A method for improving core soil removal in tunnel double side wall pilot pit method construction

Abstract

The invention belongs to the technical field of tunnel improvement, and discloses a method for improving core soil removal in tunnel double-side wall pilot pit method construction. The length of each interval section is not less than twice the length of the dismantling section; The weak parts of the surrounding rock will not be dismantled in sections; when dismantling the dismantling section, it will be dismantled in steps of upper, middle, lower, and each step has the same length; Sections continue to expand and dismantle until the core soil is completely dismantled. The invention can effectively improve tunnel excavation efficiency. For example, in a tunnel with a length of 100m, under the condition of IV-level surrounding rock, the dismantling length of each core soil dismantling section is 10m, and a total of 3 dismantling sections are set with an interval of 20m. This method can remove a length of 30m each time, so the construction speed is increased by three times, and the construction time is shortened to one-third of the original, which greatly shortens the construction period. In addition, since no large-span free surface is generated when dismantling the core soil, construction safety can also be improved.

Description

Technical field[0001]The present invention belongs to the field of tunnel improvement, and in particular, the present invention relates to a method for improving the core soil release method in the construction of the bilateral wall of the tunnel.Background technique[0002]At present, the existing technology in the industry is like this: During the construction of the tunnel bilateral wall guide, the existing core soil solution, the dismantling of the core soil is generally demolished, and the tunnel has been opened to excavated the spatial space, the dismantling efficiency is low, the construction progress is slow And when the geological conditions are not good, it is impossible to avoid it. In addition to increasing the support or suspend disassembly progress, there is no other effective solution, high construction cost, large dismantling, easy to collapse, affect construction safety .[0003]In summary, the problems existing in the prior art are: [0004](1) Existing tunnel core soil ...

AI Technical Summary

Problems solved by technology

[0004] (1) The existing tunnel core soil removal method cannot effectively avoid the weak points of the surrounding rock of the tunnel in the rock formation, including: cracks in the rock mass, or places with high stress.

[0005] (2) According to the existing tunnel core soil removal method, when the geological conditions are not good, there is no other effective solution except to increase the support strength or suspend the dismantling progress, which not only increases the construction cost and delays the progress, but also easily Collapse damage occurs, affecting construction safety

[0006] (3) The existing method of dismantling the core soil of the tunnel in sequence, each dismantling length is short, and only one working face is dismantling, the dismantling efficiency is low, and the construction progress is slow

[0007] (4) The existing tunnel core soil removal method in sequence cannot make full use of the existing space in the excavated pilot pit of the tunnel, which leads to the inability to make full use of the existing construction machinery and on-site labor, resulting in the phenomenon of idle labor and idle machinery

[0009] Difficulty: In the construction of tunnel double-side-wall pilot pit method, the existing core soil dismantling scheme cannot effectively avoid when the geological conditions are not good, which is determined by the essential characteristics of the existing core soil sequential release method The construction method also limits that the existing technology cannot significantly improve its construction efficiency, shorten the construction period, and reduce costs

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