JP3135188B2 - Construction method of underground cavity - 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 cavity, and more particularly to a method for constructing an underground cavity comprising a tunnel or other underground structure, which is constructed and installed below the ground surface.

[0002]

2. Description of the Related Art Conventionally, as a construction method of an underground cavity constructed and installed below the ground surface, for example, an underground cavity made up of an underground tunnel and other underground structures, an open-cutting method and a shield method are generally known. .

In the excavation method, the ground is excavated from the ground surface to a depth at which an underground structure such as a tunnel is to be installed, while using various types of shoring by steel sheet piles and underground continuous walls. After the construction, the earth and sand is buried above it to restore the ground.

[0004] On the other hand, the shield method is a tunnel method which is mainly used in an urban area or the like when a working area required for the open-cutting method cannot be secured or when the ground is soft and contains a large amount of groundwater. From the starting shaft excavated and formed to the reaching shaft, a cylindrical shield excavator is excavated and propelled underground, and a lining body called a segment is installed in a tubular shape behind the excavator, thereby forming the covering. This is to construct a tunnel, that is, an underground cavity, whose surroundings are firmly covered by the body.

[0005]

However, in the conventional method of constructing an underground cavity, in the case of the above-mentioned excavation method, especially in an urban area or the like, traffic on the ground surface is cut off and the like. It is difficult to secure a vast working area on the ground surface, and it is necessary to excavate and backfill a large amount of ground from the ground to the installation position of the underground cavity. Therefore, the deeper the position where the underground cavity is constructed, the more uneconomical, and the work is dangerous.

In the case of the above shield method,
Since it is only necessary to secure the area of the starting shaft and the reaching shaft as the excavated part and excavate, it is possible to minimize the influence on the environment of the nearby residents and reduce the amount of excavated soil etc. However, on the other hand, it is necessary to manufacture an expensive dedicated shield machine corresponding to the tunnel cross section, which is uneconomical especially when constructing a tunnel with a large cross section or a tunnel with a deformed cross section other than circular. At the same time, the construction work will be difficult.

On the other hand, it is generally known that an underground structure constructed and formed deep underground is advantageous in that its top surface is formed as an arch as a structure that can withstand the earth pressure from the surroundings.

Therefore, the present invention has been made in view of such a problem, and it is possible to reduce an excavated portion from the ground surface and to reduce the amount of excavated soil to a minimum amount corresponding to the underground hollow portion. To provide an underground cavity construction method that can economically construct a strong and large-section underground cavity with an arch-shaped zenith surface by combining existing tunneling methods without using a dedicated excavation machine It is intended for.

[0009]

In order to achieve the above object, the method of constructing an underground cavity according to the present invention is intended for excavation of a shaft and the propulsion work of a square steel pipe at both ends of an underground cavity to be constructed. Excavating and forming a tunnel, a step of excavating and forming a pair of guide shafts from each of the tunnels along the left and right side wall lines of the underground cavity, and one of the excavation and formation at the top end of the underground cavity to be constructed A number of square steel pipes are propelled and installed along the arch-shaped cross section in the longitudinal direction of the underground cavity from the tunnel to the other tunnel, covering the top end of the underground cavity and keeping the square steel pipe in close contact Arranged in the shape of an arch, cast concrete in the side wall in the shaft and cast concrete in the installed square steel pipe, the side wall and the top end are integrated into the underground cavity. Build an outer shell to cover the main shaft A step of forming, together with the drilling Honko portion covered by the outer shell, is made of a step of constructing a body of underground cavities in the main pit portion. Book
In the present invention, the multiple rows of square-shaped steel pipes have a leading corner.
After propulsion of shaped steel pipes, each can be added and joined
preferable.

[0010]

According to the present invention, excavations are formed at both ends of an underground cavity to be constructed for excavation of a shaft and for propulsion work of a square steel pipe. In addition, since the main pit is excavated inside the arched outer shell constructed at the top end using square steel pipes and filled concrete, compared with the case of excavating the ground above the top end In addition, the excavated portion from the ground can be limited only to the area corresponding to the shaft connecting the tunnel and the ground. In addition, the work for propelling and installing square steel pipes at the top end is performed from the tunnel, so it takes up little space, minimizing the impact of the excavation environment, and providing a large number of rows along the arch-shaped cross section. By installing a large number of square steel pipes in a straight line in the longitudinal direction of the tunnel, an underground cavity having an arch-shaped zenith surface can be easily formed. And the excavation work of the main shaft part of the underground cavity is performed inside a strong arched outer shell body that is built in advance and the main shaft part and the side wall part integrally cover the main shaft part Therefore, excavation work can be performed safely and easily without causing collapse of the surrounding ground.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the illustrated embodiments.

Underground cavity 1 to be constructed in this embodiment
Numeral 0 is a so-called double-section large-section tunnel formed by connecting two tunnels 11 as shown in FIG.

In the construction method of this embodiment, first,
As shown in FIG. 2, the construction site of the underground cavity 10 is sandwiched, and as shown in FIG. Shaft 1 for starting and reaching as a working tunnel
Excavation 2 is formed. Each shaft 12, for example, after piercing the surrounding ground by the underground continuous wall construction method or sheet pile construction method, etc., by sequentially digging down the ground inside thereof while reinforcing the retaining wall, Excavation can be easily performed to a predetermined depth.

After the shaft 12 is constructed to a predetermined depth, the underground cavity is used as the left and right side walls 14 of the underground cavity 10 to be constructed and the side walls 14 of each of the left and right tunnels 11 from the starting side shaft 12. 10 left and right tunnel 1
First-stage shafts 13 for constructing the three-row first-stage shafts 13 for constructing the central side wall 14 that is to be divided into 1 are formed toward the reaching shaft 12 on the arrival side, and the foundation piles are appropriately driven downward from the shafts 13. In addition to the installation and installation, a formwork (not shown) is provided and the side wall concrete 21 is cast to construct the lower part of the side wall 14, and then the second pit 15 for constructing the upper part of the side wall 14. Drilling to form. In this embodiment, the concrete 21 in the upper part of the side wall 14 has not yet been cast at this time. In this embodiment, in consideration of the height and the like of the underground cavity 10 to be constructed, the shaft is excavated by dividing the shaft into two-stage shafts 13 and 15. There is no need to split.

After the excavation of the second shaft 15 is completed, it is formed in advance in the longitudinal direction of the underground cavity 10 to be built, that is, in the longitudinal direction of the top end of each tunnel 11, in a size that can be carried into the shaft 12. Block-shaped square steel pipe 17 having a substantially rectangular cross section 17
Are linearly propelled in the longitudinal direction of the tunnel in a number of rows along the arch-shaped cross section of the zenith portion of each tunnel 11, whereby a number of square steel pipes 17 are closely arranged vertically and horizontally in a matrix and integrated. An arched top end 16 of the outer shell 18 covering the tunnel 11 is formed.

That is, in order to install the square steel pipes 17 in close contact with each other, for example, first, the first row of square steel pipes 17a located at the beginning of the arched top cross section is formed by an existing tunnel method. By the propulsion method, a block-shaped square steel pipe 17 is provided rearward using a propulsion jack installed in the shaft 12 on the starting side.
In the first column, the excavation is carried out in the longitudinal direction of the tunnel 11 toward the arrival-side shaft 12 while sequentially connecting the shafts a to the arrival-side shaft 12 from the start-side shaft 12 to the arrival-side shaft 12. Steel pipe rows will be installed. Next, the square-shaped steel pipes 17b in the second row along the arch-shaped cross section of the top end are placed adjacent to the installed square-shaped steel pipes 17a in the first row from the shaft 12 on the starting side to the shaft on the reaching side. Propulsion installation is performed by the same method up to 12. Below, for each row on the arched top cross section,
The same operation is sequentially repeated, and finally, the square-shaped steel pipe 17k in the last row belonging to the end of the arch is propelled and installed to form the arched top end 16 of each tunnel 11.

It is preferable that each block-shaped square steel pipe 17 has an opening formed on a side surface thereof. According to such a square steel pipe 17, a reinforcing reinforcing bar extends across each steel pipe row. In addition, since the filled concrete poured into the inside is distributed across each steel pipe row, each square steel pipe 17 is integrated to form a stronger arch-shaped. The top end 16 will be formed.

After the above, a filling concrete 19 is poured into each of the square steel pipes 17 constituting the arch-shaped top end portion 16, and the top end portion is placed in the second shaft 15. While rolling the end portion of the side wall 16, the side wall concrete 21 of the upper part of the side wall 14 is cast over the lower part of the side wall 14 formed in the first shaft 13. As a result, an outer shell 18, that is, an arch shell, is formed on the outer periphery of the underground cavity 10, in which the arch-shaped top end 16 and the side wall 14 integrally cover the main shaft 20 of the underground cavity 10. You.

Finally, a portion of the main shaft 20 surrounded by the arched outer shell 18 is excavated to construct a target underground cavity 10. Since the excavation work of the main shaft 20 is performed inside the strong outer shell 18 constructed and formed in advance, the excavation work can be performed safely and quickly without causing the collapse of the surrounding ground. The excavated sediment generated is
It is carried out to the ground via each shaft 12.

When the excavation work of the main shaft 20 is completed, the construction work of the main body of the underground cavity 10 is performed in the formed working space. That is, as shown in FIG. 1, the bottom plate 70 and the inverted portion 73 of the underground cavity 10 are formed, and the inner wall 71 and the upper floor as a secondary lining are formed inside the side wall 14 and the top end 16 of the outer shell 18. The plate 72 is formed, and various interiors are further constructed.

The bottom plate 70 can also be provided by installing the square steel pipe 17 from the bottom of the shaft 12 by the same operation as the above-described propulsion installation at the top end 16 of the outer shell 18. According to such a method, the main shaft 20
Prior to the excavation work, the entire periphery including the bottom surface is covered with the outer shell body 18, so that the excavation work of the main shaft 20 can be performed more safely.

According to the method of constructing the underground cavity 10, the cut-out portion from the ground can be reduced to only the area corresponding to the starting shaft 12. In addition, since the work of propelling and installing the square steel pipe 17 at the top end 16 is performed from the starting shaft 12 on the starting side, no space is required and the influence of the excavation environment can be minimized. In addition, it is possible to carry out the work of loading and unloading materials and equipment to the construction site, and to carry out the work of unloading excavated earth and sand through the shafts 12. Furthermore, the construction work of placing the side wall concrete 21 in the shafts 13 and 15 and the square steel pipe 17
The work of placing the filled concrete 19 in the interior can be easily performed by using a conventional technique by a concrete pump or the like. The excavation work of the main shaft 20 of the underground cavity 10 is performed by forming the strong outer shell 1 formed in advance, in which the top end portion 16 and the side wall portion 14 integrally cover the main shaft 20.
8 can be performed safely and easily without causing collapse of the surrounding ground.

In the above embodiment, after the square steel pipe 17 is propelled and installed, the concrete
However, after excavating and forming the second-stage pit 15, the side wall concrete 21 is cast before the propulsion installation of the square steel pipe 17, and the side wall 14 is placed in the first row. Square steel pipe 1
It may be made to function as a guide at the time of propulsion installation of 7a and the square steel pipe 17k of the last row.

In the above embodiment, the tunnels for excavating the shafts 13 and 15 and for propelling the square steel pipe 17 are formed by excavation from both the ground surface to the depth where the tunnel 11 is to be constructed at both ends of the tunnel 11. Shaft for starting and reaching 1
2 is used, but the present invention is not limited to this. For example, when it is not possible to secure an open area for each shaft 12 on the ground surface at both ends of the tunnel 11, FIG. As shown in the figure, a shaft 30 is excavated and formed at a position away from both ends of the tunnel 11 so as not to hinder the excavation work, and a shaft is dug to the both ends of the tunnel 11 via a horizontal tunnel 31 dug from the side. Tunnel 32 for excavation of 13 and 15 and for propulsion work of square steel pipe 17 can be formed by excavation.

[0025]

As explained in detail above, according to the present invention, the cut-out portion from the ground surface is only the area corresponding to the shaft which connects the tunnel with the ground, and the left and right sides of the underground cavity from this tunnel. Since the main shaft is to be excavated inside the arched outer shell constructed at the top end using a square steel pipe and filled concrete, the main shaft will be excavated. The amount of excavated soil can be extremely reduced as compared with the case of excavation. In addition, since the work of propelling and installing the square steel pipe at the top end is performed from the tunnel, it does not take up much space, and the influence on the surrounding environment during the work can be minimized.

Further, since the top end of the underground cavity is constructed as an arch-shaped outer shell made of square steel pipe and filled concrete, a strong and large-sized underground cavity can be economically constructed. Since the excavation work of the main shaft part of the underground cavity is performed inside the outer shell body that is formed firmly in advance and firmly formed so that the top end and the side wall part integrally cover the main shaft part, Work can be performed safely and easily without causing ground collapse.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating an underground cavity constructed by the method of the present invention.

FIG. 2 is a schematic plan view illustrating a planar positional relationship between a shaft and a shaft in the method of the present invention.

FIG. 3 is an explanatory view showing an embodiment in a case where a tunnel for excavation is formed by digging from a shaft excavated and formed apart from both ends of an underground cavity.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Underground cavity 11 Tunnel 12 Vertical shaft (Gall) 13 First stage shaft 14 Side wall 15 Second stage shaft 16 Top end 17 Square steel pipe 17a First row square steel pipe 17b Second row corner Steel pipe 17k Square steel pipe in the last row 18 Outer shell 19 Filling concrete 20 Main shaft 21 Side wall concrete 32 Tunnel

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Masahiko Miura 1-6-11 Uesugi, Aoba-ku, Sendai, Miyagi Pref. Obayashi Gumi Tohoku Branch (72) Inventor Tetsuharu Hooka 2-3-3 Kandaji-cho, Chiyoda-ku, Tokyo Address Obayashi Corporation Tokyo head office (56) References JP-A-3-279600 (JP, A)

Claims (2)

(57) [Claims] 1. A step of excavating and forming tunnels for excavation of a shaft and propulsion work of a square steel pipe at both ends of a place where an underground cavity is to be constructed. Excavating and forming a pair of shafts along an arched steel pipe in the longitudinal direction of the underground cavity from one of the excavated and formed tunnels to the other at the top end of the underground cavity to be constructed. By arranging a large number of rows along the cross section, the rectangular steel pipe is arranged in an arched shape in close contact with the top end of the underground cavity, and side wall concrete is poured into the shaft and the installation is performed. Casting the filled concrete into the square steel pipe thus formed, and forming and forming an outer shell covering the main shaft portion of the underground cavity by integrating the side wall and the top end, and covering the outer shell with the outer shell. The excavated main shaft was excavated and A method of constructing an underground cavity in a pit portion. 2. The multi-column square steel pipe is formed of a preceding square steel pipe.
It is noted that they are added and joined after the steel pipe is propelled.
The construction method of an underground cavity according to claim 1, wherein the underground cavity is constructed.