A ring-shaped frozen reinforced water-stop structure and its construction method when the shield tail brush is replaced

Abstract

The invention discloses a shield tail brush replacement annular freezing reinforcing water seal structure and a construction method thereof; the reinforcing water seal structure uses annular freezing pipe construction equipment to bury 1-2 annular freezing pipes in the soil body position needs to replace the shield tail brush, and uses an artificial freezing mode to enable the soil body around the annular freezing pipes to form a temporary annular frozen soil curtain reinforcing water seal structure; the specific technical process is listed as below: construction preparation-annular freezing pipe boring construction-freezing system and temperature measurement system installation-active freezing(temperature monitoring)-dismounting duct piece and replacing shield tail brush (freezing maintenance)-forced unfreezing-annular freezing pipe extraction (sealing hole)-back filled grouting-shield continue propulsion. The construction method is simple, easy to operate and realize, strong in construction practicality, convenient in construction quality control, good in reinforcing effect and water seal effect, outstanding in safety and reliability, and has very big application values.

Description

technical field [0001] The invention relates to a reinforced water-stop structure when the shield tail brush is replaced, in particular to an annular freezing reinforced water-stop structure and a construction method thereof when the shield tail brush is replaced. Background technique [0002] Whether it is an earth pressure balance shield machine or a mud-water balance shield machine, they all work in a closed environment, and the inside of the shield machine should be dry. However, due to various reasons, there will be different degrees of water seepage and mud seepage inside the shield machine, and the internal leakage of the shield machine is mainly concentrated at the tail of the shield. How to prevent and control shield tail leakage is another key issue in shield tunnel construction. Shield tail leakage is mainly caused by improper segment assembly, unfavorable backfill grouting, insufficient grease volume and pressure, and damage to the shield tail brush. [0003] D...

AI Technical Summary

Problems solved by technology

[0003] Due to improper assembly of segments, long-distance excavation of the shield machine, etc., the shield tail brush will inevitably be damaged. According to experience, the life of the shield tail brush is generally about 2.5km when the shield is in normal operation; the damage of the shield tail brush It will lead to a decrease in the sealing performance of the shield tail, and seriously affect the normal excavation of the shield. In this case, the damaged shield tail brush needs to be replaced; Measures such as increasing the amount of grout and changing the grouting ratio to speed up the solidification of the grout

However, the unfavorable factors of the grouting method, such as inadaptability to the formation, poor continuity and uniformity of the grouting curtain, and lack of flexibility and toughness in the cementation of the grouted soil, the shield and the segment, are objective, which can lead to poor water sealing potential risks

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