KR102633669B1 - Construction method of cast-in-place columns using lath form for top down method - Google Patents

Abstract

The present invention is economical and easy to construct by inserting a counter-impacted column assembly consisting of a lath form and internal vertical reinforcement into a drilled hole formed in the ground, pouring deep concrete inside the lath form to form a counter-impacted column, and then constructing a permanent column on the outside. This is about the construction method of cast-in-place columns for counter-punching using lath formwork.
The present invention is for constructing a column for a counter-punching method by casting it in situ, including the steps of (a) drilling the ground to form a drilling hole; (b) A plurality of internal vertical reinforcing bars are provided on the inside of a lath form formed in a cylindrical shape with a closed cross-section, and an end at a position where a steel beam is to be coupled to the inside penetrates the lath form and protrudes to the outside of the lath form in a horizontal direction. Inserting a reverse striking column assembly provided with a jointed steel frame including a steel bracket into the drilling hole; (c) pouring deep concrete into the lath form to form a counter-punching column; (d) excavating and removing the ground surrounding the counter-impacting column, and joining a steel beam to the steel bracket while excavating the ground surrounding the counter-impacting column; (e) constructing a foundation plate on top of the excavated ground; and (f) installing a form outside the reverse driving column and pouring additional driving concrete inside the form to form a permanent pillar; It is characterized by being composed of a.

Description

Construction method of cast-in-place columns using lath form for top down method}

The present invention is economical and easy to construct by inserting a counter-impacted column assembly consisting of a lath form and internal vertical reinforcement into a drilled hole formed in the ground, pouring deep concrete inside the lath form to form a counter-impacted column, and then constructing a permanent column on the outside. This is about the construction method of cast-in-place columns for counter-punching using lath formwork.

The counter-drilling method is a method of constructing a building downward from the ground floor to the basement in parallel with excavation work when constructing an underground structure. In this counter-punching method, horizontal members such as basement slabs and beams are installed first, so the stability of retaining soil is excellent, the impact on adjacent buildings is small, and the construction period can be shortened by allowing simultaneous construction of the ground and basement floors. In addition, there is less noise and vibration in urban areas. It is widely applied in construction.

The counter-punching method inevitably increases direct construction costs compared to the existing sequential pummeling method, but indirect construction costs can be reduced by shortening the construction period, and the greater the number of underground floors applied, the greater the benefit of the method.

In the counter-punching method, underground pillars are first constructed in the ground, and the basement slab is sequentially constructed downward while excavating the ground around the pillars. In other words, for the counter-punching method, counter-punch columns corresponding to the entire height of the basement must be pre-constructed.

However, if the hole diameter is increased when drilling a hole in the ground for the construction of a back-driving column, the construction cost increases significantly. Accordingly, counter-impact columns are minimized to a cross-section that can support only the load from the basement floor and a portion of the load from the ground floor, and to support the additional load from the ground floor, rebar is placed outside the counter-impact column and concrete is poured to construct a permanent column.

When constructing such a counter-driving column with a reinforced concrete member, it is difficult to install a form inside the drilling hole, so concrete must be poured throughout the drilling hole. However, in this case, it is difficult to pull out and remove the casing inserted into the drilled hole to protect the hollow wall, and the outer surface of the counter-punching column is contaminated due to long-term contact with soil, so it is difficult to ensure integrity when adding concrete to form a permanent column.

Therefore, in the past, steel columns were mainly used as counter-impact columns. Accordingly, after ground excavation and foundation plate construction, rebar is placed outside the steel column and concrete is poured to form a permanent SRC column.

However, steel columns are not economically feasible due to high material costs, and there is a problem in that steel members corrode before permanent column construction, reducing durability.

Registered Patent No. 10-0788623 was developed to solve the problems of the counter-hitting method using steel columns, and uses PC columns as counter-hitting columns. However, PC columns have a large lifting burden due to their large self-weight, and the joining process of segmented PC columns is not easy.

In order to solve the above problems, the present invention seeks to provide a method of constructing a cast-in-place column for the reverse hammering method using a lath form that is economical and easy to construct.

The present invention according to a preferred embodiment is for constructing a column for a counter-punching method by casting it in situ, including the steps of (a) drilling the ground to form a drilling hole; (b) A plurality of internal vertical reinforcing bars are provided on the inside of a lath form formed in a cylindrical shape with a closed cross-section, and an end at a position where a steel beam is to be coupled to the inside penetrates the lath form and protrudes to the outside of the lath form in a horizontal direction. Inserting a reverse striking column assembly provided with a jointed steel frame including a steel bracket into the drilling hole; (c) pouring deep concrete into the lath form to form a counter-punching column; (d) excavating and removing the ground surrounding the counter-impacting column, and joining a steel beam to the steel bracket while excavating the ground surrounding the counter-impacting column; (e) constructing a foundation plate on top of the excavated ground; and (f) installing a form on the outside of the reverse driving column and pouring additional driving concrete inside the form to form a permanent pillar; It provides a method of constructing a cast-in-place column for back-throwing method using a lath form, characterized in that it includes a.

The present invention according to another preferred embodiment provides a method of constructing a cast-in-place column for a counter-punching method using a lath form, characterized in that an external hoop root surrounding the lath form is provided on the outside of the lath form of the counter-punch column assembly.

The present invention according to another preferred embodiment provides a method of constructing a cast-in-place column for a counter-punching method using a lath form, characterized in that a support hoop is provided inside the plurality of internal vertical reinforcing bars to fix the position of the internal vertical reinforcing bars. .

The present invention according to another preferred embodiment is the construction of a cast-in-place column for the counter-driving method using a lath form, characterized in that the inside of the lath form of the counter-impact column assembly is further provided with an internal hoop bar surrounding the outside of the plurality of internal vertical reinforcing bars. Provides a method.

delete

The present invention according to another preferred embodiment is a cast-in-place column for a counter-punching method using a lath form, wherein the joined steel frame portion is provided with a vertically oriented anchored steel frame, and the steel bracket is joined to the side of the anchored steel frame. Provides a construction method.

The present invention according to another preferred embodiment provides a method of constructing a cast-in-place column for a counter-driving method using a lath form, characterized in that in step (f), a plurality of external vertical reinforcing bars are placed on the outside of the counter-impacting column. .

According to the present invention, the following effects are achieved.

First, in the counter-driving method, a counter-impacted column assembly consisting of a lath form and internal vertical reinforcement is inserted into a drilled hole formed in the ground, and then deep concrete is poured inside the lath form to form a counter-impacted column. Therefore, quick installation is possible and construction is easy because the pre-assembled counter-driving column assembly is inserted on the ground, and it is economical because site-cast concrete columns are used as counter-driving columns.

Second, unnecessary excess water is discharged during deep concrete hardening through the mesh of the lath form constituting the counter-punched column assembly, so a high-quality concrete column can be formed.

Third, a permanent pillar can be formed by excavating and removing the ground around the reverse driving column, constructing a foundation plate, and pouring reinforced concrete. At this time, the rough surface formed on the outside of the counter-poured column by the lath form and the post-poured concrete can be sufficiently integrated.

1 is a perspective view showing a counter striking column assembly.
Figure 2 is a plan view showing the counter striking column assembly.
Figures 3 to 13 are diagrams illustrating step-by-step processes for the construction method of a cast-in-place column for a counter-punching method using the lath form of the present invention.
Figure 14 is a plan view showing a counter striking column assembly equipped with a support hoop.
Figure 15 is a plan view showing a counter striking post assembly provided with internal hoop muscles.
Figure 16 is a perspective view showing a jointed steel frame part.

Hereinafter, the present invention will be described in detail according to the accompanying drawings and preferred embodiments.

Figure 1 is a perspective view showing a counter-impacted column assembly, Figure 2 is a plan view showing the counter-impacted column assembly, and Figures 3 to 13 show step-by-step processes for the construction method of a cast-in-place column for the counter-impact method using the lath form of the present invention. It is a drawing showing.

The construction method of the cast-in-place column for the counter-driving method using the lath form of the present invention is to construct the column for the counter-punching method by casting in-situ, including the steps of (a) drilling the ground (1) to form a drilling hole (11); (b) inserting a counter-driven column assembly (20) provided with a plurality of internal vertical reinforcing bars (22) inside a lath form (21) formed in a cylindrical shape with a closed cross-section into the drilled hole (11); (c) pouring deep concrete (26) into the lath form (21) to form a counter-punching column (2); (d) excavating and removing the surrounding ground (1) of the counter-hitting pillar (2); (e) constructing a base plate (4) on top of the excavated ground (1); and (f) installing a form on the outside of the reverse driving column (2) and pouring additional driving concrete (51) inside the form to form a permanent pillar (5); It is characterized by being composed of a.

The present invention is intended to provide a method of constructing a cast-in-place column for a counter-punching method using a lath form that is economical and easy to construct.

In the present invention, (a) first, the ground (1) is drilled to form the drill hole (11) (FIGS. 3 and 4).

In other words, after completing the construction of an earth retaining wall such as a slurry wall to serve as an earth block on the outside of the ground (1) to be excavated, a drilling hole (11) is formed in the ground (1) at the location where the underground structure pillar is installed.

The drilling hole 11 is formed to the lower support ground so that the counter striking pillar 2 is stably supported.

And (b) the counter-hitting column assembly 20 provided with a plurality of internal vertical reinforcing bars 22 on the inside of the lath form 21 formed in a cylindrical shape with a closed cross-section is inserted into the drilling hole 11 (Figure 5, Fig. 6).

After completing the drilling hole 11 in the ground 1, the counter striking column assembly 20 to form the counter striking column 2 is inserted into the drilling hole 11.

The counter striking column assembly 20 includes a cylindrical lath form 21 with the top and bottom open and a plurality of internal vertical reinforcing bars 22 provided inside the lath form 21 (FIG. 1, FIG. 2).

The lath form 21 is a metal mesh, such as metal lath, that is manufactured by cutting a thin carbon steel plate, hot rolled steel plate, or coil material at equal intervals in a certain direction and then stretching it in one direction to form a mesh. In particular, rib lath, which has excellent rigidity due to the formation of ribs, can be used as the lath formwork (21).

The lath mold 21 is easy to bend and can be formed into a free shape.

Since the drilling hole 11 is formed in a circular shape, it is advantageous to form the counter striking pillar 2 also in a circular shape. Therefore, it is preferable that the lath mold 21 is also formed in a cylindrical shape.

The lath formwork 21 is not removed but remains permanently after pouring deep concrete 26, which will be described later, inside.

Since unnecessary excess water is discharged during hardening of concrete through the mesh of the lath formwork 21, a high-quality concrete column can be obtained.

The reverse striking pillar assembly 20 can be installed quickly and easily because it is pre-assembled on the ground and installation is completed simply by inserting it into the drill hole 11.

The lath formwork 21 and the internal vertical reinforcement 22 may be fixed to each other by welding or binding lines.

Next, (c) deep concrete 26 is poured into the lath form 21 to form a counter-punched column 2 (FIGS. 7 and 8).

After inserting the counter-driving column assembly 20 into the drilled hole 11, deep concrete 26 is poured into the lath form 21 of the counter-driving column assembly 20.

Accordingly, a reinforced concrete counter-impacting column (2) composed of a counter-impacting column assembly (20) and deep concrete (26) is formed.

When deep concrete (26) is poured inside the lath form (21), a portion of the concrete paste flows out through the mesh of the lath form (21), thereby forming an overall rough surface on the outside of the counter-punching column (2).

Afterwards (d), the ground (1) surrounding the counter-hitting pillar (2) is excavated and removed (FIGS. 9 and 10).

After completing the construction of the reverse driving column (2), the ground (1) is excavated.

The casing installed to protect the wall of the drill hole (11) before excavating the ground (1) can be removed by pulling out.

In parallel with the excavation of the ground (1), horizontal members such as slabs and beams on each floor are constructed and joined to the counter-impacting column (2), so that the vertical load acting on the horizontal members is transmitted to the counter-impacting column (2).

And (e) construct the base plate (4) on top of the excavated ground (1) (Figure 11).

After completing the excavation to the lowest ground (1) where the underground structure will be constructed, a foundation plate (4) is constructed on the upper part of the ground (1). At this time, the foundation plate (4) can be constructed after pouring abandoned concrete or laying rubble on the upper part of the excavation floor of the ground (1).

The dowel bar 41, which is embedded in the reinforced concrete 51 to be described later and is connected to the internal vertical reinforcing bar 22, may be constructed to protrude on the upper part of the base plate 4 outside the counter striking column 2.

Finally, (f) a form is installed on the outside of the reverse driving column (2), and additional driving concrete (51) is poured inside the form to form a permanent pillar (5) (FIGS. 12 and 13).

After completing the construction of the base plate (4), a form is installed outside the counter-driving pillar (2), and additional driving concrete is poured between the form and the counter-impacting pillar (2) to form a permanent pillar (5).

In the counter-punching method, the horizontal members of the basement floor are constructed first before the permanent columns 5, so the permanent columns 5 formed by additional pummeling of the counter-punching columns 2 are sequentially constructed upward for each floor from the bottom to the top.

The counter-punching column 2 is formed with a rough outer surface by pouring deep concrete 26 while the lath form 21 is provided on the outside, so that it has sufficient unity with the back-pushing concrete 51 to be poured. It can be secured.

As shown in FIG. 2, etc., an external hoop muscle 23 surrounding the lath form 21 may be provided on the outside of the lath form 21 of the counter striking column assembly 20.

When pouring deep concrete 26 inside the lath form 21, external hoop muscles 23 may be provided on the outside of the lath form 21 to support the pouring pressure acting on the lath form 21.

Since the external hoop muscle 23 is provided on the outside of the lath form 21, the external hoop muscle 23 is provided against the concrete placing pressure without separately binding or fixing the lath form 21 to the external hoop muscle 23. It can support the lath form (21).

The external hoop bars (23) can serve as band bars of the reverse striking column assembly (20).

In addition, the external hoop bar 23 is provided on the outside of the counter-hitting column assembly 20 and is embedded within the back-hitting concrete 51, so it can ultimately serve as a band reinforcement for the permanent column 5.

As shown in FIG. 13, in step (f), a plurality of external vertical reinforcing bars 52 may be placed on the outside of the counter striking column 2.

If the internal strength of the permanent column (5) is insufficient with only the internal vertical reinforcement (22) inside the counter-impacting column (2), external vertical reinforcing bars (52) may be additionally placed outside the counter-impacting column (2).

The external vertical reinforcing bar 52 is embedded inside the reinforced concrete 51 and serves as the main bar of the permanent column 5.

A dowel bar 41 may be formed to protrude on the upper part of the base plate 4 for connection to the external vertical reinforcing bar 52 inside the reinforced concrete 51.

Figure 14 is a plan view showing a counter striking column assembly equipped with a support hoop.

As shown in FIG. 14, a support hoop 24 may be provided inside the plurality of internal vertical reinforcing bars 22 to fix the position of the internal vertical reinforcing bars 22.

The counter-impacting pillar assembly 20 is inserted into the drilling hole 11 in an integrated state by pre-assembling each member constituting the counter-impacting pillar assembly 20 on the ground.

At this time, when the external hoop bars (23) serve as band bars of the counter-hitting column assembly (20), separate band reinforcing bars are not required inside the counter-hitting column assembly (20). However, since the lath form 21 exists between the internal vertical reinforcement 22 and the external hoop reinforcement 23, it may not be easy to bind the internal vertical reinforcement 22 and the external hoop reinforcement 23.

Therefore, a support hoop 24 may be provided inside the counter striking column assembly 20 to fix the position of the internal vertical reinforcing bar 22 provided inside.

The support hoop 24 only fixes the position of the internal vertical reinforcing bar 22, and is not intended to restrain the deep concrete 26 inside, so it does not need to be arranged at close intervals. Accordingly, the support hoop 24 is composed of circular strip reinforcing bars and can be installed in 2 to 3 locations.

Figure 15 is a plan view showing a counter striking column assembly equipped with an internal hoop muscle.

As shown in FIG. 15, internal hoop bars 25 surrounding the outside of the plurality of internal vertical reinforcing bars 22 may be further provided inside the lath form 21 of the counter striking column assembly 20.

Inside the lath form 21 of the counter-hitting column assembly 20, an internal hoop bar 25 may be provided that serves as a band reinforcement in the counter-hitting column 2.

The internal hoop muscles (25) constrain the inner deep concrete (26) to increase strength and ductility.

The internal hoop bar 25 may be composed of a plurality of circular band reinforcing bars spaced apart from each other in the vertical direction, or may be composed of a spiral continuous bar.

When the lath form 21 is fixed to the internal vertical reinforcing bar 22 or the internal hoop bar 25 by a tie line, etc., the internal hoop bar 25 is attached to the lath form 21 when pouring the deep concrete 26. It can support the pouring pressure that acts.

The internal hoop muscle (25) can be used alone without a separate external hoop muscle (23) or in combination with the external hoop muscle (23).

When the internal hoop muscles 25 and the external hoop muscles 23 are used in parallel, the internal hoop muscles 25 can also serve as a support hoop for fixing the position of the internal vertical reinforcing bars 22.

Figure 16 is a perspective view showing a jointed steel frame part.

As shown in FIGS. 1, 9, 16, etc., inside the counter-hitting column assembly 20, an end penetrates the lath form 21 at a position where the steel beam 6 is to be coupled to the lath form 21. A jointed steel frame portion (3) including a horizontal steel bracket (31) protruding to the outside is provided, and in step (d), the steel bracket is connected while excavating the surrounding ground (1) of the counter striking column (2). The steel beam (6) can be joined to (31).

In the reverse striking method, the horizontal member being constructed is connected to the reverse striking column (2) and transfers the load to the reverse striking column (2).

Therefore, horizontal members such as beams are joined to the counter-hitting column (2) after excavating the ground (1).

For this purpose, the jointed steel part (3) including the steel bracket (31) is integrally assembled inside the counter striking column assembly (20), and after excavating the ground (1), the end of the steel beam (6) is attached to the steel bracket (31). It can be joined.

The steel bracket 31 is provided inside the counter-hitting column assembly 20 at a position where the steel beam 6 is to be joined, and its outer end protrudes outward through the lath form 21.

Accordingly, after completing the construction of the counter-hitting column (2) and excavating the surrounding ground (1), the end of the steel beam (6) can be joined to the protruding end of the steel bracket (31).

The steel beam (6) can be bolted to the steel bracket (31) using a joining plate.

If the difference between the diameter of the drill hole (11) and the diameter of the counter-hitting column (2) is not large, the length of the steel bracket (31) protruding out of the lath form (21) cannot be sufficiently secured, so that the steel beam (6) Joining may not be easy.

In this case, concrete can be prevented from adhering to the end of the steel bracket 31 by attaching a concrete adhesion prevention member such as foamed styrofoam to the outer surface of the end side of the steel bracket 31.

And after excavating the ground (1) around the counter-hitting pillar (2), the concrete adhesion prevention member is removed to expose the end of the steel bracket (31), and then the steel beam (6) can be joined to the steel bracket (31). .

As shown in FIGS. 1 and 16, the jointed steel frame 3 is provided with a vertical anchoring steel frame 32 in the center, and the steel bracket 31 is joined to the side of the anchoring steel frame 32. It can be.

It may not be easy to transmit the bending moment and shear force transmitted by the steel beam 6 to the counter-hitting column 2, which is a reinforced concrete member, using only the steel bracket 31.

Accordingly, the vertical anchoring steel frame 32 can be installed in the center of the joint steel frame 3, and the steel bracket 31 can be fixed to the external required surface of the anchoring steel frame 32 by welding or the like.

The anchoring steel frame 32 extends a certain length to the upper and lower parts of the steel bracket 31, respectively, and is embedded in the deep concrete 26 of the counter-hitting column 2, thereby transferring the load acting on the steel bracket 31 to the counter-hitting column ( 2) It can be delivered smoothly.

A plurality of shear studs 33 may be attached to the outside of the anchoring steel frame 32 and the steel bracket 31 so that the bonded steel frame portion 3 is structurally integrated with the deep concrete 26.

1: Ground
11: punch hole
2: Counter-Strike Pillar
20: Counter-hitting pillar assembly
21: Laser mold
22: Internal vertical rebar
23: External hoop muscle
24: Support hoop
25: Internal hoop muscle
26: Deep concrete
3: Jointed steel frame part
31: Steel bracket
32: Anchored steel frame
33: sheer stud
4: Base plate
41: Dowel bar
5: Permanent pillar
51: Reinforced concrete
52: External vertical rebar
6: Steel beam

Claims (7)

It is intended for construction by casting columns for the counter-punching method on site.
(a) forming a drill hole (11) by drilling the ground (1);
(b) A plurality of internal vertical reinforcing bars (22) are provided on the inside of the lath form (21), which is formed in a cylindrical shape with a closed cross-section, and an end at a position where the steel beam (6) is connected to the inside of the lath form (21) is provided. Inserting the reverse striking column assembly (20) provided with a jointed steel frame (3) including a horizontal steel bracket (31) that penetrates and protrudes to the outside of the lath form (21) into the drill hole (11). step;
(c) pouring deep concrete (26) into the lath form (21) to form a counter-punching column (2);
(d) Excavating and removing the surrounding ground (1) of the counter-impacting column (2), and joining the steel beam (6) to the steel bracket (31) while excavating the surrounding ground (1) of the counter-impacting column (2) step;
(e) constructing a base plate (4) on top of the excavated ground (1); and
(f) installing a form outside the reverse driving column (2) and pouring additional driving concrete (51) inside the form to form a permanent pillar (5); A method of constructing a cast-in-place column for a reverse hammering method using a lath form, characterized in that it includes.
In paragraph 1:
A method of constructing a cast-in-place column for the counter-driving method using a lath form, characterized in that an external hoop bar (23) surrounding the lath form (21) is provided on the outside of the lath form (21) of the counter-hitting column assembly (20).
In paragraph 2,
A method of constructing a cast-in-place column for a reverse striking method using a lath form, characterized in that a support hoop (24) is provided inside the plurality of internal vertical reinforcing bars (22) to fix the position of the internal vertical reinforcing bars (22).
In paragraph 1 or 2:
On-site casting for the counter-driving method using a lath form, characterized in that the inside of the lath form (21) of the counter-hitting column assembly (20) is further provided with an internal hoop bar (25) surrounding the outside of the plurality of internal vertical reinforcing bars (22). Column construction method.
delete In paragraph 1:
The joint steel frame part (3) is provided with a vertically oriented anchorage steel frame (32) in the center, and the steel bracket (31) is joined to the side of the anchorage steel frame (32). Construction method for cast-in-place columns.
In paragraph 1:
In step (f), a method of constructing a cast-in-place column for the counter-driving method using a lath form, characterized in that a plurality of external vertical reinforcing bars (52) are placed on the outside of the counter-impacting column (2).

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