JP2768178B2 - How to build underground structures - 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 of constructing an underground structure, in particular, an underground structure having a plurality of layers of underground floors and being constructed while excavating sequentially from an upper basement floor to a lower basement floor. About.

[0002]

2. Description of the Related Art Conventionally, in order to construct a plurality of basement floors, the ground is first excavated to a lowermost basement floor construction portion, and the basement floors are sequentially constructed from the lower to upper layers inside the excavation portion. There are known an in-place construction method and a reverse construction method in which each underground floor is constructed while excavating sequentially from an upper basement floor to a lower basement floor.

[0003]

However, in such a conventional method of constructing an underground structure using the reverse striking method, when constructing an underground floor from an upper floor to a lower floor, each basement floor has Excavations are to be made on all floor elevations, and floor slabs, columns, beams and walls are to be built in this excavated part. For this reason, when the height of the basement floor is high, the excavation depth corresponding to the height of the entire floor becomes deep, and in order to prevent the ground from being collapsed, it is necessary to reinforce it with bulging, cutting beams and the like.

[0004] Therefore, when excavating the entire height of each basement floor in this way, the problem is that the construction period is greatly lengthened because bulging and mounting and removal of the cutting beams are performed. there were.

[0005] In view of the above-mentioned conventional problems, the present invention constructs a continuous underground wall in order to sequentially construct each basement floor from the upper layer to the lower layer, and constructs the inside surrounded by the continuous underground wall. Excavation is performed to approximately the middle of the basement floor, and inside this continuous underground wall, the floor slabs and beams of the immediately above floor, and the excavated columns and walls of the basement floor to be constructed are constructed. In addition, a concrete wall (hereinafter, referred to as a "composite wall") acting integrally with the excavated portion of the basement floor is provided inside the continuous underground wall of the excavated portion to provide strength and rigidity. By constructing a wall, when constructing a basement floor below the basement floor,
Unexcavated lower ground and existing floor slabs, beams,
An object of the present invention is to provide a method of constructing an underground structure which can be performed while being supported by columns, walls, and a composite wall, and does not require reinforcement by bulging, cutting beams, or the like.

[0006]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention relates to a method of constructing an underground structure in which an underground structure is constructed while excavating from an upper layer to a lower layer and sequentially constructing an underground floor. After that, the inside surrounded by this continuous underground wall,
Excavation is performed to approximately the middle of the height of the basement to be constructed, then the floor slabs and beams on the floor immediately above and the columns and walls of the basement to be constructed are partially excavated, and then further excavated After that, a concrete wall (composite wall) acting as an integral part is added inside the continuous underground wall, and in this state, a deeper excavation is performed to construct a floor slab and a beam and the like on the immediately lower floor. I do.

[0007]

According to the construction method of the underground structure of the present invention having the above-described structure, first, a continuous underground wall is constructed, and the inside surrounded by the continuous underground wall is formed on the underground floor to be constructed. Excavation is performed to approximately the middle of the floor height, and floor slabs and beams on the immediately above floor and pillars and walls of the underground floor to be constructed are constructed, and then excavated further. When the composite wall is added to the inside of the continuous underground wall corresponding to the floor slab, beams, columns, walls and composite wall, when excavating the lower basement floor to be subsequently constructed, The continuous underground wall portion at the upper end portion can be supported, and the continuous underground wall portion at the lower excavation position can be supported by the unexcavated ground. Therefore, at the stage of excavating the ground one after another, the conventional construction method does not require the use of bulges or cut-off beams, which were required when the floor height is high, and the installation and removal of them is not required. Is simplified, and the construction period is shortened.

[0008] Further, due to the combined effect that the continuous underground wall constructed in advance and the composite wall extended inward later work integrally with respect to strength and rigidity, the upper part of the construction target depth is a floor slab and a beam. , The lower part can be supported by the unexcavated ground with pillars and walls in the middle, the excavation depth of each stage can be increased, and the large underground floor can be efficiently and safely secured. Can be built.

[0009]

Embodiments of the present invention will be described below in detail with reference to the accompanying drawings. 1 and 2 show an embodiment of a method for constructing an underground structure according to the present invention. FIG. 1 is an explanatory view showing the construction steps in order using the first basement floor as an example, and FIG. 2 shows the construction of a plurality of basement floors. It is sectional drawing which shows a state. FIG. 3 is a cross-sectional view for explaining the composite wall.

That is, as shown in FIG. 2, the underground structure 1 of this embodiment has a plurality of layers of basement floors 10a (first basement floor), 10 basement floors.
b (2 basement floors), 10c (3 basement floors)..., and the plurality of basement floors 10a, 10b, 10c. .

FIG. 1 shows a process of constructing the first basement floor 10a. First, a continuous underground wall (underground continuous wall) 12 is constructed around the underground structure 1 to be constructed (process A). As is generally known, the continuous underground wall 12 has a plurality of layers of basement floors 10.
A groove 14 having a depth reaching the deep portion of a, 10b, 10c,... is excavated, and concrete is poured into the excavated groove 14 to be constructed. Next, when the continuous underground wall 12 reaches the desired strength, the inside of the continuous underground wall 12 is moved to the first basement floor 10.
Excavation is performed to a substantially middle portion (depth h ₁ ) of the floor height H ₁ of a (step B). Then, a floor slab 21 and a beam 20 on the first floor 16 which is a floor directly above the excavated portion, and a pillar 22a and a wall 24a of the first basement floor 10a which are halfway excavated are constructed (C).
Process).

Thereafter, as shown in FIG.
When building a b, similarly to the first basement 10a, and drilled to a substantially middle portion of the floor height H ₂ (the depth h _2), just above floor floor slab 21a and beams 20a, basement 10b to be constructed The second basement floor 10b is constructed while constructing the pillars 22b and the walls 24b halfway through the excavation.

The pillar 22a which is an unfinished part of the upper floor
At the lower end of the wall 24a, a composite wall 23a is quickly constructed after the floor slab 21a of the lower floor is constructed.
This composite wall 23a will be described later.

In this embodiment, the floor height H _{3 of the third} basement floor 10c is set.
It is necessary to impart strength and rigidity to the continuous underground wall 12 in order to perform excavation for construction of the floor slab 21c and the like of the floor 10c. Therefore, after performing the same construction as above for drilling portion h _3, further subjected to drilling h _4, plus hit the synthetic wall 23c acting as an integral inside the underground diaphragm walls 12, after the strength development just above floor By these floor slabs 21b and beams 20b of 10b, pillars 22c, walls 24c and composite walls 23c of the floor 10c up to the middle of excavation,
Upon excavation of the lower basement floor 10d to be constructed thereafter, the continuous underground wall portion at the upper end position of the basement floor 10d can be supported, and the continuous underground wall portion at the excavation lower end position is not excavated. Can be supported by the ground,
It is possible to eliminate the need for a belly, a cutting beam, and the like, which are conventionally used. For this reason, it is possible to omit the work of attaching and removing the belly, the cut beam, and the like, and as a result, it is possible to significantly shorten the construction period.

The composite walls 23a to 23c are shown in FIG. 3. The composite walls 23a to 23c connect the continuous underground wall 12 and the post-cast concrete with joints such as joint reinforcing bars 25, and apply an external force. Therefore, the excavation depth can be increased by the cantilever structure, and the wall thickness of the post-cast concrete can be minimized.

In the method of constructing an underground structure according to the present invention having the above-described configuration, first, a continuous underground wall 12 is constructed, and the inside surrounded by the continuous underground wall 12 is to be constructed underground. was drilled to a substantially middle portion of the floor height H ₃ of the floor 10c (h _3), the floor slab 21 directly above floor 10b to the drilling portion
b, beam 20b, and basement 10 to be constructed
Construct pillars 22c and walls 24c halfway through the excavation of c,
Thereafter, the excavation was further performed (h ₄ ), and the composite wall 23c was added inside the continuous underground wall 12 corresponding to the basement floor 10c, whereby the floor slab 21b, the beam 20b, the column 22c, the wall 24c, and the composite The wall 23c can support the continuous underground wall portion at the upper end position of the basement floor 10d when excavating the lower underground floor 10d to be subsequently constructed, and can also support the continuous underground wall portion at the lower excavation bottom position. It can be supported by unexcavated ground. Therefore, at the stage of excavating the ground one by one, there is no need to use bulges or cut beams which were required when the floor height is high in the conventional construction method. Is simplified, and the construction period is shortened.

Further, the continuous underground wall 12 constructed in advance
And the composite wall 23c, which has been added to the inside later, acts integrally with respect to strength and rigidity, so that the upper part of the construction target depth is the floor slab 21b, the beam 20b, the column 22c and the wall 24c halfway, The lower part can be supported by the unexcavated ground, the excavation depth at each stage can be increased, and the large underground floor can be efficiently and safely constructed.

[0018]

As described above, according to the present invention, a continuous underground wall is constructed first, and when excavating one floor at a time without reinforcement by bulging or cutting beams in each underground floor, After excavating to approximately the middle part of the floor height, constructing the floor slabs and beams on the floor immediately above, pillars and walls halfway through the excavation, and excavating the rest of the floor, The composite wall that acts as an integral part of the floor, after the strength is developed, the composite wall and the upper part are sunk to the floor slab of the immediately above floor, supported by beams, and dug up to the almost middle part of the immediately lower floor, and the floor slab of that floor,
Because beams and the like can be constructed, it is possible to construct a basement floor with a large floor height without needing to bulge or cut beams, and achieve various excellent effects such as shortening of construction period and cost reduction. .

[Brief description of the drawings]

BRIEF DESCRIPTION OF DRAWINGS FIG. 1 is an explanatory diagram sequentially illustrating a construction process of an embodiment of the present invention, taking a first basement floor as an example.

FIG. 2 is a sectional view showing a plurality of basement floors constructed according to the present invention.

FIG. 3 is a side sectional view for explaining a composite wall.

[Explanation of symbols]

1 underground structure 10a-10d
Basement floor 12 continuous underground wall 20-20c
Beam 21-21c Floor slab 22a-22c
Pillars 24a-24c Walls 23a-23c
Synthetic wall H ₁ ~H ₃ story height

Claims (1)

(57) [Claims] 1. A method of constructing an underground structure in which an underground floor is sequentially constructed while excavating from an upper layer to a lower layer, comprising: constructing a continuous underground wall; Excavation is performed to approximately the middle of the height of the basement to be constructed, and then the floor slabs and beams of the floor immediately above and columns and walls of the basement to be constructed are partially excavated.
After further excavation, construct a concrete wall (composite wall) acting as an integral part of the continuous underground wall, and excavate deeper in this state to construct floor slabs and beams directly below the floor A method for constructing an underground structure, characterized by the following.