JPH11209956A - Arched underground structure and method for constructing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an arched underground structure such that the vertical load of the underground structure having a space-forming arch member can be transmitted to a wide area of support ground and that a horizontal force working on the structure can also be fully transmitted to the support ground. SOLUTION: An arched underground structure 1 has a space-forming arch member 10, an inverted-arch-shaped ground reaction board 30 receiving the vertical load of the arch member, and horizontal reaction boards 20, 20 each having a vertically extending part 21 and a horizontally extending part 22. The horizontally extending part 22 of the horizontal reaction board 20 supports a space-forming arch on its upper surface 23, and the lower surface 25 of the horizontally extending part 22 abuts to a surface at the end of the inverted-arch- shaped ground reaction board 30 to transmit the vertical load of the space forming arch to the inverted-arch-shaped ground reaction board 30. The vertically extending part 21 of the horizontal reaction board 20 receives horizontal forces working on both of the arch members 10, 30, and transmits the forces to the support ground behind it.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an arched underground structure and a horizontal reaction force version thereof, and a method of constructing such an underground structure.

[0002]

2. Description of the Related Art An arch-shaped underground structure in which a space-forming arch member (particularly a precast concrete slab) is supported at its legs by a cloth-like support member (foundation) is disclosed, for example, in Japanese Patent Application Laid-Open No. 6-33473. Is disclosed.
In this underground structure, the legs of the space forming arch members (each segment) made of precast concrete are supported by grooves provided at the center of the cloth-like supporting member so as to allow the rotation.

[0003]

Since the support member in the prior art is cloth-like, it has a small width and a small area in contact with the support ground. Therefore, if the ground bearing capacity of the ground is not sufficient, the structure may sink. In addition, since the underground structure resists the horizontal force of the space forming arch member by friction between the bottom surface of the cloth foundation and the supporting ground, in the ground where sufficient frictional resistance cannot be obtained, the space Both legs of the formed arch member may be displaced laterally with the support member to increase the deformation of the arch member and cause cracks.

An object of the present invention is to solve these problems, and to transmit a vertical load of a structure to a support ground in a wide area and also transmit a horizontal force acting on the structure to the support ground. It is an object of the present invention to provide an arch-shaped underground structure which can be applied to relatively soft ground.

[0005]

SUMMARY OF THE INVENTION To this end, the arched underground structure of the present invention supports an arch member forming a space and a space forming arch member so as to allow rotation of the arch leg. A first support member (horizontal reaction plate) having space forming arch member support means, and an inverted arch type second support member (ground reaction) which receives the vertical load of the space forming arch member and transmits it to the entire supporting ground having a wide area. Power version). First
The support member has a second support member engaging means connected to the space forming arch member supporting means, and the second support member engaging means is engaged with an end of the second support member. Therefore, the vertical load of the space forming arch member (and the covering soil on the upper part) can be transmitted to the inverted arch type second support member. The first support member has a vertical extension extending vertically from the space forming arch member support means. The vertical extension portion receives the horizontal load of the space forming arch member and the inverted arch type second support member and transmits the horizontal load to the back support ground.

In one embodiment, there is provided a horizontal extension portion extending laterally from the vertical extension portion of the first support member toward the space forming arch member and the inverted arch type second support member.
Upper surface of this horizontal extension (space forming arch member support means)
Supports the space forming arch member, and engages (abuts) the lower surface (second support member engaging means) of the horizontally extending portion with the end of the inverted arch type second support member. The vertical load of the space forming arch member is transmitted to the inverted arch type second support member via the horizontal extension. The horizontal load of the space forming arch member and the inverted arch type second support member is transmitted to the vertically extending portion at the space forming arch member supporting means and the second support member engaging means, respectively.

[0007]

FIG. 1 schematically shows an embodiment of an arched underground structure 1 according to the present invention. FIG. 6 shows that this structure 1 is buried underground to form a space 2 for a passage or the like. The underground structure 1 includes a space forming arch member 10 that forms a space, horizontal reaction force plates (first support members) 20, 20 that receive the arch member 10, and a space forming arch via the horizontal reaction force plate. The supporting ground 3 receives the vertical load of the member 10.
And a reverse arch type ground reaction force plate 30 (second support member) that transmits the force to the ground. The space forming arch member 10 can be composed of a plurality of precast reinforced concrete slabs 11 and, as disclosed in JP-A-6-33473.
In the above, the precast plates 11, 11 can be connected by a hinge 13 to form a three-pin arch.

Each horizontal reaction plate 20 has a vertical extension 21 and a horizontal extension 22 extending laterally from a substantially central portion of the vertical extension 21 toward the space forming arch member. The upper surface 23 of the horizontal extending portion 22 forms a groove by the rising portion 24 and receives the leg 14 of the space forming arch member 10 in this groove. Thus, if the rotation of the legs is allowed and the arch top 12 is pinned, the space forming arch 10 will be a three-pin arch. On the other hand, the lower surface 25 of the horizontal extension portion 22 of the horizontal reaction force plate 20 is in contact with the end surface of the reverse arch type ground reaction force plate 30, and the weight of the arch member 10 and the load thereon are reduced by the arch type ground reaction plate. It is transmitted to the power plate and transmitted to the support ground 3 in a wide area. Due to the force acting on the arch member 10 from above and the ground reaction force acting on the arch type ground reaction force plate 30, both arches 10,
30 is slightly flattened to generate a horizontal force, which acts on the vertically extending portion 21 of the horizontal reaction force plate 20 and is transmitted to the support ground 5 behind. Since the ground reaction force plate 30 also has an arch shape, a horizontal reaction force is generated.

Referring to FIGS. 2 to 6, a first embodiment of the method for constructing an arched underground structure 1 according to the present invention will be described. In this embodiment, the horizontal reaction plate 20 is cast-in-place concrete.

As shown in FIG. 2, first, the ground 3 is excavated to form a stepped excavation surface 6. Next, at a predetermined position on the excavation surface, the reinforcing bars 26 and the formwork 27 below the vertical extension portion 21 of the horizontal reaction force plate 20 having a predetermined length (the length direction of the underground structure) are set up. Casting concrete. Next, as shown in FIG. 3, after dismantling the formwork 27 at the lower part of the horizontal extension section 21 and backfilling the back with the improved soil 7, a plurality of supports 4 are provided at appropriate positions on the excavation surface. And a plurality of precast reinforced concrete plates 31 constituting the reverse arch type ground reaction plate 30 are spread over these supports. The top 32 of the reverse arch type ground reaction plate 30 may be hinged similarly to the top 12 of the space forming arch member,
Alternatively, the bending moment may be transmitted by coupling with a known method using other fasteners 33 (for example, bolts and nuts). Further, the precast concrete slabs 31, 31 may be connected by fasteners in the longitudinal direction of the structure. Each precast concrete slab 31 has a plurality of grout through holes 34.

[0011] Next, as shown in FIG.
Of the horizontal extension part 22 and the upper part of the vertical extension part 21 (not shown) and the construction of the formwork 28 are performed. On this occasion,
As shown in the figure, the surface of the end portion of the reverse arch type ground reaction force plate 30 is a part of a mold for the horizontally extending portion 22. After the concrete is cast in the mold 28 and an appropriate curing is performed, the mold is dismantled.

Next, as shown in FIG. 5, the space behind the vertically extending portion 21 is backfilled with the improved soil. If it is necessary to further strengthen the supporting ground 5 on the back surface of the vertically extending portion 21 because the ground 3 is soft or the like, a sheet pile (not shown)
May be laid horizontally or reinforced by hitting a pile (not shown). Then, the space forming arch member 10 (precast concrete slabs 11, 11) is moved to the horizontal reaction slab 20.
On the upper surface (groove) 23 of the horizontal extending portion 22 of FIG. Next, the space forming arch member 10 is moved to the position shown in FIG.
Is covered with embankment 9.

Next, a grout agent 36 is injected into the gap through the through hole 34 to fill the gap 35 between the reverse arch type ground reaction plate 30 and the ground 3. The injection pressure of the grout agent is not more than the total pressure of the two arch portions 30, 10 and the embankment. In order to make the grout sufficient by increasing the injection pressure, grouting is preferably performed after the embankment is performed to some extent as described above. However, grouting can also be performed immediately after the ground reaction force plate shown in FIG. 3 is laid.

As shown in FIG. 6, embankment is further performed so as to cover the space forming arch member 10, and backfilling 37 is performed so as to cover the reverse arch type ground reaction force plate 30, and a pavement plate 38 is further placed thereon. Lay. This completes the underground structure.

Referring to FIGS. 7 to 11, a second embodiment of the method for constructing an arched underground structure according to the present invention will be described. In this embodiment, the horizontal reaction plate (first support member) 20 includes a plurality of precast reinforced concrete plates 40 integrally formed to have the same vertical cross section as the reaction plate shown in FIG.

As shown in FIG. 7, the ground 3 is excavated in the same manner as in FIG. 2 to form an appropriate excavation surface 6, and a plurality of supports 4 are provided thereon (precast reinforced concrete slab 3).
1, 31).

Next, as shown in FIG. 8, a plurality of precast reinforced concrete slabs 40 are placed on the support ground 3. At this time, the lower surface 25 of the horizontally extending portion 22 of each precast reinforced concrete slab 40 is brought into contact with the surfaces of both ends of the reverse arch type ground reaction slab 30. A sheath 41 for receiving a PC steel rod is embedded in each precast plate 40, and a PC steel rod (not shown) is inserted into the sheath and tensioned to grout the sheath. Thus, the plurality of precast plates 40 can be integrated by tightening each other. Next, as shown in FIGS. 8 and 9, the lower part of the vertically extending portion 21 of the precast plate 40 is hardened with improved soil or concrete around the front and back surfaces.

In the same manner as in the first embodiment, the space forming arch member 10 is mounted on the upper surface 23 of the horizontal extension portion of the horizontal reaction force plate 20 made of precast concrete (FIG. 10), and assembled. Backfilling of the back surface, embankment of the space forming arch member 10, grouting of the gap between the reverse arch type ground reaction plate 30 and the support ground 3, backfilling of the reverse arch type ground reaction plate 30, and installation of the pavement plate It can be performed.

The above two embodiments are illustrative and do not limit the invention thereto. It will be apparent to those skilled in the art that various modifications and changes can be made to the above-described embodiment without departing from the scope or concept of the present invention. For example, in the above embodiment, the horizontal reaction plate is provided with a horizontally extending portion, and the upper surface of the horizontal extension portion rotatably receives the end of the space forming arch, and the opposite end surfaces of the reverse arch type ground reaction plate. Although it is in contact with the lower surface of the horizontal extension part, connectors having holes for passing pins are respectively embedded in the horizontal reaction plate and the ends of both arch members, and the pins are inserted into the holes of these connectors, and both arch members and It is also possible to connect horizontal reaction plates.

[0020]

According to the arch type underground structure of the present invention, since the space forming arch member is supported by the reverse arch type ground reaction plate, the vertical load can be transmitted to a wide range of supporting ground, and the horizontal ground member can be supported. The force is also relatively small. Further, since both arch members engage one horizontal reaction plate having a vertical extension,
The structure of the ground reaction force plate can be simplified, and the horizontal force can be sufficiently transmitted to the supporting ground.

[Brief description of the drawings]

FIG. 1 is a perspective view of an embodiment of an arched underground structure of the present invention.

FIG. 2 is a first diagram illustrating a method for constructing an arched underground structure according to the present invention;
It is a perspective view showing an embodiment, and is a figure showing completion of excavation, and a state where concrete of a lower part of a vertical extension part of a horizontal reaction force version has been cast.

FIG. 3 is a perspective view showing a state in which a reverse arch type ground reaction plate is installed on an excavation surface in the construction method.

FIG. 4 is a perspective view showing a state in which concrete is poured in upper portions of the horizontal extension portion and the vertical extension portion of the horizontal reaction force plate in the construction method.

FIG. 5 In the construction method, a space forming arch member is installed on the horizontal reaction force plate, backfilling is performed on the back surface of the horizontal reaction plate and the upper portion of the arch member, and the space between the ground reaction plate and the supporting ground is formed. The perspective view which shows the state which grouted the filler in the clearance gap.

FIG. 6 is a perspective view showing a state where the arched underground structure shown in FIG. 1 is completed and buried underground.

FIG. 7 is a second diagram illustrating a method of constructing an arched underground structure according to the present invention;
It is a perspective view showing an embodiment, and is a figure showing a digging surface and a ground reaction force version installed on the digging surface.

FIG. 8 shows a state in which, in the construction method, a horizontal reaction plate made of precast concrete is supported on a supporting ground, and the lower surface of the horizontal extension portion is brought into contact with the end surface of the reverse arch type ground reaction plate. FIG.

FIG. 9 is a perspective view showing a state in which the rear surface of the horizontal reaction plate is back-filled in the construction method.

FIG. 10 is a perspective view showing a state in which a space forming arch member is installed on a horizontal reaction force plate in the construction method.

[Explanation of symbols]

Reference Signs List 1 arch type underground structure 2 space 3 supporting ground 4 support 6 excavation surface 10 space forming arch member 12 top of space forming arch member 13 hinge 14 leg of space forming arch member 20 horizontal reaction force plate (first support member) 21 Vertical extension portion of horizontal reaction plate 22 Horizontal extension portion of horizontal reaction plate 23 Upper surface of horizontal extension portion (space forming arch member support means) 25 Lower surface of horizontal extension portion (second support member engaging means) 30 Reverse arch type Ground reaction force plate (second support member) 32 Top portion of reverse arch type ground reaction force plate 34 Through hole

Claims (11)

[Claims] 1. An arch member (10) forming a space, and said space forming arch member so as to allow rotation of an arch leg.
A first support member (20) having a space forming arch member supporting means (23) for supporting the (10), and a second support member (20) receiving a vertical load of the space forming arch member (10) and transmitting the vertical load to a supporting ground ( 30)
In the arch-type underground structure (1) having the following structure, the second support member (30) is provided in an inverted arch shape, and the second support member engaging means (25) engaged with the inverted arch-shaped second support member. ) Is provided on the space forming arch member support means (23), and the space forming arch member (10) and the inverted arch type second support member (3) are provided.
0) The first support member is provided with a vertical extending portion (21) extending vertically from the space forming arch member support means (23) to transmit the horizontal force to the back support ground by receiving the horizontal force of (0). Structure. 2. The structure according to claim 1, wherein said first support member (20) integrally comprises said space forming arch member support means (23) and said second support member engagement means (25). A horizontal extension (22) extending substantially horizontally from the vertical extension (21), and the upper surface of the horizontal extension serves as the space forming arch member support means (23). And a structure provided such that the lower surface of the horizontal extension portion serves as the second support member engaging means (25). 3. The structure according to claim 1, wherein said space forming arch member (10), said first support member (20),
The inverted arch type second support member (30) is a precast reinforced concrete slab. 4. The structure according to claim 1, 2 or 3, wherein
The space forming arch member is composed of a plurality of precast reinforced concrete plates (11, 11), and the precast concrete plate is connected to the arch top (1) of the space forming arch member (10).
The structure hinged in 2). 5. The structure according to claim 1, wherein the inverted arch-shaped second support member (30) comprises a plurality of precast reinforced concrete slabs (31, 31). A structure in which a plurality of precast reinforced concrete slabs of the inverted arch type second support member are connected to each other by a fastener (33). 6. A space forming arch member buried underground,
The vertical force of the space forming arch member is engaged with a reverse arch type ground reaction plate transmitted to the supporting ground by receiving the vertical force of the space forming arch member, and the horizontal force of the space forming arch member and the reverse arch type ground reaction plate is applied to the ground behind. An upper surface (23) for rotatably supporting the legs (14, 14) of the space forming arch member (10), and the reverse arch type ground reaction plate. A lower surface (25) engaged with the end to allow rotation of the end of (30).
A horizontal reaction force plate comprising: a horizontal extension portion (22) having: a vertical extension portion (21) intersecting with the horizontal extension portion (22) and extending vertically from the intersection portion. 7. A space forming arch member, a reverse arch type ground reaction plate for transmitting a vertical load of the space forming arch member to a supporting ground, the space forming arch member and the reverse arch type ground reaction plate A method of constructing an arch-type underground structure using a horizontal reaction force slab that engages with a horizontal extension portion having an upper surface and a lower surface, wherein the reverse arch-type ground reaction plate is installed on a supporting ground, The horizontal extension portion intersects the vertical extension portion extending vertically from the intersection portion and a horizontal extension portion lower surface of the horizontal reaction force plate is engaged with an end of the reverse arch type ground reaction plate, And a step of supporting the horizontal reaction plate on a supporting ground, and supporting a space forming arch member on an upper surface of the horizontal extension portion of the horizontal reaction plate. 8. The method of claim 7, wherein the horizontal reaction force slab is made of cast-in-place reinforced concrete, and the horizontal reaction force vertical is set before installing the inverted arch type ground reaction plate on the supporting ground. Performing concrete casting of a portion extending downward from the horizontal extending portion of the extending portion, and installing the inverted arch type ground reaction force plate on the supporting ground, the horizontal extending portion, and the horizontal of the vertical extending portion A method in which concrete is cast in a portion extending upward from a stretching portion. 9. The method according to claim 7, wherein the horizontal reaction plate is a precast reinforced concrete plate in which the horizontal extension portion and the vertical extension portion are integrally formed, and the inverted arch type ground reaction plate is provided. A method in which after installation on a supporting ground, the precast horizontal reaction plate is engaged with an end of the reverse arch type ground reaction plate. 10. The method according to claim 7, 8 or 9, wherein
A method further comprising the step of grouting a filler into a gap between the inverted arch ground reaction plate and the supporting ground. 11. The method according to claim 7, further comprising the step of backfilling the back surface of the horizontal reaction plate with the improved soil.