JP7622570B2 - How to build a building - Google Patents

Description

The present invention relates to a building construction method for constructing a building using the inverted construction method.

The inverted construction method is known as a construction method for constructing buildings with above-ground and underground portions. With this method, before the ground is excavated to construct the underground frame, inverted-construction pillars for supporting the above-ground portion of the building are erected into pile holes created in the ground. This allows the above-ground portion to be constructed on the inverted-construction pillars while the underground frame is constructed, including excavating the ground to form a pressure-resistant plate. This shortens the construction period for the building compared to a method in which construction of the above-ground portion is carried out after construction of the underground portion is completed.

In this type of inverted construction method, the inverted post is inserted into a pile hole and then concrete is poured into the pile hole, so that the root is fixed to the cast-in-place concrete pile (first-in construction method), or concrete is poured into the pile hole and then the post is inserted into the concrete, so that the root is fixed to the cast-in-place concrete pile (last-in construction method).

Conventionally, in order to support a reverse-driven support in a vertical position within a pile hole until the concrete pile hardens, a pantograph-type jack is attached to the side of the reverse-driven support, and the reverse-driven support inserted into the pile hole is supported in a vertical position at two points: a stand installed on the ground and the jack abutting the wall of the pile hole (see, for example, Patent Document 1).

A known technique involves attaching multiple studs spaced vertically and horizontally to the side of the upper part of the base of a cast-in-place pillar, inserting the cast-in-place pillar into a pile hole and fixing it to the concrete pile, and then pouring concrete into the bottom of the ground excavated up to the top of the concrete pile to form a pressure-resistant plate. This technique embeds the studs in the pressure-resistant plate, integrating the cast-in-place pillar and the pressure-resistant plate (see, for example, Patent Document 2).

JP 2014-218862 A JP 2013-256793 A

When a reverse-cast support pillar is fixed to a concrete pile in an inclined position relative to the vertical, this has a significant impact on the connection with the beam and the construction of the above-ground portion, so it is necessary to support the reverse-cast support pillar in a precise vertical position using a stand and a jack until the concrete pile hardens. In order to support the reverse-cast support pillar in a precise vertical position using a stand and a jack, it is effective to attach the jack as low as possible on the reverse-cast support pillar and widen the vertical distance between the stand and the jack.

However, in the above conventional technology, multiple studs are pre-attached at the factory to the upper part of the root of the inverted support column to integrate the inverted support column with the pressure plate. This means that the jack needs to be attached even higher than the part of the inverted support column where the studs are attached, which creates the problem that the jack cannot be lowered to a position directly above the root of the inverted support column.

The present invention was made in consideration of the above problems, and its purpose is to provide a building construction method that can lower the position of the jack attached to the inverted support pillar and increase the verticality of the inverted support pillar erected in the pile hole.

The building construction method of the present invention is a method for constructing a building by the inverted construction method, and is characterized by having the steps of: inserting an inverted support having a stud attachment portion above a root portion into a pile hole provided in the ground; supporting the inverted support inserted into the pile hole in a vertical position with a stand installed on the ground and a jack attached to the stud attachment portion and abutting the wall of the pile hole; pouring concrete into the pile hole to fix the inverted support to the concrete pile at the root portion; excavating the ground, and then attaching multiple studs to the stud attachment portion from which the jack has been removed; and pouring concrete to form a horizontal member into which the multiple studs are embedded.

The present invention provides a method for constructing a building that can increase the verticality of a back-cast support pillar that is erected into a pile hole by lowering the position of a jack attached to the back-cast support pillar.

This is a front view of a reverse-driving support pillar with pliers and jacks attached, which are used in a building construction method according to one embodiment of the present invention. FIG. FIG. 2A is a diagram showing a pile hole drilled in the ground, and FIG. 2B is a diagram showing the state in which a reinforcing bar has been placed in the pile hole shown in FIG. 2A is a diagram showing the state in which the inverted support shown in FIG. 1 is inserted into a pile hole, and FIG. 2B is a diagram showing the state in which concrete is poured into the pile hole into which the inverted support is inserted. This shows the state in which the ground has been excavated up to the top end of the concrete pile, and then the jack has been removed and multiple studs have been attached to the intended stud attachment portion. This figure shows the state in which concrete is poured into the bottom of the ground, up to above the area where the studs are to be installed, to form a pressure plate.

Below, a detailed example of a method for constructing a building according to one embodiment of the present invention will be described with reference to the drawings.

The inverted support pillar 1 shown in Figure 1 is erected into a pile hole provided in the ground in a building construction method according to one embodiment of the present invention.

The inverted support pillar 1 is formed into a straight pillar of a specified length from a steel pipe with a rectangular cross section. The inside of the inverted support pillar 1 is hollow. The lower part of the inverted support pillar 1 from its lower end to a specified height is the root section 2. The root section 2 is the part of the inverted support pillar 1 that is inserted into the concrete poured into the pile hole and fixed to the concrete pile once the concrete has hardened.

The inverted support 1 has a stud attachment section 3 above the root section 2. In this embodiment, the section of the inverted support 1 from the top end of the root section 2 to a predetermined height is the stud attachment section 3. The stud attachment section 3 is a section to which a stud is attached to integrate the inverted support 1 with horizontal members such as beams, slabs, and pressure-resistant plates that make up the underground portion of the building. In the building construction method of this embodiment, when the inverted support 1 is inserted into the pile hole, a stud has not yet been attached to the side of the stud attachment section 3 of the inverted support 1. The stud attachment section 3 can be configured to have, for example, an attachment hole 3a for inserting a stud, but may also be configured without the attachment hole 3a.

The inverted support pillar 1 is not limited to a structure in which the entire pillar from the top to the bottom is made of a steel pipe with a rectangular cross section, but its shape and structure can be modified as appropriate, for example, with the upper portion made of a steel pipe with a rectangular cross section and the lower portion made of a so-called cross H-shaped steel.

When inserting the inverted support 1 into the pile hole, a temporary stake 10 may be attached to the upper end of the inverted support 1. The temporary stake 10 may be, for example, a straight, hollow pillar of a given length made of a steel pipe with a rectangular cross section of the same dimensions as the inverted support 1, with a pair of hanging hooks 11 at the upper end and multiple wing-shaped stoppers 12 fixed to the side to prevent it from falling.

In the building construction method of this embodiment, a jack 20 is attached to the side of the stud attachment portion 3 of the inverted support 1 to be inserted into the pile hole. In this embodiment, a jack 20 is attached to each of the four sides of the inverted support 1 with a rectangular cross section. For convenience, only three jacks 20 are shown in FIG. 1. The jack 20 may be attached to the side of the stud attachment portion 3 of the inverted support 1 before the inverted support 1 is inserted into the pile hole, or the jack 20 may be lowered inside the pile hole along the previous inverted support 1 after the inverted support 1 is inserted into the pile hole and attached to the side of the stud attachment portion 3.

In the building construction method according to this embodiment, when the inverted support 1 is inserted into the pile hole, no stud is attached to the intended stud attachment portion 3, so the jack 20 can be attached to the side of the intended stud attachment portion 3 of the inverted support 1. It is preferable to attach the jack 20 as low as possible on the side of the intended stud attachment portion 3 of the inverted support 1.

As the jack 20, for example, as shown in FIG. 2, a pantograph type can be used, in which one link is rotatably supported on a base plate 21, the other link is rotatably supported on a drive rod 22a of a hydraulic cylinder 22, and a link mechanism 24 is rotatably connected to a pressure plate 23 at the outer end. In this case, the jack 20 is fixed to the side of the base plate 21 at the intended stud attachment portion 3 of the reverse driving support 1. The jack 20 operates so that the link mechanism 24 expands and contracts horizontally when one link is driven by the drive rod 22a of the hydraulic cylinder 22. The operation of the jack 20 can be controlled remotely from outside the pile hole.

Next, we will explain the procedure for constructing a building using the inverted construction method according to this embodiment.

First, as shown in FIG. 3(a), a pile hole 31 of a predetermined depth is excavated using a drill or other excavation device at the planned location for erecting the inverted support pillar 1 in the ground 30 at a construction site where a building is to be constructed using the inverted construction method. In the illustrated example, the shape of the pile hole is cylindrical with an expanding diameter only at the bottom, but the shape can be changed as appropriate. Next, as shown in FIG. 3(b), a reinforcing bar 32 is erected at a predetermined position on the bottom side of the pile hole 31.

Next, as shown in FIG. 4(a), the inverted driving post 1 with the pliers 10 attached to its upper end and the four jacks 20 attached to the stud mounting portion 3 is suspended by a crane (not shown) using a wire 33 connected to the hanging hook 11 of the pliers 10, and inserted into the pile hole 31 from its lower end. At this time, a stand 34 is placed above the opening of the pile hole 31, and the inverted driving post 1 and the pliers 10 are guided by guide rollers 35 provided on the stand 34 while being inserted into the pile hole 31 in a vertical position.

When the reverse driving support 1 is inserted to a position where its lower end reaches a predetermined depth in the pile hole 31, the stopper 12 is supported by the stand 34 and the reverse driving support 1 is held in that position. The vertical position of the reverse driving support 1 is adjusted by a journal jack 36 provided on the stand 34. In this way, the reverse driving support 1 is supported by the stand 34 via the pliers 10 when it is inserted to a predetermined depth in the pile hole 31.

Next, the four pantograph-type jacks 20 are opened to bring the pressure plate 23 into contact with the wall of the pile hole 31. This supports the inverted support 1 in a vertical position at two locations separated vertically by the stand 34 installed on the ground 30 and the jacks 20 with the pressure plate 23 in contact with the wall of the pile hole 31. In addition, by adjusting the opening degree of the four pantograph-type jacks 20 and the position of the guide rollers 35, the verticality of the inverted support 1 is appropriately adjusted so that it is within a specified range. The verticality of the inverted support 1 can be measured using an inclinometer (not shown) attached to the outer periphery of the inverted support 1.

Here, in the building construction method according to this embodiment, when the inverted support 1 is inserted into the pile hole 31 provided in the ground 30, the jack 20 is attached to the stud attachment portion 3 above the root portion 2 of the inverted support 1 without attaching a stud. Therefore, since the stud is attached in advance, the jack 20 can be attached to a lower portion of the inverted support 1, compared to the conventional method in which the jack can only be attached above the portion of the inverted support where the stud is attached. Therefore, the vertical distance between the stand 34 and the jack 20 is wider than in the conventional method, and the stand 34 and the jack 20 can support the inverted support 1 in a vertical position with greater precision.

In addition, in the building construction method according to this embodiment, pliers 10 are attached to the upper end of the inverted support 1, and the inverted support 1 inserted into the pile hole 31 is supported by the base 34 via the pliers 10, so that the position of the upper support point of the inverted support 1 by the base 34 can be positioned higher. Therefore, the vertical distance between the base 34 and the jack 20 is wider than when the pliers 10 are not used, and the base 34 and the jack 20 can support the inverted support 1 in a vertical position with greater precision.

Next, as shown in FIG. 4(b), while the inverted support 1 is supported in a vertical position by the stand 34 and the jack 20, a tremie pipe 37 is erected in the pile hole 31, and concrete 38 is poured through the tremie pipe 37 into the inside of the pile hole 31 from the bottom to a height corresponding to the upper end position of the root section 2. When the concrete 38 is poured into the pile hole 31, the reinforcing bar 32 and the root section 2 of the inverted support 1 are embedded in the concrete 38. When the concrete 38 poured into the pile hole 31 hardens, the inverted support 1 is fixed to the hardened concrete 38 at the root section 2, i.e., the cast-in-place concrete pile in which the reinforcing bar 32 is embedded. In this way, the inverted support 1 is fixed to the concrete pile at the root section 2.

If necessary, a predetermined number of inverted supports 1 required for the building are fixed to each of the concrete piles in a predetermined number of pile holes 31 provided in the ground 30 using a similar procedure.

When all the inverted support posts 1 are fixed to the concrete (concrete piles) 38 in the pile holes 31, the pliers 10 and the four jacks 20 are removed, the pile holes 31 are backfilled, and then, as shown in Figure 5, the work of constructing the above-ground portion 40 of the building supported by the inverted support posts 1 is carried out. At the same time, the ground 30 is excavated up to the top of the concrete piles that will secure the root portions 2 of the inverted support posts 1 so that the area is sufficient to construct the underground portion.

Next, multiple studs 50 are attached to the stud attachment portion 3, which has been exposed to the outside by excavating the ground 30 and from which the jack 20 has been removed. The multiple studs 50 are attached, for example, lined up at a predetermined interval from each other in the vertical and horizontal directions. In FIG. 5, for convenience, only one stud 50 is labeled. Each stud 50 is attached so that its head faces outward and protrudes from the side of the inverted support 1. The multiple studs 50 may be fixed to the stud attachment portion 3 by, for example, screwing them into attachment holes 3a provided in the stud attachment portion 3, or they may be fixed to the stud attachment portion 3 by welding or the like.

Next, as shown in Figure 6, concrete is poured from the tremie pipe 37 into the bottom of the ground 30 to form horizontal members 39, such as beams, slabs, and pressure-resistant plates, which will make up the underground portion 41 of the building. Figure 6 shows the case where a pressure-resistant plate is formed as the horizontal member 39 at the bottom of the ground 30. At this time, the multiple studs 50 attached to the surface of the stud attachment portion 3 of the inverted support 1 are located inside the concrete, so that when the horizontal member 39 hardens, the studs 50 are embedded in the horizontal member 39, and the inverted support 1 and the horizontal member 39 become one body. After the horizontal member 39 is formed, work to construct the underground portion 41 of the building proceeds.

In this way, in the building construction method according to this embodiment, the jack 20 is attached to the stud attachment portion 3 above the root portion 2 of the inverted support 1 without attaching a stud, and the inverted support 1 is supported in a vertical position in the pile hole 31 provided in the ground 30. Therefore, compared to the conventional method in which the jack can only be attached above the portion of the inverted support where the stud is attached because the stud is attached in advance, the jack 20 can be attached to a lower portion of the inverted support 1. As a result, according to the building construction method according to this embodiment, the vertical distance between the platform 34 and the jack 20 is wider than in the conventional method, and the platform 34 and the jack 20 can support the inverted support 1 in a vertical position with greater precision.

In addition, in the building construction method according to this embodiment, concrete 38 is poured into the pile hole 31 and the inverted support 1 is fixed to the concrete pile at the root portion 2, then the ground 30 is excavated up to the top of the concrete pile, the jack 20 is removed from the portion 3 of the inverted support 1 where the studs are to be attached, and multiple studs 50 are attached to the portion 3 where the studs are to be attached. As in the conventional technology in which an inverted support with studs attached in advance is inserted into a pile hole, the studs 50 can be embedded in a horizontal member 39 formed by pouring concrete into the bottom of the ground 30, and the inverted support 1 and the horizontal member 39 can be integrated.

Furthermore, in the building construction method according to this embodiment, after the inverted support 1 is fixed to the concrete pile, when the ground 30 is excavated up to the top position of the concrete pile, the stud 50 is not attached to the intended stud attachment portion 3 of the inverted support 1, so the ground near the inverted support 1 can be easily excavated with heavy machinery or the like without damaging the stud. Also, by performing pile head treatment to treat the excess concrete pile before attaching the stud 50 to the intended stud attachment portion 3 of the inverted support 1, pile head treatment can be easily performed without damaging the stud.

The present invention is not limited to the above-described embodiment, and it goes without saying that various modifications are possible without departing from the spirit of the invention.

For example, in the above embodiment, a pantograph type jack 20 as shown in FIG. 2 is used as the jack to be attached to the stud attachment portion 3 of the inverted support 1, but other configurations of jack 20 may be used as long as they can be attached to the side of the inverted support 1 and can support the inverted support 1 inside the pile hole 31 in an adjustable horizontal position.

In addition, in the above embodiment, the inverted support 1 is inserted into the pile hole 31, and then concrete 38 is poured into the pile hole 31 (first-in construction method). However, the concrete 38 may be poured into the pile hole 31 in advance, and then the inverted support 1 may be inserted into the pile hole 31 before the concrete 38 hardens (last-in construction method).

REFERENCE SIGNS LIST 1: inverted support pillar 2: embedded portion 3: portion to be fitted with stud 3a: fitting hole 10: pliers 11: hanging hook 12: stopper 20: jack 21: base plate 22: hydraulic cylinder 22a: drive rod 23: pressure plate 30: ground 31: pile hole 32: reinforcing bar 33: wire 34: stand 35: guide roller 36: journal jack 37: tremie pipe 38: concrete 39: horizontal member 40: above ground portion 41: underground portion

Claims (1)

A method for constructing a building by a reverse construction method,
A step of inserting a reverse-cast support having a stud mounting portion on an upper side of a root portion into a pile hole provided in the ground;
A step of supporting the reverse driving support inserted into the pile hole in a vertical position by a stand installed on the ground and a jack attached to the stud mounting portion and abutting against the wall surface of the pile hole;
Pouring concrete into the pile hole and fixing the inverted support to the concrete pile at the embedded portion;
After the ground is excavated, a step of attaching a plurality of studs to the stud attachment portion from which the jack has been removed;
and pouring concrete to form a horizontal member into which the plurality of studs are embedded.

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