JP2017203302A - Construction method of composite foundation structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a construction method, comparatively easy in arrangement work of a steel frame foundation, and capable of efficiently constructing a composite foundation structure having a plurality of independent base concrete footing.SOLUTION: A construction method of a composite foundation structure having a plurality of independent base concrete footing 2, a column lower steel frame part 4 fixed to the respective independent base concrete footing 2 and a steel frame foundation beam 5 for connecting the mutual column lower steel frame parts 4, comprises a first step of arranging a plurality of column lower steel frame parts 4 in a predetermined position floated from the ground surface 1 side, a second step of connecting by extending the steel frame foundation beam 5 between the plurality of column lower steel frame parts 4 arranged in a predetermined position and a third step of constructing the independent base concrete footing 2 in a state of fixing the respective column lower steel frame parts 4 by placing concrete on the lower side of the plurality of column lower steel frame parts 4 connected by the steel frame foundation beam 5.SELECTED DRAWING: Figure 2

Description

  In the present invention, a plurality of independent foundation concrete footings, a steel pillar part of a steel foundation fixed on the upper surface side of each foundation foundation footing, and a plurality of steel parts below the pillar are connected to each other. The present invention relates to a method for constructing a composite foundation structure including a steel foundation beam.

In such a composite foundation structure, so-called foundation rising parts and foundation beams fixed on the upper surface side of the foundation concrete footing are steel foundations composed of steel frames, so the foundation rising parts and foundation beams are composed of concrete. Compared to the structure, the construction period can be reduced and the number of labors can be reduced.
And, as a method of constructing such a composite foundation structure, conventionally, the under-column steel part of the steel foundation and the steel foundation beam are integrated in advance, and the integrated steel foundation is placed at a predetermined position floating from the ground surface. In this state, a method is known in which concrete is placed on the lower side of the steel foundation to construct a fabric foundation concrete footing (see, for example, Patent Document 1).

Japanese Patent Laid-Open No. 2001-146752 (see FIGS. 1 to 3 in particular)

  However, in the construction method described in the above-mentioned patent document, the steel foundation that is transported to the site and arranged at a predetermined position is integrally provided with the steel part under the pillar and the steel foundation beam. In each supporting steel part under the pillar, it is difficult to adjust the posture of the steel part under the pillar (level adjustment, building adjustment, etc.), and it is difficult to place the steel foundation part. It can be difficult.

  The present invention pays attention to such conventional problems, and its purpose is to relatively easily arrange the steel foundation, and to efficiently construct a composite foundation structure having a plurality of independent foundation concrete footings. It is to provide a construction method that can be constructed.

A first characteristic configuration of the present invention includes a plurality of independent foundation concrete footings, a steel base portion of the steel foundation fixed on the upper surface side of each independent foundation concrete footing, and a space between the plurality of bottom steel frames. A method for constructing a composite foundation structure including a steel foundation beam to be connected together,
A first step of disposing the plurality of columnar steel frame portions at a predetermined position floating from the ground surface side;
A second step of connecting the steel foundation beams across the plurality of under-column steel parts disposed at the predetermined positions;
A point is provided with a third step of constructing the independent foundation concrete footing in a state in which concrete is placed on the lower side of the plurality of under-column steel parts connected by the steel foundation beam to fix each under-column steel part. It is in.

According to the above configuration, the under-column steel part and the steel foundation beam that make up the steel foundation are separate from each other in an unconnected state. Therefore, compared to those in which the under-column steel part and the steel foundation beam are integrated. Thus, the posture adjustment (level adjustment, building adjustment, etc.) of the lower column steel frame part is easy, and even a delicate posture adjustment can be easily performed.
In the first step, a plurality of under-column steel parts are arranged at predetermined positions floating from the ground surface side, and then in a second step, the steel foundation beams are connected between the plurality of under-column steel parts. Therefore, during this connection work, the steel foundation beam can be used as a posture holding member for the steel column part under the column, and the posture of each steel column part under the column after posture adjustment can be reliably and efficiently performed. it can.
After that, in the third step, the concrete is placed on the lower side of each column steel part and the independent foundation concrete footing is constructed in a state where each column steel part is fixed. It is possible to efficiently construct the composite foundation structure provided.

  The second characteristic configuration of the present invention is that, in the second step, at least three of the under-column steel parts are connected by a plurality of the steel foundation beams having different beam length directions.

According to the above configuration, in the second step, three or more under-column steel parts are connected by at least a plurality of steel foundation beams having different beam length directions. For example, three under-column steel parts are connected. In this case, when four steel pillar parts are connected to the corners of the triangle in plan view, they can be arranged so as to be located at the corners of the rectangle or at the intersections with the T-shaped ends. it can.
Therefore, it is possible to more reliably and efficiently maintain the posture of each steel part under the column, and also to maintain the posture of the steel foundation beam that connects the steel parts under each column, including the subsequent third step. As a result, it becomes possible to construct a composite foundation structure more efficiently as a whole.

According to a third characteristic configuration of the present invention, in the first step, a temporary support member is installed between the columnar steel part and the ground surface side, and each columnar steel part is disposed at the predetermined position in a predetermined posture. ,
In the second step, the temporary support member is removed after the plurality of under-column steel frame portions are connected by the steel foundation beam.

According to the above configuration, in the first step, the temporary support member is installed between the columnar steel part and the ground surface side, and each columnar steel part is arranged in a predetermined posture at a predetermined position. It is possible to easily and efficiently connect the steel foundation beam to the site.
In the second step, the temporary support material is removed after the sub-column steel parts are connected to each other with the steel foundation beam, so the temporary support material is not embedded in the independent foundation concrete footing. The cross-sectional defect of the footing can be avoided, and the cost can be reduced by reusing the temporary support material.

  According to a fourth characteristic configuration of the present invention, in the second step, the temporary support member is removed after connecting at least three of the columnar steel frame portions with a plurality of the steel foundation beams having different beam length directions. The process of reusing the removed temporary support material as the temporary support material in the first step at the subsequent construction site is repeated.

According to the above-described configuration, in the second step, at least three columnar steel parts are connected by a plurality of steel foundation beams having different beam length directions. By maintaining the posture of the foundation beam, and then removing the temporary support material, even if the temporary support material is removed, it is possible to securely hold the steel parts under the columns and the steel foundation beam in place. it can.
And since the process of reusing the removed temporary support material as the temporary support material in the first step at the subsequent construction site is repeated, the number of temporary support materials required for the work is greatly reduced, and further cost reduction is achieved. Can be planned.

Perspective view showing composite foundation structure Partial longitudinal front view showing how to construct a composite foundation Perspective view showing how to construct composite foundation structure

An embodiment of a method for constructing a composite foundation structure according to the present invention will be described with reference to the drawings.
For example, as shown in FIG. 1, the composite foundation structure according to the present invention has a plurality of independent foundation concrete footings 2 made of reinforced concrete installed on the ground surface 1, and upper surfaces of the plurality of independent foundation concrete footings 2. It is provided with a steel frame base 3 made of steel frame to be fixed.
The steel foundation 3 is fixed to the upper surface of each independent foundation concrete footing 2 and supports a pillar steel part 4 supporting a pillar of a building (not shown) and a steel frame connected between the steel pillar parts 4 under the pillar. It is composed of a foundation beam 5 and, if necessary, a small beam (not shown) that connects the steel foundation beams 5 to each other. For this purpose, a plurality of connecting steel frame parts 4a are continuously provided in a state of protruding laterally.

As shown in FIG. 2, for example, temporary pillars 6 made of iron pipe are respectively installed between each columnar steel frame part 4 and the ground surface 1. Each temporary support column 6 is fixed by a plurality of construction anchor bolts 7 embedded in the ground surface 1 through a flange 6a continuously provided on the lower surface.
A large number of studs 8 each having a head at the tip protrude downward from the lower surface of each columnar steel frame part 4 and the lower surface of the connecting steel frame part 4a. In an embedded state, an independent foundation concrete footing 2 made of reinforced concrete is constructed under each column steel part 4.

Next, a method for constructing this composite foundation structure will be described.
Referring to FIG. 2 (a), first, the construction ground part of the composite foundation structure is excavated, the ground surface 1 is constructed by placing the discarded concrete after the ground improvement, and the anchor bolt is placed at a predetermined position after marking. 7 is buried. When the ground is improved as described above, it is preferable that the anchor bolt 7 is embedded in the ground in a state where the anchor bolt 7 is embedded in the ground improvement portion in order to hold the construction anchor bolt 7 firmly. Thereafter, the under-column steel part 4 in which the temporary support column 6 and the stud 8 are continuously arranged downward is arranged at a predetermined position, and temporarily supported between the connecting steel part 4 a of the under-column steel part 4 and the ground surface 1. A jack 9 as a material is installed, the temporary support column 6 is fixed by the anchor bolt 7, and the under-column steel frame members 4 are arranged at predetermined positions in a predetermined posture.
In addition, regarding the horizontal level of each column steel member 4, it is performed using level adjusting means (not shown) such as mortar previously constructed on the ground surface 1 for level adjustment, and has a predetermined structure. Adjustment and maintenance of the posture is performed using a jack 9 that can be fixed and expanded.
In this way, in the first step of the construction method, as shown in FIG. 2A, the plurality of under-column steel frame parts 4 are arranged in a predetermined posture at a predetermined position floating from the ground surface 1 side.

In the second step after the end of the first step, as shown in FIG. 2 (b), the steel foundation beam 5 is placed between the plurality of columnar steel parts 4 arranged in a predetermined position at a predetermined position, for example, Then, the connecting steel plate 4 and the bolt / nut 11 are used to connect and fix the connecting steel part 4a of the under-column steel part 4 and the end of the steel foundation beam 5, and then the jack 9 is removed.
When the steel foundation beam 5 is connected, as shown on the right side of FIG. 3, four under-column steel parts 4 are connected by a plurality of steel foundation beams 5 whose beam length directions are orthogonal to each other. It is preferable that the steel foundation 3 composed of 4 and the steel foundation beam 5 is sequentially connected while being rectangular in plan view. That is, by connecting the steel foundation 3 so as to be rectangular in plan view, the posture of each columnar steel member 4 located at the corner is stabilized, and even after the jack 9 is removed, the columnar steel part 4 and the steel frame are removed. The posture maintenance of the foundation beam 5 is ensured.

In the third step after the completion of the second step, although not shown in the drawing, reinforcing bars are arranged around the lower side of each column steel part 4 and concrete is placed by placing a concrete formwork. Then, a large number of studs 8 protruding from the lower surfaces of the under-column steel part 4 and the connecting steel part 4a are embedded in the concrete to fix the under-column steel part 4.
In this way, in the third step, as shown in FIG. 2 (c), the independent foundation concrete footing 2 is constructed in a state where each column steel part 4 is fixed to the lower side of each column steel part 4. is there.
And the jack 9 removed in the second step, for example, as shown in FIG. 3, in the first step in the subsequent construction site (the construction site on the upper left side in FIG. 3) It is reused as a new jack 9 for maintaining the posture, and a composite foundation structure is constructed while repeating these steps.

[Another embodiment]
(1) In the previous embodiment, in the first step, the jack 9 as a temporary support member is installed between the under-column steel part 4 and the ground surface 1, and the under-yield steel part 4 is predetermined by the installation of the jack 9. Although the method of adjusting and holding the posture has been described, for example, it is possible to adjust the posture to a predetermined posture when connecting the steel foundation beam 5 and hold the posture by connecting and fixing the steel foundation beam 5.
Therefore, it is not always necessary to install the jack 9 as a temporary support member in the first step, and the jack 9 can be omitted in the first step.

(2) In the previous embodiment, in the second step, the four columnar steel parts 4 are connected by a plurality of steel foundation beams 5 whose beam length directions are orthogonal, and the steel foundation 3 is rectangular in plan view. Although the method of connecting so that it becomes like this, for example, the three underframe steel frame parts 4 are connected by a plurality of steel foundation beams 5 having different beam length directions so that the steel foundation 3 becomes a triangle in plan view. In addition, it is also possible to connect the four columnar steel frame parts 4 so as to form a T shape in plan view.
In short, it is sufficient to stabilize the postures of the under-column steel part 4 and the steel foundation beam 5 by connecting at least three under-column steel parts 4 with a plurality of steel foundation beams 5 having different beam length directions. is there.

(3) In the previous embodiment, in the second step, the jack 9 as the temporary support member is removed after stabilizing the posture of the columnar steel part 4 and the temporary support in the first step at the subsequent construction part is performed. Although the method of reusing as a material was shown, it is free whether or not to reuse the removed jack 9 at a subsequent construction site.
Further, as described above, the installation of the jack 9 can be omitted in the first step, and the jack 9 can be embedded in the independent foundation concrete footing 2 without being removed. It is not always necessary to remove the jack 9 as a temporary support member in the step, and the removal of the jack 9 can be omitted.

(4) In the previous embodiment, the columnar steel part 4 provided with the connecting steel part 4a for connecting the steel foundation beam 5 was shown as the columnar steel part 4. However, the connecting steel part 4a is provided. It can also be carried out by using the under-column steel part 4 that is not.
And although the example which used the connection iron plate 10 and the volt | bolt nut 11 was shown in order to connect and fix the steel frame part 4 and the steel foundation beam 5, it can also be connected and fixed by welding, for example, Moreover, although the jack 9 was shown as an example of a temporary support material, a rod-shaped body, a tubular body, etc. can also be used as a temporary support material besides the jack 9, for example.

DESCRIPTION OF SYMBOLS 1 Ground surface 2 Independent foundation concrete footing 3 Steel foundation 4 Under-column steel part 5 Steel foundation beam 9 Temporary support material

Claims (4)

A plurality of independent foundation concrete footings, a steel base beam part of a steel foundation anchored on the upper surface side of each independent foundation concrete footing, and a steel foundation beam connected between the plurality of sub pillar steel parts A method for constructing a composite foundation structure comprising
A first step of disposing the plurality of columnar steel frame portions at a predetermined position floating from the ground surface side;
A second step of connecting the steel foundation beams across the plurality of under-column steel parts disposed at the predetermined positions;
A composite comprising a third step of constructing the independent foundation concrete footing in a state in which concrete is placed below the plurality of under-column steel parts connected by the steel foundation beam and the under-column steel parts are fixed. How to build the foundation structure.   The method of constructing a composite foundation structure according to claim 1, wherein in the second step, at least three of the under-column steel parts are connected by a plurality of the steel foundation beams having different beam length directions. In the first step, a temporary support member is installed between the columnar steel part and the ground surface side, and each columnar steel part is arranged in a predetermined posture at the predetermined position,
The construction method of a composite foundation structure according to claim 1 or 2, wherein, in the second step, the temporary support member is removed after the plurality of under-column steel frame portions are connected by the steel foundation beam. In the second step, at least three of the steel base beams having different beam length directions are connected to connect the three or more sub-column steel parts, and then the temporary support material is removed, and the removed temporary support material is followed. The construction method of the composite foundation structure according to claim 3, wherein the process of reusing the temporary support material in the first step at the construction site to be repeated is repeated.

Images