JPH0448912B2 - - Google Patents

Description

[Detailed Description of the Invention] The prefabricated construction method, in which reinforced concrete members manufactured in a factory are assembled at a construction site to create a building,
This is a powerful construction method that makes it possible to save labor in building production, such as by introducing industrial robots.

The biggest difficulty with prefabricated construction methods that use reinforced concrete members is that the weight of reinforced concrete is large and the joining of members is difficult.
This is an important issue that holds the key to the development of this prefabricated construction method.

The invention (hereinafter simply referred to as the original invention) relating to a non-slip plank structure building using random joint type prefabricated floor boards (patent application number 1982-143240, patent publication number 1983-34345) (hereinafter simply referred to as the original invention) mainly uses prefabricated reinforced concrete. This invention is aimed at structural buildings, and its main structural parts are:
It is composed of a floor plate section assembled from three types of hollow floor plates: a column-attached floor plate, a column strip floor plate, and an intermediate floor plate that are fixed to the columns, and hollow columns that support the floor plate section. A column-attached floor plate fixed to a column is a reinforced concrete box-like body with a square or rectangular plane consisting of a box-shaped main body, a column support base, and an upper floor plate, and diagonal steel bars and compressed diagonal members installed inside the box-like body. formed by. The column strip floor plate consists of a reinforced concrete box-shaped body with an octagonal or hexagonal plane consisting of a box-shaped main body, a floor support, an upper load-bearing floor plate, and a top floor plate, and a main diagonal steel bar installed inside the box-shaped body. Formed by secondary diagonal steel bars. The intermediate floor plate is a reinforced concrete box-like body with a square or rectangular plane consisting of a box-shaped main body, a floor support bundle, and an upper floor plate;
It is formed by a main diagonal steel rod and a secondary diagonal steel rod installed inside a box. The column floorboards, column strip floorboards, and intermediate floorboards that are fixed to the columns are joined by a random joint method in which the joining surfaces are shifted from each other, and they are connected to each other by bolts installed on the side panels of the box-shaped main body. is connected to. This random joint method, which allows a highly rigid floor plate portion to be formed with simple bolt connections, is a major feature of the original invention. In addition, the floor plate section has a rational structure in which the diagonal steel bars bear the tensile force and the reinforced concrete section bears the compressive force in response to vertical loads. Moreover, it is a relatively lightweight hollow structure, so it is not conventional. It is possible to form a gutter with a larger span than that of a reinforced concrete rigid frame structure. The hollow structure is compressed and fixed to the column-attached floor plate, which is fixed to the foundation or column, using a PC steel rod installed in the hollow part of the column.

As described above, the original invention uses a comparatively lightweight, random-joint type floor plate section that is capable of large-span guttering, and a lightweight, high-strength hollow column, instead of conventional pillars, beams, and floor plates that have a large self-weight. In addition to reducing the weight of the building itself, it is also attempting to solve the problem of the method of joining members, which is a weak point in prefabricated reinforced concrete structures. However, the following drawbacks are recognized in the original invention.

(1) The diagonal steel bars attached to the column floor plates, column strip floor plates, and intermediate floor plates that are fixed to columns have considerable resistance to tensile force, but buckle when compressive force is applied. It causes For this reason, there is no problem if the load acting on the floor plate is only a vertical load, but if the floor plate is torsion or vibrates, the diagonal steel bars do not work effectively and the rigidity of the floor plate decreases considerably. It seems to be.

(2) The box-shaped bodies of the column floor plates, column strip floor plates, and intermediate floor plates that are fixed to the columns are quite large, so if they are manufactured in this form at the factory, special transportation methods must be considered. Must-have.
In addition, in order to promote automation of the manufacturing process using industrial robots, etc., it is considered more advantageous to divide the box-shaped main body into several parts, manufacture them, and assemble them, rather than molding the box-like main body as one piece.

(3) When installing a duct in the hollow part of a floorboard, if the duct has a small cross-sectional area, it can be installed quite freely in the vertical and horizontal directions, but if you try to install a duct with a large cross-sectional area, it will have a complicated, winding shape. This is uneconomical as it requires several items.

The present invention improves the drawbacks of the original invention as described above as follows.

(1) Instead of diagonal steel bars that cannot bear compressive force, use diagonal members that can bear both tensile and compressive forces.

(2) Box-shaped floor plates such as floor plates fixed to pillars, column strip floor plates, intermediate floor plates, etc. will be prefabricated structures using dry construction methods. The main members that make up each box-shaped floor plate are plate-shaped bodies that are convenient for manufacturing and transportation, and the maximum dimensions are 8 m x 2.5 m, which can be transported by normal truck.
It should be about m.

(3) To improve the passage of ducts installed in hollow areas, improve the arrangement of side plates, bundles, and diagonal members of column band floor plates or intermediate floor plates.

Next, embodiments of the present invention will be described.

FIG. 1 is a longitudinal sectional view showing a part of the building of the present invention. A hollow column 2 is erected on a foundation 1, and a second floor floor plate part 3 is provided on the hollow column 2. A hollow column 2' for the second floor is built on the floor plate part 3 of the second floor, and a floor plate part 3' for the third floor is provided on the hollow column 2'. An outer wall 4 including a window is attached to the outer end of the floor plate part 3 on the second floor and the outer end of the floor plate part 3' on the third floor. Including foundation 1, hollow columns 2, 2',
The main parts of the floor plate parts 3, 3' are made of reinforced concrete or prestressed concrete.

FIG. 2 is a floor plan showing a part of the floor plate section 3 on the second floor of the building of the present invention. The floor plate section 3 includes a floor plate 5 fixed to a column installed on the upper part of the hollow column 2 on the first floor, an overhanging floor plate 6 provided protruding from the floor plate 5 fixed to the column, and a floor plate 5 fixed to the column. It is formed by a column band floor plate 7 extending between floor plates 5 fixed to columns, and an intermediate floor plate 8 installed in a portion surrounded by the column band floor plate 7.

As shown in FIGS. 3 to 6, the floor plate 5 fixed to the pillar has a cylindrical bundle 11 and a chevron-shaped diagonal member 12 inside a box-like body consisting of a square bottom plate 9 and side plates 10. A side plate 10 and a bundle 11 are provided.
A top plate 13 is attached to the top of the holder. The bottom plate 9 is formed by joining two members with bolts, and the side plate 10 is formed by joining four members with PC steel rods. Side plate 10 and bundle 1
1 is fixed onto the bottom plate 9 with bolts. 2
The diagonal member 12 formed by the diagonal member 1
By the PC steel rod 14 that penetrates the inside of 2 in a radial manner,
A steel ring 15 whose upper end is fixed to the top of the bundle 11
The lower ends are respectively connected to the ends of the bottom plate 9. 2
A top plate 13 consisting of two pieces is removably mounted on the side plate 10 and the bundle 11 by bolts. In addition to the above, when attaching the overhanging floorboard 6 to the floorboard 5 fixed to the pillar,
Connecting materials 16 as shown in FIGS. 7 and 8 are added radially to the floorboard 5 that is fixed to the pillars. The binding material 16 is passed between the upper part of the side plate 10 and the upper part of the bundle 11, and is passed through the inside of the binding material 16.
The PC steel bar 17 has one end attached to the bundle 11 and the other end attached to the side plate 1.
0 respectively.

As shown in FIGS. 7 to 9, the overhanging floorboard 6 includes a bottom plate 18 joined to the floorboard 5 fixed to the pillar, a side plate 19 provided on the bottom plate 18, and a side plate of the floorboard 5 fixed to the pillar. diagonal member 20 connecting the ends of the bottom plate 10 and the bottom plate 18; and the side plate 10 of the floor plate 5 fixed to the pillar.
It is formed by a bundle 21 attached to the top, a side plate 19, and a top plate 22 provided on the top of the bundle 21. The bottom plate 18, which is formed by joining two members with bolts, is joined with bolts to the bottom plate 9 of the floor plate 5, which is fixed to the pillar. The side plate 19 is fixed to the bottom plate 18, and the bundle 21 is fixed to the side surface of the side plate 10 of the floor plate 5, which is fixed to the pillar, by bolts. A PC steel rod 23 provided through the diagonal member 20 is connected at one end to the PC steel rod 17 of the tie member 16 of the floorboard 5 fixed to the pillar, and at the other end to the end of the bottom plate 18. Top plate 2 consisting of two members
2 is removably attached to the side plate 19 and the bundle 21 using bolts.

As shown in FIGS. 10 to 13, the column strip floor plate 7 includes an octagonal bottom plate 24, ten side plates 25 continuously provided on the outer edge of the bottom plate 24, and the bottom plate 24.
12 bundles 26 provided inside, a main top plate 27 provided on the side plate 25 and the bundle 26, the upper end connected to the main top plate 27, and the lower end connected to the bottom plate 24.
8 main diagonal members 28 and 8 secondary diagonal members 29, side plate 2
5 and two sub-top plates 3 provided on the bundle 26
Formed by 0. A rectangular bridge groove formed in the center by the bottom plate 24, the bundle 26, the main top plate 27, and the bundle 26 shown in the right half of FIG.
Bottom plate 24, side plate 25, sub-top plate 3 shown in the left half of the figure
0. Since the rectangular bridge groove formed in the center by the side plates 25 is used as the main duct space for passing a large-diameter duct, no diagonals are provided and the square bridge channel is left as is. In addition, the bottom plate 24 and the bundle 2 shown in FIG.
6. The main top plate 27, the square groove formed by the bundle 26, and the bottom plate 2 other than the square groove formed in the center part shown in the left half of FIG.
4. Since the rectangular bridge groove formed by the side plate 25, the sub-top plate 30, and the side plate 25 is also used as a duct space, no diagonals are provided and the square bridge groove is left as is. The bottom plate 24 is formed by joining three rectangular members and two trapezoidal members with bolts, and the side plates 25 and the bundle 26 are each fixed on the bottom plate 24 with bolts. Main top plate 27
are fixed onto the side plate 25 and the bundle 26 by bolts. Provided by penetrating the inside of the main diagonal member 28
The upper end of the PC steel bar 31 is attached to the main top plate 27, and the lower end is attached to the main top plate 27.
Each is connected to a PC steel rod 32 passing through the bottom plate 24. Provided by penetrating the inside of the secondary diagonal member 29
The upper end of the PC steel bar 33 penetrates the main top plate 27
The lower ends of the PC steel rods 34 are connected to the ends of the bottom plate 24, respectively. The secondary top plate 30 is removably mounted on the side plate 25 and the bundle 26 by bolts. Column strip floorboards 7 with intermediate floorboard connections on only one side are similar to those shown in Figures 10 to 13, except that the shapes of the bottom plate and secondary top plate are different.
It is formed almost in the same way as the column strip floor plate 7 shown in the figure.

As shown in FIGS. 14 to 16, the intermediate floor plate 8 includes a rectangular bottom plate 35, 12 side plates 36 continuously provided on the outer edge of the bottom plate 35, and 4 side plates 36 provided inside the bottom plate 35. a bundle 37, a side plate 36, and a main top plate 38 provided on the bundle 37;
4 main diagonal members 39 and 4 secondary diagonal members 40, side plate 3
6 and two sub-top plates 4 provided on the bundle 37
Formed by 1. Bottom plate 35, bundle 37, main top plate 38, rectangular bridge groove formed in the center by bundle 37 shown in the right half of FIG. 15, bottom plate 35, side plate 36, sub-top plate 41 shown in the left half of FIG. , a square bridge groove formed in the center by the side plates 36, a square bridge groove formed in the center by the bottom plate 35, the bundle 37, the main top plate 38, and the bundle 37 shown in the left half of FIG. , bottom plate 35, side plate 36, main top plate 3
8. The rectangular bridge groove formed by the side plate 36 at the center of the side surface is left as a square bridge groove without any diagonal members because it is used as the main duct space for passing a large-diameter duct. Further, the other quadrangular bridge grooves formed on the side surfaces by the bottom plate 35, the side plates 36, the sub-top plate 41, and the side plates 36 are also used as duct spaces, so they are left as square bridge grooves without diagonals. The bottom plate 35 is formed by joining three rectangular members with bolts, and the side plates 36 and the bundle 37 are fixed onto the bottom plate 35 with bolts. The main top plate 38 is secured onto the side plates 36 and bundle 37 by bolts. The upper end of the PC steel rod 42 provided by penetrating the inside of the main diagonal member 39 is attached to the end of the main top plate 38, and the lower end is attached to the PC steel bar 42 provided by penetrating the inside of the main diagonal member 39.
Each is connected to a steel rod 43. The upper end of the PC steel rod 44 provided to penetrate the inside of the secondary diagonal member 40 is connected to the PC steel rod 45 that penetrates the main top plate 38, and the lower end thereof is
They are connected to the ends of the bottom plate 35, respectively. Sub top plate 4
1 is removably mounted on the side plate 36 and the bundle 37 by bolts.

FIG. 17 shows the joint between the foundation 1 and the hollow column 2, and the hollow columns 2, 2' and the floor plate 5 fixed to the column.
FIG. The central column 2 on the first floor is built on the foundation 1 through an adjustment ring 46, and the lower end is fixed to the foundation 1 with a PC steel rod 47.
is attached to the through hole of the hollow column 2. The floorboard 5 fixed to the pillars on the second floor is placed on the upper part of the hollow pillar 2 with a PC steel rod 47 passing through it. Hollow columns 2 and 2 on the first floor
After adjusting the verticality or horizontality of the floorboards 5 fixed to the columns of the floor by adjusting the adjustment ring 46, tensile force is introduced into the PC steel rods 47 to fix the floorboards 5 in predetermined positions. As shown in FIG. 2, there are two
The column strip floorboards 7 of the floors are spanned, and the floorboards 5 fixed to the columns and the column strip floorboards 7 are joined as shown in FIG. 18. Floor plate 5 and column strip floor plate 7 fixed to columns
The joint is a two-sided bolt joint in which a seat is provided on the side plate 10 of the floor plate 5 which is fixed to the pillar. A gap 49 is provided between the side plate 10 of the floor plate 5 that is fixed to the pillar and the side plate 25 of the column strip floor plate 7, and the adjustment plate 50 adjusts the construction error. and the side plate 25 are connected. In addition, a filler material 52 having elasticity and fire resistance is attached to the upper and lower parts of the gap 49. As shown in FIG. 19, the joint between the column strip floor boards 7 is a butt joint provided with a gap 49, an adjusting plate 50, and a filler 52, and the side boards 25 are connected to each other by bolts 51. As shown in FIG. 2, an intermediate floor plate 8 is provided in the area surrounded by the column band floor plate 7, and the column band floor plate 7 and the intermediate floor plate 8 are joined as shown in FIG. The joint between the column strip floor plate 7 and the intermediate floor plate 8 is a two-sided bolt joint in which a seat is provided on the side plate 25 of the column strip floor plate 7. Between the side plate 25 of the column strip floor plate 7 and the side plate 36 of the intermediate floor plate 8, there is a gap 49 and an adjustment plate 5.
0 and filler 52 are provided, and the side plate 25 and the side plate 36 are
are connected by bolts 51.

As shown in Figure 17, the PC steel rod 47' on the second floor is connected to the upper end of the PC steel rod 47 that passes through the hollow column 2 on the first floor, and the hollow column 2' on the second floor is fixed to the column on the second floor. It is built on the top surface of the floor plate 5. A floor plate 5' fixed to the pillar on the third floor is placed on top of the hollow pillar 2' on the second floor,
After adjusting the verticality or horizontality of the hollow column 2' and the floor plate 5' fixed to the column by the adjustment ring 46' provided on the column base of the hollow column 2' on the floor, the PC steel bar 47' is A tensile force is introduced to fix in place the hollow column 2' and the floor plate 5' fixed to the column, respectively. Similar to the floor plate section 3 on the second floor, column strip floor plates and intermediate floor plates on the third floor are provided to form the floor plate section on the third floor.

FIG. 21 is a plan view of the building of the present invention. The office part 53 which requires a wall-free space is formed with the rigid board structure of the present invention, and the core part 5 which requires a wall, such as a stage room, elevator room or toilet,
4 is formed by conventional prefabricated wall construction.

Next, the points in which the drawbacks of the original invention are improved by the embodiments of the present invention will be described.

(1) Instead of diagonal steel rods, use reinforced concrete diagonals with PC steel rods passed through them. In particular, for floor plates that are fixed to columns where stress is concentrated, reinforced concrete chevron shells with PC steel rods radially penetrated are used as diagonal members. The diagonal members are
Since the structure is such that the load is borne by the prestressing steel rods and the compressive force is borne by the reinforced concrete, the rigidity of the floor plate section is considerably increased.

(2) There are 18 floor plates fixed to the pillars, and 18 floor plates are attached to the pillars.
There are 26 members, 50 members for the column strip floor plate, and 30 members for the intermediate floor plate, and these members are connected with bolts or PC steel rods. As assembly of the parts will be done on the construction site, this goes against one of the goals of the prefabricated construction method, which is to "reduce on-site work as much as possible." Although this box-shaped floor board assembled with PC steel rods is a reinforced concrete structure, it has considerable deformability and resilience, and can also prevent the cracking that is the fate of reinforced concrete structures to a large extent.

(3) Figure 22 shows a cross section of the floorboard section shown in Figure 2. In the figure, the thick solid line indicates the side plate or bundle, the dotted line indicates the diagonal material, and the hatched portion indicated by the thin solid line indicates the area to be removed. Each shows the main top plate that cannot be used. In the direction of the arrow, a main duct space is provided in which a duct with a rectangular cross section can be installed linearly. Furthermore, since the side plates and bundles are continuously provided, the hollow space other than the main duct space can also be used more effectively than in the original invention.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing a part of the building of the present invention, and FIG. 2 is a floor plan of the second floor thereof. FIG. 3 is a top view and an internal plan view of a floor plate fixed to a column according to the present invention, FIG. 4 is a sectional view thereof, and FIGS. 5 and 6 are side views thereof. FIG. 7 is an internal plan view of the floor plate and overhanging floor plate fixed to the pillar of the present invention.
FIG. 8 is a sectional view thereof, and FIG. 9 is a side view of the overhanging floorboard of the present invention. Fig. 10 is a top view and an internal plan view of the column band floorboard of the present invention, Fig. 11 is a side view and a sectional view thereof, Fig. 12 is an A-A sectional view thereof, and Fig. 13 is a side view and an internal plan view thereof. It is a BB sectional view. FIG. 14 is a top view and an internal plan view of the intermediate floor plate of the present invention, FIG. 15 is a side view and a sectional view taken along the line CC, and FIG. 16 is a sectional view taken along the line DD. Fig. 17 is a sectional view showing the joints between the foundation and the hollow column of the present invention, and the hollow column and the floor plate fixed to the column, and Fig. 18 is a cross-sectional view showing the joint of the floor plate fixed to the column and the column band floor plate according to the present invention. FIG. 19 is a cross-sectional view showing the joint between column band floorboards of the present invention;
FIG. 0 is a cross-sectional view showing a joint between a column band floor plate and an intermediate floor plate according to the present invention. FIG. 21 is a plan view of the building of the present invention, and FIG. 22 is a cross-sectional view showing the duct space of the floor plate portion of the building of the present invention. 1...Foundation, 2,2'...Hollow column, 3,3'...
Floor plate portion, 5, 5'... Floor plate fixed to the pillar, 6...
... Overhanging floor board, 7 ... Column band floor board, 8 ... Intermediate floor board, 12, 20 ... Diagonal material, 14, 17, 23,
31, 32, 33, 34, 42, 43, 44, 4
5, 47, 47'...PC steel bar, 28, 39...Main diagonal member, 29,40...Sub-diagonal member.

Claims (1)

[Scope of Claims] 1. A floor plate fixed to a column, a column band floor plate spanning between a floor plate fixed to a column and a floor plate fixed to a column, and a column surrounded by a column band floor plate. At least three types of intermediate floorboards are used in a section, and these floorboards are joined by a random joint method in which the joining surfaces are shifted from each other. The floor plate, column band floor plate, and intermediate floor plate to be fixed are box-shaped, with an outer shell including a bottom plate, side plates, and a top plate formed by bonding multiple members. It is formed of a bundle and a diagonal member that can bear both tensile and compressive forces inside the body, and the arrangement of the side plates, bundles and diagonal members is such as to ensure effective duct space and , box-shaped bodies, bundles, and diagonal members are assembled using dry construction methods. 2. An assembly using the box-shaped floor plate according to claim 1, in which the main parts of the bottom plate, side plate, top plate, bundle, and diagonal members are formed of reinforced concrete or prestressed concrete. Board structure building. 3. Construction of an assembled freeboard structure using a box-shaped floor board according to claim 2, wherein the bottom plate, side plate, top plate, bundle, and diagonal members are assembled using bolts or PC steel bars. thing. 4 The floorboards fixed to the pillars are provided in short columnar bundles inside the box-like body consisting of the bottom plate and side plates, the top of the bundle and the end of the bottom plate are connected by diagonal members, and the top plate is attached to the side plates and the top of the bundle. An assembly-free board structure building using a box-shaped floor board according to any one of claims 1 to 3, which is attached with a box-shaped floor board. 5 The floorboards fixed to the pillars are provided in short columnar bundles inside the box-like body consisting of the bottom plate and side plates, and the top of the bundle and the ends of the bottom plates are connected by diagonal members, and the top of the bundle and the side plates are connected by diagonal members. The box-shaped floorboard according to any one of claims 1 to 3 is used, in which the upper part is connected by a connecting material and the top board is attached to the side board and the top of the bundle. A board structure building that requires no assembly. 6. An assembly board using a box-shaped floor board according to claim 4 or 5, wherein the diagonal members of the floor board fixed to the pillars are chevron-shaped shells formed around a bundle. Structural buildings. 7. Using the box-shaped floorboard according to any one of claims 4 to 6, in which the top plate of the floorboard fixed to the pillar is attached so that it can be removed at any time. A board structure building that requires no assembly. 8. The column strip floor plate has a side plate on the outer edge of the bottom plate and a bundle inside, and a top plate is attached to the top of the side plate and the bundle, and the bottom plate, side plate, top plate,
According to any one of claims 1 to 7, which is a bundle, or a bottom plate, a bundle, a top plate, and a main rectangular frame formed by the bundle, provided with diagonal members. A building with an unassembled plank structure using the box-shaped floor boards described above. 9 Column band floorboards are provided with side plates on the outer edge of the bottom plate and a bundle inside, and a top plate is attached to the top of the side plate and the bundle, and the bottom plate, side plate, top plate,
A diagonal member connecting the top plate and the bottom plate is provided in the main grooves of the bundle, or the bottom plate, the bundle, the top plate, and the rectangular frame formed by the bundle, excluding the groove used as the duct space. A self-assembly board structure building using a box-shaped floor board according to any one of claims 1 to 7. 10 The intermediate floor plate has a side plate on the outer edge of the bottom plate and a bundle inside, and a top plate is attached to the top of the side plate and the bundle, and the bottom plate, side plate, top plate,
According to any one of claims 1 to 9, which is a bundle, or a bottom plate, a bundle, a top plate, and a main rectangular frame formed by the bundle, provided with diagonal members. A building with an unassembled plank structure using the box-shaped floor boards described above. 11 The intermediate floor plate has a side plate on the outer edge of the bottom plate and a bundle inside, and a top plate is attached to the top of the side plate and the bundle, and the bottom plate, side plate, top plate,
A diagonal member connecting the top plate and the bottom plate is provided in the main grooves of the bundle, or the bottom plate, the bundle, the top plate, and the rectangular frame formed by the bundle, excluding the groove used as the duct space. A self-assembly board structure building using a box-shaped floor board according to any one of claims 1 to 9. 12. Claim 8, in which the upper surface plates of the column strip floor plates and the intermediate floor plates consist of a main top plate attached so as not to be removable, and a sub-top plate attached so as to be removable at any time. An unassembled plank structure building using the box-shaped floor board according to any one of paragraphs 1 to 11. 13. The diagonal members of the column band floor plate consist of a main diagonal member provided in a bridge groove parallel to the side in contact with the intermediate floor plate, and a secondary diagonal member provided in a bridge groove perpendicular to the above-mentioned bridge groove, The diagonal members of the intermediate floor plate consist of a main diagonal member provided in a bridge groove parallel to one side in contact with the column band floor plate, and a secondary diagonal member provided in a bridge groove perpendicular to said one side. Claims 8 to 12 are
A non-assembly board structure building using the box-shaped floorboards described in any one of the preceding paragraphs. 14 Claims 4 to 13, in which the side plates are provided intermittently only at major locations.
A non-assembly board structure building using the box-shaped floorboards described in any one of the preceding paragraphs. 15 The joint between the floorboard fixed to the column and the column strip floorboard is a half-bolt joint with a seat provided on the floorboard fixed to the column, and the joint between the column strip floorboards is a butt bolt joint, The box-shaped floorboard according to any one of claims 1 to 14, wherein the joint between the columnar band floorboard and the intermediate floorboard is a two-sided bolt joint in which a seat is provided on the columnar band floorboard. A building with an assembly-free board structure using.