JPH08189044A - Mat foundation structure and method for construction thereof - Google Patents

Abstract

PURPOSE: To construct a mat foundation, especially for a prefabricated housing, through simple work and without requiring deep excavation and to maintain high accuracy. CONSTITUTION: A ground level constituting a mat foundation is subjected to foundation work 21 that matches the strength and quality of the ground, then a self-leveling member 22 is placed on the ground level to construct a level reference plane 23, a PC ground plate A is placed on the reference plane 23, and steel poles B are secured to the plate A and thereby installed on the ground level. The level of the top end of each steel pole B is adjusted, and the steel poles B are connected together by a steel girder C. Reinforcement 24 is placed beneath the girder C, and a form 26 is mounted on the girder C. Concrete is placed on a surface specified by the form 26, so that parts of a flange 7a and of a web 7b beneath the girder C are buried in the concrete, or up to the bottom surface of the flange 7a beneath the girder C. The period of construction work is shortened by erecting the skeleton of an upper building on the steel poles B and the girder C prior to concrete placing.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention mainly relates to a basic structure of a prefabricated house and a construction method thereof.

[0002]

2. Description of the Related Art A solid foundation structure may be adopted as the foundation structure of a prefabricated house. Among them, JP-A-3-
There is a technique disclosed in Japanese Patent Publication No. 199529. This technique relates to a solid foundation using a steel frame, and the foundation beam is configured as a steel frame reinforced concrete structure (SRC structure) composed of steel beams, reinforcing bars, and concrete. This foundation beam is installed so as to be embedded in the ground surface, and a steel beam and a steel beam are connected to each other to form a foundation. This technique is advantageous because it can improve the positional accuracy of the anchor bolt.

[0003]

In the above technique, steel beams and steel beams are directly connected to each other. For this reason, one of the beams arranged orthogonally will win, and there is a possibility that variations in the length of the beam will increase.

Further, the positional accuracy of the anchor bolt is improved as compared with the RC foundation, but in order to secure the level accuracy in the height direction or the accuracy in the horizontal direction, the beams joined after joining the beams are joined. To lift the spacer and pinch the spacer,
There is a risk that adjusting the position is not an easy task.

Further, since the foundation beams are buried under the ground surface, concrete and reinforcing bars for deeply excavating the ground and covering the steel beams are required, which requires a construction period for reinforcing work and concrete placing work and costs There is a possibility that it may become a factor of upswing, or a problem that the construction period will be lengthened because the upper structural frame will be built after the concrete is poured.

It is an object of the present invention to provide a solid foundation structure which does not require deep excavation and can be constructed with a high degree of positional accuracy and a small number of parts, and a construction method which shortens the construction period. .

[0007]

Means for Solving the Problems In order to solve the above problems, a solid foundation structure according to the present invention comprises a steel pole installed on a ground surface constituting a foundation and a steel pole connecting the steel poles. It consists of beams and concrete cast on the ground surface surrounded by steel beams on the outer periphery of the building.

In the above solid foundation structure, a self-leveling material is placed on the ground surface on which the steel pole is installed to form a horizontal reference surface, and a precast concrete base plate is installed on the reference surface, It is preferable to install a steel pole on it.

Further, the construction method of the solid foundation structure is as follows. A steel pole is installed on the ground surface constituting the foundation, the steel poles are connected by a steel beam, and the steel pole or the steel beam is connected to a superstructure frame. After installing, the concrete is placed on the ground surface surrounded by steel beams on the outer circumference of the building to form a solid foundation.

[0010]

In the solid foundation structure described above, the ground surface is excavated, the excavated ground surface is compacted, and a plurality of steel poles are installed at predetermined intervals with respect to the ground surface. It is constructed by placing concrete on the ground surface surrounded by steel beams on the outer circumference of the building.
Therefore, it is possible to construct a solid foundation (hereinafter simply referred to as "foundation") with a simple operation.

Further, a self-leveling material is cast on the ground surface constituting the foundation to form the surface as a horizontal reference surface,
Precast concrete base plate (P
When the C base plate is installed and the steel pole is installed on this PC base plate, the levelness of the reference plane can be guaranteed and the level of the steel pole can be easily guaranteed. .

The steel pole is only fixed to the PC base plate and is not connected to the ground surface. Therefore, it is possible to move the steel pole along with the PC base plate in the horizontal direction on the reference surface on which the self-leveling material is placed, and when connecting the steel beam to the steel pole, If it is necessary to adjust the directional position, the PC base plate can be easily moved and installed in the correct position.

Further, in the above-mentioned construction method, a steel pole installed on a ground surface constituting a foundation or a steel beam connecting the poles is surrounded by a steel beam after an upper structural body is installed. By placing concrete on the ground surface, it becomes possible to advance the method of constructing the superstructure frame in advance, and the construction period can be shortened.

[0014]

EXAMPLES Examples of the basic structure and construction method will be described below with reference to the drawings. FIG. 1 is a sectional view of a main part for explaining the basic structure, FIG. 2 is a developed perspective view for explaining the relationship between a PC base plate, a steel pole, and a steel beam, and FIG. FIG. 4 is a diagram for explaining the steel pole installed on the ground surface, FIG. 5 is a diagram for explaining the mounting structure of the formwork to the steel beam, and FIG. 6 is a basic plan view showing a configuration example of the foundation. Is.

In the foundation structure according to the present invention, the PC base plate A is installed at a plurality of preset positions as shown in the basic floor plan of FIG. 6 according to the upper building, and the PC base plate A is made of steel. After fixing the pole B and connecting the steel girder C between the adjacent steel poles B, the PC base plate A, the steel pole B,
It is constructed by pouring concrete up to a height within the plane defined by the girder C and including a lower flange of the girder C and a part of the web.

As shown in FIG. 3, the PC base plate A is made of precast concrete, and has a bottom plate 1 having a preset size and a mounting portion 2 on which a steel pole B or a girder C is mounted. And is configured. A plurality of reinforcing bars 1a are arranged on the bottom plate 1, and a plurality of insert nuts 2a are embedded in the mounting portion 2 at a predetermined pitch. The insert nut 2a is for fastening the bolt 3 when fixing the steel pole B and the girder C to the PC base plate A.

The base plate on which the steel pole B is installed does not necessarily have to be the PC base plate A formed of the precast concrete shown in this embodiment, and may be formed by using a steel plate or shaped steel. Is also good.

As shown in FIG. 2, the steel pole B is formed to have a height equal to that of the girder C set corresponding to the upper building, and the PC base plate A is placed on the lower end thereof. A flange 4a connected to the section 2 is provided, and a flange 4b for connecting the frame of the upper building is provided at the upper end.
A plurality of webs 5 connecting the girders C are provided in the orthogonal direction between the flanges 4a and 4b. A plurality of bolt holes 6 are formed at predetermined positions on the flanges 4a, 4b and the web 5.

In this embodiment, the steel pole B is constructed by welding ribs to the web of H-shaped steel so that the cross section becomes a cross shape, but other steel materials such as box-shaped steel and C-shaped channel are used. It is also possible to use it as a steel pole by using a material such as steel.

As shown in FIG. 2, the girder C is made of H-shaped steel having a height preset according to design conditions such as weight of the upper building and floor area. A plurality of bolt holes are formed in the flange 7a of the cross beam C at positions corresponding to the PC base plate A, and the web 7b is similarly formed in FIG.
A plurality of bolt holes 8 are formed corresponding to the connection positions of the beam L shown in FIG.

A connecting member 9 for connecting to the steel pole B is attached to the end of the girder C. The connecting member 9 is formed in an L-shape including a joint piece 9a that is joined to the girder C and a joint piece 9b that is connected to the steel pole B and has a bolt hole 9c. And the joint piece 9b is brought into contact with the web 5 of the steel pole B, the bolts 10a are inserted into the bolt holes 9c and 6 of the steel pole B, and the nuts 10b are fastened. It is possible to connect between B.

The connecting member 9 is not limited to the L-shaped connecting member as described above, but a plate-like connecting member 11 having a plurality of bolt holes 11a is formed as shown in FIG.
It is also possible to use.

The basic structure constituted by the members A to C and the construction procedure will be described with reference to FIGS. 1, 4 and 5.

First, the earthwork 21 is performed by excavating the installation position of the PC base plate A according to the basic plan. The earthwork 21 is a compaction of a predetermined site, a crushed stone laying after compaction, a compaction by excavating a predetermined site or a crushed stone laying after compaction, a surface ground improvement, a compaction or crushed stone laying after compaction, a pile There are methods such as placing, crushing stones after crushing, or laying crushed stones after crushing.

Therefore, if the ground is in good condition and the strength is sufficient, only compaction is required. When excavating the ground, the excavation depth may be such that the upper surface of the bottom plate 1 of the PC base plate A is at the same level as the ground surface (about 150 mm). After that, the self-leveling material 22 is placed at the installation position of the PC base plate A to form a horizontal reference surface 23.

Next, a PC base plate A for mounting the steel pole B on the reference surface 23 and a PC base plate A for mounting the girder C on it.
Is installed. The PC base plate A is installed at the position where the steel pole B should be installed and the position where the girder C should be installed. Then, the steel pole B is placed on the placing portion 2 of the predetermined PC base plate A and fixed by using the bolt 3. When the steel pole B is fixed to each PC base plate A, the flange 4b of the pole B is fixed.
Of the PC base plate A so that the level (the top level of the steel pole B) matches the preset level.
A spacer is appropriately disposed between the flange 4a of the steel pole B and the steel pole B. This top level adjustment work is simply a steel pole B
It is possible to carry out the work by raising the pole and interposing a spacer between the pole B and the mounting portion 2 of the PC base plate A, and the work is also easy.

In the above state, the steel pole B is placed on the ground surface via the PC base plate A, and a horizontal force is applied to the PC base plate A to which the pole B is attached. It is possible to move the reference surface 23 in a desired direction.

Next, the steel pole B installed adjacently
The girder C is connected between them. The connection of the girder C to the steel pole B is made via joining members 9 and 11 attached to the ends of the girder C, as shown in FIG. That is, the joining members 9 and 11 previously attached to the ends of the girder C are brought into contact with the web 6 of the steel pole B, and the bolts 10a and the nuts 10b are temporarily tightened, whereby the girder C is used to connect the steel poles B to each other. Connecting. After connecting the steel pole B with the large beam C, the small beam D is connected to a predetermined position of the large beam C.

When connecting the steel poles B by the girder C, if the horizontal position of the steel pole B is deviated from the reference lines X and Y shown in FIG. 2, this positional deviation is caused by the girder C.
It is adjusted by moving the PC base plate A and the steel pole B in the horizontal direction with the connection. After all the steel poles B have been adjusted to preset installation positions, the bolts 10a and nuts 10b are fully tightened.

After connecting the steel poles B with the girder C as described above, the flange 7a below the girder C is connected to the PC.
Fix to base plate A. The beam G of the beam G is smaller than the beam C of the beam G, and the upper flange of the beam D is connected to the upper flange 7a of the beam C at the same height.

Next, an upper frame is built on the steel pole B, the large beam C, and the small beam D, that is, a structural column is attached on the upper flange of the steel pole B, the large beam C, and the small beam D. , Sequentially install beams and seismic elements on the upper floor. In parallel with the erection of the upper skeleton, as shown in FIG. 1, reinforcing bars 24 are arranged in a grid pattern on the lower side of the flange 7a on the lower side of the large beam C, and further, on the web 7b of the large beam C, a U-shape. The plurality of mounting brackets 25 formed at 1 are mounted at a predetermined pitch, and the mounting frame 25 is engaged with the frame 26 to be arranged on the outer periphery of the foundation, that is, on the outermost periphery of the foundation shown in FIG.

As shown in FIG. 5, a plurality of hook metal fittings 27 formed in a hook shape at a pitch corresponding to the metal fittings 25 attached to the girder C are fixed to the back side of the form 26. The form 26 can be arranged by locking the locking metal 27 to the mounting metal 25. The length of the mold 26 is preferably set in multiples of the basic module. For example, when the basic module is 600 mm, the mold 26 having a length of 1800 mm can be used.

The formwork 26 has both a function as a formwork for the concrete to be cast and a function as a decorative plate for making up the outer surface of the foundation, and a panel such as a PC board, siding or a resin board may be used. It is possible. However, when the building is required to have fire resistance, it is not preferable to use resin as the mold 26. Further, since the formwork 26 is removably locked to the mounting member 25 attached to the girder C, it can be detached from the girder C when necessary when performing a post process such as piping work.

After defining the perimeter of the foundation by the formwork 26,
Concrete 30 is placed inside the form 26. At this time, the concrete has such a depth as to cover the lower predetermined portion of the flange 7a and the web 7b on the lower side of the girder C and not to cover the beam G having a smaller beam size than the girder C. It is cast. And when the cast concrete hardens, the desired foundation is constructed. It is also possible to place concrete up to the lower surface of the flange 7a below the girder C without covering the girder C.

In the above-mentioned foundation structure, concrete is used as the girder C.
When cast to a depth that covers the lower predetermined portion of the lower flange 7a and the web 7b, it is expected that the buckling of the girder C will be restrained by the hardened concrete, and the cross-sectional performance of the girder C will be reduced. It is possible to reduce the weight.
In addition, it is possible to precede the construction of the upper structure skeleton before placing concrete, and after arranging concrete to construct the foundation as in the conventional method, the reinforcement structure is laid in comparison with the method of constructing the upper skeleton. It is possible to shorten the work period required for work, concrete placing work, and curing.

Further, in the above-mentioned foundation construction method, there is no formwork which is removed when the concrete is hardened after the concrete is poured. Therefore, it becomes possible to lay panels such as ALC panels that compose the floor on the first floor during the curing period of the cast concrete, and it is possible to shorten the whole construction period.

Although it is possible to build the upper skeleton after pouring concrete, in this case, it can be shortened as compared with the case where the upper skeleton is built before concrete is poured. Is only for the period corresponding to the curing period of concrete.

[0038]

As described in detail above, in the foundation structure according to the present invention, the steel pole is interposed when connecting the steel beam, so that the connection work between the beam and the steel pole is easy and The structure of the beam is simple and the length variation can be reduced. Therefore, a rational foundation can be constructed without increasing the number of parts.

When the steel poles are connected by a large beam, the top end level accuracy of the poles can be easily ensured, and the poles can be moved in the horizontal direction. It is possible to easily secure the position accuracy of. For this reason, it becomes possible to construct a highly accurate foundation, and it is possible to significantly improve the construction accuracy of the superstructure frame and improve the accuracy of the first floor level.

Since it is not necessary to excavate the ground deeply,
The amount of remaining soil will be reduced, and the construction period can be shortened and costs can be reduced.

Also, after the concrete is poured, 1 during the curing.
By laying a floorboard on the floor, it is possible to make a space for the work on the upper part, which can improve workability and safety.

The foundation beam can also be used for the upper structure of the second floor and above. For this reason, it is possible to reduce the number of parts and to fix the floor board on the first floor in two ways.
It can be used in common with the method of fixing floor boards above the floor.

Further, when the lower flange of the beam and a part of the web are covered with the cast concrete, it is possible to expect the buckling of the beam to be restrained by the concrete, which reduces the cross-sectional performance of the beam. It is possible to reduce the weight. Also, because the entire beam is not covered with concrete,
The amount of concrete placed can be reduced.

Further, in the construction method according to the present invention, when concrete is placed after the upper skeleton is installed on the steel pole or steel beam, the superstructure skeleton is built first. This makes it possible to shorten the construction period.

[Brief description of drawings]

FIG. 1 is a sectional view of an essential part for explaining a basic structure.

FIG. 2 is a developed perspective view illustrating the relationship among a PC base plate, a steel pole, and a steel beam.

FIG. 3 is a diagram illustrating a connection state of a PC base plate and a steel pole.

FIG. 4 is a diagram illustrating constituent poles indirectly installed on the ground surface.

FIG. 5 is a diagram illustrating a structure for mounting a form on a steel beam.

FIG. 6 is a basic plan view showing a structural example of a basic structure.

[Explanation of symbols] A PC base plate B Steel pole C Large beam D Small beam 1 Bottom plate 1a Reinforcing bar 2 Mounting part 2a Insert nut 3 Bolts 4a, 4b Flange 5 Web 6,8 Bolt hole 7a Flange 7b Web 9,11 Connection Member 9a, 9b Joint piece 9c Bolt hole 10a, 10b, 11a Bolt, nut 21 Geotechnical work 22 Self-leveling material 23 Reference surface 24 Reinforcing bar 25 Mounting bracket 26 Formwork 27 Locking bracket

Claims (3)

[Claims] 1. A steel pole installed on a ground surface constituting a foundation, a steel beam connecting the steel poles, and a ground surface surrounded by the steel beam on the outer periphery of the building. A solid foundation structure characterized by being constructed concrete. 2. A horizontal reference surface is formed by placing a self-leveling material on the ground surface on which the steel pole is installed, and a precast concrete base plate is installed on the reference surface, and the steel pole is provided thereon. The solid foundation structure according to claim 1, wherein the solid foundation structure is provided. 3. A steel pole is installed on the ground surface constituting the foundation, the steel poles are connected by a steel beam, and an upper structure frame is installed on the steel pole or the steel beam. A method of constructing a solid foundation, which comprises constructing a solid foundation by placing concrete on the ground surface surrounded by the steel beams above.