Variable-diameter shield body and diameter changing method

Abstract

The invention discloses a variable-diameter shield body and a diameter changing method. The variable-diameter shield body comprises a central frame and block shells which can be spliced into a ring, wherein the block shells are connected to the periphery of the central frame through telescopic pieces, and a sealing structure is arranged between every two adjacent block shells, so that the sealingperformance is ensured while the flexible operation of diameter changing is realized. According to the variable-diameter shield body, the sealing structure is arranged between every two adjacent blockshells, so that the two adjacent blocks can relatively slide to change the diameter, the circumferential sealing performance of the shield body can be ensured, and rock and soil debris entering the shield body is reduced. A slag flushing mechanism is arranged at the lap joint of the sealing structures, compressed gas or high-pressure water is introduced into a main pipe, rock and soil located atthe lap joint part are flushed when the shield body is recycled, so that the retraction of the shield body is prevented from being blocked, and meanwhile, the abrasion of the sealing structures is reduced.

Description

technical field [0001] The invention relates to the technical field of shield machines, in particular to a variable-diameter shield body and a diameter-variable method. Background technique [0002] In the process of shield excavation in mountain tunnels, the jamming phenomenon caused by the extrusion deformation of the surrounding rock often occurs; the stress release and deformation performance of different grades of surrounding rock are different, and the stress release is faster in the section with better surrounding rock, and the deformation Smaller, it is suitable for timely support, while the stress release is slow and the deformation is large in the section with poor surrounding rock, which is suitable for slow back support. At this time, proper over-excavation is beneficial to improve the economy of support. Therefore, variable-diameter shields have broad application prospects in mountain tunnels. [0003] And in the prior art, if the application publication number...

AI Technical Summary

Problems solved by technology

The diameter change of the shield body is realized through the relative movement of the upper and lower shield bodies. The diameter change range of the shield body is limited, mainly for the shield-type TBM main engine is long, and the machine jams when excavating in large deformation, fractured and broken zone formations. risky problem

Moreover, the sealing performance of the variable-diameter shield body is poor during the diameter-changing process, and it is difficult to remove the muck. Therefore, it is necessary to provide a variable-diameter shield body with good sealing performance and high flexibility.

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