Underground piled column

Abstract

To easily insert a tremie pipe into a pile hole in which an underground piled column has been inserted.SOLUTION: An underground piled column, which is used in the top-down construction method and has its lower end buried in a cast-in-place concrete pile, comprises a main body that is inserted into a pile hole, and a short bracket that is attached to a side of the main body, has a beam connected to it, and is horizontally eccentric with respect to a center of the side width.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to structural columns. [Background technology]

[0002] In the basement framework construction method described in Patent Document 1, steel pipe concrete columns are used as the basement framework columns, and steel frame brackets for shear reinforcement are attached to the joints between the structural columns and the slab using high-tension bolts with friction joints, and the steel frame brackets join the columns to the flat plate slab. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 4-221148 Summary of the Invention [Problem to be solved by the invention]

[0004] In the method of erecting structural columns used in the inverted construction method, first pile holes are drilled, and then the structural columns are erected into the drilled pile holes. Next, to form cast-in-place concrete piles below the pile holes where the structural columns have been erected, tremie pipes are inserted into the pile holes and concrete is poured into the lower parts of the pile holes.

[0005] Here, short brackets for connecting beams are attached to the side of the main body of the structural column. Specifically, multiple short brackets are provided, protruding in four directions from the side of the main body when viewed from above, and attached to the center of the side width of the main body.

[0006] Therefore, when inserting the tremie pipe into the pile hole, the short bracket attached to the side of the main body may become an obstacle, making it difficult to insert the tremie pipe into the pile hole.

[0007] The object of the present disclosure is to easily insert a tremie pipe into a pile hole into which a structural column has been inserted. [Means for solving the problem]

[0008] The structural column of the first embodiment is a structural column used in the inverted construction method and whose lower end is embedded in a cast-in-place concrete pile, and is characterized by comprising a main body portion that is inserted into a pile hole, and a short bracket that is attached to the side of the main body portion and to which a beam of the basement floor is connected, and is horizontally eccentric with respect to the center of the side width of the side.

[0009] According to the above aspect, the tremie pipe can be easily inserted into the pile hole into which the structural column has been inserted, compared to when all short brackets are attached to the center of the side width of the main body portion.

[0010] The structural column of the second aspect is characterized in that, in the structural column described in the first aspect, the cross section of the main body is a rectangular tube, the short brackets are attached to each of the four side surfaces that make up the main body and are provided on each basement floor, and the pair of short brackets attached to a pair of the side surfaces facing opposite directions in the horizontal direction are each eccentric in the horizontal direction with respect to the center of the side surface width of the side surface.

[0011] According to the above aspect, by inserting tremie pipes on both sides with the main body portion in between, it is possible to prevent uneven pouring of concrete.

[0012] The structural column of the third aspect is characterized in that, in the structural column described in the second aspect, one of the pair of short brackets and the other short bracket are eccentric to opposite sides relative to the center of the side width of the side of the main body portion.

[0013] According to the above aspect, it is possible to suppress bias in poured concrete compared to when a pair of short brackets are eccentric to the same side relative to the center of the side width of the side of the main body portion.

[0014] The structural column of the fourth aspect is characterized in that, in the structural column described in the third aspect, the amount of eccentricity of one of the short brackets is the same as the amount of eccentricity of the other short bracket.

[0015] According to the above aspect, tilting of the structural column can be suppressed when the structural column is inserted into the pile hole, compared to when the eccentricity amounts of a pair of short brackets that are eccentric to opposite sides of each other are different. [Effects of the Invention]

[0016] According to the present disclosure, a tremie pipe can be easily inserted into a pile hole into which a structural pillar has been inserted. [Brief explanation of the drawings]

[0017] [Figure 1] FIG. 1 is a perspective view showing a structural column according to an embodiment of the present disclosure. [Figure 2] 1A, 1B, and 1C are schematic diagrams showing a method for erecting a structural column according to an embodiment of the present disclosure. [Figure 3] 1A, 1B, and 1C are schematic diagrams showing a method for erecting a structural column according to an embodiment of the present disclosure. [Figure 4] FIG. 1 is a plan view showing a construction method for erecting a structural column according to an embodiment of the present disclosure. [Figure 5] FIG. 10 is a perspective view showing a structural column in a comparative form to the structural column according to the embodiment of the present disclosure. [Figure 6] FIG. 10 is a plan view showing a construction method for a structural column according to a comparative example to the structural column according to the embodiment of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0018] An example of a structural column according to an embodiment of the present disclosure will be described with reference to Figures 1 to 6. Arrow H shown in each figure indicates the vertical direction, which is the up-down direction of the structural column, arrow W shown in each figure indicates the width direction of the structural column, which is perpendicular to arrow H and also indicates the horizontal direction, and arrow D shown in each figure indicates the depth direction of the structural column, which is perpendicular to arrows H and W and also indicates the horizontal direction.

[0019] The drawings used in the following description are all schematic, and the dimensional relationships and ratios of elements shown in the drawings do not necessarily correspond to the actual ones.

[0020] (Kanshin Pillar 10) The structural column 10 is a rectangular steel pipe column used in the inverted construction method. As shown in FIG. 1, the structural column 10 includes a main body 12 and short brackets 14a, 14b, 14c, and 14d. The cross section of the main body 12 is rectangular and cylindrical, and the main body 12 has four side surfaces 12a, 12b, 12c, and 12d. The side surface 12a faces one side in the width direction (the right side in the figure), the side surface 12b faces the front side in the depth direction, the side surface 12c faces the other side in the width direction (the left side in the figure), and the side surface 12d faces the back side in the depth direction. Here, the structural column 10 in this embodiment is a column used in the inverted construction method to support the above-ground structure, and will later constitute a column for the basement floor.

[0021] [Side 12a] As shown in FIG. 1, when the structural columns 10 are excavated and the basement floor framework is constructed, short brackets 14a are attached by welding to the side surfaces 12a to which the beams of each basement floor are connected. Specifically, the short brackets 14a are H-shaped brackets made by shortening H-beams. The short brackets 14a are attached to the center of the side surface width of the side surface 12a and are provided on each basement floor at intervals in the vertical direction. Here, "attaching the short brackets 14a to the center of the side surface width of the side surface 12a" means that, when viewed from above, the axis L01 of the short bracket 14a passes through the center CE01 of the side surface width of the side surface 12a (see FIG. 4). In other words, "attaching the short brackets 14a to the center of the side surface width of the side surface 12a" means that, when viewed from above, the axis L01 of the short bracket 14a passes through the center of gravity G of the main body 12.

[0022] [Side 12c] As shown in Figure 1, when the structural columns 10 are excavated and the basement floor framework is constructed, short brackets 14c are attached by welding to the side surface 12c to which the beams of each basement floor are connected. Specifically, the short brackets 14c are H-shaped brackets made by shortening H-beams. The short brackets 14c are attached to the center of the side width of the side surface 12c, and are provided on each basement floor at intervals in the vertical direction.

[0023] [Side 12b] As shown in Figure 1, when the structural columns 10 are excavated and the basement floor framework is constructed, short brackets 14b are welded to the side surfaces 12b to connect the beams of each basement floor. Specifically, the short brackets 14b are H-shaped brackets made by shortening H-beams.

[0024] The short brackets 14b are attached eccentrically to the center of the side width of the side surface 12b and are provided on each basement floor at vertically spaced intervals. Specifically, the short brackets 14b on each basement floor are attached eccentrically to the other side of the center of the side width of the side surface 12b. Here, "the short brackets 14b are attached eccentrically in the width direction with respect to the center of the side width of the side surface 12b" means that, when viewed from above, the axis L02 of the short bracket 14b is eccentric in the width direction (horizontal direction) with respect to the center CE02 of the side width of the side surface 12b. In other words, "the short brackets 14b are attached eccentrically in the width direction with respect to the center CE02 of the side width of the side surface 12b" means that, when viewed from above, the axis L02 of the short bracket 14b is spaced apart in the width direction (horizontal direction) from the center of gravity G of the main body 12.

[0025] [Side 12d] As shown in Figure 1, short brackets 14d are welded to the side surfaces 12d to connect the beams of each basement floor when the structural columns 10 are excavated and the basement floor framework is constructed. Specifically, the short brackets 14d are H-shaped brackets made by shortening H-beams.

[0026] The short brackets 14d are attached eccentrically to the center of the side width of the side surface 12d and are provided on each basement floor at intervals in the vertical direction. Specifically, the short brackets 14d on each basement floor are attached eccentrically to one side in the width direction with respect to the center of the side width of the side surface 12d. The amount of eccentricity of the short brackets 14d is the same as the amount of eccentricity of the short brackets 14b.

[0027] (action) Next, the erection method of the structural column 10 will be explained together with the erection method of the structural column 50 according to the comparative embodiment using the schematic diagrams of Figures 2 and 3. First, the structural column 50 according to the comparative embodiment will be explained, focusing on the differences between it and the structural column 10 according to this embodiment.

[0028] [Kaishin Pillar 50] 5, the structural column 50 includes a main body 52 and short brackets 54a, 54b, 54c, and 54d. The main body 52 is rectangular and cylindrical, and has four side surfaces 52a, 52b, 52c, and 52d.

[0029] Short brackets 54a are attached to the side surface 52a by welding to connect the beams of each basement floor when the structural columns 50 are excavated and the basement floor framework is constructed. Specifically, the short brackets 54a are H-shaped brackets made by shortening H-beams. The short brackets 54a are provided in the center of the side surface width of the side surface 52a and are attached to each basement floor at intervals in the vertical direction.

[0030] Similarly to side surface 52a, short brackets 54b, 54c, and 54d are attached to side surfaces 52b, 52c, and 52d by welding. The short brackets 54b, 54c, and 54d are provided at the center of the side surface width of side surfaces 52b, 52c, and 52d, and are attached to each basement floor at intervals in the vertical direction.

[0031] [Construction method using structural columns 10 and 50] First, as shown in Fig. 2(A), a surface casing 112 is erected, and a pile hole 110 having an enlarged diameter portion 110a at the lower end is drilled using an earth drill pile driver and a bottom expanding machine (not shown). Then, slime treatment (bottom dredging) is performed using a slime cleaner 140.

[0032] Furthermore, as shown in FIG. 2(B), a crane 142 is used to lower a reinforcing bar cage 114 into the lower portion of the pile hole 110 and set it in place.

[0033] 2(C), a mounting frame 120 for erecting the structural columns 10, 50 is installed above the pile holes 110, and the structural columns 10, 50 are passed through the mounting frame 120 and erected into the pile holes 110 while adjusting their positions. The mounting frame 120 is shaped like a grid when viewed from above, as shown in FIGS. 4 and 6.

[0034] Furthermore, as shown in FIG. 3(A), a tremie pipe 146 is inserted into the pile hole 110, and concrete C is poured into the lower end portion of the pile hole 110 using a pump vehicle 144.

[0035] Here, the cross sections of the structural columns 10, 50 are larger than those of normal structural columns in order to bear high axial forces. Furthermore, to prevent uneven pouring of the concrete C, two tremie pipes 146 connected to two pump trucks 144 are used. As shown in Figures 4 and 6, one tremie pipe 146 is inserted into the rear side (one side) of the main body 12, 52 in the depth direction when viewed from above, and the other tremie pipe 146 is inserted into the front side (the other side) of the main body 12, 52 in the depth direction when viewed from above. In other words, the two tremie pipes 146 are arranged with the main body 12, 52 between them when viewed from above.

[0036] In the structural column 50 according to the comparative example, the short brackets 54a, 54b, 54c, and 54d are attached to the center of the side width of the side surfaces 52a, 52b, 52c, and 52d, and are provided at intervals in the vertical direction on each basement floor, as shown in Fig. 6. For this reason, the tremie pipe 146 comes into contact with the short brackets 54b and 54d, making it difficult to insert the tremie pipe 146.

[0037] In contrast, in the structural column 10 according to this embodiment, the short brackets 14b, 14d are attached eccentrically with respect to the center of the side surface width of the side surfaces 12b, 12d, as shown in Fig. 4. Therefore, the tremie pipe 146 does not come into contact with the short brackets 14b, 14d, and the tremie pipe 146 can be easily inserted.

[0038] Then, as shown in Fig. 3(B), a cast-in-place concrete pile 150 is formed, and the lower end portions of the structural columns 10, 50 are embedded in the concrete C. The cast-in-place concrete pile 150 is an example of a cast-in-place pile.

[0039] When the pouring of the concrete C is completed and the cast-in-place concrete pile 150 is formed, concrete C is also poured inside the structural columns 10, 50. In this way, the structural columns 10, 50 become concrete-filled steel tube (CFT) structures in which the concrete C is filled inside.

[0040] 3(C), a backhoe 148 is used to backfill the pile holes 110 with backfill material M such as soil or soil sand, and the crane 142 is used to remove the building frame 120. Thereafter, the crane 142 is used to pull out and remove the surface casing 112.

[0041] (summary) As explained above, in the structural column 10, the short bracket 14b of each basement floor is attached eccentrically to the other side in the width direction with respect to the center of the side width of the side surface 12b. Furthermore, the short bracket 14d of each basement floor is attached eccentrically to one side in the width direction with respect to the center of the side width of the side surface 12d. This makes it easier to insert the tremie pipe 146 into the pile hole 110 into which the structural column 10 has been inserted, compared to the structural column 50 of the comparative embodiment.

[0042] In addition, in the structural column 10, a pair of short brackets 14b, 14d attached to a pair of side surfaces 12b, 12d facing in opposite directions in the depth direction are attached eccentrically in the width direction with respect to the center of the side surface width of the side surfaces 12b, 12d. This makes it possible to suppress unevenness of the poured concrete C by inserting tremie pipes 146 on both sides with the main body 12 between them.

[0043] Furthermore, in the structural column 10, the short bracket 14b of each basement floor is attached eccentrically to the other side in the width direction with respect to the center of the side width of the side surface 12b. Furthermore, the short bracket 14d of each basement floor is attached eccentrically to one side in the width direction with respect to the center of the side width of the side surface 12d. In other words, the short brackets 14b and 14d are eccentric to opposite sides with respect to the centers of the side widths of the side surfaces 12b and 12d. This makes it possible to suppress bias in the poured concrete C compared to when a pair of short brackets are eccentric to the same side with respect to the center of the side width.

[0044] In addition, in the structural column 10, the amount of eccentricity of the short bracket 14d is set to be the same as the amount of eccentricity of the short bracket 14b. This makes it possible to prevent the structural column 10 from tilting when inserted into the pile hole 110, compared to when a pair of short brackets that are eccentric to opposite sides have different amounts of eccentricity.

[0045] Although the present disclosure has been described in detail with respect to specific embodiments, it is clear to those skilled in the art that the present disclosure is not limited to such embodiments and that various other embodiments are possible within the scope of the present disclosure. Modifications, deletions, additions, and combinations of the embodiments are possible as long as they do not contradict the technical ideas that can be recognized by those skilled in the art from the claims, the specification, and the drawings.

[0046] In addition, in the above embodiment, the cross section of the main body 12 of the structural column 10 is rectangular tubular, but the cross section of the main body may be cylindrical, polygonal, or a cross H shape made up of combined H-shaped steel beams, and is not limited to a rectangular tubular shape.

[0047] Although not specifically described in the above embodiment, the main body 12 may be provided with an internal diaphragm, a through diaphragm, or the like.

[0048] In addition, in the above embodiment, short brackets 14a, 14b, 14c, and 14d are provided on the four side surfaces 12a, 12b, 12c, and 12d of the main body 12, respectively, but short brackets may be provided on only one side surface, or on two or three side surfaces, respectively.

[0049] In addition, in the above embodiment, the short brackets 14a, 14b, 14c, and 14d are provided on each basement floor, but they do not necessarily have to be provided on each basement floor. [Explanation of symbols]

[0050] 10 Structure pillar 12 Main body 12a side 12b Side 12c side 12d side 14a Short Bracket 14b Short Bracket 14c short bracket 14d short bracket 110 Pile hole 150 Cast-in-place concrete pile (an example of a cast-in-place pile)

Claims

1. A structural column used in an inverted construction method and having its lower end embedded in a concrete cast-in-place pile, a main body portion to be inserted into a stake hole; A short bracket attached to a side surface of the main body and connected to a beam of a basement floor, the short bracket being horizontally eccentric with respect to the center of the side surface width of the side surface; A structural pillar equipped with

2. The cross section of the main body is a rectangular tube, The short brackets are attached to the four side surfaces of the main body and are provided on each basement floor, the pair of short brackets attached to the pair of side surfaces facing in opposite directions in the horizontal direction are each eccentric in the horizontal direction with respect to the center of the side surface width of the side surface; The structural column according to claim 1.

3. One of the pair of short brackets and the other short bracket are eccentric to opposite sides with respect to a center of a side surface width of the side surface of the main body portion. The structural column according to claim 2.

4. The amount of eccentricity of one of the short brackets is the same as the amount of eccentricity of the other of the short brackets. The structural column according to claim 3.

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