JP5821042B2 - Building foundation formation method - Google Patents

Description

  The present invention relates to a method for forming a building foundation using a precast concrete block produced in advance in a factory or the like.

As a relatively small-scale building foundation such as a wooden building, one having a concrete base plate and a concrete start-up portion raised from the base plate into a wall shape is known. In such a building foundation, after excavating (root cutting) the ground to a predetermined depth, a concrete foundation slab is formed on the foundation support surface on which crushed stones are compacted, and concrete is placed on this foundation slab. Strike to form a raised part. Building foundations with such concrete foundation slabs are not limited to the so-called “solid foundations” in which the foundation slabs are formed so as to be continuous with the entire range of building construction. It includes a so-called “footing foundation” in which a foundation plate is formed so as to overhang.
The above-mentioned start-up part is installed in the direction of the wall of the outer peripheral part of the building and the internal load-bearing wall, and is firmly fixed to the concrete base plate to transmit the building's load to the base plate and disperse it to the ground. It is something to convey.

Conventionally, such a building foundation is constructed by assembling a formwork for placing the concrete of the foundation slab and placing the reinforcing bars at the building construction site. Then, after the concrete of the foundation plate is hardened, the formwork of the rising part is installed and the reinforcing bars are arranged to place the concrete of the rising part and demold. In this way, concrete placement is divided into two parts, which reduces the efficiency of work.
Under such circumstances, there has been proposed a method of forming the raised portion using a precast concrete block manufactured in a factory or the like. In this method, a plurality of precast concrete blocks are arranged on the pressed foundation support surface, and then the foundation slab concrete is placed so as to be integrated with these precast concrete blocks.

As a method for forming a foundation using such a precast concrete block, for example, there is one described in Patent Document 1 or Patent Document 2.
The forming method described in Patent Document 1 is as follows.
A plurality of foundation bodies (precast concrete blocks) made of concrete formed in a factory or the like are arranged on the foundation ground, and concrete is placed so as to embed legs provided at both ends of the foundation body. Reinforcing bars are exposed in the lower part between the legs of the foundation body, and the reinforcement bars are embedded in the concrete to be placed after the foundation body is arranged. In addition, reinforcing reinforcing bars protrude horizontally from both ends of the foundation body, and the reinforcing reinforcing bars protruding from two adjacent foundation bodies are overlapped, and concrete is placed between the two foundation bodies to embed them. It is one.

Moreover, the formation method of the foundation of patent document 2 is as follows.
Place a foundation material (precast concrete block) with a joint on the butt end face or side face and a height adjustment bracket on the bottom face, and place it on the concrete surface. Link.
After the foundation material is connected, the bottom reinforcing bars are arranged in a grid pattern on the leveling concrete, that is, below the foundation material, and the reinforcing bars protruding from the bottom surface of the foundation material are tied to the bottom reinforcement, and the concrete is placed. Integrate the bottom plate and the base material.
The height adjustment bracket is a box-shaped member with the bottom portion protruding from both sides of the foundation material, and can be placed on the upper surface of the leveled concrete to support the foundation material in a stable state. ing.

JP 2003-27497 A JP 2010-70903 A

However, the above basic formation method has the following problems.
In the forming method described in Patent Document 1, it is necessary to place concrete between two foundation bodies in order to connect the reinforcing bars protruding from the side end surfaces of the foundation body (precast concrete block). A connecting block having a complicated structure is used as a mold for placing the concrete. That is, the work efficiency of the process of forming the formwork for placing the connecting portion concrete between the base bodies is not good.

  On the other hand, in the forming method described in Patent Document 2, after the foundation material is arranged on the leveled concrete, the bottom reinforcing bars are arranged. At this time, it is desirable to arrange a reinforcing bar continuous in the axial direction of the foundation material below the foundation material. That is, it is preferable to dispose a reinforcing bar continuous in the direction along the wall surface of the building below the foundation material to resist the bending moment of the foundation in which the bottom plate and the foundation material are integrated. However, the lower side of the base material is supported by the height adjusting bracket, and the efficiency of the work of arranging the reinforcing bars is deteriorated.

  The present invention has been made in view of the above circumstances, and its purpose is to form a building foundation that can efficiently form a foundation using a precast concrete block manufactured in advance in a factory or the like. Is to provide.

In order to solve the above-mentioned problems, the invention according to claim 1 is a method for forming a building foundation having a foundation plate formed on a foundation support surface and a rising portion raised on the foundation plate. A step of forming the foundation support surface substantially horizontally on the ground, a step of arranging reinforcing bars embedded in the foundation plate substantially horizontally on the foundation support surface, and a precast concrete block constituting the rising portion attaching a temporary supporting brackets on the bottom, the precast concrete blocks by the temporary support bracket, and a step for supporting on said base support surface, the reinforcing bar and embedding said temporary support fitting, to close contact with the precast concrete blocks and a step of pouring the foundation plate of the concrete, the step of forming the base support surface, said with compacting soil A step of embedding a plate-like member in the ground supporting the support metal fitting, and finishing so that the upper surface of the plate-like member and the surface of the compacted ground around the plate-like member have substantially the same height; Removing the plate-like member, throwing the concrete into the recess after the removal, and leveling the upper surface to approximately the same height as the surface of the surrounding ground. Provide a method .

In this building foundation forming method, it is possible to simplify the process of placing the discarded concrete by placing the discarded concrete only at the position where the temporary support bracket is supported, and placing the discarded concrete. The formed area and the compacted ground surface can be a plane having a substantially uniform height. In addition, the area around the area where the discarded concrete has been cast can be firmly compacted. On the other hand, the height of the precast concrete block can be adjusted accurately because the unevenness of the position where the temporary support bracket is placed is reduced and the settlement of the temporary support bracket where the weight of the precast concrete block acts is reduced. It becomes.
It should be noted that the compacted ground that is the foundation support surface outside the range where the discarded concrete is placed may be one that compacts the ground after excavation, but it is compacted by laying crushed stones, gravel, etc. Is desirable.

The invention according to claim 2 is the method for forming a building foundation according to claim 1, wherein after the plate-like member is extracted, the concrete is disposed in the recess and placed on the ground around the recess. Including a step of laying a sheet having moisture resistance or ant repellency continuously inside the recess,
The discarded concrete shall be placed on the sheet.

In this building foundation forming method, a sheet is laid under the discarded concrete, so that moisture or ants can be prevented from entering, and the temporary support fitting can be directly supported on the discarded concrete. And the display for determining an arrangement position can be thrown away and it can attach on concrete, and it becomes possible to arrange a temporary support metal fitting correctly.
It is also possible to avoid damage to the sheet when the reinforcing bars embedded in the foundation plate are arranged on the foundation support surface, or when the precast concrete block is arranged via a temporary support fitting.

  The invention according to claim 3 is the method of forming a building foundation according to claim 1 or 2, wherein the temporary support metal fitting has a height adjustment portion that enables adjustment of the height of the leg portion. Using a thing, after the process of supporting the said precast concrete block on the said foundation support surface, the process of setting the said precast concrete block to predetermined | prescribed height by the said height adjustment part shall be included.

  In this building foundation forming method, the height adjusting portion is provided on the leg portion of the temporary support fitting, and the height of each precast concrete block arranged can be adjusted. Therefore, it becomes easy to arrange the precast concrete blocks at a predetermined height.

The invention according to claim 4 is the method for forming a building foundation according to any one of claims 1 to 3, wherein the temporary support metal fitting has leg portions protruding downward from at least two locations, It is assumed that the legs protruding from two places are supported on the foundation support surface so as to straddle the reinforcement, and the reinforcing bars arranged on the foundation support surface are lifted upward and embedded in the foundation plate. The process of arrange | positioning to the height of is supposed to be included.

In this building foundation formation method, the temporary support fittings attached to the precast concrete block support the precast concrete block on the foundation support surface across the reinforcing bars arranged on the foundation support surface. It becomes easy to arrange the reinforcing bars to the side, and the efficiency of the bar arrangement work can be improved. That is, it is not necessary to feed the reinforcing bars arranged along the axial direction of the precast concrete block directly below the precast concrete block and send them out below the precast concrete block. Therefore, it is possible to efficiently form a building foundation in which the lower side of the precast concrete block is sufficiently reinforced by the reinforcing bars.
The step of lifting the reinforcing bars arranged on the foundation support surface to a predetermined height embedded in the foundation plate is performed either before or after the step of supporting the precast concrete block on the foundation support surface. May be.

  The invention according to claim 5 is the method for forming a building foundation according to claim 4, wherein the step of lifting the reinforcing bars arranged on the foundation support surface and supporting the reinforcing bars at a predetermined height A step of binding to the leg portion is included.

  In this building foundation forming method, the reinforcing bars can be easily supported at a predetermined position embedded in the foundation plate by binding the reinforcing bars to the legs of the temporary support fitting. Moreover, since the leg part straddles the reinforcing bar, the reinforcing bar arranged immediately below the axial direction of the precast concrete block can also be lifted to a predetermined height with the leg part straddling.

  As described above, in the method for forming a building foundation according to the present invention, the foundation slab and the rising portion are formed by a single concrete placement at the site, and it is easy to directly below the precast concrete block that becomes the rising portion. The building foundation can be efficiently formed by arranging the reinforcing bars.

It is sectional drawing which shows an example of the building foundation formed by the method which concerns on this invention. It is a top view, a front view, and a side view of the precast concrete block used for the starting part of the building foundation shown in FIG. It is the top view, front view, and side view of the junction part with which the precast concrete block shown in FIG. 2 was equipped. It is the top view, front view, and side view which show the temporary support metal fittings which can be used with the method which concerns on this invention . It is a schematic sectional drawing which shows the process of forming the building foundation shown in FIG. It is a schematic sectional drawing which shows the process of forming the building foundation shown in FIG. It is a schematic sectional drawing which shows the process of forming the building foundation shown in FIG. It is the schematic plan view and schematic front view which show the other example of the temporary support metal fitting which can be used with the method which concerns on this invention . It is a schematic sectional drawing which shows the other example of the building foundation which can be formed using a temporary support metal fitting .

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a cross-sectional view showing an example of a building foundation formed by the method according to the present invention. FIG. 2 is a plan view, a front view and a side view of a precast concrete block constituting a rising portion of the building foundation. 3 is a plan view, a front view, and a side view showing the joint provided in the precast concrete block.
As shown in FIG. 1, the building foundation 1 includes a concrete floor slab 3 that is a foundation slab supported on a foundation support surface 2, and a start-up portion 4 that is continuously raised from the concrete floor slab 3. And. The rising portion 4 is formed by arranging a plurality of precast concrete blocks. Reinforcing bars are embedded in the concrete floor slab 3 and the rising portion 4, respectively, and the lower end portion of the precast concrete block 5 that becomes the rising portion 4 is formed by placing concrete on the spot. 3 is embedded. A part of the reinforcing bar embedded in the precast concrete block 5 protrudes from the bottom surface, and the protruding part of the reinforcing bar 13 is embedded in the concrete floor slab 3 so that the precast concrete block 5 and the concrete floor slab 3 are joined together. Has been. Moreover, the temporary support metal fitting 20 which temporarily supports the precast concrete block 5 on the foundation support surface 2 is embedded in the concrete of the concrete floor slab 3 with the precast concrete block 5 temporarily supported.
A structural member (not shown) of a wooden building is raised on the rising portion 4 and the load of this building is distributed and transmitted to the ground via the rising portion 4 and the concrete floor slab 3. It is supposed to be.

The foundation support surface 2 is an upper surface of the crushed stone layer 7 which is excavated (root cut) of the ground 6 and then laid with a crushed stone and is flattened by rolling. The crushed stone layer 7 is provided with a recess in a region where the temporary support metal fitting 20 is supported, and a discarded concrete 8 is placed in the recess. In addition, a sheet 9 is laid on the crushed stone layer 7, and this sheet 9 is laid along the inner surface of the recess continuously from the crushed stone layer 7. It is placed in the recess. As the sheet 9, a sheet having moisture resistance or a sheet having both moisture resistance and ant-proof properties is used.
In addition, the plate 10 made of steel or synthetic resin is placed or fixed in the region where the temporary support metal fitting 20 on the discarded concrete 8 is supported, and the height adjustment by the temporary support metal fitting 20 is easy.

  The concrete floor slab 3 is obtained by placing concrete on the foundation support surface 2 so that the upper surface is formed almost horizontally. The concrete floor slab 3 has reinforcing bars 11 and 12 embedded in a grid pattern. . In addition, although the concrete floor slab 3 of this Embodiment is formed in the whole area | region enclosed by the raising part 4 in the outer peripheral part of a building, it forms so that it may protrude on the both sides of the raising part 4 It may be a footing.

The start-up part 4 is formed by connecting a plurality of precast concrete blocks 5 manufactured in advance in a factory or the like. And it is provided along the wall surface direction under the part used as the outer wall part of a building, and an internal bearing wall.
The precast concrete block 5 is a substantially rectangular parallelepiped having the longest axis in the horizontal direction along the wall of the outer wall or the load bearing wall, and the width with respect to the axis is set based on the thickness of the wall. Further, the height is appropriately determined based on the position of the concrete floor slab 3 which is the basic version, the height of the floor surface of the building, and the like.

In each of the precast concrete blocks 5, vertical bars 13 and horizontal bars 14 are embedded in a lattice shape. As shown in FIG. 1, the vertical bars 13 are bent in an inverted U shape near the top of the precast concrete block 5, and the horizontal bars that serve as the upper main bars 14 a are embedded inside the inverted U shape. . The lower ends of the vertical bars 13 protrude from the bottom surface of the precast concrete block 5, are bent in a substantially horizontal direction, and are embedded in the concrete floor slab 3. The horizontally bent portion of the vertical bars 13 has substantially the same height as the reinforcing bars 11 arranged in the concrete floor slab 3.
A temporary support metal fitting 20 is attached to the bottom surface of the precast concrete block 5, and the precast concrete block 5 is supported on the discarded concrete 8 via the temporary support metal fitting 20. That is, the temporary support metal fitting 20 temporarily supports the precast concrete block 5 at a predetermined height until the concrete of the concrete floor slab 3 is placed and hardened.

As shown in FIG. 2, joints 15 and 16 and a shear cotter 17 are formed on the surface where the precast concrete block 5 comes into contact with another precast concrete block arranged in the horizontal direction. These joints 15 and 16 are fitted together with joints of other precast concrete blocks. Then, mortar grout is poured so as to embed the joints 15 and 16 and fill the shear cotter 17 so that adjacent precast concrete blocks are firmly connected to each other.
The precast concrete block 5 includes a female joint 15 at a connecting portion with another precast concrete block and a male joint 16 at another connecting portion, a female joint at all connecting portions, Designed according to the building to be constructed, such as those with male joints in the connection. Moreover, the joints 15 and 16 and the shear cotter 17 are provided in the side surface facing the end surface of another precast concrete block other than the end surface in the axial direction of a precast concrete block.

The male joint 16 is made of steel, and as shown in FIGS. 3A, 3B, and 3C, a base portion 16a embedded in the precast concrete block 5, a protruding portion 16b protruding from the base portion, and the base portion The main part is comprised with the anchor reinforcement 16c connected with 16a and embedded in the precast concrete block 5. FIG.
The projecting portion 16b has a head whose dimension in the width direction is enlarged near the tip, and the precast concrete block 5 projects from the contact surface 5a facing the other precast concrete block. The base portion 16a is formed integrally with the protruding portion 16b and supports the protruding portion 16b. The base portion 16a branches into two at the rear, and an anchor muscle 16c is coupled to each of the branches. The male joint 16 is fixed to the precast concrete block 5 by the anchor reinforcement 16c and the base portion 16a being embedded in the precast concrete block 5.

As shown in FIGS. 3D, 3E, and 3F, the female joint 15 forms a concave space in which the support base portion 15a embedded in the precast concrete block 5 and the protruding portion 16b of the male joint 16 are fitted. The main part is comprised by the support part 15b made and the anchor muscle 15c connected with the support base 15b.
The support portion 15b is assembled loosely so that a gap is formed between the female joint 15 and the male joint 16 when the protruding portion 16b of the male joint 16 is fitted into the concave space. . And the anchor reinforcement 15c connected with the support base 15a is embedded in the precast concrete block 5, and the female joint 15 is fixed.

  As shown in FIGS. 3 (e) and 3 (f), the female joint 15 is fixed so that the tip of the support portion 15b substantially coincides with the surface of the precast concrete block 5 or is inside the surface. The upper part of the concave space formed in the portion 15b is provided with a notch 5b in the precast concrete block 5. From the upper part of the notch 5b, the protruding portion 16b of the male joint fixed to another precast concrete block can be lowered and fitted into the recessed space of the female joint 15. And in the position which fitted the male joint 16 and the female joint 15, it can match | combine the height of both the precast concrete blocks 5 joined, and supports the weight of the precast block in which the male joint 16 was provided. It is also possible. In other words, a precast concrete block having male joints 16 at both ends can be fitted by lowering from above between two precast concrete blocks having female joints 15 and supported by two precast concrete blocks on both sides. Can be made.

  The shearcotter 17 is a recess provided below the joints 15 and 16 and is formed at a position where the adjacent precast concrete blocks 5 face each other. When the mortar grout is poured from the notch 5b formed above the female joint 15 in a state in which the female joint 15 and the male joint 16 are fitted together, the two mortar grouts are filled in the opposed two shear coaters and are adjacent to each other by the hardened mortar grout. It resists shearing forces acting between precast concrete blocks.

  The poured mortar grout is also filled between the protrusion 16b of the male joint and the support 15b of the female joint, and these are connected together to resist the tensile force acting between the precast concrete blocks. It becomes. The upper main reinforcement 14a embedded in the precast concrete block 5 is embedded in the vicinity of the anchor bars 15c and 16c, and the tensile force between the precast concrete blocks 5 is transmitted to the upper main reinforcement 14a, and the concrete has a large tensile force. Does not work.

  The temporary support fitting 20 has two bar steels 21 and 22 that have been bent, steel plate materials 23, 24, and 25 that connect them, and height adjustment that is screwed into bolt holes provided in the steel plate materials 24 and 25. It is comprised with the volt | bolt 26 for use. The steel bars 21 and 22 are provided with a substantially horizontal portion 21a at the center of a predetermined length, and both sides of the horizontal portion 21a are bent downward. Further, the vicinity of the tips of the bent-down portions on both sides is bent almost horizontally in a direction away from each other. The two steel bars 21 and 22 are juxtaposed so that the horizontal portion 21a and the bent-down portion 21c are substantially parallel to each other, the upper side of the horizontal portion 21a in the central portion, and the horizontal portions near both ends. The steel plate materials 23, 24, and 25 are joined by welding or the like below the portion 21b.

  The steel plate material 23, that is, the attachment plate joined to the upper side of the horizontal portion in the central portion of the steel bars 21 and 22 is formed with an attachment through hole 23 a for attaching the temporary support fitting 20 to the bottom surface of the precast concrete block 5. Yes, it is an attachment part for the temporary support bracket 20. Bolts (not shown) are inserted into the mounting through holes 23a and screwed into the female threads of anchor members 27 (shown in FIG. 1) embedded in the precast concrete block 5, so that the temporary support metal fitting 20 is attached to the precast concrete block 5. Can be attached.

  The portion 21c bent downward from both sides of the horizontal portion 21a at the central portion of the steel bars 21 and 22 becomes a leg portion, and welded to the lower side of the horizontal portion 21b near both ends of the steel bars 21 and 22 The steel plate members 24 and 25, ie, the leg plates joined together by the above, and the height adjusting bolts 26 screwed into the screw holes provided in the leg plates constitute a height adjusting portion. That is, by rotating the height adjusting bolt 26 screwed into the leg plates 24 and 25 fixed to the steel bars 21 and 22, and changing the screwing amount, the position in the height direction of the steel bars 21 and 22 and the temporary support metal fittings are changed. The set height of the precast concrete block 5 supported by 20 can be adjusted.

  The interval A between the two steel bars arranged in parallel is 1.5 times the diameter of the reinforcing bars 11 and 12 embedded in the concrete slab 3 and the diameter of the coarse aggregate mixed with the concrete to be placed. 1.25 times or more is set. That is, it has an interval of at least one of these values. As a result, the peripheral portions of the two steel bars 21 and 22 arranged in parallel can be sufficiently filled with concrete, and the precast concrete block 5 can be firmly fixed to the concrete floor slab 3.

Next, a method for forming a building foundation using the precast concrete block 5 to which the temporary support fitting 20 is attached will be described.
First, as shown to Fig.5 (a), the ground 6 in which a building is built is excavated (root cutting), and a crushed stone layer 7 with a flat upper surface is formed by spreading and crushing the crushed stone.
When the above-mentioned crushed stone is spread and rolled up, a plate-like member 31 of a predetermined size, for example, a wooden board, is embedded at a position for supporting the temporary support fitting 20 attached to the precast concrete block 5. The top surface of 31 and the surrounding crushed stone layer 7 are finished so as to be substantially the same height. Thereafter, the plate-like member 31 is extracted to form a recess 7 a in the crushed stone layer 7.

  On the crushed stone layer 7, a sheet 9 having moisture resistance and ant proof properties is laid, and in the concave portion 7a, as shown in FIG. 5 (b), the concave portion 7a is continuous with the upper surface of the surrounding crushed stone layer 7. The sheet 9 is laid along the inner side surface and the bottom surface. Then, the discarded concrete 8 is placed from the top of the sheet 9 into the recess 7a. Further, before the discarded concrete 8 is hardened, a plate 10 made of steel or synthetic resin is placed in a range where the legs of the temporary support metal fitting 20 on the discarded concrete abut, as shown in FIG. The top surface of the plate 10, the top surface of the discarded concrete 8 and the top surface of the surrounding compacted crushed stone layer 7 are finished so as to have substantially the same height. Thereby, the substantially flat foundation support surface 2 is formed by the upper surface of the plate 10, the upper surface of the discarded concrete 8 and the upper surface of the surrounding crushed stone layer 7. The plate 10 may be placed after the discarded concrete 8 is hardened.

  Next, as shown in FIG. 6, the reinforcing bars 11 and 12 are arranged in a grid pattern on the basic support surface 2. These reinforcing bars 11, 12 include a lower main reinforcing bar 12 a arranged immediately below the axial direction of the precast concrete block 5.

  When the rebars 11 and 12 are arranged, as shown in FIG. 6, the precast concrete block 5 having the temporary support metal fitting 20 attached to the bottom surface is lifted and loaded, and is suspended at a predetermined position on the foundation support surface 2. At this time, as shown in FIG. 7A, the precast concrete block 5 is installed at a position where the two legs of the temporary support metal fitting 20 straddle the lower main reinforcement 12 a arranged in the axial direction of the precast concrete block 5. Then, a plurality of precast concrete blocks 5 are similarly arranged and connected on the foundation support surface 2 in the same manner.

  For the arrangement and connection of the precast concrete block 5, the precast concrete block 5 provided with the female joint 15 is arranged first, the amount of screwing of the height adjusting bolt 26 is adjusted, and the precast concrete block 5 is installed at a predetermined height. To do. Thereafter, the precast concrete block 5 provided with the male joint 16 is slowly lowered, and the male joint 16 is fitted and connected to the female joint 15.

  When a plurality of precast concrete blocks 5 to be arranged are closed in a rectangular shape, male joints 16 are provided on all of the faces of the precast concrete block to be arranged facing the plurality of adjacent precast concrete blocks. A plurality of male joints 16 can be simultaneously fitted and connected to the female joints 15 of adjacent precast concrete blocks.

  Next, the reinforcing bars 11 and 12 arranged on the foundation support surface 2 are lifted to a predetermined height to be embedded in the concrete floor slab 3 as shown in FIG. ) Etc. At this time, the space between the legs of the temporary support fitting 20 is opened downward, and the lower main muscle 12a placed on the foundation support surface 2 can be lifted in this space and supported at a predetermined height. it can. Therefore, the lower main reinforcement 12a can be arranged in the axial direction directly under the precast concrete block 5 as shown in FIG.

  Further, as shown in FIG. 4, a height display 28 indicating the height at which the reinforcing bar is arranged is attached to the leg portion 21 c of the temporary support metal fitting 20, and the reinforcing bar 11, 12 can be lifted and tied to the leg 21c at this position. Thereby, the reinforcing bars 11 and 12 can be arrange | positioned to exact height on the basis of the position of the precast concrete block 5. FIG. Further, the vertical bars 13 protruding from the bottom surface of the precast concrete block 5 and bent in the horizontal direction are bound to the reinforcing bars 11 and 12.

  The reinforcing bars 11 and 12 embedded in the concrete floor slab 3 are supported at a predetermined height when arranged on the foundation support surface 2, that is, before the precast concrete block 5 is arranged on the foundation support surface. You can also keep it.

Next, as shown in FIG. 7 (b), a formwork 32 is provided outside the outer periphery of the area forming the building foundation, that is, the area where the precast concrete block 5 is arranged, and the floor slab is placed in this formwork. Place concrete. The concrete is cast to a height at which the lower portions of the temporary support metal fitting 20 and the precast concrete block 5 are embedded, and the concrete floor slab 3 is formed and fixed integrally with the precast concrete block 5 serving as a rising portion.
Thereafter, the mortar grout is poured from the notch 5b formed above the female joint 15, and the gap between the male joint 16 and the female joint 15 and the shear cotter 17 are filled. Thereby, it connects with the state which the displacement between precast concrete blocks does not arise.

In addition, this invention is not limited to the above-mentioned embodiment, It can also be implemented as another form within the scope of the present invention.
For example, the temporary support metal fittings having other forms as shown in FIG. 8 can be used.

The temporary support fitting 40 shown in FIGS. 8 (a) and 8 (b) is formed by bending a steel bar 41 of a predetermined length to be attached to a bottom surface of a precast concrete block and a leg bent downward. A portion 43 is formed.
The attachment portion 42 is obtained by rolling a central portion in the length direction of the steel bar 41 into a flat plate shape and providing a vertical through hole 42a in this portion. The temporary support fitting 40 is attached to the bottom surface of the precast concrete block 5 by inserting a bolt (not shown) through the through hole 42 a and screwing the bolt into the female screw of the anchor member 27 embedded in the precast concrete block 5. Can do. Moreover, in the front end vicinity 43a of the said leg part 43 protruded below, the part which bent the steel bar 41 in the horizontal direction is rolled, and it has the flat plate shape which has thickness. A height adjusting bolt 44 is screwed into the screw hole formed in this portion, thereby forming a height adjusting portion for adjusting the height of the precast concrete block to be supported.

Moreover, the temporary support metal fitting 50 as shown in FIG.8 (c) and FIG.8 (d) can also be used.
The temporary support fitting 50 is formed by bending a steel bar 51 having a predetermined length, rolling a horizontal portion at the center, and mounting portions similar to the temporary support fitting 40 shown in FIGS. 52 is formed. The attachment portion 52 is provided with a through hole 52a through which a bolt is inserted. And the part bent down on the both sides of the attachment part becomes the leg part 53, and the external thread is formed in the outer peripheral surface of this leg part 53 vicinity. A long nut 54 is screwed onto the male screw to form a height adjusting portion, and the height of the precast concrete block 5 is adjusted by adjusting the screwing amount of the male screw into the long nut 54.

Moreover, as shown in FIG. 9, also in the foundation in which the underground beam was provided in the outer peripheral part of the building, a foundation can be formed using a precast concrete block and a temporary support metal fitting.
In the building foundation 60 shown in FIG. 9 (a), a pillar 63 made of steel is fixed to the bottom surface of the precast concrete block 5 to be placed in a portion where the ground 61 is dug deeply to be an underground beam 62. A temporary support bracket 20 is attached to the lower end. In this way, the precast concrete block 5 to which the temporary support metal fittings 20 are attached is also installed so as to straddle the reinforcing bars 64 on which the temporary support metal fittings are arranged in the same manner as shown in FIG. be able to.

Moreover, in the building foundation 70 shown in FIG.9 (b) as a reference example , concrete is previously cast in the part used as the underground beam 72 by deeply digging the ground 71, and an upper surface is finished substantially horizontal. Thereafter, the upper surface of the crushed stone layer 73 spread and ground on the ground is compacted to the same height as the upper surface of the concrete previously placed. On top of this, similarly to the building foundation 1 shown in FIG. 1, the rebar 74 can be disposed, and the precast concrete block 5 can be supported by the temporary support fitting 20, and the concrete of the concrete floor slab 75 can be placed.

  In each of the embodiments described above, the ground support layer is formed by compacting the crushed stone layer, but the ground support surface may be formed by compacting the excavated ground as it is.

  In addition, as a method of forming a building foundation using a precast concrete block and a temporary support metal fitting, a method including the following steps is particularly recommended.
  A method for forming a building foundation having a foundation slab formed on a foundation support surface and a rising portion raised on the foundation slab, wherein the foundation support surface is formed substantially horizontally on the ground. And a step of arranging reinforcing bars to be embedded almost horizontally in the foundation plate on the foundation support surface, and a bottom part of the precast concrete block constituting the rising part, the legs protruding downward from at least two places Attaching a temporary support bracket, and supporting the precast concrete block on the foundation support surface so that the legs protruding from two locations straddle the reinforcement; and the reinforcing bars arranged on the foundation support surface Lifting up and disposing in a predetermined height embedded in the foundation plate, embedding the reinforcing bar and the temporary support fitting, A method for forming a building foundation, including a step of placing concrete of the foundation slab so as to be in close contact with a leaf block.

  In this building foundation formation method, the temporary support fittings attached to the precast concrete block support the precast concrete block on the foundation support surface across the reinforcing bars arranged on the foundation support surface. It becomes easy to arrange the reinforcing bars to the side, and the efficiency of the bar arrangement work can be improved. That is, it is not necessary to feed the reinforcing bars arranged along the axial direction of the precast concrete block directly below the precast concrete block and send them out below the precast concrete block. Therefore, it is possible to efficiently form a building foundation in which the lower side of the precast concrete block is sufficiently reinforced by the reinforcing bars.
  The step of lifting the reinforcing bars arranged on the foundation support surface to a predetermined height embedded in the foundation plate is performed either before or after the step of supporting the precast concrete block on the foundation support surface. May be.

  Moreover, what has the following structures as a temporary support metal fitting used when forming a building foundation using a precast concrete block is desirable.
  Temporarily supporting a precast concrete block serving as the start-up part of a building foundation having a base plate formed on the base support surface and a start-up unit set up on the base plate, and then placed A temporary support fitting embedded in the concrete of the foundation plate, an attachment portion attached to a bottom surface of the precast concrete block, a leg portion projecting downward from at least two places of the attachment portion, and on the foundation support surface And a height adjusting part that enables the height of the leg part to be adjusted in a state where the leg part is supported, and a space between the leg parts is opened downward. .

  Since the space between the legs of this temporary support bracket is open downward, rebars are arranged on the foundation support surface before arranging the precast concrete blocks so that the legs straddle these rebars. A precast concrete block can be supported on the foundation support surface. As a result, it is not necessary to insert reinforcing bars below the precast concrete block, and it is easy to install reinforcing bars even when there is residual soil around the building foundation or when the foundation is formed in a narrow land. it can.
  In addition, since the space is formed between the leg portions, the concrete to be placed easily wraps around between the leg portions, and the precast concrete block and the base plate are firmly integrated.

  Moreover, the said temporary support metal fitting WHEREIN: The said leg part is formed with the rod-shaped steel member, and the position of the reinforcing bar is attached | subjected to the position equivalent to the height of the reinforcing bar arrange | positioned at the said base plate. Things are desirable.

  In this temporary support bracket, the reinforcing bars to be embedded in the concrete of the foundation slab can be efficiently arranged at an accurate height by arranging the reinforcing bars based on the above indications, based on the height of the arranged precast concrete block. it can.

  In such a temporary support metal fitting, it is possible to support the precast concrete block and easily arrange a reinforcing bar directly below the axial direction of the precast concrete block to efficiently form a building foundation.

  In addition, when using the temporary support bracket, the discarded concrete is not necessarily required. A steel plate or the like is placed on a region where the temporary support bracket is supported on the foundation support surface, and the temporary support bracket is supported on the steel plate. Also good.

1: building foundation, 2: foundation support surface, 3: concrete floor slab, 4: start-up part, 5: precast concrete block, 6: ground, 7: crushed stone layer, 7a: recess provided in crushed stone layer, 8: Discarded concrete, 9: Sheet, 10: Plate, 11, 12: Reinforcing bar, 12a: Lower main bar, 13 vertical bar, 14: Horizontal bar, 14a: Upper main bar, 15: Female joint, 15a: Support base of female joint, 15b : Support part of female joint, 15c: Anchor muscle, 16: Male joint, 16a: Base part of male joint, 16b: Projection part of male joint, 16c: Anchor muscle, 17: Shear cotter,
20: Temporary support brackets 21, 22: Steel bars, 23: Steel plate material (mounting plate), 24, 25: Steel plate material (leg plate), 26: Height adjusting bolt, 27: Anchor member,
28: height display, 31: plate-like member (woodcut), 32: formwork,
40: Temporary support bracket, 41: Steel bar, 42: Mounting portion, 42a: Through hole,
43: Leg part 44: Height adjusting bolt 50: Temporary support bracket 51: Steel bar 52: Attachment part 53: Leg part 54: Long nut
60: building foundation, 61: ground, 62: underground beam, 63: support, 64: rebar, 70: building foundation, 71: ground, 72: underground beam, 73: crushed stone layer, 74: rebar, 75 : Concrete floor slab

Claims (5)

A method for forming a building foundation having a foundation plate formed on a foundation support surface and a start-up part launched on the foundation plate,
Forming the foundation support surface substantially horizontally on the ground; and
Arranging the reinforcing bars embedded substantially horizontally in the foundation plate on the foundation support surface;
Attaching a temporary support bracket to the bottom surface of the precast concrete block constituting the rising portion, and supporting the precast concrete block on the foundation support surface by the temporary support bracket;
Embedding the reinforcing bar and the temporary support metal, and placing the concrete of the foundation plate so as to be in close contact with the precast concrete block,
In the step of forming the foundation support surface, the ground is compacted and a plate-like member is embedded in the ground at a position where the temporary support fitting is supported, and the upper surface of the plate-like member and the periphery of the plate-like member are compacted. A process of finishing so that the surface of the ground is almost the same height,
Removing the plate-like member, throwing the concrete into the recess after the removal, and leveling the upper surface to approximately the same height as the surface of the surrounding ground. Method. A step of laying a sheet having moisture or ant proof properties continuously from the ground around the concave portion to the inside of the concave portion after the plate-shaped member is extracted and before placing concrete in the concave portion. Including
The method for forming a building foundation according to claim 1, wherein the discarded concrete is cast on the sheet. The temporary support metal fitting has a height adjustment part that enables adjustment of the height of the leg part,
The step of setting the precast concrete block to a predetermined height by the height adjusting unit is included after the step of supporting the precast concrete block on the foundation support surface. A method of forming a building foundation as described in 1. The temporary support metal fitting has a leg portion protruding downward from at least two locations, and the leg portion protruding from two locations is supported on the foundation support surface so as to straddle the reinforcing bar,
4. The method according to claim 1, further comprising a step of lifting the reinforcing bars arranged on the foundation support surface upward and disposing the reinforcing bars at a predetermined height embedded in the foundation plate. 5. the method of forming of the building foundation.   The building foundation according to claim 4, wherein the step of lifting and supporting the reinforcing bars arranged on the foundation support surface includes a step of binding the reinforcing bars to the legs. Forming method.

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