JP3360234B2 - Construction method of underground skeleton - 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 for constructing an underground skeleton made of, for example, reinforced concrete or steel reinforced concrete, and particularly suitable for constructing pillars and walls.

[0002]

2. Description of the Related Art Generally, when building structures such as buildings are built on the entire site in a city center or the like, when building an underground structure of the building in the ground, the ground is gradually cut off. The reverse construction method that builds the underground structure from the upper floor to the lower floor is often used.

[0003] In such a reverse striking method, first, the ground 1
The floors and beams of the floor (the so-called top plate) are formed so as to be supported by the pillar steel frame of this main column or the temporary steel column, and this is used as a work gantry for the subsequent construction work.
Excavation of the ground is continued below the floors and beams on the first floor above the ground, and after excavation for a certain depth, for example, one floor, the beams, floors, Build pillars, walls, etc. By repeating this, the skeleton of each floor is constructed sequentially from the upper floor to the lower floor, so that the underground skeleton is constructed.

Conventionally, in such a method of constructing an underground skeleton, when vertically continuous members such as columns and walls are constructed, the following is performed. That is, as shown in FIG. 7, first, the bottom form 3 is horizontally placed on the excavated root cutting surface 1 via the support members 2 and 2. Next, the column reinforcement 5 of the column 4 to be formed on the bottom form 3 and the wall reinforcement 7 of the wall 6 are arranged and assembled, and the column form 8 and the wall form 9 are assembled around the periphery thereof in a predetermined shape. , And concrete is poured here. When columns and walls (not shown) of a lower floor are formed below the columns 4 and the walls 6 formed in this way, the root cutting bottom 1 is further excavated to a certain depth and the support members 2 and 2 are excavated. Then, the bottom form 3 is removed to expose the bottom surfaces of the pillars 4 and the walls 6. Thereafter, columns and walls (not shown) of the lower floor are formed in the same manner as above. At this time,
When arranging the reinforcing bars of the columns and walls (not shown) on the lower floor, the upper ends thereof are connected to the columns 4, the column reinforcing bars 5 protruding from the bottom of the wall 6, and the reinforcing bars 5a and 7a of the wall reinforcing bars 7. ing.

[0005]

However, the above-mentioned conventional underground skeleton construction method has the following problems. First, in order to assemble the bottom formwork 3, it is necessary to assemble the support members 2, 2 and the like, which is troublesome. In order to connect the upper and lower column reinforcing bars 5 and the wall reinforcing bars 7 when forming columns and walls (not shown) of the lower floor below the columns 4 and the walls 6, a reinforcing bar is provided on the lower surface of the columns 4 and the walls 6. It is necessary to make 5a and 7a protrude. For this reason, it is necessary to make a hole in the bottom formwork 3 and pass the column reinforcing bar 5 and the wall reinforcing bar 7 therethrough, which also requires much labor. As a result, when forming the columns 4 and the walls 6, the assembling work of the column reinforcing bars 5, the wall reinforcing bars 7, and the bottom form 3 is very troublesome.
Moreover, in order to assemble the support members 2 and 2 and the bottom form 3 and the like, it is necessary to make the root bottom 1 deeper by that amount.
This is an obstacle to shortening the construction period. Furthermore, after the column reinforcing bars 5 and the wall form 7 are arranged and assembled, the reinforcing bars 5a, 7
There is also a problem that it is dangerous because a protrudes downward. The present invention has been made in consideration of the above points, and an object of the present invention is to provide a construction method of an underground skeleton that can be easily and safely constructed.

[0006]

The invention according to claim 1 is
In constructing the underground skeleton in the ground, the digging step of excavating the ground to a certain depth and the skeleton building step of constructing the skeleton of each floor on the excavated root bottom surface are alternately repeated, so that the underground skeleton is raised. The building is constructed sequentially from the floor to the lower floor, and in each of the skeleton building steps, a concrete disc having a constant thickness is formed on the root bottom surface, and concrete hardens on the discard concrete board.
Before disposing a tubular reinforcing bar connection, after inserting and connecting the lower end of the main reinforcing bar of the column or wall to be formed to the reinforcing bar connecting device to assemble the reinforcing bar of the column or wall into a predetermined shape, Around the rebar
Form pillars and side walls on discarded concrete boards
When assembling a formwork and casting concrete into the formwork to form pillars and walls with a fixed length, and when performing the excavation step to excavate the root bottom below, When excavating the bottom of the root and demolishing the discarded concrete board to expose the lower surfaces of the pillars and walls and the rebar connector, and then performing the skeleton building step to construct a lower floor, It is characterized in that the upper end of the main reinforcing bar of the pillar or wall to be formed below is inserted and connected to the connecting tool.

According to a second aspect of the present invention, in the method of constructing an underground skeleton according to the first aspect, when the rebar connection fitting is disposed on the discarded concrete board in the skeleton construction step, the rebar connection fitting is connected to the underground skeleton. It is characterized in that it is embedded into a discarded concrete board for a certain length.

[0008]

According to the first aspect of the present invention, when pillars and walls are formed to a fixed length in the frame building process, a concrete disc having a fixed thickness is formed on the bottom of the root, and concrete is placed thereon.
Before the hardening, a tubular rebar connector was arranged and the lower end of the main rebar was inserted and connected to the rebar connector. Thus, the reinforcing bar can be disposed on the concrete board and disposed and assembled without using the bottom formwork as in the related art. Then, by excavating the discarded concrete slab when excavating the ground further to a certain depth in the excavation process, the rebar connection fittings are exposed on the lower surfaces of the pillars and walls formed in the skeleton building process, and then the skeleton of the lower floor is removed. At the time of construction, the upper end of the main reinforcing bar of the pillar or wall to be formed below is inserted and connected to the reinforcing bar connecting tool. This makes it possible to easily connect the main reinforcing bars of columns and walls up and down.

According to the second aspect of the present invention, when arranging the reinforcing bar connecting piece on the discarded concrete board in the frame building step,
Reinforcing bar fittings were discarded and a certain length was embedded in a concrete board. This makes it possible to easily position the rebar connection tool without using a jig or the like.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to an embodiment shown in the drawings. Here, for example, an embodiment in the case of constructing an underground skeleton having a multi-story floor in which the beams are made of reinforced concrete and the columns are made of steel reinforced concrete will be described. FIG. 1 shows an example of an underground skeleton constructed by applying the underground skeleton construction method according to the present invention. As shown in FIG. 1, the underground skeleton 10 is constructed on a foundation (not shown) formed in the ground G, and has a basement floor composed of, for example, five layers below the ground floor 11. It has become.

In this underground skeleton 10, the columns 12 are made of, for example, steel reinforced concrete (hereinafter referred to as "SRC").
The wall 13, the beams 14 on each floor, and the floor 15 are made of reinforced concrete (hereinafter, referred to as "RC"). As shown in FIGS. 1 and 2, each column 12 arranged at a predetermined interval includes a column steel frame 16 erected on a foundation (not shown), a column reinforcing bar 17 arranged at four corners, and a sectional view. It is formed from concrete C cast in a rectangular shape. Each of the walls 13 arranged between the columns 12, 12, ... so as to form a lattice shape in a plan view has a wall reinforcing bar 18 arranged along the center in the thickness direction, and a predetermined thickness around the wall reinforcing bar 18. It is formed from concrete C that has been cast over a long time.

Next, a construction method for constructing such an underground skeleton 10 will be described with reference to FIGS. First, as shown in FIG. 3, a column steel frame 16 of each column 12 is placed at a predetermined position on the ground G (a position where each column 12 is to be erected).
The lower end is driven so as to reach a predetermined depth.

(Excavation process) Next, the ground G is excavated at a constant depth.

(Structural Construction Step) Around the steel columns 16 projecting above the excavated primary root cut surface (root cut bottom surface) G1 and the position where the wall 13 is to be formed, a predetermined thickness is provided. Concrete (straight) to form discarded concrete discs 21, 21,. Then, before the concrete of each discarded concrete board 21 is hardened, a predetermined position on the discarded concrete board 21 (the main reinforcement 17
a, the position where the vertical bars 18a of the wall reinforcing bars 18 are to be arranged), the reinforcing bar connectors 22, 22,... are disposed so that about half of the length thereof is buried in the discarded concrete board 21. The rebar connection tool 22 is cylindrical and has a female screw portion formed on the inner peripheral surface. At this time, for example, a resin cap (not shown) is put on the lower end of each rebar connection tool 22 in order to prevent concrete from entering the inside.

Next, the lower ends of the main reinforcing bars (main reinforcing bars) 17a, 17a,... Of the column reinforcing bars 17 of the column 12 are inserted and connected to the reinforcing bar connecting tools 22, 22,. The main reinforcing bar 17a is a so-called threaded bar having a male screw portion formed on the outer peripheral surface of the upper and lower ends. Subsequently, hoop bars (not shown) of the column reinforcing bar 17 are arranged, and the column reinforcing bar 17 is assembled into a predetermined shape. And pillar reinforcement 1
For example, a tubular pipe 25 such as a winding pipe is disposed on the discarded concrete board 21 inside the hoop 7 (not shown). This pipe 25 is, for example, 100 to
It has a diameter of about 200φ and a length such that its upper end is exposed or protrudes above the floor 15 to be formed. Next, a column formwork (formwork) 26 is assembled on the discarded concrete board 21 around the column reinforcing bar 17. The column formwork 26 does not need a bottom formwork, and may be assembled so as to form only the side surfaces of the columns 12.

In parallel with the assembly of the column reinforcing bar 17,
The assembling work of the wall reinforcing bar 18 and the wall formwork (formwork) 27 is performed as follows. First, the lower ends of the vertical reinforcing bars (main reinforcing bars) 18a, 18a,... Of the wall reinforcing bars 18 are inserted and connected to the reinforcing bar connectors 22, 22,. The vertical streak 18a is a so-called threaded bar having male screw portions formed at upper and lower ends, similarly to the main streak 17a. Subsequently, a horizontal bar (not shown) of the wall reinforcing bar 18 is arranged, and the wall reinforcing bar 18 is assembled into a predetermined shape. Then, as shown in FIGS. 2 and 3, pipes 25, 25,.
At regular intervals along the wall 13 to be formed, for example 200
It is placed on the discarded concrete board 21 every 0 mm. Next, as shown in FIG. 3, the wall form 27 is assembled on the discarded concrete board 21. This wall form 27 does not need a bottom form as well as the column form 26, and may be assembled so as to form only the side surface of the wall 13.

Next, after assembling the beam formwork 28 and the floor formwork (not shown) on the column formwork 26 and the wall formwork 27, the reinforcing bars (not shown) of the beams 14 and the floor 15 are formed into a predetermined shape. Assemble to

Thus, the column formwork 26, the wall formwork 27,
After assembling the beam formwork 28 and the floor formwork (not shown), concrete C is cast inward. At this time, the concrete C is not poured into each pipe 25. After the cast concrete C is cured and a predetermined strength is developed, the column formwork 26, the wall formwork 27, the beam formwork 28,
Disassemble the floor formwork (not shown). Thus, beam 1
4, the floor 15 is formed, and the fixed length pillar 12 and the wall 13 are formed on the lower surface, and the construction of the ground floor 11 is completed.

Next, an underground first floor B1 is constructed below the first ground 11 as follows. (Excavation process) First, the primary root cut surface G1 is excavated to a certain depth. At this time, the discarded concrete board 21 formed in the frame building step is demolished simultaneously with excavation. Since the discarded concrete board 21 is made of plain concrete, the pillars 12 and the walls 13 formed on the upper surface thereof can be easily demolished without being damaged. Then, the pillar 12, the wall 13
And the lower half of the rebar connection tool 22 is exposed. The cap (not shown) is also removed.

(Building Construction Step) Subsequently, as shown in FIG. 4, the first basement B1 is constructed on the excavated secondary root cutting plane (root cutting bottom) G2 in the same manner as in the above-mentioned building construction step. That is, the discarded concrete board 21 is formed at the position where the column 12 and the wall 13 are to be formed. Reinforcing bar fitting 2 at a predetermined position on concrete board 21
Are arranged so as to be embedded. The main rebar 1 of the column rebar 17 is attached to the rebar connectors 22, 22,.
7a, the lower end of the vertical bar 18a of the wall reinforcing bar 18 is inserted and connected.

In the above, the main bar 17a and the vertical bar 18a
Are inserted and connected to the reinforcing bar connectors 22, 22,..., The upper ends 17 b, 18 b of the reinforcing bar connectors 22, 22 projecting from the lower surfaces of the pillars 12 and the walls 13 formed in the frame building step. Insert and connect to, ...

Subsequently, the column reinforcing bar 17 and the wall reinforcing bar 18 are assembled on the discarded concrete board 21, and the pipe 25 is arranged. And between this pipe 25 and the upper pipe 25,
A pipe (concrete casting pipe) 29 is connected.
As the pipe 29, for example, a winding pipe is used like the pipe 25. The column formwork 26 and the wall formwork 27 are assembled. After assembling the beam formwork 28 and the floor formwork (not shown),
Assemble beam reinforcement and floor reinforcement. Concrete C is poured into the column formwork 26, the wall formwork 27, the beam formwork 28, and the floor formwork (not shown), and after the concrete C hardens, each formwork is dismantled.

In this manner, the beam 1 on the first basement B1
4, a floor 15 is formed, and on the lower surface thereof, columns 12 and walls 13 having a fixed length are formed. At this time, the pillar 12 formed on the lower surface of the ground floor 11, the lower end of the wall 13, and the ground floor B
The concrete C of the columns 12 and the walls 13 is not cast between the upper surface of the floor 15 and the column 15, and the column steel frame 16, the column reinforcing bar 17,
The wall reinforcement 18 is exposed.

Thereafter, the excavation step and the skeleton building step are repeated in exactly the same manner as described above, and as shown in FIG. 5, the underground skeleton 10 is built up to the fifth floor B5 which is the lowest floor. The pipe 25 is not buried in the floor 15 of the fifth basement B5.

(Column / Wall Concrete Casting Step) Next, as shown in FIG. 6, the portions of the columns 12 and 13 of the fifth basement B5 where the column steel frame 16, the column reinforcing bar 17, and the wall reinforcing bar 18 are exposed are shown. A column formwork 30 and a wall formwork 31 are assembled around the periphery. continue,
A concrete supply hose 32 for supplying concrete C from a concrete supply source (not shown) such as a mixer into the pipes 25 and 29 arranged on the pillars 12 and the walls 13 from above the ground floor 11. To reach the column formwork 30 and the wall formwork 31 of the fifth basement B5. Then, from the concrete feed hose 32, the column form 3
0, Concrete C is poured into the wall form 31 to form the columns 12 and the walls 13 of the fifth basement B5.

Next, the pipe member 29 on the fourth basement floor B4 is removed. Then, in the same manner as above, concrete C is cast from the concrete supply hose 32 to form the columns 12 and the walls 13 of the fourth basement B4. At this time, each pipe 2 buried in the pillar 12 and the wall 13 of the fourth basement B4
Concrete C is poured into the inside of the pipe 5 and the pipe 25 is
2. Try to bury in the wall 13.

Thereafter, the above operation is repeated in the same manner, and concrete C is poured into the columns 12 and the walls 13 of each floor from the lower side to the upper side. And pillars 12 on each floor,
After the concrete C of the wall 13 is cured and a predetermined strength is developed, the column formwork 30 and the wall formwork 31 are sequentially dismantled, whereby the construction of the underground skeleton 10 shown in FIG. 1 is completed.

In the construction method of the underground skeleton 10 described above, when the pillars 12 and the walls 13 are formed in the skeleton building process, the discarded concrete board 21 is formed, and the discarded concrete board 2 is formed.
1 and the rebar connection tool 22 on the
The main reinforcement 17a and the lower end of the vertical reinforcement 18a of the wall reinforcement 18 are inserted and connected to the reinforcement fitting 22. Thereby, the column reinforcing bar 17 and the wall reinforcing bar 18 can be arranged and assembled without using the bottom form 3 (see FIG. 7) as in the related art. Thus, the assembling work of the wall form 27 can be greatly facilitated, the construction period can be shortened, and the root cutting depth can be minimized. In addition, since the reinforcing bar connector 22 is discarded and embedded in the concrete board 21 at a fixed length, the positioning of the column reinforcing bar 17 and the wall reinforcing bar 18 can be performed easily and accurately without using a jig or the like. As a result, work efficiency can be improved, and from this point, the construction period can be shortened. Also, in the excavation process, the ground G is formed to form the pillars 12 and the walls 13 on the lower floor below the pillars 12 and the walls 13 formed in the frame building process.
When excavating a further depth to a certain depth, the discarded concrete board 21 is demolished, and the lower
1 is exposed, and then, in the frame building process, the main reinforcements 17 of the columns 12 to be formed on the rebar connection fittings 21 are formed.
a, the upper ends 17b and 18b of the vertical stripes 18a of the wall 13 are inserted and connected. Thereby, the main reinforcing bar 1 of the column reinforcing bar 17 is formed.
7a, the vertical bars 18a of the wall reinforcing bars 18 can be easily and reliably connected up and down. In addition, in a state where the discarded concrete board 21 is demolished in the excavation process, the main reinforcement 17
a, the vertical bars 18a of the wall reinforcing bar 18 do not protrude downward, so that it is possible to improve safety. Further, a pipe 25 is provided in the pillar 12 and the wall 13,
Since the concrete C is cast from the pipe 25, the concrete C can be cast on the columns 12 and the walls 13 easily and with high quality.

In the above embodiment, after the reinforcing bars 22 are arranged on the discarded concrete board 21 in the frame building process, the main bars 17a of the column bars 17 and the vertical bars 1 of the wall bars 18 are formed.
8a is inserted and connected to the rebar connection tool 22,
A structure in which the main reinforcing bar 17a of the column reinforcing bar 17 and the longitudinal bar 18a of the wall reinforcing bar 18 are inserted and connected to the reinforcing bar connecting tool 22 in advance may be arranged on the discarded concrete board 21. Further, the rebar connection tool 22 is configured to be buried in the discarded concrete board 21, but may be configured to be simply placed on the discarded concrete board 21. Furthermore, the underground skeleton 10
In constructing the pillar, after the state shown in FIG.
2. The concrete C is cast on the wall 13 sequentially from the lower floor to the upper floor, but the present invention is not limited to this.
When the beams 14 and floors 15 of each floor are sequentially constructed from the upper floor to the lower floor, concrete C may be simultaneously poured into the columns 12 and the walls 13. In addition, although the pipes 25 and 29 are used to cast the concrete C, the concrete C is cast from the upper end side of the form in the same manner as before without using this. Is also good.
Also, in the above embodiment, the construction method using the rebar connection tool 22 is applied to both the pillar 12 and the wall 13.
Of course, the above-described construction method may be applied to only one of the column 12 and the wall 13, and a conventional construction method that does not use the rebar connector 22 may be applied to the other.

Further, when constructing the underground skeleton 10 of the above embodiment, the column steel frame 16 of the main column 12 is previously driven in, and the column steel frame 16 is used as a column, and the ground floor 11 and the like are used.
Although it was configured to support the load of the underground skeleton 10 during construction,
Of course, a temporary column is driven in place of this column steel frame 16,
The temporary column may support the load of the underground skeleton 10 under construction. Furthermore, if the construction is performed using the temporary columns as described above, the present invention can be applied to the case where the columns 12 of the underground skeleton 10 are made of RC. Similar effects can be obtained. In addition to the above, other configurations, such as the configuration of the underground skeleton 10 and the procedure of construction, may have the same effect as described above, regardless of the configuration, as long as the configuration does not deviate from the gist of the present application. Needless to say.

[0031]

As described above, according to the method for constructing an underground skeleton according to the first aspect, when a column or a wall is formed to a fixed length in the skeleton building process, a fixed thickness is formed on the root cutting bottom. Form a discarded concrete board on which concrete hardens
Before the installation, a tubular rebar connector is arranged and the lower end of the main rebar is inserted and connected to the rebar connector. As a result, instead of using a bottom formwork as in the past, the steel bars were discarded and supported on concrete boards to reinforce the columns and walls.
Since it can be assembled, the work of assembling the reinforcing bars and formwork of columns and walls can be greatly facilitated, the construction period can be shortened, and the root cutting depth can be minimized. it can. Then, by excavating the discarded concrete slab when excavating the ground further to a certain depth in the excavation process, the rebar connection fittings are exposed on the lower surfaces of the pillars and walls formed in the skeleton building process, and then the skeleton of the lower floor is removed. At the time of construction, the upper end portion of the main reinforcing bar of the pillar or wall to be formed on the reinforcing bar connector is inserted and connected. This makes it possible to easily and reliably connect the main reinforcing bars of the columns and walls to be continuously formed below the already formed columns and walls. In addition, when the discarded concrete slab is demolished in the excavation process, the reinforcing bars do not protrude below the columns and walls, so that it is possible to improve safety.

According to the construction method of the underground skeleton according to the second aspect, when arranging the rebar connection fitting on the discarded concrete board in the skeleton building step, the rebar connection fitting is discarded and embedded in the concrete board with a fixed length. did. This makes it possible to easily position the rebar connection tool without using a jig or the like, so that the work efficiency of rebar assembly can be improved, and from this point, the construction period can be shortened. Become.

[Brief description of the drawings]

FIG. 1 is a front sectional view showing an example of an underground skeleton constructed by applying an underground skeleton construction method according to the present invention.

FIG. 2 is a plan sectional view showing a part of the underground skeleton.

FIG. 3 is a front sectional view showing a construction process of the underground skeleton, showing a state where a first floor above ground is constructed.

FIG. 4 is a front sectional view showing a construction process of the underground skeleton, in which a first basement is constructed below a first floor above the ground;

FIG. 5 is a front sectional view showing a construction process of the underground skeleton and showing a state where the underground skeleton is constructed up to the fifth floor underground.

FIG. 6 is a front sectional view showing a construction step of the underground skeleton, showing a state in which concrete is cast on columns and walls.

FIG. 7 is a front sectional view showing an example of a conventional method of constructing an underground skeleton.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Underground frame 12 Column 13 Wall 17 Column reinforcing bar 17a Main reinforcing bar (main reinforcing bar) 17b, 18b Upper end portion 18 Wall reinforcing bar 18a Vertical reinforcing bar (main reinforcing bar) 21 Discarded concrete panel 22 Reinforcing bar connection 26 Column form (form) 27 Wall type Frame (Form) C Concrete G Ground G1 Primary root (root bottom) G2 Secondary root (root bottom)

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-5-179668 (JP, A) JP-A-6-173283 (JP, A) JP-A-7-82759 (JP, A) 107632 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) E02D 29/045 E04B 1/35 E21D 13/00

Claims (2)

(57) [Claims] When constructing an underground skeleton in the ground, an excavation step of excavating the ground to a certain depth and a skeleton construction step of constructing a skeleton of each floor on the excavated root bottom are alternately repeated. The underground skeleton is constructed sequentially from the upper floor to the lower floor, and in each of the skeleton building steps, while forming a discarded concrete board having a constant thickness on the root bottom, and on the discarded concrete board , Before the concrete is hardened, a tubular reinforcing bar connection is arranged, and the lower end of the main reinforcing bar of the column or wall to be formed is inserted and connected to the reinforcing bar connecting unit to assemble the column or wall reinforcing bar into a predetermined shape. After that, throw away the concrete around the rebar
Then, the formwork is assembled so as to form the side surfaces of the columns and walls , and concrete is poured into the formwork to form the columns and walls to have a fixed length, and the root cutting surface below them is excavated. When performing the excavation step, to excavate the root bottom and demolish the discarded concrete board to expose the lower surface of the pillars and walls and the rebar connector, and then to construct a lower floor When performing the skeleton building step, to the rebar connector,
A method for constructing an underground skeleton, comprising inserting and connecting an upper end of a main reinforcing bar of a pillar or a wall to be formed below. 2. The method for constructing an underground skeleton according to claim 1, wherein when the reinforced joint is arranged on the discarded concrete board in the skeleton building step, the reinforced joint is fixed inside the discarded concrete board. A method of constructing an underground skeleton characterized by embedding the length.