JP2003206697A - Construction method of underground structure - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a construction method of an underground structure hardly influencing a neighboring existing structure, and efficiently constructing the underground structure having a large underground space as much as possible under an extremely limited ground face of urban areas or the like. <P>SOLUTION: Shield holes 7 and 8 are bored in both sides of the underground structure intended to construct respectively. A working space c is formed on the upper end of the inside of the shield hole 7 by making the inside space height h<SB>1</SB>of the shield hole 7 higher than the inside space height h<SB>2</SB>of the shield hole 8. Next, a plurality of steel pipes 5a are jacked from the side of the shield hole 7 to the side of the shield hole 8 in the working space c, and a pipe roof 5 is formed in ground 11 between the shield holes 7 and 8. Next, the ground 11 under the pipe roof 5 is excavated. A ground improving body 6 is formed in the ground of the upper side of the pipe roof 5 if necessary. <P>COPYRIGHT: (C)2003,JPO

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 structure, and is capable of widening construction, such as underpasses, underground transportation facilities for subways, lifeline facilities such as electricity, gas, water and sewage, and widening construction. It is applied to the construction of underground structures that are widely used as urban facilities such as subway stations, underground malls, and underground parking lots that may accompany.

[0002]

2. Description of the Related Art Up to now, roads, railways,
When constructing underground structures such as underground transportation facilities under the ground in limited public facilities such as rivers and parks, if the site area is large and there is relatively room, excavation works from the ground It was done by the construction method.

However, when the excavation scale is very large, temporary construction work such as earth retaining walls for holding the surrounding ground, support piles, support works, etc. becomes large-scale, and a large amount of excavated soil and backfilled soil are produced. It occurred, and its treatment and handling became a big issue.

Further, the shield construction method is often used in the case of a linear underground structure having a relatively small excavation cross section such as a subway tunnel, but when the excavation cross section is very wide even in a subway such as a station building. If the excavation cross-section width changes during the process, it was extremely difficult to construct.

Further, two shield holes are dug in parallel, and an arch pipe is propelled from one of the shield holes to the other shield hole side. Methods for excavating and building the skeleton have also been developed.

[0006]

However, when constructing an underground structure that has a relatively large area within a limited site and the excavation cross-section width changes in the middle by the excavation method, the soil for excavation must be constructed. Since the retaining wall needs to be constructed close to the surrounding structures, the deformation and subsidence of the surrounding ground caused by large-scale excavation will have a large impact on the nearby structures, and to reduce the impact. Protective works such as ground improvement were required.

In addition, since a vast work zone is required on the ground during construction, there is no choice but to restrict the use of some ground facilities such as roads and parks on the ground, leading to traffic congestion and the like, leading to civilian life. However, the shield method, which is a non-excavation method, has been widely used.

On the other hand, the shield construction method is not only extremely difficult to construct because a shield machine with special specifications is required for constructing a wide cross section or a structure whose cross section width changes, There was a problem that the cross section of the shield hole that could be constructed was very limited.

In the method of cutting and expanding with an arch pipe using two shield holes with circular cross sections, which has already been applied in the construction of subway stations, it is necessary to excavate a wider width than the rectangular shield hole, There is a problem that it cannot be applied when there is an embedded object, and that the accuracy of drilling becomes poor on gravel ground, etc.

For this reason, when the land width is narrow or when there is an obstacle in the ground, it may not be possible to construct a predetermined structure.

The present invention has been made to solve the above problems, and has a very small effect on existing structures in the vicinity, and has a space as large as possible in extremely limited ground such as an urban area. It is an object of the present invention to provide a method for constructing an underground structure that can construct an underground structure extremely efficiently.

[0012]

The method for constructing an underground structure according to claim 1 excavates shield holes on both sides of an underground structure to be constructed, and at the same time, the inner height of one of the shield holes is set to the other. A work space is formed at the upper end of one shield hole by making it higher than the inner height of the shield hole, and then multiple steel pipes are propelled from one shield hole side to the other shield hole side in the work space. Then, a pipe roof made of a plurality of steel materials is formed in the ground between the shield holes on both sides, and then the ground under the pipe roof is excavated.

The shape of the excavated cross section of the shield hole in this case is not particularly limited, but a shield hole having a rectangular cross section is particularly desirable because it does not generate a wasteful space when used as an underground space. Further, as the lining material for the shield hole, for example, steel synthetic concrete used as a main body by placing concrete in a steel shell, RC segment as a primary lining, or steel segment may be used,
In the case of a shield hole with a rectangular cross section, it is preferable to use steel synthetic concrete, which can be used as the main lining material, because it can freely follow changes in the size and shape of the excavated cross section.

Further, when a steel pipe or a steel sheet pile is propelled as a steel material in the ground between the shield holes to construct a pipe roof and the ground between the shield holes is relatively stable, the steel pipes are connected to each other. Can be installed to some extent, but if the ground between the shield holes is soft, it is possible to install them by closely attaching the steel pipes to each other, and if there is concern about groundwater, It is possible to join steel pipes to each other through a joint and to perform water-stop treatment on the joint.

By increasing the shield size (especially height) on the starting side of the pipe roof, a pipe roof having a large cross section (large diameter) can be constructed, and it is possible to cope with a large gap between the shields.

A construction method for an underground structure according to claim 2 is
The method for constructing an underground structure according to claim 1, wherein a ground improvement body is formed in the ground above the pipe roof. In this case, the method for constructing the ground improvement body may be a conventional construction method such as placing a horizontal jet grout.

A construction method for an underground structure according to claim 3 is
In the method for constructing an underground structure according to claim 1 or 2, the tip side of each steel pipe is placed on the upper end of the frame of the other shield hole.

[0018]

1 and 2 show a subway station building portion and an underground structure constructed as a branch portion of a line extending from the station building portion in a main line direction. In the drawings, reference numeral 1 is a subway station building portion. Reference numeral 2 is a subway main line section, and reference numeral 3 is a branch section connecting the station building section 1 and the main line section 2.

The branch part 3 has the widest frontage (excavation cross-section width) on the side of the station building 1 and is kept away from the station building 1 and the main line 2
Is constructed so that the frontage gradually narrows as
Further, pillars or walls 4 are arranged at appropriate intervals in the branch portion 3.

The outer peripheries of both end portions a of the branch portion 3, that is, the skeletons of the top board portion 3a, the floor board portion 3b and the side wall portions 3c of both end portions a are located inside the primary lining such as the RC segment and the steel segment. It is constructed continuously by reinforced concrete that has been cast, or steel synthetic concrete that is formed by casting concrete in a steel shell.
d, the skeleton of the floor part 3e is constructed of reinforced concrete.

Particularly, the skeleton of the central portion b is the top board portion 3 on both end sides.
It is constructed in a space secured by a pipe roof constructed by bridging a plurality of steel pipes 5a between a and 3a at predetermined intervals and forming a ground improvement body 6 in the ground above the steel pipes. In addition, the pillar or wall 4 has both end portions a
It is constructed by RC or SRC at the boundary between the center part b and the center part b.

Lines connecting the station building portion 1 and the main line portion 2 are laid at both end portions a and the central portion b, respectively.

With such a structure, an example of a method for constructing an underground structure of the present invention will be described with reference to FIGS. 3 (a) to 3 (f). First, the station building 1 is constructed, and then the station building 1 is used as the starting shaft for the shield, and the shield tunnels 7 and 8 of rectangular cross section are formed.
Are digged in parallel to construct both end portions a of the branch portion 3. At this time, the inner height h ₁ of the shield tunnel 7 on one side is changed to the inner height h ₂ of the shield tunnel 8 on the other side.
By making the height higher, the working space c is formed in the upper end portion of the shield tunnel 7. Also, shield tunnels 7 and 8
The inner circumference of each is lined with a steel shell. If there is an existing underground structure 9 such as a viaduct foundation around the shield tunnels 7 and 8, protection works such as a ground improvement body 10 should be built in advance in the surrounding ground if necessary. . The ground improvement body 10 in this case shall be constructed by the ground improvement method which has been generally performed so far.

Next, the roof pipe 5 composed of a plurality of steel pipes 5 a is constructed between the upper ends of the shield tunnels 7 and 8. At that time, each steel pipe 5a penetrates the lining body (steel shell) of the shield tunnel 7 from the work space c formed at the upper end of the shield tunnel 7, and the inside of the ground 11 between the shield tunnel 7 and the shield tunnel 8 is penetrated. Shield tunnel 7
Side to the shield tunnel 8 side, and the tip side 5a thereof is placed on the lining body (steel shell) of the shield tunnel 8. In this case, the steel pipe 5 is propelled by the hydraulic jack 12 in the working space c provided at the upper end of the shield tunnel 7.

Next, the ground improvement body 6 having a constant thickness is constructed in the ground above the roof pipe 5. The ground improvement in this case is performed, for example, by placing a horizontal jet grout in the ground above the roof pipe 5 in the working space c.

Next, the lining body of the side wall portions facing the shield tunnels 7 and 8 is removed, and the ground 11 between the shield tunnels 7 and 8 is excavated to construct the central portion b. In this case, the supporting work 13 required in the shield tunnels 7 and 8 and between the shield tunnels 7 and 8 is assembled to ensure work safety. Excavation of the ground in the central part b shall be performed with heavy equipment.

Next, the top board portion 3a, the floor board portion 3b, the side wall portion 3c, and the top board portion 3d and the floor board portion 3e of the central portion b on both end sides a are covered with concrete. Then, the support work 13 is removed to complete the construction. Also, FIG.
As shown in (a) and (b), it is possible to construct a cross section in which the height and the hierarchy change.

[0028]

The invention of the present application is as described above.
By excavating shield holes on both sides of the underground structure to be constructed, forming a pipe roof in the ground between these two shield holes, and excavating the ground under the pipe roof, the required underground space is created. The existing underground structure can be easily constructed, especially because it is a non-excavation method, and large-scale excavation is not required, so there is no need to change the structure of the above-ground facility or the service limit. The amount can be minimized, the amount of backfill soil does not occur, and the existing surrounding structures are not adversely affected.

Since the excavation cross section can be freely changed,
Although it is a non-excavation method, it is possible to easily construct an underground structure with a wide cross section and varying width, and it is also applicable to structures with varying heights and floors.

Furthermore, a rectangular shield, a rectangular structure,
By using steel shells (segments) as part of the main body as necessary, it is possible to construct underground structures by effectively utilizing the limited land width and the space enclosed by existing buried objects. In addition, it is possible to sufficiently secure the distance from the adjacent structure.

[Brief description of drawings]

FIG. 1 is a plan view showing an example of an underground structure.

2A is a sectional view taken along the line EE in FIG. 1, and FIG.
FIG. 3 is a cross-sectional view taken along the line Loro in FIG.

3 (a) to 3 (f) are cross-sectional views taken along the line EE in FIG. 1 showing the construction method.

4 (a) and 4 (b) are cross-sectional views taken along the line ii in FIG. 1 showing another example of the underground structure.

[Explanation of symbols]

1 Subway station building 2 Subway main line Branch of 3 subway 3a Side top part 3b Side floor part 3c Side wall part 3d Central part top part 3e Central floor part 4 pillars or walls 5 roof pipe 5a steel pipe 6 Ground Improvement Department 7 Shield tunnel (shield hole) 8 Shield tunnel (shield hole) 9 Existing underground structure 10 ground improvement body 11 ground 12 hydraulic jack 13 Support work

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Hiromitsu Kida             Kashima-ken, 1-2-7 Moto-Akasaka, Minato-ku, Tokyo             Inside the corporation (72) Inventor Tadashi Yoshikawa             Kashima-ken, 1-2-7 Moto-Akasaka, Minato-ku, Tokyo             Inside the corporation (72) Inventor Hidekazu Anai             Kashima-ken, 1-2-7 Moto-Akasaka, Minato-ku, Tokyo             Inside the corporation (72) Inventor Yoshihiko Morikichi             Kashima-ken, 1-2-7 Moto-Akasaka, Minato-ku, Tokyo             Inside the corporation F-term (reference) 2D054 AA05 AB05 AC15                 2D055 BA01 BB04

Claims (3)

[Claims] 1. The inside of one shield hole is formed by excavating shield holes on both sides of an underground structure to be constructed, and by making the inner sky height of one shield hole higher than the inner sky height of the other shield hole. A work space is formed at the upper end of the pipe, and a plurality of steel materials are propelled from one shield hole side to the other shield hole side in the work space to form a pipe roof in the ground between the shield holes on both sides. Next, a construction method for an underground structure, characterized by excavating the ground under the pipe roof. 2. The method for constructing an underground structure according to claim 1, wherein a ground improvement body is formed in the ground above the pipe roof. 3. The steel according to claim 1, wherein the front end side of each steel material is placed on the upper end of the frame of the other shield hole.
Construction method for the underground structure described.