Plugging method of pressure-bearing water piping in deep foundation pit engineering

Abstract

The invention discloses a plugging method of pressure-bearing water piping in deep foundation pit engineering, and relates to the technical field of deep foundation pit engineering. The plugging method comprises the steps that A, a steel pipe (2) is pressed into a clayey soil layer (3) below an excavation surface with a pressure-bearing water piping point A as the center; B, the position, within 2m of the radius out of the steel pipe (2), is filled with bagged cement or bagged sand soil; C, the steel pipe (2) is filled with gravel (7); D, multiple sections of short steel pipes are used for lengthening the steel pipe (2) until the top of the steel pipe (2) is more than 0.5m above the piping pressure-bearing water level; E, a grouting pipe (5) is inserted in the steel pipe (2) along the pressure-bearing water piping point A; F, grouting is performed; G, water in the steel pipe (2) is extracted until the water no longer occurs in the steel pipe (2); and H, a water-stop steel plate (8) iswelded outside the steel pipe (2), the portion, located above reinforcements on the upper layer of a bottom plate, of the steel pipe (2) is cut out, and the concrete pouring is carried out on the bottom plate (9). The plugging method of pressure-bearing water piping in deep foundation pit engineering has characteristics of simple construction, high operability, good plugging effect and wide applicability, and provides technical support for deep foundation pit engineering quality.

Description

technical field [0001] The invention relates to the technical field of deep foundation pit engineering, in particular to a sealing method for pressurized water piping in deep foundation pit engineering. Background technique [0002] With the development and development of urban underground space, the excavation depth of deep foundation pits is getting deeper and deeper. When there is a confined aquifer under the excavation surface of the foundation pit (such as the attached figure 1 As shown in ) 1, the phenomenon of confined water inrush may occur during the excavation process, which poses a threat to the stability of the foundation pit and the safety of the facilities around the foundation pit, and it is necessary to take timely measures to prevent the Surge blocking. [0003] According to Chinese patent 201510081737.5, there is a method and device for quick plugging of piping in deep foundation pits. After the geotechnical bag is sent into the impermeable layer of the ...

AI Technical Summary

Problems solved by technology

However, this method of piping plugging depends entirely on experience to judge whether the plugging is successful, which is prone to misjudgments and potential safety hazards.

[0004] Further analysis shows that this piping plugging scheme has the following defects: first, it is only applicable to the situation where the water inflow and pressure of the pressurized water pipe are small; Unfavorable effects such as pressurized water piping channels and increasing the pressure of the pressurized water in the piping channels may further accelerate the scope of the pressurized water piping, resulting in pressurized water piping accidents; finally, when grouting into the geotechnical bag, due to the pressure Due to the action of water, the pressed cement slurry is lost with the pressurized water, and cannot be solidified at the preset position, and the grouting effect cannot be effectively exerted, resulting in plugging failure

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