JPH0711140B2 - Formwork construction method in reverse construction method - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a reverse striking method for constructing an underground structural body of a building from the ground surface portion toward the lower floor while rooting the ground, particularly a concrete construction pillar. Formwork construction method for assembling side molds of

2. Description of the Related Art Conventionally, as a pillar formwork construction method in the upside-down construction method, as shown in FIG. 3, a concrete panel 3 is supported by a support 2 ... Standing on a root cutting bottom surface 1. It is carried out in a configuration in which the side frame 4 of the pillar is assembled on the above. In the figure, 5 is a pillar main bar, 8 is a hoop bar wound around the main bar 5, 6 is a main column steel frame (structured column), and 7 is a temporary steel frame that supports the steel frame.

Problems to be Solved by the Present Invention According to the conventional formwork construction method as illustrated in FIG. 3, the pillar main bars 5 penetrate the concrete panel 3 and are projected downward. There are 5 pillars
It is indispensable to make a hole to drill through, and this hole is troublesome. In addition, it is very troublesome and difficult to mount the concrete panel 3 while passing the pillar main bar 5 through the hole and erection of the side mold 4 of the pillar, or the demolding work after placing concrete. Moreover, there is a problem that it is difficult to position and fix the side mold 4 of the column, and it is difficult to secure the accuracy of the mold.

Means for Solving the Problems As means for solving the problems of the above-mentioned prior art, the formwork construction method in the reverse construction method according to the present invention is a preferred embodiment shown in FIGS. 1 and 2 of the drawings. As shown in the figure, in the reverse construction method, in which the construction of the underground structure of the building is carried out sequentially toward the lower floor according to the progress of the root cutting work, the root cutting of the ground is advanced to the depth of the construction unit, and the root cutting bottom 1. A sand formwork 10 is installed on the sand mold 10 and the sand formwork 10 is filled with sand 11 up to the height of the bottom of the pillar. Mortar, the same applies below) 12 is laid, a concrete panel 13 is laid inside the main reinforcement of the same column, a plastic sheet is laid on the surfaces of the waste concrete 12 and the concrete panel 13, and the filling sand 11 is used. Then concrete The steps of arranging the column main bars 5 on the outer periphery of the flannel 13, the steps of marking on the surface of the waste concrete 12 to assemble the side mold 4 of the pillar, and placing the concrete 15; After the hardening of 15, the sand mold 10 and the side mold 4 of the pillar are dismantled, the filling sand 11 is disintegrated to dismantle the waste concrete 12 and the concrete panel 13, and the root cutting of the ground is promoted again. did.

The side formwork 4 of the working column is firmly supported by the compaction effect of the sand 11 filled in the sand formwork 10.

The column main bars 5 are arranged in a state of being pierced into the filling sand 11 in the sand formwork 10, and the outer portion of the column main bars 5 is a waste concrete 12,
Since the concrete panels 13 are used as mold substitutes for the inner parts, it is not necessary to make holes in the concrete panels 13 and the assembling construction of the pillar side mold 4 can be performed very easily.

Further, since the side mold 4 of the pillar can be marked out on the waste concrete 12 and assembled, the positioning and fixing thereof can be easily performed and the accuracy can be easily obtained.

A plastic sheet (polyethylene film 9) that makes it easy for the skin to come out when releasing from the mold after placing concrete
Since the waste concrete 12 and the concrete panel 13 are laid, the sand formwork 10 can be disassembled very easily by dismantling the sand formwork 10 and collapsing it into the filling sand 11.

Example Next, an example shown in FIGS. 1 and 2 of the drawings will be described.

The drawing shows the construction method of the pillar formwork in the process of constructing the pillars of the underground structure of the steel reinforced concrete building by the upside down construction method toward the lower floor while proceeding with the root cutting work of the ground. is there. The illustrated example shows a stage where the ground root cutting has been advanced to the depth of the construction unit for the first basement floor. In the figure, 1 is the root cutting bottom, on which a sand formwork 10 having a height of about 900 mm is assembled, and sand 11 is filled up to the height level of the pillar bottom (height of about 700 mm from the root cutting bottom 1). There is.

On the upper surface of the filling sand 11 in the sand mold 10, especially on the outer side of the position of the column main bar 5 (described later), a waste concrete (or waste mortar) 12, which is used as a substitute for the form, is placed with a thickness of about 50 mm,
A concrete panel 13 is laid inside the main pillar position. 12mm thick for concrete panel 13
An iron plate divided into two along the transverse cross-sectional shape of the temporary steel frame 7 is used at the position, and by butting these two iron plates together, the size and shape are formed so as to cover the entire inner surface of the column main bar 5. Therefore, it can be easily sandwiched from both sides of the temporary steel frame 7, and is thus placed on the upper surface of the filling sand 11. The concrete panel 13 and the discarded concrete 12 are sand formwork.
It is supported by packed sand 11 which is constrained and compacted within 10. For this reason, for the filling sand 11, hydrating soil is used that is easy to compact and has a stable supporting force.

On the surfaces of the waste concrete 12 and the concrete panel 13, a plastic sheet such as a thin polyethylene film 9 for ensuring smooth contact with the cast concrete 15 is laid. Then, the pillar main bar 5 is projected from the polyethylene film 9 along the outer periphery of the concrete panel 13 by a predetermined length from the bottom of the pillar and pierced into the filling sand 11 to be arranged, and the hoop bar 8 is arranged on the upper part. Is wrapped around. Regarding the concrete panel 13, it is not necessary to process the holes through which the pillar main bars 5 pass.

The side mold 4 of the pillar is assembled so as to be supported on the surface of the waste concrete 12 (polyethylene film 9). In assembling and constructing the side mold 4, the surface of the waste concrete 12 is marked in advance to accurately position and fix the mold 4. The frame 4 is also tightly assembled by the column clamp 14.

When the concrete 15 is poured and the mold is removed after the curing period, the sand mold 10 and the pillar side mold 4 are disassembled. When the sand mold 10 is dismantled, the filling sand 11 therein can be easily collapsed. Since the polyethylene film 9 is laid on the surfaces of the waste concrete 12 and the concrete panel 13 as described above, when the sand formwork 10 is dismantled, the waste concrete 12 and the concrete panel 13 are also pillar-shaped as the filling sand 11 collapses. It is easily dismantled as it is disentangled with the cast concrete 15. As a result, the pillar main bar 5
It is easy to obtain a projecting splicing part for the next splicing. That is, thereafter, while continuing the ground cutting work, the main pillars 5 can be continuously spliced to efficiently construct the main pillars 6 toward the basement floor.

Effect of the present invention According to the formwork construction method in the reverse construction method according to the present invention, the filling sand 11 and the waste concrete 12 and the concrete panel 13 provided on the filling sand 11 and the plastic sheet laid on it Since it is used, the work of building or removing the side frame 4 of the pillar can be performed easily and quickly, and
It is possible to accurately position and fix the side mold 4 of the pillar on the waste concrete 12 and easily secure the mold accuracy.

[Brief description of drawings]

1 and 2 are a vertical sectional view and a horizontal sectional view when the formwork construction method according to the present invention is applied to a column bottom, and FIG. 3 is a vertical section showing a conventional formwork construction method for the same column bottom. FIG. 1 …… Root cutting bottom, 4 …… Column side form, 5 …… Column main bar 10 …… Sand form, 11 …… Filled sand, 12 …… Scrap concrete 13 …… Concrete panel, 15 …… Pasting concrete

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI technical display location E21D 13/00

Claims (1)

[Claims] 1. In the reverse construction method in which the construction of the underground structure of the building is performed toward the lower floor in accordance with the progress of the root cutting work, the root cutting of the ground is advanced to the depth of the construction unit, and the root cutting bottom (1) Install sand formwork (10) on the sand formwork (10)
Filling sand (11) up to the height of the bottom of the pillar, and placing concrete (12) on the outside of the pillar main bar position on the surface of the filling sand (11), A concrete panel (13) is laid in the inner part, a plastic sheet is laid on the surfaces of the waste concrete (12) and the concrete panel (13), and the filled sand (11) is used to remove the concrete panel (13). At the stage of arranging the column main bars (5) on the outer periphery, and marking out on the surface of the waste concrete (12) to assemble the side formwork (4) of the column, and then concrete (15)
And after the setting concrete (15) is hardened, the sand formwork (10) and the side formwork (4) of the pillar are dismantled, and the filling sand (11) is disintegrated and the waste concrete (12) and A method of constructing a formwork in a reverse construction method, which comprises the steps of dismantling a concrete panel (13) and advancing root cutting again.