JP3682504B2 - Building foundations and construction methods - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a building foundation and its construction method.
[0002]
[Prior art]
The foundation of the steel structure is generally constructed from reinforced concrete, and a cloth foundation or a solid foundation is used. In other words, the entire foundation concrete supports the horizontal force at the time of the earthquake, and transmits the vertical load of the entire building to the ground through the foundation. In this case, in a three-story steel-framed house, the overall weight of the building body and the foundation is large, so that it is impossible to support a vertical load only by providing a cloth foundation or a solid foundation in a weak ground. For this reason, in such an area, the foundation is usually reinforced with a pile driven into the ground.
[0003]
[Problems to be solved by the invention]
However, the method of reinforcing concrete foundations with piles has the disadvantage that the number of piles increases because the foundation itself is heavy. Moreover, the ground has to be excavated along the foundation by about 1 m to place concrete, which causes a problem of a large amount of residual soil treatment, which increases the cost. In addition, since the number of piles required is not determined without a geological survey, there is a problem that it takes time to estimate.
[0004]
The present invention eliminates such conventional drawbacks and significantly reduces the weight of the entire foundation, thereby greatly reducing the number of piles and the amount of residual soil processing, thereby enabling construction at low cost. It was made for the purpose of providing the foundation and its construction method.
[0005]
[Means for Solving the Problems]
In order to solve the above problems, the basis of the present invention is to support a horizontal force with a steel base beam connecting between the column bases, and with a pile provided corresponding to the column bases, a vertical load from the column bases The foundation concrete placed to cover the periphery of the top end of the pile is placed between the column base and the pile, and the column base and the foundation concrete are fastened using anchor bolts. And anchors that are projected downward from the lower ends of the column bases in advance are buried in and connected to the foundation concrete.
[0008]
Similarly, the construction method of the present invention for solving the above-mentioned problem is that a pile is placed corresponding to the position of each column base and the column base is connected with a steel foundation beam, and then the upper end of the pile and the column Between the legs, foundation concrete is placed so as to cover the periphery of the upper end of the pile, and the column base and the foundation concrete protrude downward downward in advance from the lower end of the column base without being fastened with anchor bolts. It is characterized by burying and connecting the anchors to the foundation concrete.
[0009]
Furthermore, in the invention of claim 3 of this application, there is provided one in which the foundation concrete and the soil concrete are cast together.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
1 and 2, (1) is a column base made of a square steel pipe, and a short bracket (2) made of H-shaped steel is attached to the flange (3) at the lower end portion of the column base (1). ) And (3) are fixed by welding at one end so that they are parallel in the vertical direction. In this case, plates (4) and (5) corresponding to the flanges (3) and (3) are fixed to the column base (1) at the lower end surface and the intermediate portion in advance, and the web of the bracket (2) (6) is welded to the side surface of the column base (1), and the flanges (3) and (3) are welded to the corresponding plates (4) and (5).
[0011]
(7) is a base beam made of H-shaped steel having the same cross section as the bracket (2). The end of the base beam (7) is abutted against the end of the bracket (2), and the base beam ( The web (8) of 7) and the web (6) of the bracket (2) are joined to the flange (10) (10) of the base beam (7) and the flange (3) of the bracket (2) by the vertical joining plate (9). 3) are joined by bolts (12), (12), respectively, by horizontal joining plates (11), (11),. A short anchor (13) is provided at the center of the lower surface of the plate (5) at the lower end surface of the column base (1) so as to protrude vertically downward.
[0012]
The foundation beam (7) is installed in a state slightly raised from the ground surface without excavating the ground. Although not shown, a horizontal brace is provided in the inner part surrounded by the base beam (7).
[0013]
(14) is a foundation pile, which is driven into the ground corresponding to the column base (1), and as shown in FIG. The foundation concrete (15) is placed in the groove (20) excavated in the periphery, and the anchor (13) is embedded in the foundation concrete (15).
[0014]
(16) is interstitial concrete placed on the ground surface surrounded by the foundation beam (7) at the lower part of the foundation beam (7), and is placed at the same time as the foundation concrete (15). Is. Furthermore, decorative concrete (17) is provided so as to cover the outer periphery of the base beam (7) and the column base (1), and this decorative concrete (17) is also made of soil concrete (16) and foundation concrete. (15) At the same time, it will be cast together. (10) shows a reinforcing bar arrangement embedded in the foundation concrete (15).
[0015]
Next, the structure of the foundation constructed as described above will be explained according to the construction sequence. First, the groove (20) in the peripheral portion of the foundation pile (14) to be placed corresponding to the column base (1) is excavated. After that, each foundation pile (14) is driven or the rear groove (20) into which the foundation pile (14) is driven is excavated. Pile driving methods include a method of driving directly into the ground and a method of inserting into a previously formed hole and solidifying the periphery with concrete or the like.
[0016]
Next, as shown in FIGS. 2 and 3, the column base (1) and the base beam (7) are joined together using the joining plates (9) and (11), and the column base (1) A lower end is installed above the pile (14) in a state of floating from the pile (14), and further, a horizontal brace (not shown) is provided inside the foundation beam (7). In this state, the necessary temporary frames for placing concrete are provided, and reinforcing bar reinforcement (19) is applied. As shown in Fig. 4, the foundation concrete (15) part and soil concrete (16), and the outer periphery Of decorative concrete (17).
[0017]
In addition, the floor is attached by providing a direct draw between the base beams (7). Moreover, the column base (1) is about 1 meter high as shown in the figure, and the column work on the column side is connected to the upper end of the column base (1).
[0018]
【The invention's effect】
As described above, according to the present invention, since the foundation portion that has been conventionally cast by concrete is constituted by a steel base beam, the weight of the entire building is much longer than that of a concrete foundation member. It is not necessary to drive foundation piles that support this foundation weight. For this reason, since the foundation pile only needs to support the weight of the building main body transmitted via the column base, it is only necessary to drive it into a position corresponding to this column base portion, and the number of piles is greatly reduced.
[0019]
On the other hand, the foundation beam made of steel does not need to be lower than the ground like the foundation, so the residual soil treatment by excavation is greatly reduced, and the amount of residual soil is about 1/6 to 1/8 compared to the conventional fabric foundation Thus, in conjunction with the reduction in the number of piles, construction can be performed at a cost that is almost the same as or lower than that of the conventional solid foundation alone. In addition, the cost estimate can be presented to the customer in a short time.
[0020]
Normally, foundation concrete is placed between the pile head and the column base, but this foundation concrete only transmits the vertical load from the column base to the pile. It is not necessary to fix the legs, it is only necessary to embed one anchor welded to the column base in the foundation concrete, and it does not require strict positional accuracy such as positioning of the anchor bolt and the bolt hole of the column base. In this respect, the cost can be reduced.
[0021]
In addition, since it is possible to excavate the soil part, the underground storage and the basement can be easily provided at a cost equivalent to that of the solid foundation.
[Brief description of the drawings]
FIG. 1 is a longitudinal sectional view of a column base portion in an embodiment of the present invention.
FIG. 2 is a perspective view of a column base portion before foundation concrete is similarly placed.
FIG. 3 is an overall perspective view of the foundation before foundation concrete is similarly placed.
FIG. 4 is a perspective view of the entire foundation after foundation concrete placement.
[Explanation of symbols]
(1) Column base
(7) Foundation beam
(13) Anchor
(14) Foundation pile
(15) Foundation concrete

Claims (3)

While supporting the horizontal force with the steel base beam connecting each column base, and supporting the vertical load from the column base with the pile provided corresponding to the column base, between the column base and the pile, An anchor that has been placed to cover the periphery of the upper end of the pile and anchored in advance downward from the lower end of the column base, without anchoring the column base and the basic concrete using anchor bolts. A building foundation characterized by being embedded in and connected to foundation concrete. After placing the piles corresponding to the position of each column base and connecting each column base with a steel base beam, cover the periphery of the pile upper end between the pile upper end and the column base. The foundation concrete is cast and the column base and the foundation concrete are connected to each other by burying the anchor that protrudes downward in advance from the lower end of the column base into the foundation concrete without using an anchor bolt. Foundation construction method.   The foundation construction method according to claim 2, wherein the foundation concrete is cast together with the soil concrete.

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