Novel tunnel advanced small guide pipe, advanced support system and construction method

Abstract

The invention discloses a novel tunnel advanced small guide pipe, an advanced support system and a construction method and relates to the technical field of tunnel construction advanced support. The advanced small guide pipe comprises a guide pipe body and a casing pipe. A grouting opening is formed in one end of the guide pipe body, a plurality of grouting holes are formed in the other end of theguide pipe body. The guide pipe body is fixedly sleeved with the casing pipe. The casing pipe covers a portion of the grouting holes, and the other portion of the grouting holes are located in the side, away from the grouting opening, of the casing pipe. By the adoption of the novel tunnel advanced small guide pipe, the advanced support system and the construction method, the grouting effect of the advanced small guide pipe can be ensured, and the construction safety is ensured.

Description

technical field [0001] The invention relates to the technical field of advance support in tunnel construction, in particular to a novel tunnel advance small conduit, an advance support system and a construction method. Background technique [0002] The tunnel advance support structure system is the key to the stability control of the surrounding rock, and is also the basic task of tunnel design and construction. For the weak and broken surrounding rock with poor self-stability, advance pre-reinforcement and advance pre-support measures are usually used to improve the safety of tunnel construction. . The essence of advanced reinforcement is to increase the strength of surrounding rock, making it less prone to serious damage, maintaining a certain self-stabilization time, and mobilizing the bearing capacity of surrounding rock; the essence of advanced support is to form a load-bearing arch in advance to bear the load of surrounding rock and protect the excavation surface. and...

AI Technical Summary

Problems solved by technology

[0003] Under the premise of satisfying the safety of tunnel construction, different types of pre-support measures have different adaptability to the advanced failure mode. For the instability of surrounding rock with frontal extrusion failure, the best pre-support measure is the advanced Small conduit + grouting, but advanced small conduits are often processed and produced in a factory, and the specifications and formats cannot fully meet the actual needs of the site

[0004] At the same time, in the weak and broken surrounding rock section of the tunnel, whether mechanical excavation or blasting is adopted, local over-excavation generally exists. The leakage is outside the surrounding rock (or the surface of the inserted surrounding rock is too weak and broken), the grout leakage is serious during the grouting process of the advanced small conduit, the design pressure cannot be reached, the grout cannot diffuse and solidify, and the advanced support is used as the tunnel support system. An important component, which can effectively control the deformation of the surrounding rock during the whole process of tunnel construction. If the grouting fails to achieve the expected effect, the deformation of the surrounding rock will be difficult to control. It may be necessary to take remedial measures such as lining jumping, which affects the normal construction organization

Images