JP2757209B2 - Cut-and-joint underground construction method using synthetic steel beams - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial application field) The present invention relates to a method of constructing an underground skeleton using a synthetic steel beam as a cutting beam.

(Conventional technology) Conventionally, in the underground framing work, underground excavation is carried out by arranging cut beams and bulges using a normal H-shaped steel in a grid pattern. At this time, since the cutting beams are only temporary, they are dismantled and removed at the time of placing the frame or after the placing and are carried out of the site.

In addition, a reverse-casting method in which concrete is poured sequentially from the upper floor of the basement floor is performed.

(Problems to be Solved by the Invention) In the former method, it takes a lot of labor and time to dismantle and remove the girder and carry it out of the field, and the construction period is postponed.

Further, in the latter method, concrete is sequentially poured from the upper floor of the basement floor, so that all the columns and walls are reverse-punched, and it is extremely difficult to join the concrete.

The present invention has been proposed in view of the problems of the prior art described above, and the object thereof is to reduce the amount of labor required for construction, and to use a synthetic steel beam having a high structural reliability as well as construction. The point is to provide a dual-purpose underground construction method.

(Means for Solving the Problems) In order to achieve the above-mentioned object, according to the combined use of undercutting method using a synthetic steel beam according to the present invention, a retaining wall, a pile, and a timber column are erected and firstly excavated. After that, the first-floor steel frame beam, in which adjacent beams whose ends are detoured so as to surround the straight pillar, are tightly connected to each other, is lowered to a predetermined position using the straight pillar as a guide, and Temporarily supporting the underground floor steel beam constructed similarly to the first floor steel beam at the lower part of the first floor steel beam, and then performing the second excavation using the first floor steel beam as a cutting beam, Lower the steel beam on the first basement floor temporarily placed under the steel beam to a predetermined position, set it on the timber column and make it work as a girder, and repeat the same process as above to construct the bottom floor After that, concrete is poured in order from the lower floor to build an underground skeleton.

(Operation) According to the present invention, as described above, after the pile retaining wall, the pile, and the trussed pillar are erected and the primary excavation is performed, the beam ends do not penetrate the trussed pillar but surround the pillar. Adjacent adjacent beams circumventing each other are connected to each other to form a first-floor steel beam, and the first-floor steel beam is lowered to a required position along the same pillar using the straight pillar as a guide. In step (1), the steel beams are temporarily supported by the straight pillars, and a lower steel beam having the same configuration as the lower steel beam is temporarily placed below the first floor steel beam.

Next, a temporary beam was used as the temporary steel beam on the first floor, and after secondary excavation, the underground 1 was temporarily placed under the steel beam on the first floor.
The floor steel beam is lowered to a predetermined position by using the straight beam as a guide, and is set on the straight beam to act as a cutting beam.
Thereafter, the same steps are repeated to construct the lowermost floor.

At this time, since the empty space between the steel beam and the timber column in the connection part of the column beam is large, the steel beam on the basement floor can be easily lifted down.

As described above, the steel beam is detoured around the timber column at the end as described above, and the beams are tightly connected to each other, and are temporarily received by the timber column at a predetermined position. Since it is configured to work as a cutting beam, an axial force acts on the steel beam from all sides of the straight column, and the force from one beam is transmitted to the left and right steel beams at 45 ゜ and further transmitted. Is 45
゜ Branched and transmitted to the opposite beam, balanced with the force from the opposite side, and the steel beam reliably functions as a cutting beam.

After the construction to the lowest floor is completed in this way, concrete is poured in order from the lower floor to build an underground skeleton, at this time, the steel beam used as a cutting beam is integrated with slab concrete Therefore, it forms part of the skeleton as a composite beam, so there is no need to remove and carry it out after completion of the skeleton.

(Example) Hereinafter, the present invention will be described with reference to an illustrated example.

As in the case of the conventional reverse striking method, the retaining wall (1) and the pile (2) or the deep foundation and the timber pillar (3) are erected. (Refer to FIG. 1.) Next, as the first excavation, the excavation is performed to a predetermined depth, and the first floor steel beam (4) and the lower floor steel beam (4 ′) are erected in the straight column (3).
Down along the same pillar (3) as a guide, and the first floor steel beam (4) is positioned at a predetermined position in the straight pillar (3).
The temporary base bracket (5) attached to the same pillar (3) is supported, and the steel beams in the basement floor are sequentially placed through the hanging members (6).
Suspended from the steel floor beam (4) and temporarily placed. (See FIG. 2) In the illustrated embodiment, for simplicity of description,
Only the basement floor steel beams (4 ') are shown.

As shown in FIGS. 5 and 6, each of the steel beams (4) and (4 ') has a flared form which is detoured so as to surround the straight pillar (3) at the beam ends (4a) and (4'a). And adjacent beams are connected to each other by welding or bolts.

Next, the second floor excavation is started by using the first floor steel beam (4) as a cutting beam, excavating to a predetermined depth from the first basement level, and then temporarily placed under the first floor steel beam (4). The steel beam (4 ') on the first basement floor is lowered using the straight pillar (3) as a guide, and is supported at a predetermined position by a temporary bracket (5) attached to the pillar (3). 4 ') acts as a cutting beam. (Refer to FIG. 3) After the above steps are repeated to construct the lowermost floor, concrete is poured in order from the lower floor in the same manner as in the case of a normal ground floor frame, to complete the underground frame. . (4th
(See figure.) In the figure, (7) is the foundation beam, (8) is the underground wall, (9) is the underground floor concrete, (10) is the first floor concrete, (1)
1) beam concrete, (12) pillar concrete, (1
3) is the main column, and (14) is the hoop.

At the connection between the steel beams (4) (4 ') and the straight columns (3), the clearance between the two members is large, so that the steel beams (4') on the lower floor can be easily lifted down. In addition, the construction accuracy of the straight pillar required by the conventional reverse striking method can be constructed with a relatively rough accuracy by this method.

When each of the steel beams (4) and (4 ') is supported by the temporary receiving bracket (5) of the straight pillar (3) and acts as a cutting beam, an axial force acts on the steel beam from four directions, The force from one direction splits at the tip of the beam at 45 ° and is transmitted to the left and right beams, then branched and transmitted to the opposite beam to balance the force from the opposite side.

(Effects of the Invention) According to the present invention, as described above, the first floor steel beam and the basement floor steel beam that are lifted down along the straight pillar are used as guides. By arranging adjacent beams diverted so as to surround the column, they are tightly connected to each other, so that the empty space between the straight pillar and the steel beams in the connection portion becomes large, and the lift-down of the steel beams is reduced. In addition, the precision of the straight pillar is not required to be strictly accurate as in the conventional reverse driving method, and the construction is simplified.

Then, the first-floor steel beam is lowered to a predetermined position by using the timber column as a guide, and is temporarily supported by the timber column at this position, and the underground floor steel beam is temporarily placed under the steel beam. The second floor excavation is performed by using the first floor steel beam as a cutting beam, and the first basement floor steel beam is lowered to a predetermined position, set on the straight pillar, and then operated as a cutting beam. The process is repeated to the lowest floor, and when the steel beams act as cutting beams, the transmission of stress between the steel beams is performed smoothly, and the steel beams serve as cutting beams. Functions are fully demonstrated, and construction is performed smoothly and safely.

Thus, after constructing to the lowest floor, concrete was sequentially poured from the lower floor to complete the underground skeleton, so the column concrete was struck in order, and the end of the steel beam without penetrating the column Since the steel sheet is detoured so as to surround the column, high-quality column concrete can be cast without disturbing the reinforcement of the column reinforcing bars and the concrete casting.

Also, as described above, the steel beam used as the cutting beam is integrated with the slab concrete and forms a part of the underground skeleton as a composite beam, so there is no need to remove and transport it after completion of the same skeleton, and labor is reduced. As a result, the construction period is reduced and the construction cost is reduced.

[Brief description of the drawings]

1 to 4 are longitudinal sectional views showing the steps of an embodiment of a combined girder underground construction method using a synthetic steel beam according to the present invention, and FIG. 5 is a diagram showing a steel beam acting as a girder during excavation and a structure. Fig. 6 is a plan view showing the relationship with the columns, and Fig. 6 is a side view thereof, Fig. 6 is a side view, and Fig. 5 is an arrow VI-VI diagram. FIG.
FIG. II and FIG. 8 are longitudinal sectional views taken along arrows VIII-VIII of FIG.
FIG. (1) ... Mounting wall, (2) ... Pile, (3) ... Structural pillar, (4) ... First floor steel beam, (4a) ... End of first floor steel beam, (4) ') ... steel beam on the first basement floor (4'a) ... end of the steel beam on the first basement floor (5) ... temporary bracket, (6) ... hanging material, (7) ... foundation Beam, (8)… Underground wall, (9)… Underground floor concrete, (10)… First floor concrete, (11)… Beam concrete, (12)… Column concrete.

 ──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Shin Furuta 1-25-1, Nishishinjuku, Shinjuku-ku, Tokyo Taisei Corporation (56) References JP-A-53-144117 (JP, A) JP-A 63-312438 (JP, A) JP 51-30363 (JP, B1) JP 43-13938 (JP, B1)

Claims (1)

(57) [Claims] 1. A first floor in which a retaining wall, a pile and a timber column are erected, primary excavation is performed, and adjacent beams whose ends are detoured so as to surround the timber column are connected to each other. Steel beams,
Lowering the straight pillar as a guide to a predetermined position and temporarily supporting the same pillar, temporarily placing a basement steel beam constructed in the same manner as the same beam below the first floor steel beam, and then The second floor excavation is performed by using the first floor steel beam as a cutting beam, and the basement first floor steel beam temporarily placed under the steel beam is lowered to a predetermined position, and set on the straight pillar as a cutting beam. Act
Thereafter, the same steps as above are repeated to construct the lowermost floor, and then concrete is poured in order from the lower floor to construct an underground skeleton.