An anti-seepage treatment method for ring beams of subway station portals

Abstract

The invention provides an anti-seepage treatment method for a ring beam of a tunnel door of a subway station. The anti-seepage treatment method is as follows: before the reinforcement of the ring beam of the tunnel door is bound, the grouting steel pipe is pre-buried at the seepage point of the ring beam of the tunnel door, and the full-section grouting steel pipe is installed at the interface between the ring beam of the tunnel door and the external structure and the shield segment respectively. Grouting pipe; part of the grouting part of the pre-embedded grouting steel pipe extends into the soil layer, and part is placed in the casting area of ​​the ring beam of the tunnel door; after the reinforcement of the ring beam of the tunnel door is tied and before the formwork is closed, install the full-section grouting pipe at the interface Apply the water-swellable water-stop glue separately, and then pour the ring beam and the water-receiving groove in one piece. After they meet the design strength requirements, grouting is carried out through the pre-embedded grouting steel pipe and the full-section grouting pipe. The sink is communicated with the drains on both sides of the track. The invention effectively makes up for the inevitable process defects in the pouring process of the ring beam of the tunnel door, perfectly controls the water leakage phenomenon of the ring beam of the tunnel door, and ensures the construction quality.

Description

technical field [0001] The invention relates to the field of shield tunnel construction, in particular to an anti-seepage treatment method for a door ring beam of a subway station. Background technique [0002] At present, the shield method has become the most commonly used construction method in subway construction. Shield tunnels inevitably pass through water-bearing strata, and water seepage is particularly common at the joints between segments and door ring beams and at segment joints. . The leaking water at the joints of the segments is usually treated by synchronous grouting and secondary grouting through the grouting holes reserved on the segments; the ring beam of the portal is usually made of ordinary concrete with an impermeability grade of P10, with large particle size, The fluidity is poor. Since only the pouring window is reserved at 12 o’clock during the pouring process of the portal ring beam, the concrete is not compacted well, especially the portal ring bea...

AI Technical Summary

Problems solved by technology

The leaking water at the joints of the segments is usually treated by synchronous grouting and secondary grouting through the grouting holes reserved on the segments; the ring beam of the portal is usually made of ordinary concrete with an impermeability grade of P10, with large particle size, The fluidity is poor. Since only the pouring window is reserved at 12 o’clock during the pouring process of the portal ring beam, the concrete is not compacted well, especially the portal ring beam is only relying on the self-weight of the concrete and the vibrating rod on the outside of the portal ring beam to vibrate the formwork during the pouring process. There are even cavities in the range from 11 o'clock to 1 o'clock on the top; at the same time, because the grouting pipe is not effectively protected, it is easy to be blocked during the pouring process of the door ring beam, resulting in subsequent grouting failure. These process defects inevitably cause severe water leakage

If there are no reliable waterproof and plugging measures, groundwater will invade the tunnel, affecting its internal structure and auxiliary pipelines, and even endangering the later operation and maintenance, reducing the service life of the tunnel

[0003] At present, the domestic treatment of leaking water from ring beams of portals usually uses single chemical material grouting such as epoxy resin for plugging. However, single chemical material grouting not only consumes a lot of manpower, but also consumes a lot of materials, with a low one-time success rate and high probability of re-leakage. , and will inevitably pollute the finished concrete structure

Therefore, it is difficult to meet the needs of on-site construction in terms of safety, quality, cost, management, and work efficiency by using the traditional waterproofing process and plugging process that only rely on concrete itself.

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