RU2516630C1 - Method of pipe driving in soil - Google Patents

Abstract

FIELD: mining.

SUBSTANCE: proposed method consist in driving the pipe in soil, forming the soil core in pipe face section, forcing said core by air pressure portions in annulus, cutting off the core portions to make the chamber ahead of soil core portion by displacing the soil duct in the axis of submergence. Said soil duct is composed by submersible pipe to be displaced in submergence axis by static force. Soil core portions transfer is conducted by creating vacuum at submersible pipe external end.

EFFECT: lower power intensity, lower costs.

3 cl, 3 dwg

Description

The technical solution relates to mining and construction equipment and can be used for trenchless laying of underground utilities.

A known method of trenchless laying of underground utilities according to the patent of the Russian Federation No. 2229566, E02F 5/18, E02D 7/10, F16L 1/028, publ. 05/27/2004, which consists in driving the pipe into the soil to the required length in sandy loam sections of length no more than 9, and in clay no more than 7 of its inner diameters, while stopping it with emphasis, removing soil from the clogged section of the pipe with impacts communicated to it, stop the impact on the pipe and disconnect the stop from the pipe after clogging each of its sections.

The disadvantage of this method is the decrease in productivity in the limit to zero at the end of the process, the instability of the process and the inability to completely clean the pipe from the ground, because as cleaning, the soil is redistributed along the entire length of the pipe, the height of the soil layer decreases, therefore, the friction forces that ensure the movement of soil through the pipe are reduced.

The closest in technical essence and combination of essential features is the method of trenchless laying of pipelines in the ground (see N.Ya. Kershenbaum and V.I. Minaev. Drilling of horizontal and vertical wells by the impact method. M .: "Nedra". 1984, p. 36-37), which consists in immersing the pipe into the soil with an open front end, forming a soil core in its bottomhole part, which is transported in portions of the air pipe built into the submersible pipe by the pressure of air entering the annulus, cutting off the portion th core core and the formation of the chamber in front of a portion of the soil core by displacing the soil pipe along the axis of immersion by air pressure.

The disadvantage of this method is the large power consumption of the process of immersion of the pipe due to the significant joint drag of the immersed coarse and soil core in the soil pipe due to the high degree of compression, which leads to an increase in the friction forces of the soil core against the inner surface of the pipe. The presence of the reciprocating motion of the soil pipe in an abrasive soil environment can lead to jamming of the soil pipe in some position, which will lead to disruption of the process of separation and transportation of portions of soil core. In addition, the reciprocating motion of the soil pipe complicates the design that implements the method.

Solved technical problems are to reduce the energy intensity of the process of immersing the pipe by reducing the drag of the immersed pipe, to increase the reliability of separation and removal of portions of soil core from the immersed pipe by moving it along the axis of the well from the bottom, and to reduce the cost of a set of equipment that implements the method for by applying vacuum instead of overpressure.

The problem is solved due to the fact that in the method of trenchless laying of pipes in the soil, which consists in immersing the pipe in the soil, forming a soil core in the bottomhole part of the submerged pipe, transporting it through the soil pipe in portions with the pressure of air entering the annulus, cutting off portions of the soil core and forming chambers in front of a portion of soil core by displacing the soil pipe along the axis of immersion, according to the technical solution, an immersion pipe is used as the soil pipe, which is displaced along the axis immersing static force and transporting soil core portions is carried out by creating a vacuum on the outer end of the submerged pipe.

The use of an immersion pipe as a soil pipe significantly reduces its frontal resistance due to the absence of a soil pipe inside it, and the transportation of portions of soil core using vacuum eliminates the need for compressed air to reach the downhole end of an immersion pipe: it is enough to have a connection between the downhole end of an immersed pipe and the atmosphere. In addition, the cost of vacuum installations is much cheaper than similar installations for creating excess pressure at the same flow rate.

It is advisable to form longitudinal channels in the annulus at the same time as the pipe is immersed using one or more local expanders with openings by which this chamber is connected to the annular space installed on the bottomhole end of the immersed pipe. Local expanders displace the soil in the annulus and form longitudinal channels connecting the chamber to the atmosphere. This will increase the reliability and speed of transportation of portions of soil core due to the greater influx of atmospheric air into the chamber.

It is advisable after displacement of the immersed pipe along the axis of immersion to carry out its rotation around this axis. Holes in local expanders may become clogged with soil. The indicated rotation of the immersion pipe will allow the camera to communicate with the atmosphere over the entire cross section of the longitudinal channels formed by the local expanders. This will increase the reliability and speed of transportation of portions of soil core due to an even greater influx of atmospheric air into the chamber.

The essence of the technical solution is illustrated by examples of a specific implementation of the method and the drawings of figures 1-3.

Figure 1 shows a diagram of the implementation of the method of trenchless pipe laying in the ground.

Figure 2 shows a fragment of a diagram of the implementation of the method with local expanders at the downhole end of the immersed pipe.

Figure 3 shows a section A-A in figure 2. The arrow indicates the direction of rotation.

The method of trenchless laying of pipes in the soil is implemented as follows.

The immersed pipe 1 (hereinafter referred to as the pipe 1) is immersed with the open end into the ground by any known method (pressing F, impact, etc.). Soil enters the interior of pipe 1 and forms a soil core 2 (hereinafter - core 2). As the length of core 2 increases, an earth plug forms, immersion of pipe 1 slows down until it stops completely. To eliminate the dirt plug, the pipe 1 is displaced along the axis of immersion away from the bottom by a certain distance. To do this, an emphasis 3 is mounted on the pipe 1, transmitting the static force from the static force source 4 to the pipe 1, for example, hydraulic cylinders fixed as shown in Fig. 1. The displacement of the pipe 1 leads to the separation of the portion of the core 2 from the soil mass and the formation of the chamber 5 in the space free from the pipe 1 of the well. Using a vacuum pump 6, a vacuum is created at the outer end of the pipe 1, and atmospheric air penetrating into the chamber 5 through the annulus 7 creates pressure on the core portion 2 over the entire cross section of the pipe 1. Under the influence of atmospheric pressure, the core portion 2 begins to move through the soil pipe into in the form of an immersed pipe 1 until it gets into the core receiver 8 installed on the outer end of the pipe 1. Then the core receiver 8, the vacuum pump 6, the stop 3 and the source of static force 4 are dismantled and the immersion process of the pipe 1 is resumed.

For a more reliable connection of the chamber 5 with the atmosphere, one or more local expanders 9 with holes 10 can be fixed at the downhole end of the pipe 1 (Figs. 2 and 3). Local expanders 9 displace the soil in the annulus 7 and form longitudinal channels 11 through which atmospheric air through the openings 10 will enter the chamber 5. Since local expanders 9 are located only in several places along the perimeter of the cross-section of pipe 1 and their overall dimensions are insignificant (in FIGS. 2 and 3 they are shown on an enlarged scale for clarity), then the drag of the pipe 1 as a whole will increase slightly, and the presence of longitudinal channels 11 will improve the reliability and speed of transportation of portions of core 2.

The rotation of the pipe 1 (Fig. 3) after its axial displacement will also increase the air flow from the atmosphere into the chamber 5. In this case, the local expanders 9 will move to the side along the circumference and open the entire cross section of the longitudinal channels 11. This will provide a connection between the atmosphere and the chamber 5 along the entire cross section of the longitudinal channels 11, and not only through the holes 10.

Claims (3)

1. The method of trenchless laying of pipes in the soil, which consists in immersing the pipe in the soil, forming a soil core in the bottomhole part of the submerged pipe, transporting it through the soil pipe in portions with the pressure of air entering the annulus, cutting off portions of the soil core and forming a chamber before the portion of the soil core by displacement of the soil pipe along the axis of immersion, characterized in that as the soil pipe use an immersion pipe, which is displaced along the axis of immersion by static force, and transport ings precoat core portions is carried out by creating a vacuum on the outer end of the submerged pipe. 2. The method according to claim 1, characterized in that longitudinal channels are formed in the annulus at the same time as the pipe is immersed using one or more local expanders with openings by which this chamber is connected to the annular space installed on the bottomhole end of the immersed pipe. 3. The method according to claim 2, characterized in that after displacement of the immersed pipe along the axis of immersion, it is rotated around this axis.

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