JPH06128976A - Underground structure and construction thereof - Google Patents

Abstract

PURPOSE:To reduce the cost of execution by installing a base block to the lower section of a side wall constructed so as to form a space on the inside by excavating the ground, forming a stepped section with an end face facing a lower section to the lower section of the internal surface of the side wall and engaging the peripheral section of the base block with the stepped section shaped to the side wall. CONSTITUTION:A side wall 12 is constituted while being brought into contact with the ground 11, and a hollow section is formed on the inside. A stepped section 14 with an end face 13 facing a lower section is formed to the lower internal surface of the side wall 12. A base block 15 is constructed to the inner lower section of the side wall 12, and the peripheral section 16 of the base block 15 is engaged with the stepped section 14 shaped to the side wall 12. The side wall 12 is built, and soil and sand on the inside are excavated and discharged onto the ground. Accordingly, the head pressure of groundwater gushing out from an underground section works in the direction that the base block 15 is pushed from the lower section of the base block 15 in a constructed underground structure, but no base block 15 is displaced because the peripheral section 16 of the base block 15 is interlinked with the stepped section 14 of the side wall 12, and the base block 15 is maintained under the state, in which it is fixed at a specified position.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a building structure, an underground structure constructed as a civil engineering structure, and a construction method thereof.

[0002]

2. Description of the Related Art Generally, when constructing an underground structure,
For example, an underground continuous wall that will be the side wall of an underground structure is built in the ground in advance, the ground surrounded by the underground continuous wall is excavated, and the bottom plate of the space is joined to the underground continuous wall to form a slab. The method of construction is adopted. In this construction, groundwater is unavoidable by excavating the ground, and groundwater accumulates in the excavated space. As a method of constructing a bottom slab at the bottom of the space, forcibly drain the accumulated water with a deep well, etc., dry up this space and then construct a bottom slab, and while keeping groundwater in this space, A construction method for building a bottom slab at the bottom of a space is known. Of these construction methods, the former is
The latter is advantageous when the amount of groundwater discharge is large, because the drainage work of groundwater that springs out is large.
The latter is also advantageous when it is a problem to cause ground subsidence due to drainage.

Conventionally, a construction method shown in FIG. 5 is known as a construction method for constructing a bottom slab at the bottom portion while groundwater is stored in a space. In the figure, in the ground 1, an underground continuous wall is constructed by excavating the ground 1, and the underground continuous wall constitutes a side wall 2 of an underground structure. When the area surrounded by the side wall 2 is further excavated, groundwater 4 springing into the space 3
Is stored. To build the bottom plate 5 at the bottom of the side wall 2,
Before placing the underwater concrete, the dowel 6 is attached to the place where the bottom slab 5 is constructed on the lower part of the inner surface of the sidewall 2. At this time, as a method for attaching the dowel 6, welding or side wall 2
There is a method of implanting the same in the side wall, or bending and setting the dowel 6 provided on the side wall 2 in advance. After that, underwater concrete is poured to form the bottom plate 5. In the above-mentioned bottom slab structure and its construction method, in order to prevent the bottom slab 5 from being displaced upward due to the pumping pressure of the ground water that springs out, it is essential to fix the bottom slab 5 at a fixed position on the side wall 2 by the dowel 6. is there.

[0004]

However, according to the above-mentioned bottom slab structure and its construction method, the attachment of the dowel requires diving work, which is dangerous and requires a separate safety measure cost in order to take safety measures for this work. However, there was a problem that the cost required for the construction would be enormous. In addition, as a matter of course, the work in water was inefficient, though it required a lot of labor and time. In addition, the worker who installs the dowel must be familiar with the diving technique because the dowel installation work is diving work.

The present invention has been made in view of the above circumstances, and it is possible to easily and efficiently perform the bottom slab construction work in a state in which groundwater that springs in the space surrounded by the side walls is stored, and to shorten the construction period. Another object of the present invention is to provide an underground structure that can be performed at low cost and a construction method therefor.

[0006]

An underground structure according to claim 1, wherein the ground is excavated and a bottom slab is provided at a lower portion of a side wall constructed so that a utilization space is formed therein. In the lower part of the inner surface of the side wall, a step portion having an end face facing downward is formed, and a peripheral portion of the bottom plate is
It is characterized in that it is engaged with a step formed on the side wall.

An underground structure according to a second aspect is an underground structure in which a bottom slab is provided at a lower portion of a side wall constructed so as to excavate the ground and form a utilization space therein.
A step portion having an end face facing downward is formed in a lower portion of the inner surface of the side wall, and a peripheral portion of the bottom plate is engaged with a step portion formed on the side wall, and a first bottom plate thereof. And a second bottom plate constructed on the upper side of the bottom plate.

The method for constructing an underground structure according to claim 3 is
After excavating the ground and constructing a side wall so as to surround the planned use area, the planned use area is further excavated, and the inside is used as the use space, and the groundwater that springs into the use space is stored in the state. In the method of constructing a bottom slab at the bottom of the side wall, when constructing the side wall, a step having an end face facing downward is formed at the bottom of the side wall, and the bottom slab is attached to the peripheral portion thereof. It is characterized in that it is constructed by engaging with a step portion of the side wall.

The construction method of the underground structure according to claim 4 is:
After excavating the ground and constructing a side wall so as to surround the planned use area, further excavating the planned use area to make the inside thereof a use space, and storing the groundwater that springs into the use space, the side wall In the method of constructing a bottom slab in the lower part of the above, when constructing the side wall, a step portion having an end face facing downward is formed in the lower portion of the side wall, and then engaged with the step portion. The first bottom plate is constructed, and the second bottom plate is constructed on the upper side of the first bottom plate.

[0010]

According to the first aspect of the present invention, the pumping pressure of groundwater that springs from underground acts in the direction of pressing the bottom slab from below the bottom slab, but the peripheral edge of the bottom slab becomes a step formed on the side wall. Because of the engagement, the bottom slab remains fixed in place without displacement.

According to the second aspect of the present invention, the pumping pressure of the groundwater which is spouted from the underground causes the first bottom slab from below the first bottom slab and the second bottom slab provided on the upper side thereof. Although it works in the pressing direction, since the first bottom plate is engaged with the stepped portion formed on the side wall at its peripheral portion, the first bottom plate and the second bottom plate are fixed in place without displacement. Is maintained.

According to the third aspect of the present invention, groundwater is stored in the space surrounded by the side wall in the work for constructing the bottom plate at the lower portion of the side wall, but the peripheral portion of the bottom plate is connected to the step portion of the side wall. The bottom plate is not displaced from the determined position due to the pumping pressure of groundwater.

According to the invention of claim 4, the first bottom slab is engaged with the step portion of the side wall, and then the second bottom slab is constructed on the upper surface side thereof. Is not affected by pumping pressure.

[0014]

Embodiments of the present invention will be described with reference to the drawings. FIG. 1 shows an underground structure of this embodiment. In the figure, reference numeral 11 is the ground, and a side wall 12 that is an underground continuous wall made of reinforced concrete is constructed in contact with the ground 11. These side walls 12 form the outer wall of the underground structure, and the inside thereof is a hollow portion. Side wall 1
A step portion 1 having an end face 13 facing downward is provided on the inner surface of the lower portion of 2.
4 are formed. On the other hand, a bottom slab 15 made of reinforced concrete is constructed below the inside of the side wall 12. The peripheral portion 16 of the bottom plate 15 has a step portion 14 formed on the side wall 12.
Is engaged with.

Next, a method of constructing an underground structure having the above structure will be described with reference to FIGS. 3 (a), 3 (b), 3 (c) and 3 (d). First, as shown in FIG. 3A, the ground 11 is excavated to construct the sidewall 12. The side wall 12 is constructed as a so-called variable cross section connecting wall, and a step portion 14 having an end face 13 facing downward is formed in the lower inner surface of the side wall 12. After the construction of the side wall 12 is completed, the earth and sand inside the side wall 12 are excavated and discharged to the ground. Here, the discharged earth and sand is excavated until the bottom slab 15 can be built to a predetermined depth. In this state, the side wall 12
A groundwater 18 is stored and stored in the space 17 formed inside. Then, as shown in (b), the reinforcing bar 19 is installed on the ground floor. After this, as shown in (c), underwater concrete 20 is poured. The underwater concrete 20 forms a bottom slab 15 and is engaged with the step portion 14 of the side wall 12. Next, as shown in (d), the groundwater 18 stored in this space 17 is dried up. After that, pillars and other partition walls are constructed in the space 17 as needed to form an underground structure.

In the underground structure constructed in this way, the pumping pressure of the groundwater 18 that springs from the underground is the bottom slab 15
The bottom plate 15 works in a direction of pressing the bottom plate 15 from below, but since the peripheral part 16 of the bottom plate is engaged with the step part 14 of the side wall 12, the bottom plate 15 is not displaced and is fixed in a fixed position. Is maintained.

In the underground structure of this embodiment, since the step portion 14 formed on the side wall 12 and the peripheral portion 16 of the bottom slab 15 are maintained in a fixed position as described above,
It is not necessary to fix the bottom plate 15 to the side wall 12 again by using a dowel or the like. As a result, the groundwater storage space 1
Underwater work for diving to 7 and attaching the dowel is unnecessary. Therefore, it is possible to avoid the danger associated with underwater work. In addition, it is possible to reduce the cost for safety measures taken when performing underwater work. Furthermore, by excluding underwater work from the bottom plate construction work, the time required to complete the bottom plate can be shortened, and the construction cost can be reduced. In addition, by excluding work that requires extremely special skills such as underwater work, the construction process can be continued throughout the general construction process.

Next, FIG. 2 which is another embodiment will be described. In the figure, reference numeral 31 indicates the ground. This ground 3
A side wall 32 which is an underground continuous wall made of reinforced concrete is constructed in contact with 1, and the side wall 32 constitutes an outer wall of an underground structure, and the inside thereof is a hollow portion. A step portion 34 having an end face 33 facing downward is formed on the inner surface of the lower portion of the side wall 32. On the other hand, a bottom slab 35 is constructed below the inside of the side wall 32. This bottom slab 35 has a double structure, and its peripheral edge portion 36 engages with the step portion 34 of the side wall 32 and is made of concrete.
And a second bottom plate 38 made of reinforced concrete on the upper surface of the first bottom plate 37.

Next, a method of constructing the bottom slab structure having the above construction will be described with reference to FIGS. 4 (a), (b), (c) and (d). First, the work of constructing the side wall 32 shown in FIG. 4A is the same as the work described with reference to FIG. 3A of the above-described embodiment, and thereafter, the work is surrounded by the side wall 32. The earth and sand are excavated, and the earth and sand surrounded by the side wall 32 are excavated and discharged to the ground until the bottom slab 35 can be built to a predetermined depth. In this state, the space 39 in the side wall 32
Groundwater 40 is stored in this area. Next, as shown in FIG. 4B, the underwater concrete 41 is poured into the bottom of the space 39 in which the groundwater 40 is accumulated to form the first bottom slab 37. This underwater concrete 41 is a step portion 34 of the side wall 32.
To complete the first bottom plate 37. Then, the space 39 is dried up. Next, as shown in FIG. 4 (c), the reinforcing bars 42 are installed on the first bottom slab 37 in the space 39 after the dry-up, and the concrete 43 is poured as shown in FIG. 4 (d). Thus, the second bottom plate 38 is completed. The first bottom slab 37 may also have reinforcing bars. After this, pillars and other partition walls are constructed in the space 39 as needed to form an underground structure.

In the underground structure constructed in this manner, the pumping pressure of the groundwater 40 that springs from the underground acts in the direction of pressing the bottom plate 35 upward from below the first bottom plate 37. Since the peripheral edge portion 36 is engaged with the step portion 34 of the side wall 32, the bottom plate 35 is not displaced,
It remains fixed in place.

In the underground structure of this embodiment, it is not necessary to fix the side wall 32 and the first bottom plate 37 again with a dowel or the like, as in the above-mentioned embodiments. This makes it possible to avoid the danger associated with underwater work, as in the above-described embodiment. In addition, it is possible to reduce the cost for safety measures taken when performing underwater work. Furthermore, by excluding underwater work from the bottom plate construction work, the time required to complete the bottom plate can be shortened, and the construction cost can be reduced. In addition, by excluding the work requiring extremely special skill such as underwater work, the construction process of the present embodiment can be generalized.

Further, in the above-mentioned underground structure, the first bottom plate 37 is formed in advance and the groundwater 40 stored in the space 39 is stored.
After drying up, the second bottom slab 38 is newly constructed on the upper side of the first bottom slab 37, whereby the construction work of the second bottom slab 38 can be easily performed. Also,
Since the bottom slab of this underground structure is composed of two bottom slabs 37 and 38, not only are each bottom slab constructed to have the same structure and strength, but also workability is improved when constructing an underground structure to improve work efficiency. To raise, for example, the first bottom plate 37
Can be constructed as a temporary bottom plate and the second bottom plate 38 as a permanent bottom plate, and different bottom plates can be constructed.

[0023]

According to the underground structure of the first aspect and the method of constructing the underground structure of the third aspect, the pumping pressure of the groundwater flowing from the underground works in the direction of pressing the bottom plate from below the bottom plate. Since the step portion having the end surface facing downward and formed on the lower portion of the inner surface of the side wall is engaged with the peripheral portion of the bottom plate, the state where the bottom plate is fixed at the fixed position is maintained. This eliminates the need to fix the bottom slab to the side wall by fixing the bottom slab to a fixed position by performing operations such as attaching a dowel. Therefore, the bottom slab construction work can be efficiently performed in a short period of time, and the construction cost can be reduced.

Further, according to the underground structure of claim 2 and the method of constructing an underground structure of claim 4, the pumping pressure of the groundwater flowing out from underground is from below the first bottom plate to the first bottom plate. And the second bottom slab, and the step portion having the end face facing downward and formed in the lower portion of the inner surface of the side wall is engaged with the peripheral portion of the first bottom slab, so that the two bottom slabs are engaged. Remains in place. As a result, in addition to the above effects, the bottom slab construction work can be easily performed.

[Brief description of drawings]

FIG. 1 is a front sectional view showing an embodiment of the present invention.

FIG. 2 is a front sectional view showing another embodiment of the present invention.

3 (a), (b), (c) and (d) are front cross-sectional views showing the construction process of the embodiment shown in FIG. 1, respectively.

4 (a), (b), (c) and (d) are front cross-sectional views showing a construction process of the embodiment shown in FIG.

FIG. 5 is a front sectional view showing a conventional bottom slab structure.

[Explanation of symbols]

 11 Ground 12 Sidewalls 13 End Faces 14 Steps 15 Bottom Slabs 16 Peripherals 17 Spaces 18 Groundwater 31 Ground 32 Sidewalls 33 End Faces 34 Steps 36 Peripherals 37 First Bottom Slabs 38 Second Bottom Slabs 39 Spaces 40 Groundwater

Claims (4)

[Claims] 1. An underground structure in which a bottom plate is provided at a lower portion of a side wall constructed so as to form a utilization space inside by excavating the ground, and a lower part is provided at a lower portion of an inner surface of the side wall. An underground structure, wherein a step portion having an end face facing to is formed, and a peripheral portion of the bottom slab is engaged with a step portion formed on the side wall. 2. An underground structure which is constructed by excavating the ground and having a bottom slab at the bottom of a side wall constructed so that a utilization space is formed inside the ground. A first bottom slab formed with a step having a facing end surface, the peripheral edge of which is engaged with the step formed on the side wall, and a second bottom slab constructed above the first bottom slab An underground structure characterized by consisting of. 3. The ground is excavated, a side wall is constructed so as to surround the planned use area, the planned use area is further excavated, and the inside is used as a use space, and groundwater that springs into the use space is discharged. In the method of constructing a bottom slab in the lower part of the side wall in a stored state, when constructing the side wall, a step portion having an end face facing downward is formed in the lower part of the side wall, and the bottom slab is A construction method for an underground structure, characterized in that the peripheral portion thereof is constructed by engaging with a step portion of the side wall. 4. The ground is excavated and a side wall is constructed so as to surround the planned use area, and then the planned use area is further excavated to make the inside thereof a use space, and ground water flowing out into the use space is stored. In the method of constructing a bottom slab in the lower part of the side wall in this state, when building the side wall, a step part having an end face facing downward is formed in the lower part of the side wall, and then the step. A method for constructing an underground structure, comprising engaging a part to construct a first bottom slab, and constructing a second bottom slab on the upper side of the first bottom slab.