JP2001040675A - Foundation structure for building - Google Patents

Abstract

PROBLEM TO BE SOLVED: To shorten the term of works, save labor in construction work, improve work accuracy and also reduce cross section of foundation. SOLUTION: An underground beam 4 made of shape steel having a plurality of studs with heads 12 is installed at the bottom of continuous gutter in ridge direction. A stud with head 12 is projected out at the bottom surface of the underground beam. A plurality of side panels 5a are installed as the form of foundation at both the side of underground beam 4. Foundation concrete is poured surrounding the underground beam 4 between the side panel 5a.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a foundation structure of a low-rise building, and is mainly used as a foundation of a warehouse, a supermarket, a factory, a gymnasium and the like.

[0002]

2. Description of the Related Art In general, the foundation of a building transmits the stress of the superstructure to the ground or the earthwork by means of split rubble stones constructed under the foundation. Most foundations are constructed of reinforced concrete.

[0003] Fig. 6 shows an example of a conventional foundation. In the figure, a split stone 30 and a discarded concrete 31 are constructed in this order on the ground at the bottom which is continuously cut and excavated in a groove shape in the girder direction. And the underground beam 3 on the discarded concrete 31
2 is constructed of reinforced concrete.

A footing 34 is constructed of reinforced concrete integrally with the underground beam 32 immediately below the position where the column 33 is built.

[0005]

However, the construction of an underground beam using reinforced concrete requires deep and wide excavation because of the footing 34 and the like, so that a large amount of excavated soil is discharged. And other issues.

In addition, since the cross-sectional shape of the entire foundation including the footing 34 becomes complicated, much work is required for processing and assembling the formwork, as well as for the foundation work such as the processing of the reinforcing bar and the arrangement of the reinforcing bars, and the construction period is prolonged. In addition to this, there is a problem that the construction is complicated and the construction accuracy is reduced.

If an underground beam continuous in the span (between beams) direction is not arranged between the footings 34, a large shear force and a bending moment are generated in the footings 34 due to a horizontal external force acting in the span direction. In addition, there is also a problem that the bottom area of the footing 34 needs to be considerably increased.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and provides a basic structure of a building capable of shortening a construction period, saving labor of construction, improving construction accuracy, and further reducing a foundation section. The task is to provide.

[0009]

According to a first aspect of the present invention, there is provided a foundation structure for a building according to the present invention, in which a section steel is installed as an underground beam. A shear connector is provided on the lower surface.

According to a second aspect of the present invention, in the foundation structure of the building according to the first aspect, anchor frames are provided at intervals in the girder direction. According to a third aspect, in the foundation structure of the building according to the first or second aspect, a shear connector is provided on the upper surface of the underground beam and / or the anchor frame near the position where the pillar is installed.

According to a fourth aspect of the present invention, in the foundation structure of a building according to the first to third aspects, a side panel on which a waist panel can be laminated is used as a foundation formwork.

[0012]

1 and 2 show an example of a foundation structure of a building according to the present invention. In the figures, split stones 1 are spread on the ground at the bottom of a root cutting continuous in a girder direction. On top of that, a waste concrete 2 is cast to a predetermined thickness as a pretreatment for performing ink removal or the like.

Further, a plurality of anchor frames 3 and underground beams 4 are installed on the discarded concrete 2, and side panels 5a and 5b are installed on both sides thereof. Further, the foundation concrete 6 is cast between the side panels 5a and 5b on both sides, and the anchor frame 3 and the underground beam 4 are embedded in the foundation concrete 6. In this way, a base 7 having a substantially rectangular cross section continuous in the girder direction is formed.

A steel column 8 is erected on the foundation 7 and a waist panel 9 is installed on the outdoor side panel 5a. Further, a concrete slab 10 is cast on the foundation 7 continuously from the floor.

The anchor frame 3 is arranged on the discarded concrete 2 so that the axial direction (longitudinal direction) of the anchor frame 3 matches the span (between beams) direction and a predetermined interval in the girder direction via a plurality of level adjusters 11. It is installed.

The underground beam 4 is bridged between the anchor frames 3 and 3 on the discarded concrete 2 in such a manner that the axial direction of the beam coincides with the girder direction, and both ends thereof are anchor frames 3.
Are joined to each other by joining plates and joining bolts.

The underground beam 4 does not use an anchor frame, but may be installed continuously as shown in FIGS. 3 and 4, for example. The anchor frame 3 and the underground beam 4 are both formed of a shape steel such as an H-beam, and a plurality of headed studs 12 are provided as sheer connectors on the lower surface of the underground beam 4 at predetermined intervals in the girder direction. A plurality of headed studs 13 project from the underground beam 4 and / or the anchor frame 3 as sheer connectors.

In particular, the headed studs 12 project from the undersurface of the underground beam 4 in one or more rows. As described above, since the studs 12 with the head project from the undersurface of the underground beam 4, the foundation 7 forms a composite structure from the underground beam 4 and the foundation concrete 6, and is formed by the ground reaction force from the supporting ground. Since it functions as a composite beam against the bending moment,
The depth of the foundation can be reduced, and the amount of excavated soil can be reduced.

Further, since the studs 13 with heads are protrudingly provided on the upper surface of the underground beam 4 and / or the anchor frame 3, the foundation 7 and the slab concrete 10 form an integral structure and act on the column base of the column 8. The horizontal force to be applied can be shared by the soil concrete 10. Further, since the bending moment acting on the foundation 7 can be reduced by this, the foundation 7
Base width can be reduced.

As the shear connector, a continuous plate-like body such as a steel plate may be used, or projections may be provided at intervals. In addition, irregularities may be formed on the surface of the underground beam 4 and the anchor frame 3, and the adhesion between the underground beam 4 and the foundation concrete 6, the underground beam 4 and / or the anchor frame 3 and the interstitial concrete 10. What is necessary is just to be the structure which can obtain sufficient adhesive force. The soil concrete 10 is also provided with soil reinforcement as necessary.

The position where the shear connector is provided on the upper surface of the underground beam 4 and the anchor frame 3 is not particularly limited.
It is preferable to keep the concrete at a distance of 50 mm or more from the column 8 so that the concrete sufficiently turns around the shear connector, and it is preferable that the concrete be within 500 mm from the column 8 in order to sufficiently exhibit the effect of reducing the bending moment.

The shear connector provided on the upper surface of the underground beam 4 and the anchor frame 3 may be a stud with a head, a steel plate or the like, similarly to the connector provided on the lower surface.
When a plate-like body such as a steel plate is used as the shear connector, its longitudinal direction may be perpendicular or parallel to the girder direction. May be used.

Further, when the anchor frame 3 is provided, a stud 12 with a head may be protruded from the lower surface thereof as a shear connector. The level adjusting body 11 is composed of a fixing metal 11a, a movable metal 11b, a level adjusting bolt 11c, and the like, and is installed at an end of a section steel forming the underground beam 4.

When the anchor frames 3 are provided, they are provided on both ends of each anchor frame 3. The fixing metal 11a is fixed on the discarded concrete 2 by the anchor bolt 14, the movable metal 11b is fixed to the side of the fixing metal 11a by the fixing bolt 15, and the movable metal 11b is fixed to the underground beam 4 or the anchor frame 3. It is connected to the end by a bolt or the like.

Further, both the fixed metal member 11a and the movable metal member 11b are formed of a section steel such as a channel steel or an L-section steel. The level adjusting bolt 11c is erected near the fixing bracket 11a, and is movable by the level adjusting bolt 11c.
Before being fixed to the fixture 11a, height adjustment and leveling are performed.

As described above, since the height can be adjusted and the leveling can be performed, the mounting accuracy of the anchor frame 3 and the underground beam 4 can be increased, and the construction accuracy can be improved.

A level adjusting nut 11d that moves in the axial direction (vertical direction) is screwed into the level adjusting bolt 11c, and the movable metal fitting 11 is turned by turning the level adjusting nut 11d.
b can be raised and lowered freely.

After completing the level adjustment, the level adjustment bolt 11c may be removed together with the level adjustment bolt 11d so that the level adjustment bolt 11c can be used repeatedly. The side panels 5a and 5b also serve as the formwork of the foundation 7 and are left as a surface material of the foundation 7, and are formed of, for example, a dry panel such as an FRC plate.

The side panels 5a and 5b are fixed to the runner 16 mounted on the discarded concrete 2 and having a substantially groove-shaped cross-section opening right above. The runner 16 is formed of a lightweight channel steel or two lightweight angle steels.

As the side panels 5a and 5b, those having a shape in which the waist panel 9 can be laminated on the upper part are preferably used.
For example, it is preferable to form an uneven shape such that the upper end of the side panel and the lower end of the waist panel 9 can be fitted.

The columns 8 are respectively erected on the underground beam 4 or the anchor frame 3 via column bases 17, and the lower ends of the columns 8 are fixed to the column bases 17 with several fixing bolts 19. ing.

The column base bracket 17 is fixed on the underground beam 4 or the anchor frame 3 with anchor bolts 18. The anchor bolt 18 penetrates the underground beam 4 or the anchor frame 3 downward, is bent in the girder direction on the lower side, and is extended a predetermined length in the girder direction, so that a sufficient anchoring length can be obtained. Have been.

The anchor bolt 18 is used for the underground beam 4
Alternatively, it may be bent in the span direction (the direction perpendicular to the axis of the underground beam) below the anchor frame 3 and extended a predetermined length in the span direction. In addition, a high-strength bolt or a middle bolt is used for the anchor bolt 18.

FIGS. 3 and 4 show an example of the foundation structure of a building according to the present invention. In particular, there is no anchor frame as described above, and the underground beam 4
Only have been installed.

The underground beam 4 is disposed on the discarded concrete 2 in such a manner that the axial direction of the beam coincides with the direction of the girder, and a plurality of the underground beams are connected via a plurality of level adjusters 11. At 21 they are joined together.

By adjusting the height of the underground beam 4 and leveling it out with the level adjusting body 11, the mounting accuracy of the underground beam 4 can be increased, and the construction accuracy can be improved. ing.

The column 8 is erected not on the anchor frame but on the underground beam 4 via the column base bracket 17. The lower end of each column 8 is fixed to the column base 17 with a plurality of fixing bolts 19. Pillar bracket 17 is underground beam 4
Is fixed on the base with a plurality of anchor bolts 22.

An anchor bolt 22 penetrates the underground beam 4 downward, and a fixing plate 23 attached to a lower end portion.
And are anchored in the foundation concrete 6. The anchor bolt 22 has a so-called unbonded structure so that the anchor nut 24 screwed to the upper end portion can be tightened again later.

Further, one side panel 5 also serving as a base formwork
a is fixed with its lower end erected between two runners 25, 25 made of, for example, lightweight angle irons, which are mounted on the discarded concrete 2 so as to form concave grooves.

Further, a level adjusting bolt 26 is protrudingly provided on the waste concrete 2 between the runners 25, 25, and the level adjusting bolt 26 is turned up and down to adjust the level of the side panel 5a and level out. Howl can be done. Other configurations are substantially the same as those shown in FIGS. 1 and 2.

In such a configuration, a construction method will be briefly described next (see FIG. 5). First, root cutting A that is continuous in a groove shape in the girder direction is performed. Then, crushed stone 1 was carefully laid on the ground at the bottom of the root cut while being compacted, and concrete 2 was discarded on top of it.
Is cast to a predetermined thickness. Next, the level adjuster 11 and the runner 16 are respectively mounted on the discarded concrete 2 in accordance with the marking position, and a necessary amount of round steel or deformed reinforcing bar is laid as the basic reinforcing bar 27. Next, the anchor frames 3 are respectively bridged between the level adjusters 11 and 11 and fixed to the movable fittings 11b.

The level adjustment bolt 11c and the level adjustment nut 11d of the level adjustment body 11 level the anchor frame 3 and adjust the level. Then, the movable fitting 11b is fixed to the fixing fitting 11a by tightening the fixing bolt 15. Next, the column base bracket 17 and the anchor bolt 18 are attached to each anchor frame 3 respectively. The column base 17 and the anchor bolt 18 may be attached to the anchor frame 3 in advance. Next, the underground beam 4 is bridged between the anchor frames 3 and 3, and both ends are joined to the anchor frame 3 with joining plates and joining bolts.

A stud 13 with a head is provided at the upper end of the anchor frame 3, and a stud 12 is provided at a lower end of the underground beam 4.
Respectively. Note that studs 12 and 13 with heads
It is desirable to install in advance. Next, on both sides of the anchor frame 3 and the underground beam 4,
Each of the side panels 5 is also erected as a base formwork. At this time, the lower end of the side panel 5 is inserted into the runner 16 and fixed. Next, the foundation concrete 6 is cast between the side panels 5a and 5b on both sides. The outside of the side panels 5a and 5b is backfilled with backfill soil 28, respectively. The backfill soil 28 may be buried before the foundation concrete 6 is cast.

By laying the foundation concrete 6 between the side panels 5a and 5b in this manner, the anchor frame 3 and the underground beam 4 are embedded in the foundation concrete 6, whereby the cross-section substantially continuous in the girder direction. A rectangular cloth base 7 is formed. Next, the column 8 is mounted on the anchor frame 3 and the lower end is fixed to the column base bracket 17 with fixing bolts 19, respectively.

The waist panel 9 is set on the side panel 5a. At this time, the waist panel 9 can be attached flush with the side panel 5 of the cloth foundation 7, and the workability is extremely good. Next, the soil concrete 10 is cast on the foundation 7 continuously from the soil portion.

In addition, before the column 8 is erected, the slab concrete 10 may be cast first, and then the column 8 may be erected. In this case, the column base bracket 17 is attached to the slab concrete 10. A frame (not shown) for blocking concrete is provided around the column base bracket 17 in a rectangular shape so as not to be buried, and a so-called box is removed.

[0047]

The foundation structure of a building according to the present invention is as described above, and an underground beam made of a section steel having a shear connector is installed at the bottom of a root cutting continuous in a girder direction. Since the base concrete is cast in the periphery, the composite structure composed of the shape steel and the concrete is formed, so that the cross section can be reduced and the amount of excavated soil can be reduced.

Further, the foundation is made of a composite structure of shaped steel and concrete, and the shear connector is protruded from the underground beam or the upper surface of the anchor frame, so that the foundation is continuously cast from the floor to the top of the foundation. Since the foundation and soil concrete have an integral structure, the horizontal force acting on the column base can be shared by the soil concrete, and the bending moment acting on the foundation can be reduced. The width can be reduced, and the basic section can be reduced.

Further, since the height of the anchor frame can be adjusted and leveled out by the level adjuster, the mounting accuracy of the anchor frame and the underground beam can be improved.
Thereby, improvement of construction accuracy can be achieved.

Further, by leaving the side panels installed as the foundation formwork on both sides of the anchor frame and the underground beam as the surface material of the foundation, the work of rebars, the rebar arrangement work, and the formwork disassembly / removal. The work can also be omitted, and the labor can be saved significantly and the construction period can be significantly shortened.

[Brief description of the drawings]

FIG. 1 shows an example of a basic structure according to the present invention, wherein (a)
FIG. 2 is a longitudinal sectional view, and FIG. 2B is an enlarged view of a portion A in FIG.

FIG. 2 is a partial perspective view showing an example of a basic structure according to the present invention.

FIG. 3 is a longitudinal sectional view showing an example of a basic structure according to the present invention.

FIG. 4 is a longitudinal sectional view showing an example of a basic structure according to the present invention.

5A to 5G are cross-sectional views illustrating an example of a construction method.

FIG. 6 is a partial perspective view showing an example of a conventional foundation.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Split chestnut 2 Discarded concrete 3 Anchor frame 4 Underground beam 5a Side panel 5b side panel 6 Foundation concrete 7 Foundation 8 Column 9 Waist panel 10 Soil concrete 11 Level adjuster 11a Fixing bracket 11b Movable bracket 11c Level adjusting bolt 11d Level adjusting nut 12 Stud with Head (Shear Connector) 13 Stud with Shear (Shear Connector) 14 Anchor Bolt 15 Fixing Bolt 16 Runner 17 Column Base 18 Anchor Bolt 19 Fixing Bolt 20 Joining Plate 21 Joining Bolt 22 Anchor Bolt 23 Fixing Plate 24 Anchor Nut 25 Runner 26 Level adjustment bolt 27 Foundation reinforcement 28 Backfill soil

Claims (4)

[Claims] 1. A foundation for a building, wherein a section steel is used as an underground beam, and a shear connector is provided on a lower surface of the underground beam. 2. The foundation structure of a building according to claim 1, wherein anchor frames are provided at intervals in the girder direction. 3. The foundation structure of a building according to claim 1, wherein a shear connector is provided on an undersurface beam and / or an upper surface of the anchor frame near a position where the pillar is installed. . 4. The foundation structure of a building according to claim 1, wherein a side panel on which a waist panel can be stacked is used as the foundation formwork.