JP2003328686A - Earth and sand transport system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an earth and sand transport system which is carried out in a simple manner, and copes with a long-range transport. <P>SOLUTION: The earth and sand transport system is comprised of a feed pipe 21 for transporting a transporting medium to a source, a transport pipe 22 for discharging the transporting medium and earth and sand from the source of the earth and sand, an intermediate tank 11 arranged at some midpoint of the feed pipe 21, for storing therein the transporting medium, a separator 13 arranged at some midpoint of the transport pipe 22, for separating the transporting medium from the earth and sand, a returning pipe 24 for returning the transporting medium separated by the separator 13 to the intermediate tank 11, an air feeding device 14 for feeding air to the transport pipe 25 on a downstream side of the separator 13, and a sucking device 15 arranged at some midpoint of the transport pipe 25 on one side of the air feeding pipe 14 closer to a transport destination. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sediment transport system.

[0002]

2. Description of the Related Art In construction involving excavation of earth and sand such as shield construction method, cast-in-place pile construction method, continuous underground wall construction method, and replacement work of contaminated soil, a treatment facility is provided at a position away from the place where sediment is generated. The space between them is connected by piping and transported by pumping. For example, in the muddy water shield construction method, a large-scale treatment facility placed on the ground side and the face of the shield machine are connected by two lines of pipes (mud pipe and drain pipe), and a pressure pump is provided in the middle of each pipe. The muddy water is pumped and circulated between the face and the treatment facility while the muddy water is separated from the face and is collected in a slurry state at the treatment facility.

[0003]

However, the above-mentioned earth and sand transportation technology has the following problems. <B> When the transportation distance becomes long due to the piping resistance, we are installing additional relay pumps in the piping of each system, but as the transportation distance becomes longer, the number of relay pumps installed will increase and the transportation cost will increase. Grows. Furthermore, in general, work vehicles pass through the tunnel and various pipes are laid down, so the space is narrow. Therefore, it is difficult to secure a space for installing an additional relay pump. <B> In the case of ultra-long-distance transportation of several kilometers, it is necessary to set the pressure in the pipe to a high level, but there remains a technical problem with increasing the withstand pressure of transport equipment such as pumps and piping, and It becomes expensive. <C> When the rotary vane type slurry pump that is generally used as a transport pump passes through, the soil lumps are finely crushed, and the turbulent flow action in the pipe makes the soil fine. Considering the recovery efficiency of the excavated sediment in the treatment facility, it is desirable to collect the sediment in the form of lumps as much as possible. )Is required. <D> In the conventional transportation system, in order to avoid a blockage accident in the mud pipe, not only the amount of sediment per unit time but also the critical sedimentation velocity of the soil particles dissolved in the muddy water must be considered. Equipment scale increases.

The present invention has been made in view of the above points, and an object of the present invention is to provide a sediment transport system which can cope with long-distance transport by a simple method.

[0005]

According to the present invention, a supply pipe for transporting a transportation medium to a source of sediment, a transportation pipe for discharging the transportation medium and the sediment from the source of sediment, and a pipe disposed in the middle of the supply pipe. A relay tank for storing the transport medium, a separator disposed in the middle of the transport pipe for separating the transport medium and the sediment, and a reflux pipe for transferring the transport medium separated by the separator to the relay tank, A sediment transport system. Further, the present invention provides a supply pipe for transporting a transportation medium to a source of sediment, a transportation pipe for discharging the transportation medium and the sediment from the source of sediment, and a relay tank arranged in the middle of the supply pipe for storing the transportation medium. And a separator arranged in the middle of the transportation pipe to separate the transportation medium and the sediment, a reflux pipe for transferring the transportation medium separated by the separator to a relay tank, and a transportation pipe upstream of the separator. And a mixer for arranging and mixing a transport medium. Furthermore, the present invention is any one of the above-mentioned earth and sand transportation system, wherein an air supply device for supplying air to a transportation pipe downstream of the separator and a transportation direction side of the air supply device for the transportation pipe. And a suction device. Furthermore, the present invention is any one of the above-mentioned earth and sand transportation system, wherein the transportation medium is muddy water.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. In this example, a shield tunnel will be described as an example, but the transport medium includes water and various liquids in addition to muddy water, and the earth and sand includes general earth and contaminated soil.

<A> Outline of Transportation System FIG. 1 shows a model diagram of the transportation system according to the present invention. A first supply pipe 20 connects the above-ground tank 10 for storing muddy water and the relay tank 11 in the tunnel. From the ground supply pump P1 through the first supply pipe 20 to the relay tank 11
The mud is used to replenish the circulating mud of the face and to control the properties of the mud. Relay tank 1
1 and the face of the shield machine 30 are connected by a second supply pipe 21. The control pump P2 provided in the middle of the second supply pipe 21 can supply the muddy water in the relay tank 11 to the face while controlling the supply amount.

A muddy water / sand / sand separator 13 is installed in the tunnel. The face (screw conveyor 31) of the shield machine 30 and the muddy water / sand / sand separator 13 are connected by a first transport pipe 22, and the first transport between the face and the muddy / sand / sand separator 13 is performed. A discharge pump P3 is interposed in the pipe 22. If gravel or the like is expected due to the soil condition, a crusher is installed near the face of the discharge pump P3, if necessary.

The muddy water / sand / sand separator 13 and the relay tank 11
Between them are connected by a reflux pipe 24, and only the muddy water separated and collected by the muddy water / sand / sand separator 13 is transported to the relay tank 11, and the muddy water can be circulated and used without returning to the ground tank 10. To do. Further, a second transportation pipe 25 is provided from the muddy water / sand / sand separator 13 to the ground, and transports only the soil / sand separated and collected by the muddy / sand / sand separator 13.

In the second transport pipe 25, an air supply device 1 which will be described later in order from the muddy water / sediment separation device 13 toward the vertical shaft 40.
4, the suction device 15, and the soil discharge pump P4 are interposed. The suction device 15 is installed at the tunnel entrance or the bottom of the shaft 40. Although the soil discharge pump P4 is installed at the bottom of the vertical shaft 40, it may be omitted. The terminal end of the second transportation pipe 25 is connected to the plant equipment 16 on the ground, and the collected earth and sand is subjected to a predetermined treatment. It should be noted that reference numerals V1 to V6 in FIG. 1 denote valves provided in each tube.

<B> Muddy water / sediment separation device Discharge pump P3
The sediment separating device 13 is installed. Muddy water / sediment separation device 13
Is an apparatus for separating muddy water and earth and sand, and various known separating means can be applied. For example, classifiers such as cyclones that separate (classify) and remove solids such as gravel and sand from slurry-like soil, a tank that separately stores the separated mud water and sediment, and a storage tank It can be configured by a pump that supplies muddy water to the relay tank 11. The tank for storing the sediment content is connected to the starting end of the second transport pipe 25.

<C> Means for Transporting Sediment The present invention is to combine an air supply device 14 and a suction device 15 to efficiently transport sediment by the synergistic effect of both devices 14, 15.

The air supply device 14 is a device for forcibly feeding air into the second transport pipe 25. The air supply device 14 has small holes formed in the body of the second transport pipe 25 to continuously supply air to the entire inner peripheral surface. To form an insulating layer by air between the inner peripheral surface of the pipe and the sediment content.

The suction device 15 is composed of, for example, a sealed tank and a suction pump for generating a negative pressure (vacuum) in the tank, and cooperates with the air supply device 14 to suck the earth and sand into the tank. ing. When the vertical shaft 40 is shallow, the suction device 15 may be installed on the ground. in this way,
By using the air supply device 14 and the suction device 15 in combination, it is not necessary to use the rotary blade type slurry pump, the stirring action and the turbulent flow action when passing through the pipe are eliminated, and the destruction of the lump of sand and sand can be suppressed.

[0015]

[Operation] Next, a method of transporting muddy water and earth and sand will be described.

<A> Face Pressure Control The face pressure is controlled using a control pump (slurry pump) P2. If the supply pump P1 on the side of the aboveground tank 10 and the cutting face are directly connected by a pipe as in the conventional case, the situation of the cutting face changes when mud water adjusted based on the pressure information of the cutting face reaches the cutting face, which is difficult to cope with. However, in the present invention, since the transport distance of the muddy water can be greatly shortened, the muddy water adjusted based on the information on the face can be instantaneously supplied to the face, which improves the adaptability. Moreover, since the pressure propagation of the muddy water is blocked before and after the relay tank 11, the pressure of the face is controlled to an optimum pressure without being affected by the pressure of the muddy water over the section from the ground tank 10 to the relay tank 11. You can
In particular, when the shaft 40 is very deep, the shield machine 30 can be safely started and excavated without being affected by the pressure caused by the potential energy of the muddy water filled in the first supply pipe 20. Further, even when the pressure on the natural side of the face changes during excavation, the supply pressure of the muddy water can be controlled by following this pressure change. When the relay tank 11 has a sealed structure, it is possible to control the pressure of the face by using the ground control pump P2 in addition to the discharge pump P3.

Further, the rotation speed variable type discharge pump P3 installed on the drainage side contributes to the stability of the face by smoothing the amount of muddy water carried out from the face, and performs a constant value control of the flow rate of the drainage. Keep the limiting sedimentation flow rate.

<B> The screw conveyor 31 is operated by the operation of the muddy water transport discharge pump P3.
The slurry-like soil in the face is transported to the muddy water / sand / sand separator 13 through the first transport pipe 22. The muddy water / sand / sand separation device 13 separates the excavated soil and muddy water, respectively. The separated mud moisture flows back to the relay tank 11 through the reflux pipe 24. By returning the muddy water to the middle of the supply pipe via the relay tank 11 instead of transporting it to the plant facility 16 on the ground, it is possible to shorten the muddy water transportation distance and improve the transportation efficiency.

<C> Transportation of excavated soil The sediment content separated and stored by the muddy water / sediment separation device 13 is produced by the cooperation of the air supply device 14 and the suction device 15.
It is transported through the second transport pipe 25, and the soil discharge pump P4 is operated to transport it to the plant facility 16 on the ground.

The principle of sediment transport will be described with reference to FIG. The white arrow indicates the second transport pipe 2 by the air supply device 14.
5 indicates the air forcibly fed, and the black arrow indicates the suction force forcibly generated in the second transport pipe 25 by the suction device 15, and acts in the same direction. The air forcibly fed into the second transport pipe 25 by the air supply device 14 forms an insulating layer between the sediment 50 and the pipeline to prevent the sediment 50 from adhering to the inner surface of the pipeline, It acts as a pushing force toward the transportation direction. Since the air acts on the earth and sand 50 in an insulated state from the pipeline as a pushing force and a pulling force in the transportation direction, the air can be easily transported.

If the earth and sand 50 is sucked only by the suction device 15, transportation becomes extremely difficult. This is because the sediment 50 adheres to the inner surface of the pipeline due to the viscosity and adhesiveness of the sediment, and when the sediment is located on the entire transport cross section of the pipeline, clogging easily occurs. Further, if the supply amount of the earth and sand 50 is adjusted so that a cavity is formed in a part of the cross section of the pipeline, the suction force escapes through the cavity and is not transmitted to the earth and sand 50 as a transport force. Therefore, the present invention enables the long-distance transportation of the earth and sand 50 by using the air supply device 14 and the suction device 15 in combination.

[0022]

Embodiment 2 In order to improve the transportability of slurry-like earth and sand in the first transport pipe 22, as shown in FIG. 1, a mixer 12 is provided in the first transport pipe 22 near the face and You may make it connect the 2nd supply pipe 21 and the mixer 12 with the branch pipe 23, and may add a suitable amount of muddy water to earth and sand in the mixer 12.

[0023]

Third Embodiment Although the case where one relay tank 11 is provided in the middle of the supply pipe has been described above, a plurality of relay tanks 11 may be arranged in series at a predetermined distance. . In this case, the control pump P2 is also added according to the number of additional relay tanks 11. Similarly, a plurality of sets of earth and sand transportation means including the air supply device 14 and the suction device 15 may be arranged in the second transportation pipe 25 at a predetermined distance. Further, a combination in which a plurality of air supply devices 14 are arranged with respect to one suction device 15 may be used. This example is suitable for transporting earth and sand over an extremely long distance.

[0024]

According to the present invention, at least one of the following effects can be obtained. <B> A relay tank may be provided in the middle of the supply pipe so that the transportation medium can be returned to the relay tank without returning to the ground and used, and the replenishment of muddy water from the ground can be minimized. Especially, since the pressure propagation of the transportation medium is blocked before and after the relay tank, the transportation from the relay tank to the source of sediment is not affected by the pressure medium from the ground to the relay tank. The medium can be controlled to the optimum pressure. <B> Since it is not necessary to additionally install a relay pump in the supply pipe and the transportation pipe, the facility cost and maintenance cost can be reduced, and the transportation cost can be significantly reduced as a whole. <C> Space saving and energy saving can be achieved by omitting the relay pump. <D> By using the air supply device and the suction device in combination, it is possible to avoid the accident of clogging of the separated soil and sand and efficiently transport it. <E> Since the rotary vane type slurry pump is not used as a means for transporting the separated earth and sand, the earth and sand can be collected in a lump form. Therefore, not only is the efficiency of soil collection improved, but new equipment (secondary treatment equipment) is not required. <F> The present invention can be applied to a shield construction method, a cast-in-place pile construction method, a continuous underground wall construction method, a contaminated soil replacement construction, and the like, and is highly versatile.

[Brief description of drawings]

[Fig.1] Model diagram of sediment transport system

[Fig. 2] An explanatory diagram of the transport principle of partially broken soil

[Explanation of symbols]

10 aboveground tanks 11 Relay tank 12 Mixer 13 Muddy water / sediment separation device 14 Air supply device 15 Suction device 16 plant equipment 20 First supply pipe 21 Second supply pipe 22 First Transport Pipe 24 reflux pipe 25 Second Transport Pipe 30 shield machine 40 shafts P1 supply pump P2 control pump P3 discharge pump P4 earth pump

Claims (4)

[Claims] 1. A supply pipe for transporting a transport medium to a source of sediment, a transport pipe for discharging the transport medium and the sediment from the source of sediment, and a relay tank arranged in the middle of the supply pipe for storing the transport medium. A sediment transport system that includes a separator disposed in the middle of the transport pipe to separate the transport medium and the sediment from each other, and a reflux pipe that transfers the transport medium separated by the separator to a relay tank. 2. A supply pipe for transporting the transport medium to a source of sediment, a transport pipe for discharging the transport medium and the sediment from the source of sediment, and a relay tank arranged in the middle of the supply pipe for storing the transport medium. A separator that is arranged in the middle of the transport pipe to separate the transport medium and the sediment, a reflux pipe that transfers the transport medium separated by the separator to a relay tank, and a transport pipe upstream of the separator. A sediment transport system, which is arranged and comprises a mixer for mixing transport media. 3. The air supply device for supplying air to a transportation pipe downstream of the separator, and the suction device installed on the transportation direction side of the air supply device of the transportation pipe. The sediment transport system described in 2. 4. The sediment transport system according to claim 1, wherein the transport medium is muddy water.