JP6368630B2 - Foundation construction method - Google Patents

Description

  The present invention relates to a foundation construction method.

  Conventionally, various methods have been proposed as a foundation construction method for constructing a foundation including a footing that is a foundation of a building and a column (hereinafter referred to as a target column) that is directly supported by the footing. (For example, refer to Patent Document 1). Here, when constructing a column made of precast concrete (hereinafter referred to as PCa) as the target column, it is necessary to connect the target column manufactured separately from the footing to the footing. Conventionally, the following method has been adopted.

  20 to 23 are vertical sectional views showing a structure constructed by a conventional foundation construction method. FIG. 20 is a step 1, FIG. 21 is a step 2, FIG. 22 is a step 3, and FIG. It is a vertical sectional view showing the structure constructed in Step 4. Hereinafter, a conventional foundation construction method for constructing the foundation 100 will be described with reference to FIGS. 20 to 23.

  First, as in step 1 shown in FIG. 20, the footing main reinforcement 111 is assembled at the bottom of the mold 120 of the footing 110, and then concrete is placed on the bottom of the mold 120 so as to cover the footing main reinforcement 111, and the bottom of the footing. 112 is constructed. Then, after the footing bottom 112 is solidified, a base 140 is formed on the upper surface of the footing bottom 112, and the foundation column main reinforcement 130 is attached around the base 140. Next, by installing the template 150 formed with a plurality of holes along the vertical direction so that each foundation column main reinforcement 130 passes through the hole of the template 150 with respect to the foundation pillar main reinforcement 130, the foundation portion The position of the column main reinforcement 130 is fixed.

Next, as in step 2 shown in FIG. 21, concrete is cast into the mold 120 of the footing 110 to form the footing main body 113, and solidified to a reference strength (for example, 21 N / mm ² ). Thus, the gantry 140 and the foundation column main reinforcement 130 arranged in the process 1 are fixed. Here, since the template 150 is attached to the foundation column main reinforcement 130 as described above, and the position of the foundation column main reinforcement 130 is fixed by the template 150, the foundation accompanying the placement of the footing main body 113. Variations in the position of the columnar main bars 130 can be suppressed.

  Next, as in Step 3 shown in FIG. 22, the slab 160 is formed by placing the slab reinforcement 161 above the footing 110 and placing the slab concrete 162 so as to cover the slab reinforcement 161. At this time, the upper end portion of the foundation column main reinforcement 130 positioned by the template 150 arranged in step 1 protrudes upward from the upper surface of the slab 160.

  Finally, as in step 4 shown in FIG. 23, after the slab concrete 162 placed in step 3 is solidified to the standard strength, the template 150 is removed from the base column main reinforcement 130, and the target column 170 made of PCa is removed. Place on slab 160. At this time, it is necessary to install a heavy machine (not shown) for lifting the target pillar 170 on the slab 160. In order to reinforce the slab 160 so that the slab 160 is not deformed by the weight of the heavy machine. In some cases, a reinforcing plate or the like is installed on the slab 160 and a heavy machine is further installed thereon. Then, the upper ends of the base column main bars 130 protruding above the upper surface of the slab 160 and the column main bars 171 inserted through the target column 170 are connected to each other by a known method (for example, filling with mortar).

  Although not shown in the drawings, as another method, not only the target pillar but also the footing is formed as a member made of PCa, and the footing is placed at a predetermined position using a heavy machine, so that concrete is placed on the construction site. There has also been proposed a method that eliminates the trouble of doing this.

JP 2009-74349 A

  However, in the foundation construction method using the pedestal 140 and the template 150 as described above, the concrete (footing main body 113) placed inside the mold 120 and the concrete (slab slab) placed so as to cover the slab reinforcement 161 are used. Since the target pillar 170 cannot be installed until the concrete 162) is solidified to the standard strength, there is a possibility that the construction period will be prolonged.

  In addition, in the foundation construction method in which not only the target pillar as described above but also the footing itself is a member made of PCa, it is necessary to carry the footing made of PCa, which is a very large member, to the construction site, which requires cost and labor. In addition, a large heavy machine for lifting the footing at the site is required, which is very laborious and expensive.

  The present invention has been made in view of the above, and the construction period can be shortened, and the labor and cost of bringing a large PCa member into the construction site, and a large heavy machine at the construction site. An object is to provide a foundation construction method capable of reducing the labor and cost of using a slab.

  In order to solve the above-described problems and achieve the object, the foundation construction method according to claim 1 includes a precast concrete target column through which a column main reinforcement is inserted, and a footing that supports the target column. A foundation part construction method for constructing a foundation part to be provided, which is a formwork of the footing, a formwork forming process for forming a formwork having an opening surface on an upper surface, and for supporting the target column A column support part and a base part column main reinforcement inserted through the column support part in a vertical direction, and having a base part column main reinforcement projecting part protruding upward from the column support part; A foundation installation step of installing a foundation portion provided at the bottom of the footing, a mold filling step of placing concrete so as to be filled up to an opening surface of the mold and applying the footing, and the mold Before the filling process Alternatively, before the concrete placed in the mold filling step is solidified to a standard strength, the target column is placed on the upper surface of the column support portion, and the column main reinforcement of the target column and the foundation column A column construction process for connecting the foundation main column protrusions of the main bars to each other.

  The foundation part construction method according to claim 2 is the foundation part construction method according to claim 1, wherein the column support part is a support column and a column base made of precast concrete placed on the support column. The base column main reinforcement is inserted through the column base along the vertical direction, and in the base installation step, the bottom surface of the support column is in contact with the bottom of the footing, and the column base The base portion is installed so that at least a part is located above the opening surface of the mold.

  The foundation part construction method according to claim 3 is the foundation part construction method according to claim 1, wherein the column support part includes a column base part made of precast concrete, and the foundation part column main reinforcement is the column base part. In the base installation step, the bottom surface of the column base is in contact with the bottom of the footing, and at least a part of the column base is positioned above the opening surface of the formwork. The base portion is installed so as to do so.

  The foundation part construction method according to claim 4 is the foundation part construction method according to any one of claims 1 to 3, wherein a slab bar is installed above the formwork so as to cover the slab bar. Including a slab forming step of forming concrete with a predetermined thickness to form a slab, wherein in the foundation installation step, the upper surface of the column support portion is flush with the upper surface of the slab or above the upper surface of the slab The base portion is installed so as to be positioned at the position, and the column construction step is performed before the slab formation step or before the concrete cast in the slab formation step is solidified to a standard strength.

  The foundation part construction method according to claim 5 is the foundation part construction method according to any one of claims 1 to 4, wherein the foundation part is formed in the vicinity of the upper end of the pillar support part inside the pillar support part. A column support part that includes the internal reinforcement of the column support part, and connects the internal reinforcement of the column support and the upper end of the footing formed above the footing or the slab reinforcement formed above the formwork Includes internal muscle connection process.

  According to the foundation part construction method according to claim 1, since the base part capable of supporting the target column is provided, the concrete placed before or during the mold filling process is solidified to the reference strength. Before, the target pillar can be constructed, and the construction period of the foundation can be greatly shortened. In addition, since the foundation can be constructed without using PCa footings, the labor and expense of bringing large PCa parts into the construction site and the labor and expense of using large heavy machinery at the construction site are eliminated. It becomes possible to reduce.

  According to the foundation part construction method according to claim 2, since a part of the column support part is constituted by the support column and the remaining part is constituted by the column base part made of precast concrete, the entire column support part is precast. Compared with the case where it is made of concrete, the column support portion can be reduced in weight, and the labor required for carrying in the column support portion can be reduced. Moreover, since a space is formed around the support column as compared with the case where the entire column support part is made of precast concrete, it is possible to improve the degree of freedom of the bar arrangement.

  According to the foundation part construction method according to claim 3, the bottom surface of the column base is in contact with the bottom of the footing, and at least a part of the column base is positioned above the opening surface of the formwork. Since the base part is installed in the columnar part, the column base part can be configured with higher strength, and the target column can be supported more stably.

  According to the foundation part construction method of claim 4, since the upper surface of the column support part is located on the same plane as the upper surface of the slab or above the upper surface of the slab, before the slab forming step, or the slab The target pillar can be constructed before the concrete cast in the forming process is solidified to the standard strength, and the construction period can be greatly shortened. In addition, when the target column is constructed before the slab formation process, the target column can be constructed without causing the slab to bear the load of heavy equipment for constructing the target column, and the labor for reinforcing the slab may be omitted. It becomes possible.

  According to the foundation part construction method of claim 5, since the column support part internal reinforcement and the footing upper end reinforcement formed above the footing or the slab reinforcement formed above the formwork are connected to each other. It is possible to improve the strength of the target column, slab or column support.

It is a vertical sectional view showing the foundation part concerning Embodiment 1 of the present invention. It is a figure which shows a base part, Comprising: Fig.2 (a) is a top view, FIG.2 (b) is a front view. It is a vertical cross section which shows the structure constructed | assembled at the process 1 of the foundation part construction method which concerns on Embodiment 1 of this invention. It is a vertical sectional view showing the structure constructed in step 2 of the foundation construction method. It is a vertical cross section which shows the structure constructed | assembled in the process 3 of the foundation part construction method. It is a vertical cross section which shows the structure constructed | assembled in the process 4 of the foundation part construction method. It is a vertical sectional view showing the structure constructed in step 5 of the foundation construction method. It is a vertical sectional view showing the structure constructed in step 6 of the foundation construction method. It is a vertical sectional view showing the structure constructed in step 7 of the foundation construction method. It is a vertical sectional view showing a foundation part according to Embodiment 2 of the present invention. It is a figure which shows a base part, Comprising: Fig.11 (a) is a top view, FIG.11 (b) is a front view. It is a vertical sectional view showing the structure constructed in step 1 of the foundation construction method according to Embodiment 2 of the present invention. It is a vertical sectional view showing the structure constructed in step 2 of the foundation construction method. It is a vertical cross section which shows the structure constructed | assembled in the process 3 of the foundation part construction method. It is a vertical cross section which shows the structure constructed | assembled in the process 4 of the foundation part construction method. It is a vertical sectional view showing the structure constructed in step 5 of the foundation construction method. It is a vertical sectional view showing the structure constructed in step 1 of the foundation construction method according to the modification. It is a vertical sectional view showing the structure constructed in step 2 of the foundation construction method. It is a vertical cross section which shows the structure constructed | assembled in the process 3 of the foundation part construction method. It is a vertical sectional view showing the structure constructed in step 1 of the conventional foundation construction method. It is a vertical sectional view showing the structure constructed in step 2 of the conventional foundation construction method. It is a vertical sectional view showing the structure constructed in step 3 of the conventional foundation construction method. It is a vertical sectional view showing the structure constructed in step 4 of the conventional foundation construction method.

  Hereinafter, each embodiment of the foundation construction method according to the present invention will be described in detail with reference to the drawings. However, the present invention is not limited by this embodiment.

[Basic concept of each embodiment]
First, the basic concept of the embodiment will be described. Embodiments generally relate to a foundation construction method for constructing a foundation including a target column made of precast concrete and a footing that supports the target column. Note that the specific structure of the building formed on the footing is publicly known unless otherwise specified, and a detailed description thereof will be omitted.

[Specific contents of the embodiment]
Next, specific contents of each embodiment will be described.

(Embodiment 1)
First, the first embodiment will be described. Below, the structure of the foundation part constructed | assembled by the foundation part construction method which concerns on this Embodiment 1 first is demonstrated, and next, the order of the foundation part construction method itself which constructs the said foundation part for every process is demonstrated. I will explain later.

(Constitution)
FIG. 1 is a vertical sectional view showing a foundation 1 according to the first embodiment. As shown in FIG. 1, the foundation portion 1 includes a foundation pile 10, a formwork 20, a footing 30, a backfill portion 40, a foundation portion 50, a slab 60, and a target pillar 70. In the following description, the XX ′ direction in each figure is the width direction (X direction is right, X ′ direction is left), and YY ′ direction (that is, the direction orthogonal to the XZ plane). Are referred to as the front-rear direction (Y direction is the front, Y ′ direction is the rear), and the ZZ ′ direction is the height direction (Z direction is the upper direction, Z ′ direction is the lower direction).

(Configuration-foundation pile)
The foundation pile 10 is a pile driven into the ground to support a building, and in the first embodiment, the foundation pile 10 is disposed on both the left and right sides of the base portion 50 in plan view. The foundation pile 10 is roughly composed of a columnar foundation pile concrete 11 arranged so as to reach slightly above the bottom surface of the formwork 20 from deep underground, and the formwork 20 from the inside of the foundation pile concrete 11. The fixing muscles 12 are arranged so as to reach the vicinity of the opening surface (described later). In addition, since the construction method of such a foundation pile 10 is well-known, detailed description is abbreviate | omitted. Moreover, as the foundation pile 10, not only such a structure but arbitrary well-known structures can be employ | adopted, For example, the pile using a steel pipe and the pile made from PCa may be sufficient.

(Configuration-formwork)
The mold 20 is a well-known mold provided on the ground for constructing the footing 30. This formwork 20 is generally a frame material placed on the upper surface of a leveled concrete (abandoned concrete) 21 having a thickness of about 50 mm laid on the bottom of excavated soil, and the upper surface is an open surface. It has become. The material of the mold 20 and the production method are arbitrary. For example, the mold 20 is configured by nailing and joining four veneer plates that respectively cover the right surface, the left surface, the front surface, and the rear surface of the footing 30.

(Configuration-footing)
The footing 30 is a structure provided on the ground in order to improve the earthquake resistance of the building. The footing 30 is generally configured to include a footing main reinforcement 31, a footing side reinforcement 32, a footing bottom 33, and a footing main body 34. Here, the footing main bar 31 is a reinforcing bar for structurally reinforcing the footing 30 and is arranged so as to cover the inner surface of the mold 20 and the upper surface of the leveled concrete 21 as shown in the figure. Specifically, a plurality of reinforcing bars arranged along the width direction on the upper surface of the leveled concrete 21 and a plurality of reinforcing bars arranged along the front-rear direction on the upper surface of the leveled concrete 21 are provided. All the reinforcing bars are turned up vertically around the end portion in the width direction of the smoothing concrete 21 or the end portion in the front-rear direction, and are turned back inward again at the position of the slab 60. The footing side bars 32 are reinforcing bars for structurally reinforcing the footing 30 and are juxtaposed on the inner surface of the mold 20. Each footing side bar 32 extends along the width direction or the front-rear direction. Is arranged. The footing bottom 33 is a concrete that fixes the footing main bar 31 and is the foundation of the foundation part 50, and is placed at a position above the leveled concrete 21 so as to cover a part of the footing main bar 31. . The footing main body part 34 is concrete for fixing the base part 50 and the footing side reinforcement 32, and is placed so as to reach the opening surface of the mold frame 20 from the footing bottom part 33.

(Configuration-backfill)
The backfill portion 40 is a portion formed by backfilling earth and sand excavated for the construction of the footing 30 and is formed on both sides in the width direction of the mold 20 and both sides in the front-rear direction. In addition, since the structure and formation method of such a backfill part 40 are well-known, detailed description is abbreviate | omitted.

(Configuration-foundation part)
The foundation part 50 is a means that serves as a foundation for supporting the target pillar 70, and is installed at the bottom of the footing 30. Here, “installed at the bottom of the footing 30” includes being installed on the upper surface of the footing bottom 33 and being installed on the upper surface of the leveled concrete 21, but in this embodiment, A description will be given on the assumption that it is installed on the upper surface of the footing bottom 33. 2A and 2B are diagrams showing the base portion 50, in which FIG. 2A is a plan view and FIG. 2B is a front view. The base portion 50 is disposed at a substantially central position of the footing 30 in a plan view, and is roughly configured to include a column support portion 51 and a foundation column main reinforcement 52.

(Configuration-foundation-pillar support)
The column support portion 51 is a portion for supporting the target column 70. In the first embodiment, the column support portion 51 schematically includes a lower support column 51a, an upper support column 51b, and a column base 51c. Has been.

  Here, the lower support column 51a is a steel frame located at the lowest position in the column support part 51, and is formed as, for example, a known H-shaped steel. As shown in FIG. 1, the lower support column 51 a is joined to the footing bottom 33 by being anchored to the footing bottom 33 from a base plate plate provided at the lower end. The lower support column 51a is joined to the upper support column 51b at the upper end by a known method such as welding or bolt joining. However, the joining method is not limited to the above method, and any method can be applied. The height of the lower support column 51a is described as being half the height from the footing bottom 33 to the opening surface of the mold 20 (the lower surface of the slab 60), but is limited to this height. I can't.

  The upper support column 51b is a steel frame located between the lower support column 51a and the column base 51c, and is formed as, for example, a known H-shaped steel. The upper support column 51b is joined to the lower support column 51a at the lower end by a known method such as welding or bolt joining. Further, as shown in FIG. 1, the upper support column 51b is joined to the column base 51c by being anchored to the lower surface of the column base 51c from the base plate plate provided at the upper end. Yes. The joining method is not limited to the above method, and any method can be applied. In addition, the height of the upper support column 51b is described as being half the height from the footing bottom 33 to the opening surface of the mold frame 20, similarly to the lower support column 51a. Not limited to. As described above, the lower support column 51 a and the upper support column 51 b are combined with each other to have the same height as the height from the upper surface of the footing bottom 33 to the opening surface of the mold frame 20.

  The column base 51c serves as a base on which the target column 70 is placed and serves as a connecting portion between the slab 60 and the target column 70, and is placed on the upper support column 51b as shown in FIG. Has been. The shape of the column base 51c is arbitrary. For example, the column base 51c may be a columnar body having the same planar shape as the target column 70 (circular in the first embodiment), or a planar shape different from the target column 70. It may be a columnar body having However, in this Embodiment 1, it demonstrates as what is formed in the rectangular parallelepiped shape in planar view. Here, the height of the column base 51c is arbitrary, but in the first embodiment, as shown in FIG. 1, the lower end is positioned slightly below the opening surface of the mold 20, It is formed at such a height that the upper end is located on the same plane as the upper surface of the slab 60 (that is, substantially the same height as the height (thickness) of the slab 60). Therefore, the entire surface of the four side surfaces of the column base 51c is in contact with the slab concrete 62 (described later). As described above, by positioning the lower end portion of the column base portion 51c slightly below the opening surface of the mold frame 20, the column base portion 51c can be slightly embedded in the footing 30 and formed. The leg 51c can be fixed more stably.

  Here, the column base 51c is provided with a column support portion internal muscle 51d. As shown in FIG. 2A, the column support portion internal reinforcement 51d includes a plurality of reinforcing bars that pass through the column base 51c along the front-rear direction and a plurality of posts that pass through the column base 51c along the width direction. These rebars are arranged at different heights so as not to cross each other. Further, these reinforcing bars and the base column main reinforcement 52 penetrating the column base 51c up and down are also arranged so as not to cross each other.

  And the internal thread part is formed in the both ends (namely, the position close | similar to the side surface of the column base part 51c) of each column support part internal muscle 51d, and the edge part of the slab muscle 61 mentioned later is said female screw. The column support part internal reinforcement 51d and the slab reinforcement 61 can be connected to each other by screwing to the part. A detailed description of this point will be described later.

(Structure-foundation part-foundation pillar main reinforcement)
The foundation column main reinforcement 52 is a means for reinforcing the footing 30 and connecting the footing 30 and the target column 70 to each other. The foundation column main reinforcement 52 is a plurality of reinforcing bars arranged to cover the periphery of the lower support column 51a and the upper support column 51b in the base unit 50. Specifically, as shown in FIG. 2 (a), each base column main reinforcement 52 is inserted in the vertical direction with respect to the column base 51c, and has a predetermined interval in a circular shape in plan view. A plurality (12 in the first embodiment) are arranged in parallel. In FIG. 2B and FIG. 1, only the base column main reinforcing bars 52 at the left and right ends are shown for convenience of illustration, and the other base column main reinforcing bars 52 are not shown. The base column main reinforcing bars 52 are bent so that the upper end passes through the column base 51c and is positioned further above the column base 51c, and the lower end is along the upper surface of the footing bottom 33. It is formed in a substantially L shape as a whole. Here, the portion of the foundation column main reinforcement 52 that protrudes further upward from the upper surface of the column base 51c will be referred to as a “base column reinforcement projection 53” below. In this embodiment, the base column main reinforcement 52 is substantially L-shaped in order to ensure the contact area with the concrete. However, when a sufficient contact area can be ensured, the foundation column main reinforcement 52 52 may be a straight line.

(Configuration-Slab)
The slab 60 is a slab that constitutes a floor surface of a building, and is a known slab formed so as to be in contact with the footing 30 above. The slab 60 generally includes slab reinforcement 61 and slab concrete 62.

  The slab reinforcement 61 is a reinforcing bar arranged in a mesh shape along the front-rear direction and the width direction in the vicinity of the upper end and the lower end of the slab 60. As shown in the figure, a column base 51c having substantially the same thickness (height) as the slab 60 is formed at the center position in the plan view of the footing 30. Therefore, the portion where the column base 51c is formed. The slab muscle 61 cannot be provided in the case. Therefore, the slab muscle 61 may be disposed so as to avoid the portion where the column base 51c is disposed. However, in the first embodiment, in order to further improve the strength of the building, The ingenuity is given. That is, since the male screw part is formed at the end of the column base 51c side of the slab bar 61, and the female screw part is formed at both ends of the column support part internal bar 51d as described above, The slab bars 61 can be screwed to the column support part internal bars 51d to be connected to each other. Thus, it becomes possible to improve the intensity | strength of a building by mutually connecting the slab reinforcement 61 and the column support part internal reinforcement 51d. Here, as described above, since the column base 51c is formed in a rectangular parallelepiped shape, the slab muscle 61 and the column support internal muscle 51d can be easily connected to each other. That is, since the column support portion internal bars 51d can be formed to have the same length, the column support portion internal bars 51d can be easily formed, and a plurality of female screw portions are positioned on the same plane. Thus, the length of the slab muscle 61 can be easily adjusted.

  The slab concrete 62 is concrete that forms the floor surface of the slab 60, and is concrete that is placed so as to cover the slab reinforcement 61.

(Structure-Target pillar)
The target pillar 70 is a pillar that forms a part of the structure of the building, and is placed on the base portion 50. The shape of the target column 70 is arbitrary, and may be, for example, a quadrangular column or a hexagonal column. However, in the first embodiment, the target column 70 is described as being formed in a cylindrical shape. . The target column 70 is a column made of precast concrete (hereinafter referred to as PCa), which is prepared in advance at a factory or the like, is carried into a construction site, and is placed on the base unit 50 using a heavy machine or the like. Is installed as shown. Note that only one target column 70 is illustrated, but actually, another PCa column is placed on the target column 70, and the illustration of such PCa column is omitted. ing.

  Here, a plurality of column main bars 71 for reinforcing the target column 70 are inserted into the target column 70. The column main bars 71 are known reinforcing bars arranged in an annular shape with a predetermined interval from each other in plan view, and the positions of the column main bars 71 are the positions of the base column main bars 52 of the foundation part 50 described above. The position corresponds to the position. And this column main reinforcement 71 and the foundation part column main reinforcement 52 of the base part 50 are mutually connected by the well-known method. For example, a concave hardware having an opening on the lower side is formed integrally with the column main reinforcement 71 at the lower end portion of the column main reinforcement 71, and the base column main reinforcement protrusion of the base column main reinforcement 52 of the base portion 50 is formed on this concave hardware. The connection can be made by a known method of connection by grouting with 53 inserted.

(Foundation method)
Then, the foundation part construction method which constructs said foundation part 1 is demonstrated in detail, referring a figure. FIGS. 3 to 9 are vertical sectional views showing structures constructed in each step of the foundation construction method according to the first embodiment. FIG. 3 is step 1 and FIG. FIG. 5 is a step 3, FIG. 6 is a step 4, FIG. 7 is a step 5, FIG. 8 is a step 6, and FIG. In the following, the foundation construction method is divided into a plurality of processes, and each process is named (foundation pile formation process, formwork formation process, foundation installation process, footing side reinforcement installation process, formwork filling process, column construction process. , A slab forming process, a column support part internal reinforcement connecting process) will be described, but each of these processes and the numbered processes (process 1 to process 7) shown in FIGS. For example, step 1 shown in FIG. 3 includes a plurality of steps (foundation pile forming step, mold forming step, and foundation setting step).

(Foundation method-foundation pile formation process)
First, step 1 shown in FIG. 3 is performed. Specifically, first, a pile hole is excavated deeply into the ground, and the anchor reinforcement 12 assembled in advance is dropped into the pile hole, and the foundation pile concrete 11 is poured into the pile hole and solidified to be fixed with the foundation pile concrete 11. The foundation pile 10 is formed so that the muscle 12 is integrated. In general, in order to refill the pile hole after the concrete is solidified, the earth and sand above the foundation pile 10 is excavated to form a space for forming the footing 30. Note that the two foundation piles 10 can be formed in the same manner.

(Foundation construction method-formwork forming process)
Then, the leveled concrete 21 is placed on the bottom of the excavated earth and sand. When the leveled concrete 21 is solidified, the mold 20 is formed on the leveled concrete 21. At this time, the mold 20 is formed so that the upper end of the foundation pile concrete 11 and the fixing reinforcement 12 are included in the mold 20.

(Foundation construction method-foundation installation process)
Next, the footing main bar 31 is installed inside the mold 20 so as not to contact the fixing bar 12. Next, the earth and sand at the time of excavation is returned to the side of the mold 20 to form the backfill portion 40 to fix the mold 20. Here, the timing of forming the backfill portion 40 in this way is arbitrary, and for example, it may be formed at the timing after the footing 30 shown in FIG. 1 is formed. The mold 20 can be removed and reused. However, in the present embodiment, as described above, it is assumed that the backfill portion 40 is formed at the timing before the footing 30 is formed and the mold 20 is not reused. Next, the footing bottom 33 is formed by placing concrete on the bottom of the mold 20 so as to cover the footing main reinforcement 31 and solidifying the concrete. In addition, since each process until forming the footing bottom part 33 shown above can adopt a well-known method, detailed description shall be abbreviate | omitted and the order which performs each process will also be limited to said order. Not. Finally, the lower support column 51a is anchored and fixed to the footing bottom 33 thus formed.

  Next, as in step 2 shown in FIG. 4, the upper support column 51b and the like are placed on the lower support column 51a. Specifically, the lower support in which the column base 51c, the base column main reinforcement 52 inserted through the column base 51c, and the upper support column 51b screwed to the bottom surface of the column base 51c are attached in step 1. The column is placed so that the lower support column 51a and the upper support column 51b are in contact with the column 51a. In the first embodiment, the column base 51c, the foundation column main reinforcement 52, and the upper support column 51b are described as being carried into the construction site in a state of being integrally connected to each other as illustrated. For example, the screwing of the column base 51c and the upper support column 51b may be performed at the construction site.

  Next, as in step 3 shown in FIG. 5, the lower support column 51 a and the upper support column 51 b are connected to each other. Specifically, a metal plate (not shown) is disposed so as to cover both a part of the side surface of the upper support column 51b and a part of the side surface of the lower support column 51a, and the metal plate is supported by the lower support column 51a and the upper support column. Bolts to both columns 51b. The connection method is not limited to this, and for example, the lower support column 51a and the upper support column 51b may be connected to each other by welding. Alternatively, the lower support column 51a and the upper support column 51b may be welded in advance at a factory or the like and then carried into the construction site.

(Foundation part construction method-footing side muscle installation process)
Next, the footing side streak 32 is installed as in step 4 shown in FIG. Specifically, a plurality of footing side bars 32 are formed by a known method (for example, a method of joining at a predetermined height interval to reinforcing bars (not shown) arranged along the height direction). Are arranged in parallel at predetermined intervals along the height direction.

(Foundation part construction method-formwork filling process)
Next, the footing main body 34 is formed as in Step 5 shown in FIG. Specifically, the footing main body 34 is formed by placing concrete in the mold 20 so as to be filled from the footing bottom 33 to the opening surface of the mold 20 and solidifying the concrete.

(Foundation method-pillar construction process)
Next, as in step 6 shown in FIG. 8, the target column 70 is placed on the column base 51c. Specifically, first, the target column 70 is placed on the column base 51c via a spacer (not shown) so that a space is formed between the target column 70 and the column base 51c. . At this time, the base column main bar protruding portion 53 of the base column main bar 52 is placed in a sleeve joint provided at the lower end of the column main bar 71 of the target column 70. Next, the grouting is performed so that these sleeve joints and the base column main reinforcement protrusions 53 are connected to each other. A part of the grout injected in this manner overflows from the sleeve joint and is filled between the upper surface of the column base 51c and the lower surface of the target column 70. In this way, the target column 70 and the column base 51c are connected to each other. Can be firmly joined. A position adjusting bolt or the like may be used instead of the spacer.

  Here, in this application, since the foundation part 50 used as the foundation of the object pillar 70 is formed, the footing main body part 34 which set | placed the object pillar 70 of this process 6 in the process 5 is a reference | standard. This can be done before solidifying. That is, in the above-described prior art, since the target column 70 is directly placed on the concrete filled in the formwork 20 without having the foundation portion 50, the concrete has a standard strength (that is, the target). The target column 70 could not be placed unless it was solidified to a strength sufficient to allow the column 70 to be placed. However, in the first embodiment, since the base portion 50 capable of supporting the target pillar 70 is formed in the mold frame 20, regardless of whether or not the footing main body portion 34 is solidified to the reference strength. The target pillar 70 can be placed.

  In this way, since the target pillar 70 can be placed without waiting for the footing main body 34 placed in the mold 20 to solidify to the reference strength, the upper floor can be constructed from an earlier stage, The construction period can be greatly shortened. Naturally, as described later, the target column 70 can be placed before the slab concrete 62 is formed on the footing main body 34, so that the construction period can be greatly shortened.

  In the first embodiment, as shown in step 5, after filling the mold 20 with the footing main body 34 and before the footing main body 34 is solidified, the target column 70 is shown in step 6. Is placed on the column base 51c, but the order of the steps 5 and 6 may be reversed. That is, the target column 70 may be placed on the base portion 50 and then the mold 20 may be filled with the footing main body 34. By performing each step in this order, the target column 70 can be placed before the footing main body 34 is placed in the mold 20, so that the entire construction period can be further shortened. Is possible.

(Foundation part construction method-slab formation process, column support part internal reinforcement connection process)
Next, the slab reinforcement 61 is installed above the mold 20 as shown in Step 7 shown in FIG. Specifically, a plurality of slab bars 61 are arranged along the front-rear direction and the width direction at a position where the slab 60 is formed, and a part of the slab bars 61 is formed on the side surface of the column base 51c. By screwing the slab muscle 61 into the threaded portion, the column supporting portion internal muscle 51d is joined.

  Finally, concrete is cast so as to cover the slab reinforcement 61 to form the slab concrete 62, whereby the foundation portion 1 shown in FIG. 1 is completed.

  Here, in the prior art shown in FIGS. 20 to 23, with the upper surface of the slab 160 as a boundary, the strength of the slab concrete 162 positioned below the boundary and the concrete of the target column 170 positioned above the boundary. It was common to make a difference in strength. Therefore, in the first embodiment, a column base 51c is provided separately from the target column 70, and a difference is provided between the strength of the column base 51c and the strength of the target column 70. It is possible to provide a difference in strength at the upper surface.

  Further, in the prior art shown in FIGS. 20 to 23, after placing the slab concrete 162, the target column 170 is placed, so that, as described above, the weight of heavy equipment for lifting the target column 170 is received. The slab 160 needs to be reinforced. However, in the first embodiment, since the target pillar 70 can be placed before the slab concrete 62 is placed, it is possible to directly install heavy machinery on the ground or the like. Therefore, it is possible to place the target column 70 without requiring the above-described reinforcement, and it is possible to reduce labor and cost required for reinforcement.

(Effect of Embodiment 1)
Thus, according to the foundation part construction method of the first embodiment, since the base part 50 that can support the target pillar 70 is provided, the concrete cast before or during the mold filling process. Before solidifying to the standard strength, the target pillar 70 can be constructed, and the construction period of the foundation 1 can be greatly shortened. Moreover, since the foundation part 1 can be constructed without using the PCa footing 30, labor and cost of carrying a large PCa member to the construction site, and labor of using a large heavy machine at the construction site, Costs can be reduced. In addition, since the column base 51c and the target column 70 can be constructed and carried into the site at a factory or the like, the column base 51c and the target column 70 can be installed without hitting the site. It is possible to construct a high foundation 1.

  Further, a part of the column support portion 51 is constituted by a lower support column 51a and an upper support column 51b made of steel, and the remaining portion is constituted by a column base portion 51c made of PCa. Compared to the case of manufacturing (for example, the structure of the second embodiment to be described later), the column support portion 51 can be reduced in weight, and the labor required for carrying in the column support portion 51 can be reduced. Further, since the space is formed around the lower support column 51a and the upper support column 51b as compared with the case where the entire column support unit 51 is made of PCa, it is possible to improve the flexibility of the bar arrangement. Become.

  Moreover, since the upper surface of the column support part 51 is located on the same plane as the upper surface of the slab 60 or above the upper surface of the slab 60, the concrete cast before or in the slab forming process is provided. The target pillar 70 can be constructed before solidifying to the standard strength, and the construction period can be greatly shortened. Moreover, when constructing the target column 70 before the slab forming step, the target column 70 can be constructed without causing the slab 60 to bear the load of the heavy machinery for constructing the target column 70, and labor for reinforcing the slab 60. Can be omitted.

  Moreover, since the column support part internal reinforcement 51d and the slab reinforcement 61 are connected to each other, the strength of the target pillar 70, the slab 60, and the column support part 51 can be improved.

  Moreover, since the part from the opening surface of the formwork 20 to the upper surface of the slab 60 in the column support part 51 is formed in a rectangular parallelepiped shape, the column support part internal reinforcement 51d and the slab reinforcement 61 can be easily connected to each other. The streak 51d can be configured, and the labor and cost required for construction can be reduced.

(Embodiment 2)
Next, the second embodiment will be described. The configuration of the second embodiment is substantially the same as the configuration of the first embodiment unless otherwise specified. The configuration substantially the same as the configuration of the first embodiment is the same as that used in the first embodiment. The same reference numerals are attached as necessary, and the description thereof is omitted.

  Below, the structure of the foundation part constructed | assembled with the foundation part construction method which concerns on this Embodiment 2 is demonstrated, and the foundation part construction method itself which constructs the said foundation part is demonstrated for every process later on in order. .

(Constitution)
FIG. 10 is a vertical sectional view showing the base portion 2 according to the second embodiment. As shown in FIG. 10, the foundation portion 2 includes a foundation pile 10, a formwork 20, a footing 30, a backfill portion 40, a foundation portion 80, a slab 60, and a target pillar 70. In addition, since it can comprise similarly to Embodiment 1 about components other than the base part 80, detailed description is abbreviate | omitted and only the structure of the base part 80 is demonstrated below.

(Configuration-foundation part)
The foundation portion 80 is a means that becomes a foundation for supporting the target pillar 70. 11A and 11B are diagrams showing the base portion 80, in which FIG. 11A is a plan view and FIG. 11B is a front view. The base portion 80 is disposed at a substantially central position of the footing 30 in a plan view, and is roughly configured to include a column support portion 81 and a foundation column main reinforcement 82.

(Configuration-foundation-pillar support)
The column support portion 81 is a portion for supporting the target column 70. In the second embodiment, the column support portion 81 includes only the column base portion 81a. As in the first embodiment, the lower support column 51a and the upper support column 51 are provided. The support column 51b is not provided.

  The column base part 81a serves as a base on which the target column 70 is placed and serves as a connection part between the slab 60 and the target column 70, and is placed directly on the upper surface of the footing bottom 33 as shown in FIG. Has been. Here, the height of the column base portion 81 a is formed to be substantially the same as the height from the upper surface of the footing bottom portion 33 to the upper surface of the slab 60. Therefore, in the vicinity of the upper end of the column base part 81 a, the entire surface of the four sides is in contact with the slab concrete 62, and the remaining most part of the entire surface of the four sides is in contact with the footing main body 34 of the footing 30. The shape of the column base part 81a is arbitrary, and for example, it may be a columnar body having the same planar shape as the target column 70 (circular in the second embodiment), or a plane different from the target column 70. It may be a columnar body having a shape. However, in the second embodiment, description will be made on the assumption that the planar view is formed in a rectangular parallelepiped shape.

  Here, the column support part internal reinforcement 81b is provided at the upper end of the column base part 81a. As shown in FIG. 11 (a), the column support portion internal reinforcement 81b includes a plurality of reinforcing bars that pass through the column base portion 81a along the front-rear direction and a plurality of bars that pass through the column base portion 81a along the width direction. These rebars are arranged at different heights so as not to cross each other. Each of these reinforcing bars and the foundation column main reinforcement 82 penetrating the column base 81a up and down are also arranged so as not to cross each other.

  Further, at both ends of each column support portion internal muscle 81b (that is, a position close to the side surface of the column base portion 81a), a female screw portion is formed, and an end portion of the slab muscle 61 described later is connected to the female screw. The column support portion internal reinforcement 81b and the slab reinforcement 61 can be connected to each other by being screwed to the portion. A detailed description of this point will be described later.

  Further, a fine cotter (unevenness) (not shown) is provided on the entire side surface of the column base portion 81a in contact with the footing main body 34. This cotter is a surface area increasing means for increasing the surface area of contact between the column base part 81a and the footing main body part 34 to more firmly fix the column base part 81a. For example, the surface of the column base part 81a has fine scratches. It can be easily formed by attaching etc. In addition, for example, a cotter may be formed on the column base part 81a by forming the column base part 81a by providing irregularities on the mold itself when generating the column base part 81a.

(Structure-foundation part-foundation pillar main reinforcement)
The base column main reinforcement 82 is a connection means for connecting the footing 30 and the target column 70 to each other. The foundation column main reinforcement 82 is a plurality of reinforcing bars arranged so as to vertically pass through the column base 81a, and protrudes from the column base 81a at the upper end and the lower end, and the upper surface of the footing bottom 33 at the lower end. And is formed in a substantially L shape as a whole. In addition, the part which protruded further upwards from the upper surface of the column base part 81a in the base part column main reinforcement 82 is hereafter called the "base part column main reinforcement protrusion part 83". In the second embodiment, the base column main reinforcement 82 is substantially L-shaped in order to secure the contact area with the concrete. However, if a sufficient contact area can be ensured, the base column The main muscle 82 may be a straight muscle.

(Foundation method)
Then, the foundation part construction method which constructs said foundation part 2 is demonstrated in detail, referring a figure. FIGS. 12 to 16 are vertical cross-sectional views showing structures constructed in the respective steps of the foundation construction method according to the second embodiment. FIG. 12 shows step 1 and FIG. FIG. 14 is a vertical sectional view showing the structure constructed in step 3, FIG. 15 in step 4, and FIG.

(Foundation method-foundation pile formation process)
First, step 1 shown in FIG. 12 is performed. Specifically, first, the foundation pile 10 is formed by the same method as in the first embodiment, and then the soil above the foundation pile 10 is excavated to form a space for forming the footing 30.

(Foundation construction method-formwork forming process)
Then, the leveled concrete 21 is placed on the bottom of the excavated earth and sand. When the leveled concrete 21 is solidified, the mold 20 is formed on the leveled concrete 21. At this time, the mold 20 is formed so that the upper end of the foundation pile concrete 11 and the fixing reinforcement 12 are included in the mold 20.

(Foundation construction method-foundation installation process)
Next, the footing main bar 31 is installed inside the mold 20, the backfill 40 is formed on the side of the mold 20, and the footing bottom 33 is formed on the bottom of the mold 20. As in the first embodiment, the backfill portion 40 may be formed at a timing after the footing 30 shown in FIG. 10 is formed. Finally, the base 80 is placed on the upper surface of the footing bottom 33.

(Foundation part construction method-footing side reinforcement installation process, formwork filling process, pillar construction process, slab formation process, pillar support part internal reinforcement connection process)
Subsequent steps can be performed in the same manner as in the first embodiment. That is, first, as shown in step 2 shown in FIG. Next, as shown in step 3 shown in FIG. 14, concrete is poured into the mold 20 so as to be filled from the footing bottom 33 to the opening of the mold 20 to form the footing main body 34. Since the side surface of the column base part 81a is provided with a plurality of fine cotters as described above, the column base part 81a can be firmly attached to the footing main body part 34. Next, as in step 4 shown in FIG. 15, the target column 70 is placed on the column base 81a. The step 4 can be performed without waiting for the concrete cast in the step 3 to solidify to the reference strength. Next, as in step 5 shown in FIG. 16, a plurality of slab bars 61 are arranged, and a part of the slab bars 61 is screwed into a female screw part formed on the side surface of the column base part 81a. By joining, it joins with the column support part internal reinforcement 81b. Finally, a slab concrete 62 is placed so as to cover the slab reinforcement 61 to form a slab 60, thereby completing the foundation portion 2 shown in FIG.

(Effect of Embodiment 2)
Thus, according to the foundation construction method of the second embodiment, as the column support portion 81, the column base portion 81a extending from the upper surface of the footing bottom 33 to the upper side of the opening surface of the mold frame 20 is provided. The column base part 81a can be configured with higher strength, and the target column 70 can be supported more stably.

[Modifications to Embodiment]
Although the first and second embodiments according to the present invention have been described above, the specific configuration and means of the present invention are arbitrarily modified and modified within the scope of the technical idea of each invention described in the claims. It can be improved. Hereinafter, such a modification will be described.

(About problems to be solved and effects of the invention)
First, the problems to be solved by the invention and the effects of the invention are not limited to the above contents, and may vary depending on the implementation environment and details of the configuration of the invention. May be solved, or only some of the effects described above may be achieved. For example, even if the construction period cannot be shortened compared with the conventional foundation construction method by the foundation construction method according to each embodiment, The problems of the invention have been solved.

(About dimensions and materials)
The dimensions, shapes, ratios, and the like of the respective portions of the basic portions 1 and 2 described in the detailed description of the invention and the drawings are merely examples, and other arbitrary dimensions, shapes, ratios, and the like can be used.

(About the column base)
In each embodiment, it has been described that the positions of the upper ends of the column base portions 51c and 81a coincide with the position of the upper surface of the slab 60. However, the present invention is not limited to this. For example, if the column bases 51c and 81a may be exposed above the slab 60 after the slab 60 is constructed, the positions of the upper ends of the column bases 51c and 81a are higher than the upper surface of the slab 60. It does not matter if it is located. Even in this case, the column base portions 51c and 81a can be made inconspicuous by matching the shape of the column base portions 51c and 81a with the shape of the target column 70. Further, the positions of the upper ends of the column base portions 51 c and 81 a may be positioned below the upper surface of the slab 60. However, in this case, when the slab concrete 62 is placed, the column base portions 51c and 81a are buried in the slab concrete 62, and the target column 70 cannot be placed on the column base portions 51c and 81a. Therefore, it is necessary to place the target column 70 on the column bases 51c and 81a before placing the slab concrete 62.

  In the configuration of the first embodiment, the column base 51c may be omitted. That is, the target column 70 may be placed directly on the upper support column 51b. When the column base portion 51c is omitted in this way, the lower end portion of the target column 70 comes into contact with the slab 60, but, similar to the column support portion internal reinforcement 51d according to the first embodiment, It is possible to improve the strength of the target column 70 by arranging a reinforcing bar having a female screw part at the lower end and connecting the reinforcing bar and the slab bar 61 to each other.

  Further, by providing a cotter on the four side surfaces of the column base 51c of the first embodiment in the same manner as the column base 81a of the second embodiment, the surface area of the portion in contact with the slab concrete 62 in the column base 51c is reduced. The column base 51c can be more firmly fixed. Similarly, cotters may also be provided on the four side surfaces of the portion that contacts the slab concrete 62 in the column base portion 81a of the second embodiment.

  Moreover, in each embodiment, although the column base parts 51c and 81a and the object pillar 70 were formed as mutually different members, you may form these as an integral member. For example, when the floor height is low, a column having a sufficient height can be obtained simply by installing only the integral member.

(About lower support pillar and upper support pillar)
In the first embodiment, the lower support column 51a and the upper support column 51b are formed as separate members in order to improve workability, but they may be integrally formed. Further, a mechanism for adjusting the height of the lower support column 51a or the upper support column 51b may be provided. For example, a plate-like body is disposed below the lower support column 51a or above the upper support column 51b to adjust the height. You may do it. Moreover, the hole for inserting the anchor in the lower support column 51a or the upper support column 51b may be a long hole so that the position can be finely adjusted.

(About Slab)
In each embodiment, the slab 60 is described as being formed. However, the slab 60 may not be formed.

(About the bottom of the footing)
In each embodiment, the footing bottom 33 is placed and the foundations 50 and 80 are installed on the footing bottom 33. However, the present invention is not limited to this, and the footing bottom 33 is not placed. Also good. FIGS. 17 to 19 are vertical cross-sectional views showing the structures constructed in the respective steps of the foundation construction method according to the modification, wherein FIG. 17 is step 1, FIG. 18 is step 2, and FIG. FIG. 3 is a vertical sectional view showing a structure constructed in step 3. In addition, since it is the same as that of each embodiment except the case where it mentions specially about the structure of the foundation part construction method which concerns on this modification, and the foundation part 3 constructed | assembled by the said foundation part construction method, description is abbreviate | omitted suitably. To do.

  First, step 1 shown in FIG. 17 is performed. Specifically, first, the foundation pile 10, the formwork 20, and the backfill portion 40 are formed in the same manner as in each embodiment, and then the lower support pillar 51 a is anchored and fixed to the foundation pile 10. Next, as in step 2 shown in FIG. 18, the upper support column 51b and the like are placed on the lower support column 51a and fixed by a known method. Next, as in step 3 shown in FIG. 19, the footing main body portion 90 is formed by installing the footing main reinforcement 31 and the footing side reinforcement 32 and placing and solidifying the concrete so as to cover them. The footing main bar 31 may be disposed so as to bypass the lower support column 51a, or a hole penetrating the lower support column 51a may be formed and passed through the hole. Further, the subsequent steps are the same as those in the first embodiment, and thus detailed description thereof is omitted. Thus, in this modification, since the lower support pillar 51a is directly fixed to the foundation pile 10 without forming the footing bottom 33 (see FIG. 1), the labor for forming the footing bottom 33 is omitted and the construction period is shortened. It is possible to do. In addition, in this modification, although demonstrated as what connects the foundation part 50 which concerns on Embodiment 1 to the foundation pile 10, not only this but the foundation part 80 which concerns on Embodiment 2 is connected to the foundation pile 10. May be.

(About column support section internal muscle)
In each embodiment, although column support part internal reinforcement 51d and 81b were demonstrated as what is connected to slab reinforcement 61, it is not restricted to this. For example, the column support portion internal muscles 51d and 81b may be connected to the footing upper end muscle formed above the footing 30, or may be connected to both the slab muscle 61 and the footing upper end muscle. Further, when sufficient strength can be ensured without performing such connections, the column support portion internal bars 51d and 81b are not connected, or the column support portion internal bars 51d and 81b are provided. It does n’t matter if you do n’t. In this case, the slab muscle 61 and the footing upper end muscle are distributed to the front, rear, left and right of the column base portions 51c and 81a, or the slab muscle 61 and the footing upper end muscle are arranged so as to bypass the column base portions 51c and 81a. Also good.

(Appendix)
The foundation part construction method of Supplementary Note 1 is a foundation part construction method for constructing a foundation part including a target column made of precast concrete through which a column main reinforcement is inserted, and a footing that supports the target pillar. A mold for footing, a mold forming process for forming a mold having an opening surface on the upper surface, a column support for supporting the target column, and the column support along the vertical direction. A foundation installation step of installing a foundation part comprising a foundation pillar main reinforcement having a foundation pillar principal reinforcement protruding upward from the pillar support part at the bottom of the footing, The concrete was placed so as to be filled up to the opening surface of the formwork, and placed in the formwork filling process for constructing the footing, before the formwork filling process, or in the formwork filling process. Concrete is standard Before solidifying to a certain strength, the target column is placed on the upper surface of the column support portion, and the column main reinforcement of the target column and the base column main reinforcement protrusion of the base column main reinforcement are connected to each other And a construction process.

  The foundation part construction method according to appendix 2 is the foundation part construction method according to appendix 1, wherein the column support part includes a support column and a column base made of precast concrete placed on the support column. The foundation column main reinforcement is inserted through the column base along the vertical direction, and in the base installation step, the bottom surface of the support column is in contact with the bottom of the footing, and at least a part of the column base is The base portion is installed so as to be positioned above the opening surface of the mold.

  The foundation part construction method of appendix 3 is the foundation part construction method of appendix 1, wherein the column support part is provided with a column base part made of precast concrete, and the foundation part column main reinforcement is vertically arranged on the column base part. In the base installation step, the bottom surface of the column base is in contact with the bottom of the footing, and at least a part of the column base is positioned above the opening surface of the mold, The foundation is installed.

  The foundation part construction method according to appendix 4 is the foundation part construction method according to any one of appendices 1 to 3, wherein a slab reinforcement is installed above the formwork, and a concrete having a predetermined thickness so as to cover the slab reinforcement. A slab forming step in which a slab is formed by placing the slab so that the upper surface of the column support portion is located on the same plane as the upper surface of the slab or above the upper surface of the slab. The base portion is installed, and the column construction process is performed before the slab forming process or before the concrete cast in the slab forming process is solidified to a standard strength.

  The foundation part construction method according to supplementary note 5 is the foundation part construction method according to any one of supplementary notes 1 to 4, wherein a column support part formed inside the pillar support part in the vicinity of the upper end part of the pillar support part. A column support part internal muscle connecting step that includes an internal line and connects the column support part internal line and a footing upper end line formed above the footing or a slab line formed above the formwork. including.

(Additional effects)
According to the foundation construction method described in appendix 1, since the base portion that can support the target column is provided, before the mold filling process or the concrete cast in the mold filling process is solidified to the reference strength In this case, the target pillar can be constructed, and the construction period of the foundation can be greatly shortened. In addition, since the foundation can be constructed without using PCa footings, the labor and expense of bringing large PCa parts into the construction site and the labor and expense of using large heavy machinery at the construction site are eliminated. It becomes possible to reduce.

  According to the foundation construction method described in appendix 2, a part of the column support part is constituted by the support column, and the remaining part is constituted by the column base part made of precast concrete. Therefore, the entire column support part is precast concrete. The column support portion can be reduced in weight as compared with the case where it is made, and the labor required for carrying in the column support portion can be reduced. Moreover, since a space is formed around the support column as compared with the case where the entire column support part is made of precast concrete, it is possible to improve the degree of freedom of the bar arrangement.

  According to the foundation construction method described in appendix 3, the bottom surface of the column base is in contact with the bottom of the footing, and at least a part of the column base is positioned above the opening surface of the formwork. Since the base portion is installed, the column base portion can be configured with higher strength, and the target column can be supported more stably.

  According to the foundation construction method described in appendix 4, since the upper surface of the column support portion is located on the same plane as the upper surface of the slab or above the upper surface of the slab, the slab formation or before the slab formation step The target column can be constructed before the concrete cast in the process is solidified to the standard strength, and the construction period can be greatly shortened. In addition, when the target column is constructed before the slab formation process, the target column can be constructed without causing the slab to bear the load of heavy equipment for constructing the target column, and the labor for reinforcing the slab may be omitted. It becomes possible.

  According to the foundation part construction method described in appendix 5, because the column support part internal reinforcement and the footing upper end reinforcement formed above the footing or the slab reinforcement formed above the formwork are connected to each other, It is possible to improve the strength of the target column, slab, and column support.

1, 2, 3 Foundation part 10 Foundation pile 11 Foundation pile concrete 12 Anchor reinforcement 20 Formwork 21 Leveling concrete 30 Footing 31 Footing main reinforcement 32 Footing side reinforcement 33 Footing bottom part 34 Footing main part 40 Backfill part 50 Base part 51 Column support 51a Lower support column 51b Upper support column 51c Column base 51d Column support internal reinforcement 52 Base column main reinforcement 53 Base column main reinforcement protrusion 60 Slab 61 Slab reinforcement 62 Slab concrete 70 Target column 71 Column main reinforcement 80 Base 81 Column Support part 81a Column base part 81b Column support part internal reinforcement 82 Foundation part column principal reinforcement 83 Foundation part column principal reinforcement protrusion 90 Footing main part 100 Foundation part 110 Footing 111 Footing principal part 112 Footing bottom part 113 Footing main part 120 Formwork 130 Base part column Main reinforcement 140 Base 150 Template 160 Sura 161 slab muscle 162 slab concrete 170 target columns 171 poster main reinforcement

Claims (5)

A foundation part construction method for constructing a foundation part including a target column made of precast concrete through which a column main reinforcement is inserted, and a footing that supports the target pillar,
A mold forming step for forming a mold for the footing and forming a mold having an opening on the upper surface;
A column support for supporting the target column; and a base column main reinforcement inserted through the column support along the vertical direction, the base column main reinforcement projecting portion protruding upward from the column support. A foundation installation step of installing a foundation portion comprising a foundation pillar main reinforcement having a bottom portion of the footing;
Placing the concrete so as to be filled up to the opening of the mold, and filling the mold with the footing;
Before the mold filling step, or before the concrete cast in the mold filling step is solidified to a standard strength, the target column is placed on the upper surface of the column support portion, and the target column A column construction step for connecting the column main reinforcement of the base portion and the base column main reinforcement protrusion of the foundation column main reinforcement to each other,
Foundation construction method. The column support portion includes a support column and a column base made of precast concrete placed on the support column,
The base column main reinforcement is inserted through the column base along the vertical direction,
In the base installation step, the base portion is installed such that a bottom surface portion of the support column is in contact with a bottom portion of the footing and at least a part of the column base portion is positioned above an opening surface of the formwork. ,
The foundation part construction method according to claim 1. The column support portion includes a column base made of precast concrete,
The base column main reinforcement is inserted through the column base along the vertical direction,
In the base installation step, the base portion is installed such that a bottom surface portion of the column base portion is in contact with a bottom portion of the footing, and at least a part of the column base portion is positioned above an opening surface of the formwork. To
The foundation part construction method according to claim 1. Including a slab forming step of forming a slab by placing slab reinforcement above the mold and placing concrete of a predetermined thickness so as to cover the slab reinforcement;
In the base installation step, the base portion is installed such that the upper surface of the column support portion is located on the same plane as the upper surface of the slab or above the upper surface of the slab,
The column construction step is performed before the slab formation step or before the concrete cast in the slab formation step is solidified to a reference strength.
The foundation part construction method according to any one of claims 1 to 3. In the vicinity of the upper end portion of the column support portion, a column support portion internal line formed inside the column support portion is provided,
A column support part internal reinforcement connecting step of mutually connecting the column support part internal reinforcement and a footing upper end reinforcement formed above the footing or a slab reinforcement formed above the mold;
The foundation part construction method according to any one of claims 1 to 4.

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