A sealing device and sealing construction method for a shield tunnel reaching a portal

Abstract

The invention provides a shield arrival tunnel portal sealing device and a sealing construction method. The specific construction of the sealing device comprises the steps that before a shield tunneling machine arrives a tunnel portal, an annular flexible sealing member and an externally-arranged tunnel portal ring are mounted on an outer annular plate of a pre-embedded tunnel portal ring outside the tunnel portal; the annular flexible sealing member is composed of an annular rubber cord fabric and a plurality of cord fabric pressing plates; the externally-arranged tunnel portal ring is composed of a plurality of arc steel members; the shield tunneling machine continues to advancing, and before the shield tunneling machine is pushed out of the tunnel portal, an annular rigid sealing member is mounted on the pre-embedded tunnel portal ring, wherein the rigid sealing member is composed of two annular steel plates and a sponge, and the space between the two steel plates is filled with the sponge; and when the distance of the tail end face of a shield tail of the shield tunneling machine and the exterior of the externally-arranged tunnel portal ring is 30-50 cm, an annular sealing steel plate is welded between the shield tail of the shield tunneling machine and the externally-arranged tunnel portal ring to conduct sealing. The construction method is easy to operate and safe and reliable, slurry can be fully sealed, the sealing effect is good, and the whole construction process is safe and easy to operate.

Description

technical field [0001] The invention relates to the field of tunnel construction by shield tunneling method, in particular to a sealing device and a sealing construction method for a shield tunnel arrival portal. Background technique [0002] In today's urban subway traffic construction, the shield method is widely used because of its fast construction and little impact on the ground. The shield tunneling is relatively safe during normal excavation, and its risk points are mainly concentrated in the starting and receiving stages of the shield tunneling. The arrival of the shield tunneling means that after the shield tunneling completes the construction of a certain section of the tunnel in the stratum, it maintains the surrounding soil While stabilizing, advance along the designed route to the penetration surface of the receiving well, and then introduce the shield into the receiving well from the pre-prepared hole for a series of operations. However, under the complex geol...

AI Technical Summary

Problems solved by technology

Moreover, in the actual use process, since the cord rubber and the shield shell cannot be completely tightly fitted and sealed, it is impossible to completely seal the water gushing from the portal, and if the grout is injected at the portal, there will inevitably be grout leakage

When the gushing water is large or takes a long time, it is easy to cause major safety accidents

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