Method for replacing tail brush in extra large diameter shield driving under high water pressure condition

Abstract

The invention relates to the technical field of tunnel shield construction, in particular to a method for replacing a tail brush in extra large diameter shield driving under a high water pressure condition. The method solves the problems of huge risks, high technical requirement, optimization of structural defect of the original tail brush, long construction period, high cost and the like when the tail brush is replaced in the conventional shield driving under the high water pressure condition. The method comprises the following steps of: performing preparation before the tail brush is changed; plugging high pressure underground water, synchronously injecting bentonite mud, injecting polyurethane at the shield tail, and injecting double-liquid slurry of cement and water glass to the back of a duct piece; and replacing the tail brush, detaching a capping block, detaching adjacent blocks, then cutting the damaged tail brush, optimizing the structure of the tail brush of the original design, welding a new tail brush, replacing the rest tail brush in a supporting reversal mode, replacing the tail brush at the last duct piece, and completing assembly of the duct piece of the capping block. The method has the advantages of simplicity in process, short construction period, low cost, controllable risk and the like, gains good economic benefit and social benefit, and has wide application range.

Description

technical field [0001] The invention relates to the technical field of tunnel shield construction, in particular to a method for replacing shield tail brushes during super-large-diameter (diameter greater than 10 meters) shield excavation under high water pressure conditions. Background technique [0002] With the development of urban construction in our country, many large cities have begun to expand to surrounding cities, especially the coastal intercity traffic is gradually becoming public transportation, and there are more and more shield tunnels across rivers, rivers and seas, and shield tunnels are gradually extending to the long With the development in the direction of distance, large diameter, and large buried depth, the number of shield segments is also gradually reduced, and the segment ring width is increased to reduce water seepage in segment assembly. [0003] The shield tunneling method is a mechanized construction method that integrates machinery, electricity,...

AI Technical Summary

Problems solved by technology

[0006] In order to solve the problems of huge risks, high technical requirements, optimization of the structural defects of the original shield tail brush, long construction period and high cost when replacing the shield tail brush under high water pressure conditions in the existing large-diameter shield tunnel excavation, the present invention provides a A new method for replacing shield tail brushes in super-large diameter shield tunneling under high water pressure conditions