JPH04350221A - Construction method for underground beam - Google Patents

Abstract

PURPOSE:To dispense with a temporary scaffold for bar arrangement, dispense with the shuttering of an underground beam, and improve the construction property by shortening the protrusion length of stirrups driven into the underground beam. CONSTITUTION:Part of lower main reinforcements and stirrups of an underground beam are arranged on a pressure-proof plate 1, and concrete is placed on the pressure-proof plate 1. Synthetic precast plates 5 storing stirrups 4 are provided in parallel on the pressure-proof plate 1, upper end main reinforcements 7 are arranged, and concrete 8 is placed.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of constructing an underground beam with pressure plates.

0002

[Prior Art] When constructing a conventional underground beam with pressure plates, as shown in Fig. 4, the reinforcing bars b of the underground beam are placed at the same time as the reinforcement of the pressure plate a, and the concrete of the pressure plate a is poured. Then, formwork c is assembled on the same pressure plate concrete and concrete d
and construct an underground beam e as shown in Fig. 5.

0003

[Problems to be Solved by the Invention] In the conventional construction method, when reinforcing underground beams, temporary scaffolding is required to hold the reinforcing bars. The work space is divided and work efficiency is poor. The present invention was proposed in view of the problems of the prior art, and is a method for constructing underground beams that does not impede workability during pressure plate concrete placement and does not require formwork for underground beams. The point is to provide the following.

0004

[Means for Solving the Problems] In order to achieve the above-mentioned object, according to the method for constructing an underground beam according to the present invention, the lower end main reinforcement and a part of the cost reinforcement of the underground beam are arranged in the pressure plate part. Then, pressure plate concrete is poured, a synthetic precast slab with built-in reinforcing bars is set opposite to the pressure plate, main reinforcement at the upper end is arranged, and then concrete is poured inside the composite precast slab. .

[0005]

[Operation] According to the present invention, as described above, the lower end main reinforcement of the underground beam and a part of the cost reinforcement are arranged in the pressure plate part along with the reinforcing bars of the pressure plate, and the cost reinforcement has the length required for the lap joint. By protruding, there is no need for temporary scaffolding when arranging reinforcement. Furthermore, a synthetic precast plate with built-in reinforcing bars was installed oppositely on the pressure plate, and the lower protruding parts of the ribs of the same plate were connected to the ribs of the underground beam protruding onto the pressure plate, and the upper end main reinforcement was connected. By arranging reinforcement and then pouring concrete, underground beams can be constructed without using formwork.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the illustrated embodiments. As shown in Figure 1, when pouring concrete for the pressure plate 1, the lower end main reinforcement 2 of the underground beam and the reinforcement bars 3 of the underground beam are placed on the pressure plate 1.
Reinforcement will be placed along with the reinforcing bars. The ribs 3 are provided with a protruding length necessary for the lap joint.

Next, as shown in FIG. 2, after pouring concrete pressure plates, a pair of synthetic precast plates 5 with built-in reinforcing bars 4 are placed oppositely. The lower protruding end portion 4a of the rib 4 from the composite precast plate is provided to protrude by a length necessary for lap jointing with the rib 3, and the upper protruding portion 4b is bent into a hook shape. Next, a floor form 6 or a composite floor board is installed, upper main reinforcements 7 are arranged, and then concrete 8 is poured to construct an underground beam.

FIG. 3 shows a case where the present construction method is applied to the conventional construction method, and in the figure, parts equivalent to those of the above embodiment are given the same reference numerals.

[0009]

[Effects of the Invention] Since the method for constructing an underground beam according to the present invention is configured as described above, the protruding length of the reinforcing bars driven into the underground beam from the pressure plate is short, so that the reinforcement arrangement can be improved. It does not require temporary scaffolding and does not impede workability when placing pressure plate concrete. Furthermore, according to the present invention, formwork for underground beams is not required, so there is no need to assemble, dismantle, or transport formwork, and workability is significantly improved.

[Brief explanation of drawings]

FIG. 1 is a longitudinal cross-sectional view showing the reinforcing process of lower end main reinforcement and sub-reinforcement reinforcement of an underground beam in an embodiment of the underground beam construction method according to the present invention.

FIG. 2 is a vertical cross-sectional view showing the concrete placement process for underground beams.

FIG. 3 is a longitudinal sectional view showing a state in which the construction method of the present invention is applied to a conventional construction method.

FIG. 4 is a vertical cross-sectional view showing the implementation status of the conventional construction method.

FIG. 5 is a longitudinal cross-sectional view of an underground beam with pressure plates constructed by a conventional construction method.

[Explanation of symbols]

1 Pressure plate 2 Lower end main reinforcement 3. Rib muscles ４　　　Synthetic precast board ribs 7 Top main reinforcement 8 Concrete

Claims (1)

[Claims] [Claim 1] Place the lower end main reinforcement and part of the reinforcing bars of the underground beam on the pressure plate part, cast pressure plate concrete, and place a synthetic precast plate with built-in reinforcing bars on the pressure plate. A method of constructing an underground beam, which is characterized in that, after arranging the upper main reinforcement, concrete is poured into the composite precast slab.