Vertical freezing construction method for underneath comprehensive pipeline such as high voltage cable of city subway

Abstract

The invention discloses a vertical freezing construction method for an underneath comprehensive pipeline such as a high voltage cable of a city subway. The method comprises the following steps that 1,construction preparation is conducted, and fender posts are constructed on the periphery of the pipeline; 2, drill hole construction and freezing station installing are conducted; 3, positive freezing and maintenance freezing are conducted; 4, a foundation pit is excavated, and after dewatering and freezing, fender post structures are constructed; 5, a freezing pipe is cut off and blocked, thaw settlement grouting is conducted, and construction is completed. According to the vertical freezing construction method for the underneath comprehensive pipeline such as the high voltage cable of the city subway, construction is safe and reliable, the economic benefit is large, wall connection notches of the fender post structures form water-proof plates, a condition is provided for deep foundationpit excavation and dewatering, wherein a frozen wall can bear certain water and oil pressure in the foundation pit excavation process; underground water is not polluted in the freezing process; and in addition, the protection degree and reliability degree of a 220 KV electric stay tube are high, and influence caused by pipeline changing is avoided.

Description

Technical field [0001] The invention relates to the technical field of subway construction methods, in particular to a vertical freezing construction method for urban subways to pass under high-voltage cables and other integrated pipelines. Background technique [0002] With the development of economy, the scale of urban subway construction is gradually expanding. The use of suitable subway construction methods is an important factor in determining the construction speed and construction quality of subways. The subway construction method is restricted by the characteristics of the low-level construction and the construction environment. For example, the construction of the deep foundation pit retaining structure is greatly affected by the urban integrated pipeline. Generally, the excavation depth of the station foundation pit is large, and the quality of the retaining structure construction is related to the foundation pit Surrounding surface settlement, building tilt, seepage, a...

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Problems solved by technology

The subway construction method is restricted by the characteristics of the low-level construction and the construction environment. For example, the construction of the deep foundation pit enclosure structure is greatly affected by the urban comprehensive pipeline. Generally, the excavation depth of the station foundation pit is relatively large, and the construction quality of the enclosure structure is related to the construction of the foundation pit. Surrounding surface subsidence, building inclination, seepage and stability of foundation pit excavation, etc., especially in areas with many urban comprehensive pipelines; vertical freezing method construction is to solve the problem that the deep foundation pit enclosure water-stop structure is not closed in water-rich strata It is an effective means of construction problems, which can effectively prevent water inrush disasters in foundation pits, and improve the formation characteristics and construction environment; however, in the current deep foundation pit construction, the freezing method has a long construction cycle, pipelines are affected by low temperature, and foundation pit precipitation has a relatively large impact on frozen walls. major issues

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