JP3003535B2 - How to build underground space - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for constructing an underground space, and more particularly to a method for constructing an underground space for providing a large-scale underground space underground.

[0002]

2. Description of the Related Art In recent years, in order to make effective use of underground areas,
Underground ground is excavated by various tunnel construction methods, etc. to form an underground space, and this is used for roads, railways, electric power facilities, sewage facilities,
Alternatively, use as various facilities such as an underground shopping mall has been studied and implemented. And, as a method of providing such underground space in the ground, an open-cutting method, a tunnel method, etc. are adopted.However, when an underground space is provided at a considerable depth in the ground, especially in an urban area, a shield method, etc. It is common to use a tunnel method.

On the other hand, it has been desired to construct a large-scale underground space underground for the purpose of responding to the demand for the enlargement of the underground facility and to make more effective use of the underground area. In the tunnel construction method using a tunnel excavation machine such as a construction method, there is a limit to the cross-sectional size of the excavation machine, and the sole construction method using the excavation machine excavates and forms an underground space of a desired size. Is often difficult. Also, a method is considered in which the ground where the underground space is to be excavated and formed is improved and solidified in advance using auxiliary methods such as the chemical injection method and the groundwater level lowering method, and then the underground space is excavated and formed in the same way as the mountain tunnel method. Has been
Construction of such an auxiliary construction method on a large scale requires enormous construction cost and construction period, and because it is difficult to perform the construction with high accuracy, leakage of groundwater and collapse of the ground cause a problem in excavation work. Often.

In view of the difficulty in forming such an underground space, as a construction method combining the tunnel construction method, for example, shafts are formed at both ends of a large-scale underground space to be constructed, and these shafts are formed. As a shaft for starting or reaching, a large number of outer shell tunnels are installed continuously and closely in the circumferential direction of the underground space to form an outer shell covering the surrounding of the underground space, and the outer shell formed after that There has been proposed a method of excavating the inside of a building to form an underground space.

According to this method, the ground on which an underground space is to be excavated is firmly covered with an outer shell formed by continuously installing outer shell tunnels before the excavation work. Therefore, the excavation work in the underground space can be performed easily and reliably.

[0006]

However, according to the method of constructing an underground space by combining the above tunneling method, the outer shell tunnel forming the outer shell body needs to remove the surrounding ground prior to the excavation work of the underground space. In order to secure sufficient strength and waterproofness as an outer shell for strong protection in advance,
Since many of them are arranged close to each other continuously, there has been a problem that the construction period and construction cost for the construction work are increased.

Accordingly, the present invention has been made in view of such a problem, and has a simpler and more economical structure of the outer shell to facilitate the construction work thereof and to quickly perform the inner excavation work. It is an object of the present invention to provide a method of constructing an underground space capable of easily and efficiently forming a reliable underground space covered by a structure having sufficient strength and water-blocking property, Things.

[0008]

SUMMARY OF THE INVENTION The present invention has been made to achieve the above-mentioned object, and the gist of the invention is that a tunnel main body and wing-like projections formed on both sides of the tunnel main body are formed. In addition, a number of outer shell tunnels extending in the horizontal axis direction of the planned underground space are arranged such that each of the overhangs projects between adjacent tunnel main bodies along the circumferential direction of the underground space. A step of forming an outer shell structure covering the ground where the underground space is to be excavated and formed by continuously arranging the outer shell portion of the underground space, and forming a lining body inside the outer shell structure while doing,
The ground covered by the outer shell structure is sequentially excavated at predetermined divided lengths, so that a cover integrated with the outer shell structure is formed inside the outer shell structure. And a step of constructing and forming an underground space covered with an engineering body.

In the above description, the term "horizontal axis direction of the underground space" is a concept used to distinguish it from the vertical axis direction, which is the axis of the underground space mainly excavated and formed in a vertical direction such as a shaft. In addition to the axial direction extending in the horizontal direction, for example, the horizontal direction also includes an axial direction extending in a horizontal direction with a certain inclination, and an oblique axial direction in a shaft.

[0010] The predetermined length obtained by sequentially excavating the ground covered by the outer shell structure is as follows:
Even if the inside is excavated to a hollow state while both ends are supported by the ground before excavation or the lining body formed inside, each outer shell tunnel will not be damaged by the load from the outside Span length, which is appropriately designed in consideration of the bending strength of each outer shell tunnel, the geology and earth pressure of the surrounding ground, and the like.

According to the method of constructing an underground space of the present invention, in the step of forming the outer shell structure, the adjacent outer shell tunnel is formed on the ground at the tip of the overhang portion of each outer shell tunnel. It is preferable to form the improved ground by joining the overhanging portions.

[0012]

According to the underground space construction method of the present invention, prior to the underground space excavation work, the outer shell structure covering the ground where the underground space is to be excavated is formed by the tunnel main body, the overhang portion, By arranging the overhanging tunnel consisting of the overhanging portion in such a manner that each overhanging portion protrudes between adjacent tunnel main bodies along the circumferential direction of the underground space, and continuously arranged on the outer peripheral portion of the underground space. Form. That is, while the overhanging portion acts as an equivalent to a horizontal sheet pile in the parent pile horizontal sheet pile method used for a vertical excavation wall surface or the like that supports the earth pressure between adjacent tunnel main bodies, the tunnel main body is By acting as an equivalent to the parent pile, the outer shell tunnel is installed while providing a considerable interval without closely arranging the tunnel main body, reducing the number of installations and making the outer shell structure simple and economical Can be installed as

On the other hand, the excavation work of the inner ground covered by the outer shell structure is performed by sequentially excavating every predetermined length while forming a lining body inside the outer shell structure. Therefore, the inside of the outer shell structure is not made hollow at one time over the entire section. That is, in each of the divided excavation sections, the outer shell structure is supported while supporting both ends of the outer shell structure having a hollow inside by the ground before excavation or the lining body of the already formed front section. The excavation work can be performed stably while preventing the damage even if it is simple, and when the excavation work is completed, the outer shell structure and the lining A strong structure with high strength and waterproofness is formed around the underground space.

In the step of forming the outer shell structure, the ground at the tip of the overhang of each outer shell tunnel may be
If the improved ground is formed by joining the overhanging portions of the adjacent outer shell tunnels, the water stopping of the outer shell structure can be improved and the inside excavation work can be performed more stably.

[0015]

Next, embodiments of the present invention will be described in detail with reference to the accompanying drawings. FIG. 1 (a) and (b)
1 shows a method of constructing an underground space according to one embodiment of the present invention, in which a ground 11 covered with an outer shell structure 10 is formed into a lining 12 made of reinforced concrete, various steel materials, or the like. A state in which a semicircular large-scale tunnel 14 having a diameter of about 20 m as an underground space is formed by sequentially excavating each divided span having a predetermined length while supporting the outer shell structure 10. It is shown.

In this embodiment, the outer shell structure 10 is formed by using a shield machine 20 described later to form an outer shell tunnel 15 extending in the horizontal axis direction of the large-scale tunnel 14 as shown in FIG. Large scale tunnel 1
Each of the outer shell tunnels 15 is composed of a tunnel main body 16 having a circular cross section and wing-like projections 17 formed on both sides of the tunnel main body 16 in a wing shape. , And each outer shell tunnel 15
Since the overhanging portion 17 is disposed so as to protrude along the circumferential direction of the large-scale tunnel 14, the overhanging portion 17 substantially covers the space between the adjacent tunnel main bodies 16, and The outer shell structure 10 protects the entire periphery of the shell 14.

Further, according to the outer shell structure 10 in the underground space, the overhang portion 17 of each adjacent outer shell tunnel 15 is joined to the ground at the tip portion of each overhang portion 17 so that the improved ground 19 Are formed.

Then, the outer shell structure 10 having the above configuration
In order to form the large-scale tunnel 14 in the ground, as shown in FIG. 3, the ground 11 where the large-scale tunnel 14 is to be formed is placed before and after the ground 11 to partition both ends of the large-scale tunnel 14. By constructing the shafts 40 in advance using a wall method or the like, and making these shafts 40 as starting shafts or reaching shafts, the shield machine 20 shown in FIG.
A large number of outer shell tunnels 15 are continuously arranged around the ground 11 where a large-scale tunnel 14 is to be excavated.

That is, the shield machine 20 used for such an operation is, for example, as shown in FIGS.
It comprises a cylindrical mud pressure type shield excavator main body 21, and a pair of helical drum excavating devices 22 provided to protrude radially outward from the side surfaces of the excavator main body 21 while facing each other. The earth and sand cut by the cutter head 25 of the machine body 21 are taken into the earth pressure chamber 23 located behind the cutter head 25, the thrust of the shield machine 20 is controlled to adjust the mud pressure in the earth pressure chamber 23, and the screw conveyor is used. The excavation work of the outer shell tunnel 15 is performed while discharging the excavated earth and sand in the earth pressure chamber 23 by 41. Further, the helical drum excavating device 22 includes a helical drum 24 communicating with the earth pressure chamber 23 so that the excavated earth and sand of the overhang portion cut by the screw-shaped cutter bit 26 can be sent into the earth pressure chamber 23. Has become. According to the shield machine 20, the skin plate 4 is provided behind the machine 21.
2, a segment 27 is assembled in a cylindrical shape to lining the inside of the outer shell tunnel 15, and a propulsion reaction force is obtained from the segment 27 by a propulsion jack 29a. In the excavation groove 44 of the overhang portion 43 of the skin plate 42,
For example, an overhanging plate 28 made of PC concrete or cast-in-place concrete is installed, and the overhanging plate 2
8, the propulsion jack 29b obtains the propulsion reaction force of the helical drum excavating device 22, so that the shield excavator 20 can be advanced in a well-balanced manner.

Here, the helical drum is a member having a cylindrical shape as a whole, in which a plate member such as a steel plate is spirally attached around a central axis, and the earth and sand, other materials, Refers to equipment having a configuration that can send waste materials etc. along a spiral shape, for example, as a leveling device for asphalt mixture in an alphalt finisher, or as an accumulation device for crushed road material in pavement surface crushing work The helical drum used can be partially modified and used in the present invention. That is, a bit for earth and sand cutting is appropriately attached to the outer peripheral portion of these devices, and can be used as a helical drum constituting the present invention.

Further, in association with the excavation work, for example, the distal end of the helical drum excavating device 22, the distal end of the excavation groove 44 of the overhang portion, or the installed overhanging plate 28
By injecting and solidifying various cement-based or resin-based soil improvement materials from the front end portion, an improved ground 19 that joins the overhang portions 17 of the adjacent outer shell tunnels 15 can be easily formed.

According to this embodiment, the large-scale tunnel 14 is formed by excavating the ground 11 whose periphery is covered by the outer shell structure 10 formed as described above.
That is, as shown in FIG. 1B, for example, as shown in FIG. 1B, a distance of about 10 m in the horizontal axis direction of the tunnel is divided into one span a, and the excavation work of the tunnel 14 and the inner peripheral surface of the excavation are performed for each span a. The tunnel 14 is constructed while sequentially repeating the construction of the lining body 12 described above. The work for each span a is not strictly performed in a divided manner, and the work in the preceding span a and the work in the succeeding span a may be partially performed in parallel.

Here, an outer shell tunnel 15 composed of a tunnel body 16 and an overhang 17 is provided around the tunnel 14.
Is covered by a relatively simple outer shell structure 10, but the excavation work is performed separately for each span a, so that the ground of one span a is excavated and Until the surrounding ground is built, the surrounding ground is supported by the ground of the trailing span a before excavation and the lining 12 of the preceding span a that has already been completed. Since the inner shell structure 10 covers the outer shell structure 10, the load such as earth pressure from the surroundings is efficiently supported by the tunnel body 16 and the overhanging part 17 of each outer shell tunnel 15, and the excavation work in the span a is stabilized. You can go. That is, since the inside of the outer shell structure 10 is not made hollow at one time over a long section,
Even if the outer shell structure 10 is simple, it is possible to easily prevent breakage of each outer shell tunnel 15.

Further, the outer shell tunnel 15 which is connected to form the outer shell structure 10 is provided with a high waterproofness by being integrated via the improved ground 19, so that the ground of the ground in each span a is provided. Excavation work and construction work of the lining body 12 can be performed more quickly and stably.

The outer shell structure 10 can continue to support the earth pressure from the surrounding ground on the outer periphery of the lining body 12 even after the lining body 12 is constructed. By forming an integral structure with the underlayer 12, a structure having sufficient strength and waterproofness to firmly cover the underground space is formed. After the lining body 12 is constructed, a gap between the lining body 12 and the outer shell structure 10 is appropriately filled with a backfill material made of backfill soil, foamed mortar, or the like.

FIG. 2 shows another embodiment of the present invention. According to this embodiment, in a relatively solid ground 31 where no groundwater exists, a width 20 as an underground space is used.
In order to form a rectangular large-scale tunnel 34 having a height of about 5 m and a height of about 5 m, the outer shell structure 30 is formed by using the above-described shield machine 20 and other various types of tunnel excavating devices to form a tunnel main body portion 36 and an overhang portion. A large number of outer shell tunnels composed of 37 are provided in a rectangular shape. As described above, depending on the geology of the ground, the outer shell structure 30 can be formed without forming the improved ground, and the large-scale tunnel 34 is formed with the outer shell formed in the same manner as in the above-described embodiment. The ground 31 whose periphery is covered by the structure 30
By forming the lining body 32 and excavating sequentially at predetermined spans while supporting the outer shell structure 30, the lining body 32 can be formed quickly and efficiently.

Further, according to the present invention, in the step of forming the outer shell structure 10, the outer shell tunnels 15 can be connected while the overhanging portions of the adjacent outer shell tunnels 15 are wrapped. The cross-sectional shape of the outer shell structure 10 can also be changed by changing.

[0028]

As described above, according to the method for constructing an underground space of the present invention, a large number of outer shell tunnels each having a tunnel main body and wing-shaped protrusions formed on both sides of the tunnel main body. Are arranged continuously on the outer periphery of the underground space to form a shell structure covering the ground where the underground space is to be excavated and formed, and the ground covered by the shell structure is A step of excavating the shell in a predetermined length sequentially while forming a lining body inside the shell structure, so that the structure of the outer shell is simplified and economical. In addition to being able to facilitate work, the outer shell structure and the lining body are integrated to form a structure with sufficient strength and water-blocking properties, and thereby the surroundings are firmly covered by reliability Easily and efficiently forms high underground spaces It can be.

In the step of forming the outer shell structure, the improved ground is formed by joining the overhang of each adjacent outer tunnel to the ground at the tip of the overhang of each outer tunnel. In addition, the watertightness of the outer shell structure can be improved, and the inner excavation work can be performed more stably.

[Brief description of the drawings]

FIGS. 1A and 1B are explanatory views showing a situation in which an underground space is formed by a construction method according to an embodiment of the present invention, wherein FIG. 1A is a cross-sectional view and FIG.

FIG. 2 is a cross-sectional view showing a situation where an underground space is formed by a construction method according to another embodiment of the present invention.

FIG. 3 is an explanatory view showing a situation in which a shield tunneling machine is started from a shaft formed across an underground space to form an outer shell tunnel continuously.

4A and 4B show a shield machine for excavating and forming each outer shell tunnel. FIG. 4A is a plan sectional view, FIG. 4B is a side sectional view, and FIG. 4C is a front view.

[Description of Signs] 10,30 Outer shell structure 11,31 Ground (Soil for excavating and forming underground space) 12,32 Lining body 14,34 Large-scale tunnel (underground space) 15,35 Outer shell tunnel 16,36 Tunnel body 17, 37 Overhang 19 Improved ground

(56) References JP-A-6-93792 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) E21D 13/02 E21D 9/06 301 E21D 13/04

Claims (2)

(57) [Claims] 1. A plurality of outer shell tunnels each comprising a tunnel main body and wing-shaped projections formed on both sides of the tunnel main body and extending in a horizontal axis direction of a planned underground space. It is planned to excavate and form the underground space by arranging the parts so as to protrude between adjacent tunnel bodies along the circumferential direction of the underground space and continuously arranging them on the outer peripheral portion of the underground space A step of forming an outer shell structure covering the ground, and forming a lining body inside the outer shell structure, the ground covered by the outer shell structure is divided into predetermined lengths at predetermined intervals. Constructing and forming an underground space covered by a lining united with the outer shell structure inside the outer shell structure by successively excavating. How to build an underground space. 2. In the step of forming the outer shell structure, the improved ground is joined to the ground at the tip of the overhang of each of the outer shell tunnels by joining the overhangs of the adjacent outer shell tunnels. The method according to claim 1, wherein the underground space is formed.