JPH06146309A - Construction method of underground structure - Google Patents

Abstract

PURPOSE:To construct a composite wall acting as a unit on the inside of a continuous underground wall constructed in advance, to increase strength and rigidity as an earth retaining wall by the composite effects and to make unnecessary wale or shore strut in the case basement stories have a big story height. CONSTITUTION:In the case of a basement story 10c having high story height H3, after a floor slab 21b, a beam 20b, etc., right above the story are contracted, excavation (h4) is carried out, and a composite wall 23c acting as a unit on the inside of a continuous underground wall 12 is constructed. After the strength of the composite wall 23 is displayed, excavation (h5) is made up to the intermediate part right under the floor, a floor slab 21c, a beam 20c, etc., of the basement floor 10c are constructed.

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, particularly an underground structure having a plurality of basement floors, which is constructed by sequentially excavating from an upper basement floor to a lower basement floor. Regarding

[0002]

2. Description of the Related Art Conventionally, in constructing a plurality of basement floors, the ground is first excavated up to the construction part of the lowermost basement floor, and the basement floors are constructed inside the excavation part in order from the lower layer to the upper layer. There are known a sequential driving method and a reverse driving method in which each underground floor is constructed by sequentially excavating from the upper basement floor to the lower basement floor.

[0003]

However, in such a conventional method of constructing an underground structure using the reverse construction method, when constructing an underground floor from an upper floor to a lower floor, All floor heights are excavated and floor slabs, columns, beams and walls are constructed in this excavated portion. Therefore, when the floor height of the basement floor is high, the excavation depth corresponding to the height of all the floors is deep, and in order to prevent the collapse of the ground, it is inevitable to reinforce the ground floor by using upholstery or cutting beams.

Therefore, when excavating the entire height of each basement floor in this way, a problem arises in that the construction period is greatly lengthened because the uprising and the attachment and detachment of the beams are performed. there were.

In view of such conventional problems, the present invention constructs a continuous underground wall in order to construct each basement from the upper layer to the lower layer one by one, and constructs an inner side surrounded by the continuous underground wall. Excavation is performed up to approximately the middle of the height of the basement floor, and inside this continuous underground wall, the floor slab and beam of the floor directly above, and the pillars and walls up to the midway of the excavation of the basement to be constructed are constructed. In addition, a concrete wall (hereinafter referred to as "composite wall") that works together with the continuous underground wall of this excavated portion was added to the underground floor to add strength and rigidity to the Yamadome. By constructing a wall, when constructing a basement below the basement, the part to be excavated is
Lower ground not excavated and existing floor slabs, beams,
An object of the present invention is to provide a method for constructing an underground structure, which can be carried out in a state of being supported by columns, walls, and synthetic walls, and which does not require reinforcement such as a waving or a cutting beam.

[0006]

[Means for Solving the Problems] In order to achieve the above object, the present invention is a method of constructing an underground structure in which a basement floor is sequentially constructed while excavating from an upper layer to a lower layer. After that, the inside surrounded by this continuous underground wall,
Excavation is performed up to approximately the middle of the floor height of the basement to be constructed, then the floor slab and beam of the floor directly above and the pillars and walls up to the midway of the excavation of the basement to be constructed, and then further excavation. After that, a concrete wall (composite wall) that acts as an integral part is added to the inside of the continuous underground wall, and in this state, deeper excavation is performed, and floor slabs and beams on the floor directly below are constructed. To do.

[0007]

In the method for constructing an 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 constructed on the basement floor to be constructed. The ground floor slab, beams, and pillars and walls up to the midway of the basement that is to be built are constructed in this excavation area by excavating up to approximately the middle of the floor, and then further excavation By adding the above synthetic wall to the inside of the continuous underground wall corresponding to, when excavating the lower basement that is subsequently constructed by these floor slabs, beams, columns, walls and synthetic walls, The continuous underground wall portion at the upper end position can be supported, and the continuous underground wall portion at the excavated lower end position can be supported by the ground not excavated. Therefore, at the stage of sequentially excavating the ground, it is not necessary to use the uprising and the cutting beam, which were required in the conventional construction method when the floor height is high, and it is not necessary to install and remove them. This simplifies the process, which in turn shortens the construction period.

In addition, due to the combined effect that the continuous underground wall constructed in advance and the composite wall added to the inside work together as one unit regarding strength and rigidity, the upper part of the depth to be constructed is set to the floor slab or beam. The pillars and walls up to the middle can support the lower part on the ground that has not yet been excavated, and the excavation depth at each stage can be increased, making it possible to efficiently and safely secure large basements. Can be built into.

[0009]

Embodiments of the present invention will now be described 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 diagram showing the construction steps in order taking the first basement floor as an example, and FIG. 2 has constructed a plurality of underground floors. It is sectional drawing which shows a state. FIG. 3 is a cross-sectional view for explaining the synthetic wall.

That is, as shown in FIG. 2, the underground structure 1 of this embodiment has a plurality of layers of basement floors 10a, 10b.
b (2nd basement floor), 10c (3rd basement floor) are provided, and the basement floors 10a, 10b, 10c ... of these multiple layers are constructed by sequentially excavating downward from the basement floor of the upper floor by the reverse construction method. .

FIG. 1 shows a process for constructing the first basement floor 10a. First, a continuous underground wall (underground wall) 12 is constructed around the underground structure 1 to be constructed (process A). The continuous underground wall 12 is, as is generally known, a multi-story basement floor 10.
Grooves 14 having a depth reaching a large depth of a, 10b, 10c ... Are excavated, and concrete is placed in the excavated trenches 14 to construct the construction. Next, when the continuous underground wall 12 reaches the desired strength, the inside of the continuous underground wall 12 is placed on the first basement floor 10
Excavation is performed to a substantially middle portion (depth h ₁ ) of the floor height H ₁ of a (process B). Then, in the excavated portion, a floor slab 21 and a beam 20 on the first floor 16 which is directly above the floor, a beam 20, and a pillar 22a and a wall 24a up to the midway of the excavation on the first basement floor 10a are constructed (C
Process).

Then, as shown in FIG. 2, the second basement floor 10
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 While constructing the pillar 22b and the wall 24b up to the middle of excavation, the second basement floor 10b will be constructed.

Pillar 22a which is an unfinished part of the upper floor
And the synthetic wall 23a is immediately constructed at the lower end portion of the wall 24a after the floor slab 21a of the lower floor is constructed.
The synthetic wall 23a will be described later.

In this embodiment, the floor height H _{3 of the third} basement floor 10c is
Is large, and it is necessary to give strength and rigidity to the continuous underground wall 12 in order to perform excavation for building the floor slab 21c 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 With these floor slabs 21b of 10b, beams 20b, pillars 22c, walls 24c and composite walls 23c of the floor 10c up to the middle of excavation,
When excavating 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 lower end portion of the excavation is not excavated. Can be supported by the ground,
It is possible to eliminate the conventionally used uprising, cutting beams, and the like. For this reason, it is possible to omit the work of attaching and detaching the abdomen and the cut beam, and as a result, it is possible to achieve a significant reduction in the construction period.

The synthetic walls 23a to 23c are shown in FIG. 3, and the synthetic walls 23a to 23c connect the continuous underground wall 12 and the post-cast concrete by a joint such as a joint reinforcing bar 25 to apply an external force. As a result, the cantilever structure enables a deep excavation depth and a minimum wall thickness of the post-cast concrete.

In the method of constructing an underground structure according to the present invention having the above-mentioned structure, first, the 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 built
Building the pillar 22c and the wall 24c up to the middle of excavation of c,
After that, by further excavating (h ₄ ) the synthetic wall 23c was added to the inside of the continuous underground wall 12 corresponding to the basement 10c, so that the floor slab 21b, the beam 20b, the pillar 22c, the wall 24c, and the synthetic structure. The wall 23c can support the continuous underground wall portion at the upper end position of the underground floor 10d at the time of excavation of the lower underground floor 10d that is subsequently constructed, and at the same time, can connect the continuous underground wall portion at the lower end portion of the excavation to the continuous underground wall portion. It can be supported by the ground that has not been excavated. Therefore, at the stage of sequentially excavating the ground, it is not necessary to use the uprising and the cutting beam, which were required in the conventional construction method when the floor height is high, and it is not necessary to install and remove them. This simplifies the process, which in turn shortens the construction period.

Further, the continuous underground wall 12 constructed in advance.
And, due to the combined effect that the combined wall 23c that is added to the inside later acts integrally on the strength and rigidity, the upper part of the construction target depth is the floor slab 21b, the beam 20b, the pillar 22c and the wall 24c up to the middle, The lower part can be supported by the ground that has not been excavated, the excavation depth at each stage can be increased, and a large basement floor can be constructed efficiently and safely.

[0018]

As described above, according to the present invention, in the case where the continuous underground wall is first constructed and one floor cannot be excavated at one time without reinforcement by each of the basement floors, such as uprising and cutting beams. In addition, after excavating up to approximately the middle part of the floor height, building floor slabs and beams on the floor directly above, columns and walls up to the middle of excavation, and further excavating the rest of the floor, inside the continuous underground wall After adding strength to the synthetic wall that acts as an integral part of this, the synthetic wall, and the upper part of the synthetic slab, the upper part is the floor slab on the floor immediately above, and the beams are supported to dig into the approximately middle part of the floor directly below, and the floor slab on that floor,
Since it is possible to construct beams, etc., it becomes possible to construct a basement floor with a large floor height without the need for angling or cutting beams, etc., and various excellent effects such as shortening construction period and cost reduction are achieved. .

[Brief description of drawings]

FIG. 1 is an explanatory diagram sequentially showing a construction process of an embodiment of the present invention, taking a basement floor as an example.

FIG. 2 is a cross-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 Codes] 1 Underground structures 10a to 10d
Basement floor 12 Continuous underground wall 20-20c
Beams 21-21c Floor slabs 22a-22c
Pillars 24a-24c Walls 23a-23c
Composite wall H ₁ ~ H ₃ floor height

Claims (1)

[Claims] 1. A method of constructing an underground structure, in which a basement floor is sequentially constructed while excavating from an upper layer to a lower layer, wherein a continuous underground wall is constructed, and an inner side surrounded by the continuous underground wall is Excavating to about the middle part of the floor height of the basement to be constructed, then building the floor slab and beam of the floor directly above, and the pillars and walls up to the midway of the excavation of the basement to be constructed,
After further excavation, add a concrete wall (composite wall) that works as an integral part inside the continuous underground wall, excavate deeper in this state, and construct floor slabs and beams on the floor directly below. A method for constructing an underground structure, characterized by: