchor rods. After advanced core soil of the face of the soft rock tunnel is pre-reinforced, the anti-pulling and anti-shearing capacity of the anchor rods can be fully exerted, total-length anchoring is achieved, the stability of the tunnel face is greatly improved, arch apex excessive convergence and pre-convergence deformation in the radial direction of the tunnel and extrusion deformation of the tunnel face can be avoided, an excavation machine can directly excavate and pass the tunnel, the safety in the construction process is improved, the labor intensity of workers can also be relieved, the tunneling speed is increased, the supporting cost is low,economic benefits of engineering are increased, and the application prospects are broad.

Description

technical field [0001] The invention relates to the technical field of advance reinforcement of soft rock tunnels, in particular to a reinforcement device for the tunnel face of soft rock tunnels and a construction method thereof. Background technique [0002] During the construction of the tunnel project, it is inevitable to encounter various complex engineering geological conditions, which bring difficulties to the project construction; for example, after the excavation of the soft rock tunnel, due to the deformation around the tunnel, the support is not timely implemented Causes such as operation and groundwater erosion will cause disasters such as collapse, falling rocks, and falling blocks on the face of the soft rock tunnel; these not only cause construction difficulties, destroy construction equipment, prolong the construction period, and more seriously, directly endanger the lives of construction personnel. safety, causing significant economic losses; in the construc...

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Problems solved by technology

[0002] During the construction of the tunnel project, it is inevitable to encounter various complex engineering geological conditions, which bring difficulties to the project construction; for example, after the excavation of the soft rock tunnel, due to the deformation around the tunnel, the support is not timely implemented Causes such as operation and groundwater erosion will cause disasters such as collapse, falling rocks, and falling blocks on the face of the soft rock tunnel; these not only cause construction difficulties, destroy construction equipment, prolong the construction period, and more seriously, directly endanger the lives of construction personnel. safety, causing significant economic losses; in the construction of large-section shallow tunnels in weak rock, the step method, CRD method, and double-side-wall pilot pit method are usually used for construction; but these methods have complicated construction procedures, serious waste of materials, and slow project progress. Difficult to meet the needs of current engineering construction

[0003] With the construction of a large number of underground projects, the degree of mechanized construction has been continuously improved, and new technologies and processes have been adopted by many domestic projects; It is widely used in some tunnel projects with very complex engineering geological conditions; however, pre-reinforcement measures usually use steel bars and shotcrete to pre-reinforce the advanced core soil in front of the tunnel face under weak surrounding rock geological conditions; but after the core soil is reinforced Excavation still needs to be carried out, and the cutting of steel bars will not only increase the investment in engineering construction, but the second-stage production process is complicated, resulting in waste of materials, which greatly reduces the efficiency of tunnel excavation, which is not conducive to rapid construction and difficult to popularize and apply

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