Full-section pre-reinforcing construction method for tunnel free-machining anchor bar

Abstract

The invention discloses a tunnel easy-cutting anchor-rod full-section pre-consolidation construction method, comprising the following steps: firstly, survey design before construction is carried out, pre-consolidation is carried out to a face core body to be excavated by adopting an easy-cutting anchor rod according to the sampling analysis and classification of rock-soil, meanwhile, a measuring instrument is installed to monitor the change thereof, and then full-section excavation is carried out. The construction method takes the problem of how to deal with the 'core body to be excavated' in front of the face as the key for controlling the integral stability of the tunnel, an easy-cutting glass fiber anchor rod which is pre-consolidated along tunnel vertical full-section is used for improving the equivalent stiffness of the 'core body to be excavated' and controlling the deformation of the 'core body to be excavated' so as to cause arching effect around the tunnel to function naturally, thus guaranteeing the full-section, safe and quick excavation and drivage of the tunnel. The construction method is safe and reliable, can realize tunnel full-section mechanized and modernized construction, and has good production efficiency, continuous and stable construction progress, and controllable project cost.

Description

technical field [0001] The invention relates to a construction method for full-section pre-reinforcement of an easy-cut anchor rod in a tunnel. The construction method is suitable for soil surrounding rocks or weak gravel layer surrounding rocks, and even rocky surrounding rocks. "Tunnel" here generally refers to any kind of tunnel with regular geometric shape to be excavated. Background technique [0002] For the design and construction engineers of underground engineering, another characteristic of this type of engineering is that the load on the structure is not just the self-weight load of the unchanging soil and structure. In each construction stage, the stress on the structure is often not the stress of the final completed state, and the external load on the structure has been specified in the design stage. The load conditions during the construction phase were quite complex because the disturbance of the ground balance caused by the excavation could not be completely...

AI Technical Summary

Problems solved by technology

[0006] The third situation is: after the cavern is excavated, the rock mass around the cavern cannot bear the deflection stress caused by the excavation at all, eventually leading to collapse

[0008] In addition to the above limitations, the construction of the new Austrian construction method has the following disadvantages: 1. The construction of the new Austrian construction method uses the drill-and-blast method, which requires professional blasting design, which involves the layout and depth of the blast hole and the amount of explosives. If the design If it is unreasonable, it will disturb the properties of the surrounding rock of the tunnel during the blasting process, causing the excavation surface to be too large, that is, over-excavation or large-scale under-excavation, which will increase the project cost; Management also requires skilled technicians and surveyors, otherwise mistakes will occur, and the quality of construction work is closely related to everyone's careful operation; 3. The geology exposed by excavation will immediately change its state, so construction geology is required Personnel must visit the site in person to find problems; 4. Using controllable construction measurements often brings inconvenience to the construction; 5. The dust brought by dry spraying and the damage caused by chemicals must be strengthened, especially for the eyes Although wet spraying can avoid this shortcoming, under the same conditions, there are still problems such as high engineering cost and insufficient initial strength; That is, the initial support), resulting in a long cycle interval of the process