Building construction method

Abstract

To provide a building construction method which lowers a position of a jack mounted on an inverted support and can improve verticality of the inverted column built in a pile hole.SOLUTION: A building construction method for constructing a building by an inverted construction method includes the steps of: inserting an inverted support 1 having a stud mounting planned part 3 on the upper side of an embedded part 2 into a pile hole 31; supporting the inverted support 1 on a trestle 34 installed in a foundation 30 and a jack 20 mounted on the stud mounting planned part 3 in a vertical attitude; placing concrete 38 in the pile hole 31, and fixing the inverted support 1 to a concrete hole; excavating the ground 30, and then mounting a plurality of studs 50 on the stud mounting planned part 3 from which the jack 20 has been removed; and placing the concrete and forming a horizontal member 39 where the plurality of studs 50 are buried.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present invention relates to a method for constructing a building by an inverted construction method. [Background technology]

[0002] The inverted construction method is known as a construction method for constructing a building having an aboveground portion and an underground portion. In the inverted construction method, before excavating the ground to construct the underground frame, inverted support columns for supporting the aboveground portion of the building are erected in pile holes in the ground, so that the aboveground portion can be constructed on the inverted support columns while the underground frame is constructed, such as by excavating the ground to form a pressure-resistant plate. This allows the construction period of the building to be shortened compared to a construction method in which the construction of the aboveground portion is carried out after the construction of the underground portion is completed.

[0003] 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, thereby fixing the post to the cast-in-place concrete pile at its root portion (first-in construction method), or concrete is poured into the pile hole and then the post is inserted into the concrete, thereby fixing the post to the cast-in-place concrete pile at its root portion (last-in construction method).

[0004] Conventionally, in order to support an inverted support pillar in a vertical position within a pile hole until the concrete pile hardens, a technology is known in which a pantograph-type jack is attached to the side of the inverted support pillar, and the inverted support pillar inserted into the pile hole is supported in a vertical position at two points: a base installed on the ground and the jack abutted against the wall of the pile hole (see, for example, Patent Document 1).

[0005] In addition, a technology is known in which a number of studs are attached to the side of the upper part of the root section of an inverted support pillar, spaced apart in the vertical and horizontal directions, and the inverted support pillar is inserted into a pile hole and fixed to the concrete pile.After that, concrete is poured into the bottom of the ground excavated up to the top end of the concrete pile to form a pressure plate, and the studs are embedded in the pressure plate to integrate the inverted support pillar and the pressure plate (see, for example, Patent Document 2). [Prior art documents] [Patent documents]

[0006] [Patent Document 1] JP 2014-218862 A [Patent Document 1] JP 2013-256793 A Summary of the Invention [Problem to be solved by the invention]

[0007] If the inverted support pillar is fixed to the concrete pile in a position inclined to the vertical direction, it will have a significant effect on the connection with the beam and the construction of the above-ground portion, so it is necessary to support the inverted support pillar in a precise vertical position using a stand and a jack until the concrete pile hardens. In order to support the inverted support pillar in a precise vertical position using a stand and a jack, it is effective to attach the jack as low as possible to the inverted support pillar and widen the vertical distance between the stand and the jack.

[0008] However, in the above-mentioned conventional technology, multiple studs for integrating the reverse-driven support with the pressure-resistant plate are pre-attached to the upper part of the root portion of the reverse-driven support at the factory, so the jack needs to be attached even higher than the part of the reverse-driven support where the studs are attached, which creates the problem that the jack cannot be lowered to a position directly above the root portion of the reverse-driven support.

[0009] The present invention has been made in consideration of the above-mentioned problems, and its purpose is to provide a building construction method that makes it possible to increase the verticality of the inverted support pillar that is erected into a pile hole by lowering the position of the jack attached to the inverted support pillar. [Means for solving the problem]

[0010] The building construction method of the present invention is a building construction method for constructing a building by a reverse driving method, and is characterized by comprising the steps of: inserting an inverted driving post having a stud attachment portion above a root portion into a pile hole provided in the ground; supporting the inverted driving post inserted into the pile hole in a vertical position using a stand installed on the ground and a jack attached to the stud attachment portion and abutting the wall surface of the pile hole; pouring concrete into the pile hole and fixing the inverted driving post to the concrete pile at the root portion; excavating the ground, and then 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 in which the plurality of studs are buried. Effect of the Invention

[0011] According to the present invention, a method for constructing a building can be provided that makes it possible to increase the verticality of a drive-in pillar that is erected into a pile hole by lowering the position of a jack attached to the drive-in pillar. [Brief description of the drawings]

[0012] [Figure 1] 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. [Diagram 2] FIG. [Diagram 3] FIG. 1A is a diagram showing a pile hole drilled in the ground, and FIG. 1B is a diagram showing the state in which a reinforcing bar has been placed in the pile hole shown in FIG. [Figure 4]FIG. 2A is a diagram showing the state in which the inverted support shown in FIG. 1 has been inserted into a pile hole, and FIG. 2B is a diagram showing the state in which concrete has been poured into the pile hole into which the inverted support has been inserted. [Diagram 5] 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. [Figure 6] 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. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] Hereinafter, a method for constructing a building according to one embodiment of the present invention will be described in detail with reference to the drawings.

[0014] The inverted-cast support pillar 1 shown in FIG. 1 is erected in a pile hole provided in the ground in a building construction method according to one embodiment of the present invention.

[0015] The inverted-cast support pillar 1 is formed into a straight pillar of a predetermined length from a steel pipe with a rectangular cross section. The inside of the inverted-cast support pillar 1 is hollow. The lower part of the inverted-cast support pillar 1 from its lower end to a predetermined height is the embedded part 2. The embedded part 2 is the part of the inverted-cast support pillar 1 that is inserted into the concrete poured in the pile hole and fixed to the concrete pile after the concrete has hardened.

[0016] The inverted support 1 has a stud attachment portion 3 on the upper side of the root portion 2. In this embodiment, the portion of the inverted support 1 from the upper end of the root portion 2 to a predetermined height is the stud attachment portion 3. The stud attachment portion 3 is a portion to which a stud is attached to integrate the inverted support 1 with horizontal members such as beams, slabs, and pressure-resistant plates that constitute 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 portion 3 of the inverted support 1. The stud attachment portion 3 can be configured to have, for example, an attachment hole 3a for inserting a stud, but may be configured not to have the attachment hole 3a.

[0017] The inverted support pillar 1 is not limited to a configuration in which the entire pillar from top to bottom is made of a steel pipe with a rectangular cross section, but its shape and configuration can be modified as appropriate, for example, by having 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.

[0018] When inserting the inverted driving support 1 into the pile hole, a pliers (temporary pile) 10 may be attached to the upper end of the inverted driving support 1. The pliers 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 driving 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.

[0019] 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 a pile hole. In this embodiment, a jack 20 is attached to each of the four side surfaces of the inverted support 1 having 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.

[0020] 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 stud attachment portion 3, so the jack 20 can be attached to the side surface of the stud attachment portion 3 of the inverted support 1. It is preferable to attach the jack 20 as low as possible on the side surface of the stud attachment portion 3 of the inverted support 1.

[0021] 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 an outer end of the link mechanism 24 with a pressure plate 23. In this case, the jack 20 is fixed to the side surface of the base plate 21 at the portion 3 to which the stud is to be attached of the back-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 remotely controlled from outside the pile hole.

[0022] Next, a procedure for constructing a building by the inverted construction method using the building construction method according to this embodiment will be described.

[0023] 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 a planned position for erecting the inverted driving support 1 in the ground 30 of a construction site where a building is to be constructed by the inverted driving method. In the illustrated example, the shape of the pile hole is cylindrical with the diameter expanding 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.

[0024] Next, as shown in Fig. 4(a), the inverted driving support 1 with the pliers 10 attached to its upper end and the four jacks 20 attached to the stud mounting portion 3 is hung by a crane (not shown) using a wire 33 connected to the hanging hook 11 of the pliers 10, and inserted from the lower end into the pile hole 31. At this time, a stand 34 is installed above the opening of the pile hole 31, and the inverted driving support 1 and the pliers 10 are inserted into the pile hole 31 in a vertical position while being guided by guide rollers 35 provided on the stand 34.

[0025] When the back-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 back-driving support 1 is held in that position. The vertical position of the back-driving support 1 is adjusted by a journal jack 36 provided on the stand 34. In this way, the back-driving support 1 is supported by the stand 34 via the pliers 10 when it is inserted into the pile hole 31 to a predetermined depth.

[0026] 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 in the vertical direction 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 as to be within a predetermined range. The verticality of the inverted support 1 can be measured using an inclinometer (not shown) attached to the outer circumferential surface of the inverted support 1.

[0027] Here, in the building construction method according to this embodiment, when inserting the inverted support 1 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, so that 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 by attaching the stud in advance. Therefore, the vertical distance between the base 34 and the jack 20 is made wider than in the conventional method, and the base 34 and the jack 20 can support the inverted support 1 in a vertical position with greater accuracy.

[0028] 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.

[0029] 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 into the pile hole 31 through the tremie pipe 37 from the bottom to the top end of the embedded part 2. When the concrete 38 is poured into the pile hole 31, the reinforcing bar 32 and the embedded part 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 embedded part 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 embedded part 2.

[0030] If necessary, a predetermined number of inverted support columns 1 required for the building are fixed to the respective concrete piles in a predetermined number of pile holes 31 provided in the ground 30 in a similar procedure.

[0031] Once all of the inverted supports 1 have been 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 work proceeds to construct the above-ground part 40 of the building supported by the inverted supports 1 as shown in Figure 5. At the same time, the ground 30 is excavated up to the upper end of the concrete piles that will fix the root portions 2 of the inverted supports 1 so that the ground is wide enough to construct the underground part.

[0032] Next, the 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 predetermined intervals from each other in the vertical and horizontal directions. In FIG. 5, for convenience, only one stud 50 is labeled with a reference number. 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.

[0033] Next, as shown in Fig. 6, concrete is poured into the bottom of the ground 30 through a tremie pipe 37 to form horizontal members 39, such as beams, slabs, and pressure plates, which will constitute the underground portion 41 of the building. Fig. 6 shows the case where a pressure 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 are integrated. After the horizontal member 39 is formed, the work of constructing the underground portion 41 of the building proceeds.

[0034] 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, so that 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 by attaching the stud in advance. 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 made wider than in the conventional method, and the inverted support 1 can be supported in a vertical position with greater precision by the platform 34 and the jack 20.

[0035] In addition, in the building construction method of this embodiment, after 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, the ground 30 is excavated up to the upper end position 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 then multiple studs 50 are attached to the portion 3 where the studs are to be attached.Therefore, as in the conventional technology in which the inverted support with studs previously attached is inserted into the pile hole, the studs 50 can be buried in a horizontal member 39 formed by pouring concrete at the bottom of the ground 30, and the inverted support 1 and the horizontal member 39 can be integrated.

[0036] 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 upper end position of the concrete pile, the stud 50 is not attached to the 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 excess concrete pile fill before attaching the stud 50 to the stud attachment portion 3 of the inverted support 1, pile head treatment can be easily performed without damaging the stud.

[0037] The present invention is not limited to the above-described embodiment, and it goes without saying that various modifications can be made without departing from the spirit and scope of the present invention.

[0038] For example, in the above embodiment, a pantograph type jack 20 as shown in Figure 2 is used as the jack to be attached to the stud mounting portion 3 of the reverse driving support 1, but other configurations of jack 20 may be used as long as they are attached to the side of the reverse driving support 1 and can support the reverse driving support 1 inside the pile hole 31 so that the horizontal position can be adjusted.

[0039] 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). [Explanation of symbols]

[0040] 1. Reverse-strike support 2 Root section 3 Stud mounting area 3a Mounting hole 10 Yattoko 11 Hanging hook 12 Stopper 20 Jack 21 Base plate 22 Hydraulic cylinder 22a Drive rod 23 Pressure plate 30 Ground 31 Pilehole 32 Reinforcement 33 Wire 34 Mounting 35 Guide roller 36 Journal Jack 37 Ptolemy Tube 38 Concrete 39 Horizontal Members 40 Above ground part 41 Underground part

Claims

[Claim 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.

Images