JPS63197776A - Construction of ground space - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention mainly relates to a method of constructing a submerged underground space used for storing gas, liquid, solid, etc. in soft ground or rock.

(Prior art and its problems) In cities and industrial areas that are becoming more and more crowded every year, it is becoming difficult to build above-ground storage tanks for oil, LPG, and other liquids, gases, and even solids due to their location. It is also very expensive. Furthermore, the construction of gas tanks and the like that store gas under pressures of 1 atmosphere or more is restricted because it is necessary to consider the danger to the surrounding environment.

Therefore, recently, proposals have been made to solve the above-mentioned problems such as location ability and economic efficiency by constructing a storage tank in an underground space at a depth of about 100 to 1000 m.

However, with conventional construction methods in which workers enter the borehole and construct a storage structure made of reinforced concrete or steel, it is necessary to deal with the dangers of walls collapsing and seepage of muddy water during the work. As a result, costs will increase and the construction period will become longer. Particularly in Japan, where cities and industrial areas are located underground, there is soft rock such as the so-called Quaternary or Tertiary layer.
It is no exaggeration to say that it is impossible to construct an underground space for a storage tank at a depth of 0.000 to 1000 m using conventional construction methods.

(Purpose of the Invention) The present invention has been made with the purpose of providing a method for safely, quickly and economically constructing a submerged underground tank at a deep depth, particularly in soft ground or bedrock. The details will be explained using the drawings.

(Means of the present invention for solving the problems) As shown in FIG. 1(a) showing one embodiment, the present invention is as follows: Flexible, watertight, abrasion resistant with opening (3a) and bottom (3b) maintained to maintain watertightness between two points of feed pipe (2) with feed hole (2a) inside. A bag-like membrane (bag-like membrane body) with abrasion resistance 2 elasticity, such as a membrane (3) made of one or more layers of strong artificial fiber rubberized cloth or thin steel plates, is shrunk. Under this condition, the feed pipe (2
).

■Next, as shown in Figure 1 (b) and (C), between the wall surface (1) of the borehole and the membrane (3), the side view of Figure 1 (C) and the front view of (d1) The caterpillar-shaped running wheels (4a) operated from the ground allow for front, rear, left and right movement.

Excavating tools such as chainsaws (4
b) The torpedo-shaped excavating tool (4) is mounted on the excavation surface (1) and the membrane (3) with
The running wheels (4a) and the excavation tool (4a) are located on the side.
One or more pieces are inserted using the suspension cable (5) equipped with the drive type cable cable (b) using its own weight.

(2) Thereafter, as shown in FIG. 1(b), a liquid such as water is injected into the membrane (3) from the ground through the feed pipe (2).

Then, the excavation surface (1) and the feed pipe (2) are connected so that the pressure of leached mud water from the rock that occurs between the excavation surface (1) and the membrane (3) is appropriately lower than the water pressure inside the membrane (3). Using a discharge pipe (7) inserted between the pipes and a water pump (not shown) installed on the ground, the muddy water (8) can be discharged by airlift, for example, or the water pressure by the supply pipe (2) can be adjusted. , to create a back pressure on the membrane (3) necessary to press the excavation tool (4) against the excavation surface to the extent that it can be moved.

(2) After that, the excavation tool (4b) and the running wheel (4a) are driven from the ground, and then the direction of the running wheel (4a) is controlled.

For example, the excavation is performed by moving up and down while turning as shown by the arrow in Fig. 1(e), and by varying the number of excavations in the same location depending on the shape of the space to be excavated. While discharging the earth and sand through the discharge pipe (7) by reducing the differential pressure between the membranes (3) to zero, the membrane (3)
) is inflated according to the size of the space and excavation is performed. Then, as shown in Fig. 1(e), (f), and (g), the diameter of the space (9) in Fig. 1(h) is gradually expanded to have the desired shape and capacity.
) to form.

■Finally, the water in the membrane (3) is drained using the feed pipe (2), and the excavating tool (4) is pulled up using the hanging cable (5), and then the liquid to be stored is removed from the feed pipe (2). It is completed by leaving it as a gas and solid supply pipe.

(Other Embodiments) Although one embodiment of the present invention has been described above, the following method can be used as a method for generating a differential pressure for pressing the excavation tool (4) against the excavation surface (1). One of them, as shown in Figure 2, is a feed pipe that passes through the lower end of the membrane (3) fixed to the feed pipe (2) and communicates with the space between the excavation surface (1) and the membrane (3). The trachea aω is provided concentrically within the feeding tube (2). Then, as shown by the arrow in the figure, the excavation surface (1)
Compressed air is blown into the leachate mud (8) between the membrane (3) and the membrane (3), or a mixed air jet is poured into it. This creates a water flow in the leaching mud (8) from below to above in the direction of the dotted arrow in the figure, thereby creating negative pressure that presses the excavation tool (4) against the excavation surface (1). In addition, this method can be used in conjunction with a method that utilizes this rising water flow to discharge muddy water containing soil, sand, rock fragments, etc. to the ground or to assist in its discharge.

The second method is to install a flexible air pipe α (0 (the exhaust pipe (7) may be shared) at the bottom of the membrane (3) as shown in Figure 3 (al (b)). A plurality of pipes are provided so as to reach each other, and a digging tool (
4) and excavate while creating an upward flow in the muddy water (8) between the excavation surface (1) and the membrane (3) through the discharge pipe (7). ), and when applying the above-mentioned upward flow, the drilling tool (4) is provided with a mud water circulation hole (4c) as shown in Figure 4, and the drilling tool (4) is may be made so that it does not become an obstacle to water flow. Moreover, an upward flow can be created by providing a water flow generating device such as an air mixture jet pump in the circulation hole provided in the excavation tool (4). It is also possible to inject a foaming agent into the waste water between the excavation wall surface and the membrane to foam it, thereby obtaining water-stopping properties on the excavation wall surface and reducing the power of the excavation tool.

In addition, in the embodiment described above, as shown in FIG. 1(h), the space (9
) was left excavated, but the following method can be used to prevent the excavated surface from collapsing due to the nature of the ground and rock, the amount of leached mud, etc. That is, after excavating the space (9) as shown in Figure 1 (fh), the differential pressure between the mud water pressure and the membrane (3) is adjusted to ensure sufficient strength and watertightness between the excavated surface (1) and the membrane (3). Maintain the spacing so that a concrete wall with good properties can be formed. Then, while maintaining this condition, the leached mud is drained through the concrete supply pipes αυ inserted alternately at equal intervals between the discharge pipes (7) and the discharge pipes (7) as shown in Fig. 5(a) and (b). Lining materials that harden in water, such as underwater concrete (b)
A method can be adopted in which the wall surface is lined by pouring it between the excavated surface (1) and the membrane (3). In this case, the remaining membrane (3) will serve as a reinforcement for the concrete wall.

Furthermore, as shown in Figure 6, a casing pipe (7) is provided outside the discharge pipe (7), and underwater concrete (2) is poured between this and the borehole wall (1) to cover the entire surface including the borehole wall. Can be lined. This method is suitable when it is desired to finally pull out the feed pipe (2) or the discharge pipe (7) to enlarge the diameter.
If the pipe is left as a supply pipe for liquid such as petroleum, after pulling out the discharge pipe (7), connect the borehole wall fl) and the feed pipe (
A method can be used in which the lining material @ is poured directly between 2) and the entire surface of the excavation, including the borehole wall, is lined.

Moreover, in the above embodiment, the excavating tool (4) is driven by a drive source supplied with electric power by a cable. However, as shown in Fig. 7, the guide wheel α on the drive pipe (10) inserted outside the feed pipe (2) and the annular chain belt Qη rotated by the drive wheel αe are connected in series. With multiple excavators (4) attached, the rotation of the drive wheel (151) causes vertical movement in the direction of the solid line arrow in the figure, and the rotation of the drive pipe Q4) causes the excavator (4) to rotate in the direction of the dotted line arrow in the figure. It is also possible to use a method of excavating by moving.

Furthermore, any known driving method may be used, such as providing the excavator with a mixed air water jet device facing various directions and allowing the tool to move freely by controlling the jetting direction of the mixed air water jet. . Furthermore, although a chainsaw has been described above as an example of the excavation tool (4b), it is possible to select and use a chain saw according to the nature of the rock to be excavated, such as one using a mixed water jet jet from a mixed water jet nozzle. Moreover, although the example of construction consisting of a borehole and a storage space following the borehole has been described above, it is also possible to construct an underground space having a shape other than that shown in FIG. 8, for example.

(Effect of the invention) As mentioned above, in the boring method, a steel rod is used to crush the rock while drilling the hole, and the diameter can only be expanded to about three times the hole diameter. It's impossible.

Therefore, it is necessary to bore the hole to a required depth and then have workers enter the inside of the hole to excavate. However, this requires measures to prevent walls from collapsing, requiring a long construction period and large costs.

However, in the present invention, a membrane that expands and contracts with water pressure is used, and the difference between the water pressure inside the membrane and the leached mud water pressure can be used to generate lateral pressure that is effective in preventing collapse of the excavation surface and from the ground that is sandwiched between the excavation surface and the membrane. Excavation is performed by applying force in the direction of the excavation wall to a freely movable excavation tool. Therefore, a storage space having a desired shape and capacity can be created in the ground at a depth possible by boring without danger, even when the soil is soft and there is a lot of leached mud, without the need for workers to enter the borehole at all.

In addition, in the present invention, concrete lining can be performed unmanned by simply pouring concrete using the membrane as a formwork following excavation. Furthermore, in the present invention, since the underwater capacity of the excavated soil is limited by the membrane, the concentration of the excavated soil can be increased, and the upward flow of the mud by injecting air or mixed jet water into the leach mud is utilized. This enables efficient discharge.

Therefore, according to the present invention, it is possible to construct a storage space on soft ground while reducing the construction period and cost compared to conventional construction methods.

[Brief explanation of the drawing]

FIG. 1 is an embodiment of the present invention, FIG. 2, and FIG. 3. FIG. 4, FIG. 5, FIG. 6, FIG. 7, and FIG. 8 are diagrams showing other embodiments of the present invention, respectively. (1)... Excavation surface, (2)... Feed pipe, (2a
)...Feeding port, (3)...Membrane, (4)...
... Excavation tool, (4a) ... Caterpillar-shaped running wheel,
(4b)...Drilling tool, (5)...Suspension cable, (
6)... Water, (7)... Discharge pipe, (8)... Leach mud, (9)... Excavation space, ao... Air supply pipe, αt... Lining material supply pipe, @...Lining material, 03)...Casing pipe, 0 ship...Drive pipe,
QSI...Guide shaft, ao...Drive chain wheel, 0η...Annular chain belt.

Claims (10)

[Claims] (1) A membrane that is attached to one end of the feed pipe and expands and contracts with the supply and discharge of gas or liquid is lowered into the borehole using the feed pipe, and then placed between the membrane and the excavation wall from the ground. Back pressure from the membrane that pushes the excavation tool toward the excavation wall by adjusting the differential pressure between the drainage water pressure generated between the membrane and the excavation wall and the internal pressure of the membrane. A method for constructing an underground space, characterized in that the excavating tool is operated and moved under this back pressure to excavate the underground space. (2) A method for constructing an underground space according to claim 1, characterized in that the wall of the excavated space is lined by injecting a lining material between the excavated wall and the membrane. (3) In claims 1 and 2, a casing pipe is inserted between the feed pipe and the borehole wall, and a lining material is injected between the borehole wall and the casing pipe to form an excavation space wall. A method of constructing an underground space characterized by lining both the wall and the wall of the borehole. (4) In claim 1, an air flow is generated that causes a flow of muddy water from downward to upward in the drained muddy water between the excavation wall and the membrane, thereby generating back pressure that presses the excavation tool against the excavation surface. A method of constructing an underground tank characterized by the following. (5) In claim 1, the back pressure that presses the excavation tool against the excavation surface is created by generating a mixed air jet flow that causes a mud flow from below to upward in the waste mud water between the excavation wall and the membrane. A method for constructing an underground space characterized by creating an underground space. (6) Claims 4 and 5 provide that the air flow and air-fuel mixture jet flow are generated by a water flow generation pipe provided in the feed pipe to the membrane so as to penetrate the lower end of the membrane. A distinctive underground space construction method. (7) In claims 4 and 5, a plurality of air flows and mixed air jet flows are provided at intervals between the excavation wall and the membrane so that the openings are located at the bottom of the membrane. A method for constructing an underground space characterized by using a water flow generating pipe. (8) A method for constructing an underground space, characterized in that the excavating tool according to claims 4, 5, 6, and 7 has a mud flow hole. (9) A method for constructing an underground space according to claims 4 and 5, characterized in that the generation of the upward flow is performed by an air mixture jet generator provided on an excavator. (10) Claims 1, 4, 5, and 6
Items 1, 7, 8, and 9 are characterized in that a foaming agent is injected into the waste water between the excavation wall and the membrane, and the resulting air bubbles improve the water-stopping properties of the excavation surface. Method of constructing underground space.