Freezing construction method and freezing system of connected aisle

Abstract

The invention relates to the technical field of tunnel excavation, in particular to a freezing construction method and a freezing system of a connected aisle. The method comprises the following stepsthat a plurality of freezing holes, a plurality of temperature measuring holes and a plurality of pressure relief holes are arranged on two sides of the contacted aisle; a freezing station is arrangedin the tunnel at one side of the contacted aisle, and multiple rows of freezing and discharging pipes are laid on the contacted aisle opposite to the freezing station along the peripheral freezing wall of the aisle; the freezing system is arranged at the freezing station, and the freezing system is debugged and operated; soil between the two sides of the tunnel is actively frozen, the frozen soiltemperature between the two sides of the tunnel is measured by using temperature measuring holes, the average temperature of a freezing wall is calculated, and when the average temperature reaches apreset value, the excavation condition of the contacted aisle is judged to be met; during the excavation period, maintenance freezing is carried out, and the frozen data is monitored and maintained. According to the freezing construction method and the freezing system, a secondary drilling process is adopted in a drilling stage, and the situation that a large amount of mud and water are dischargedwhen a duct piece is drilled in a penetrating mode is prevented; in the freezing process, the brine water temperature change of each group of freezing devices is detected and analyzed, and the construction safety of the contacted aisle is guaranteed.

Description

technical field [0001] The invention relates to the technical field of tunnel excavation, in particular to a freezing construction method and a freezing system of a communication channel. Background technique [0002] The tunnel freezing construction method is mainly used in areas with poor geological environment, such as unstable rock formations, which may collapse during construction, etc., which are not conducive to engineering or cause danger to construction personnel. The principle of this method is to use low temperature to stabilize the rock formation and facilitate construction. [0003] The freezing method is suitable for geology with high water content and loose sand and gravel, such as round gravel layer, weathered mudstone and sand liquefaction. The round gravel layer is a medium-permeable layer with abundant water. During the construction of the freezing hole, large seepage water may occur, resulting in flow of soil, piping, and the risk of pipe breakage in dri...

AI Technical Summary

Problems solved by technology

The advantage of this method is that the environment after freezing is better, which is conducive to construction, and it is also non-polluting to the environment, which is beneficial to underground construction. Its disadvantage is that the cost may be high, and it has requirements for the surrounding environment. It is best to have more water, and will extend the duration

[0005] However, such an accident occurred during the construction of the communication channel by the freezing method. Due to the influx of a large amount of water and quicksand in the construction work surface of the tunnel communication channel, part of the structure of the tunnel was damaged and the ground in the surrounding area subsided, causing three buildings to seriously tilt. The partial collapse of the flood control wall caused piping in the cofferdam of the flood control wall, and the direct economic loss was preliminarily estimated at about 150 million yuan

The conclusion of the accident investigation showed that the cause of the accident was that the construction unit failed to take effective measures to eliminate the danger in time when the refrigeration equipment used for the freezing method broke down, signs of danger appeared, and the project was shut down. , which directly caused the accident

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