JP7338995B2 - Building foundation construction method and partition frame - Google Patents

Description

TECHNICAL FIELD The present invention relates to a building foundation construction method for constructing a building foundation on the upper side of a pile-shaped ground reinforcement driven into the ground, and a partition frame that can be used in this building foundation construction method.

Conventionally, in order to prevent uneven subsidence of buildings on soft ground, a pile-shaped ground reinforcement method has been used in which pile-shaped ground reinforcements such as steel pipe piles or concrete piles are driven into the ground. Further, in the conventional method of constructing the concrete building foundation on the pile-shaped ground reinforcement, in order to eliminate the influence of the construction error of the pile head level of the pile-shaped ground reinforcement, the pile head and the concrete building foundation It was also practiced to place dump concrete between the footings.

In addition, in Patent Document 1, a steel pipe pile driving process for driving a plurality of steel pipe piles from the ground surface of soft ground to the hard supporting ground, and the upper end positions of these steel pipe piles that are driven are even. A method for improving soft ground is disclosed, which includes a steel pipe pile cutting step of cutting the upper end side of the steel pipe pile and an H-shaped steel fixing step of horizontally fixing the H-shaped steel to each of the steel pipe piles.

Japanese Patent Application Laid-Open No. 2004-60363

However, in order to place the dump concrete between the pile head and the footing of the concrete building foundation, a pump truck for pouring the dump concrete is required at the construction site, which increases the construction cost. There is In addition, if an attempt is made to increase the bearing capacity of the dump concrete as the bearing capacity of the pile-shaped ground reinforcement increases, the viscosity of the dump concrete increases, making it difficult to smoothly flow the dump concrete within the formwork.

In view of the above circumstances, the present invention provides a building foundation construction method that eliminates the need to place dump concrete between the pile head of a pile-shaped ground reinforcement driven into the ground and the bottom surface of the building foundation, and An object of the present invention is to provide a partition frame that can be used in this building foundation construction method.

In order to solve the above problems, the construction method of the building foundation of the present invention includes a step of exposing the pile head of the pile-shaped ground reinforcing body driven into the ground, and a pile for placing concrete on the upper side of the pile head. A step of arranging a partition frame that forms an overhead space, a step of laying crushed stone around the partition frame and compacting it, a step of providing a building foundation formwork in an area including the pile overhead space, and the formwork. and C. placing concrete in the inside and the above-mentioned pile head space.

With the above method, concrete for the building foundation is placed in the formwork for making the building foundation and in the space above the pile head, so that it is integrated with the building foundation in the space above the pile head at the same time as the building foundation. A concrete part above the pile head is formed. As a result, it is possible to eliminate the influence of construction error at the level of the pile head without using dump concrete. That is, when an error occurs in the pile head level with respect to the bottom side of the building foundation, this error can be dealt with by changing the thickness of the pile head concrete portion. Moreover, since it is not necessary to use discarded concrete, it is possible to facilitate the fabrication of the building foundation and reduce the cost. In addition, in the building foundation manufactured by this method, the pile head of the pile-shaped ground reinforcement does not enter the above-mentioned concrete part above the pile head, and the building foundation is placed so that it can slide on the above-mentioned pile head via the above-mentioned concrete part above the pile head. As a result, the structure reduces the bending load on the pile head due to an earthquake.

The inner periphery of the partition frame may be spaced apart from the peripheral edge of the pile head. According to this, since the outer shape of the above-mentioned pile head concrete part is larger than the outer shape of the pile head, even if the contact point between the pile head and the above-mentioned pile head concrete part is displaced due to an earthquake or the like, the pile head will not be deformed. It is possible to keep the entire upper surface in contact with the above pile head concrete portion.

In addition, the partition frame of the present invention prevents the crushed stone laid around the pile head of the pile-shaped ground reinforcement driven into the ground from entering the pile head side, and the concrete placed on the pile head is prevented from entering the pile head. It is characterized by having a rising wall that stops the flow to the crushed stone side.

By using the above-mentioned partition frame for producing the building foundation, the concrete part forming part of the building foundation can be accurately constructed on the above-mentioned pile heads.

Further, the partition frame may include an outer protruding portion that protrudes outward from a lower edge of the rising wall. According to this, since the crushed stone laid on the peripheral side of the partition frame presses the outer protruding portion downward, the partition frame is prevented from being lifted up and detached due to vibration when compacting the crushed stone. be able to. Further, even if the partition frame is made of easily deformable resin material or the like, deformation of the lower side of the rising wall is prevented by the outer protruding portion, so that the compacted crushed stone does not deform the rising wall. Even if pressure is applied to the upper side, deformation of the upper side of the rising wall is suppressed.

The partition frame may include a rib portion connected to the rising wall and the outer projecting portion. According to this, the effect of further suppressing deformation of the rising wall can be obtained.

The partition frame may have a fixing portion for fixing the partition frame to the ground, or may have a fixing member mounting portion to which a fixing member for fixing the partition frame to the ground is mounted. According to this, the partition frame can be fixed to the ground side by the fixing portion or the separately mounted fixing member, so that the partition frame is more difficult to rise.

Further, in the partition frame, the outer shape of the upper part of the rising wall is smaller than the inner shape of the lower part of the rising wall, and the upper part of the rising wall is set up by another partition frame. It may be adapted to fit within the lower side of the wall. According to this, when stacking a plurality of partition frames, the upper and lower partition frames can be partially overlapped, so that the volume of stacking can be reduced.

With the construction method of the building foundation of the present invention, it is not necessary to place dump concrete between the pile head of the pile-shaped ground reinforcement driven into the ground and the bottom side of the building foundation, so foundation construction can be performed. Ease of construction and reduction of construction costs can be achieved. In addition, by using the partition frame of the present invention to fabricate a building foundation, a concrete portion forming a part of the building foundation can be accurately constructed on the pile head.

It is explanatory drawing which showed the construction method of the building foundation which concerns on embodiment of this invention. 1(A) is a cross-sectional view of a building foundation fabricated by the building foundation construction method of FIG. 1, and FIG. 1(B) is a plan view of the same. It is the perspective view which showed the partition frame which concerns on embodiment of this invention. FIG. 4 is a cross-sectional view showing a part when two partition frames of FIG. 3 are vertically stacked; FIG. 5 is a perspective view showing a partition frame according to another embodiment of the present invention; FIG. 6 is an explanatory view showing a state in which the partition frame in FIG. 5 is pressed downward by crushed stones and a state in which the partition frame is fixed to the ground with a nail-like object; FIG. 5 is a perspective view showing a partition frame according to another embodiment of the present invention; FIG. 5 is a perspective view showing a partition frame according to another embodiment of the present invention;

A construction method for a building foundation according to an embodiment of the present invention will be described below with reference to the accompanying drawings. As shown in FIG. 1(a), at the construction site where the pile-shaped ground reinforcing bodies 2 are driven into the ground and covered with soil, the soil is excavated (root cutting). In this work, the soil is dug up so that the upper end surface of the pile head 21 of the pile-shaped ground reinforcing body 2 is flush with the bottom of the excavated root. In addition, this work exposes the pile heads 21 of the plurality of pile-shaped ground reinforcements 2 present at the construction site, and forms the trenches 3 for the footings of the building foundation. Steel pipe piles, concrete piles, or the like are used as the pile-shaped ground reinforcing bodies 2 . A steel pipe pile is provided with a pile head cap on the pile head 21 .

Next, as shown in (b) of the figure, a partition frame 100 is arranged on the bottom of the excavation so as to surround the pile head 21 of the pile-shaped ground reinforcement 2 . At this time, the pile head 21 is positioned at the center of the partition frame 100 . The partition frame 100 can be produced by cutting a round steel pipe into a length of about 70 mm, for example. By arranging the partition frame 100 , a pile head space 31 surrounded by the partition frame 100 is formed above the pile head 21 . Moreover, the partition frame 100 has an inner diameter that ensures a distance of, for example, 30 mm or more between the inner peripheral portion of the partition frame 100 and the peripheral edge of the pile head 21 .

Next, as shown in (c) of the figure, crushed stone 4 is laid on the bottom of the excavated area except for the inside of the partition frame 100, and this crushed stone 4 is compacted with a rammer or a compactor. At this time, the partition frame 100 functions to prevent the crushed stone 4 from entering the space 31 above the pile head. When the crushed stone 4 is compacted, as shown in (d) of FIG. is fixed. Further, in a place where the ground is lower than the pile head 21 in the partition frame 100, the soil 41 is replenished to a height flush with the pile head 21.例文帳に追加The crushed stone 4 is compacted according to the standards for crushed stone ground work for spread foundations. The upper level of the crushed stone 4 becomes the standard for the bottom of the building foundation.

After the crushed stone 4 is compacted, a formwork 5 for building a building foundation is provided in an area including the pile overhead space 31 . Reinforcing bars (not shown) are provided in the formwork 5 .

Next, concrete (ready-mixed concrete) is poured into the formwork 5 and the space 31 above the pile head. By placing the concrete, a building foundation 6 is produced as shown in FIGS. 2(A) and 2(B). The building foundation 6 has a raised portion 62 on the footing portion 61 and a pile overhead concrete portion 63 below the footing portion 61 . That is, by placing the concrete for the building foundation 6 also in the pile head space 31, the pile head concrete part 63 is integrated with the building foundation 6 in the pile head space 31 at the same time as the building foundation 6 is produced. is formed. During this placement, the partition frame 100 prevents the concrete from flowing out of the frame.

After curing the building foundation 6, the formwork 5 is removed, and the footing portion 61 is covered with soil. In addition, in the foundation structure including the building foundation 6 and the pile-shaped ground reinforcement 2, the pile head 21 of the pile-shaped ground reinforcement 2 does not enter the pile head concrete portion 63 on the bottom side of the building foundation 6, The building foundation 6 is placed on the pile head 21 through the pile head concrete portion 63 so as to be able to slide sideways, thereby reducing the bending load of the pile head 21 due to an earthquake. Moreover, the above-mentioned partition frame 100 makes it possible to accurately form the concrete portion forming part of the building foundation above the pile head, that is, the above-mentioned pile-head concrete portion 63 . The partition frame 100 is left under the footing portion 61 .

In the construction method of the building foundation, concrete for the building foundation is placed in the formwork 5 for making the building foundation 6 and in the space 31 above the pile head. , the pile overhead concrete portion 63 integral with the building foundation 6 is formed. As a result, the influence of construction error at the level of the pile head 21 can be eliminated without using dump concrete. That is, when an error occurs in the pile head level with respect to the bottom side of the building foundation 6, this error can be dealt with by changing the thickness of the pile head concrete portion 63. Moreover, since it is not necessary to use discarded concrete, it is possible to facilitate the fabrication of the building foundation and reduce the cost.

In the construction method using the partition frame 100, the inner peripheral portion of the partition frame 100 is separated from the peripheral edge of the pile head 21, and the outer shape (outer diameter) of the pile head concrete portion 63 is the above Since it is larger than the outer shape (outer diameter) of the pile head 21, even if the contact point between the pile head 21 and the pile head upper concrete portion 63 shifts due to an earthquake or the like, the entire upper surface of the pile head 21 is above the pile head. It becomes possible to maintain a state of contact with the concrete portion 63 .

Next, the resin partition frame 1 of this embodiment will be described with reference to FIGS. 3 and 4. FIG. This partition frame 1 prevents the crushed stone 4 laid around the pile head 21 of the pile-shaped ground reinforcing body 2 from entering the pile head 21 side, and prevents the concrete placed on the pile head 21 from breaking the crushed stone. A rising wall 11 is provided to stop the flow to the 4 side. The rising wall 11 has a lower wall portion (lower side portion) 11a and an upper wall portion (upper side portion) 11b having different sizes. larger than the outer diameter. The thickness of the lower wall portion 11a and the thickness of the upper wall portion 11b are the same.

With the partition frame 1 having such a structure, the lower wall portion 11a of another partition frame 1 can be fitted onto the upper wall portion 11b of the partition frame 1 concerned. Therefore, when stacking a plurality of partition frames 1, the lower wall portion 11a of the upper partition frame 1 is overlapped with the upper wall portion 11b of the lower partition frame 1 to reduce the stacking volume. Since the partition frame 1 is made of resin and is lightweight, many partition frames 1 can be stacked. As the resin for the partition frame 1, a biodegradable resin that is decomposed into water and carbon dioxide by the action of microorganisms in the soil can be used.

Here, in the construction of the building foundation, if the partition frame 100 made of the steel pipe is used, the partition frame 100 will not be lifted when the crushed stone 4 is compacted. When the building foundation is constructed using the lightweight partition frame 1 made of resin or the like, vibrations generated by rammers or the like during compaction of the crushed stone 4 may cause the partition frame 1 to break. It may pop up and come off.

Therefore, a partition frame 1A shown in FIG. As with the partition frame 1, the partition frame 1A prevents the crushed stone 4 from entering the pile head 21 side and prevents the concrete placed on the pile head 21 from flowing toward the crushed stone 4 side. It has an upper wall 11 and further has a ring-shaped outward protrusion 12 horizontally protruding outward from the lower edge of the rising wall 11 . In addition, a plurality of through holes 12a are formed in the outer protruding portion 12 to serve as a fixing member mounting portion for driving a nail-like object (peg or the like) 15 as a fixing member into the ground.

In the case of the partition frame 1A, as shown in FIG. 6, the outer projecting portion 12 is pressed downward by the crushed stones 4 laid on the peripheral side of the partition frame 1A, so that the crushed stones 4 are compacted. It is possible to prevent the partition frame 1A from being lifted up due to the vibration at the time. Further, even if the partition frame 1A is made of a resin that is easily deformed, the deformation of the lower wall portion 11a of the rising wall 11 is prevented by the outer protruding portion 12, so that the crushed stone 4 prevents the rising wall from deforming. Even if pressure is applied to the upper side of the rising wall 11, deformation of the upper side of the rising wall 11 can be suppressed.

Further, in the case of the partition frame 1A, the partition frame 1A can be fixed to the ground by driving the nail-like object 15 into the ground (root cutting bottom) from the through-hole portion 12a. This makes it more difficult for the partition frame 1A to rise. The partition frame 1A having the outer projecting portion 12 does not sink into the ground when the crushed stone 4 is compacted. can be to some extent.

A partition frame 1B shown in FIG. 7 can also be used. The partition frame 1B has a structure in which a rib portion 13 connected to the rising wall 11 and the outer projecting portion 12 is added to the partition frame 1A. The rib portion 13 has a right-angled side portion, and this right-angled side portion is fixed to the rising wall 11 and the outer projecting portion 12 . Of course, the rib portion 13 may be formed integrally with the partition frame 1A. By providing the rib portion 13, a further effect of suppressing deformation of the rising wall 11 can be obtained. Further, in this example, the height of the rib portion 13 is set to be less than the height of the lower wall portion 11a. Therefore, when stacking a plurality of partition frames 1B, the lower wall portion 11a of the upper partition frame 1B is placed at the lower wall portion 11a. can be superimposed on the upper wall portion 11b of the lower partition frame 1B to reduce the stacking volume.

A partition frame 1C shown in FIG. 8 can also be used. This partition frame 1C has a structure in which a nail-like object 14 as a fixing member for fixing the partition frame to the ground is added to the structure of the partition frame 1 described above. The nail-like object 14 has its upper part embedded in a resin convex portion 16 as a fixing member mounting portion which is formed in an outward convex shape on the outer peripheral portion of the lower wall portion 11a. The nail-like object 14 can be inserted into the ground by pressing or striking from the ground. It should be noted that the resistance to lifting can be increased by forming a warped portion on the tip side of the nail-like object 14 . Further, the nail-like object 14 may be detachably attached to the resin protrusion 16 . Further, the nail-like object 14 integrated with the resin protrusion 16 can be used as a fixing portion for fixing the partition frame 1C to the ground.

Further, although not shown in the drawings, instead of the ring-shaped continuous outer protrusion 12, a plurality of outer protrusions are provided in a dispersed manner, and the dispersed outer protrusions are engaged with each other. The nail-like object 15 may be driven into the ground. Although this configuration cannot suppress the deformation of the partition frame, the effect of suppressing the floating is obtained.

Moreover, although the partition frame 1 and the like have a circular frame shape, the shape is not limited to such a shape, and may be formed in a square frame shape. Further, the rising wall 11 is not limited to being formed in a cylindrical shape or a square tube shape. The rising wall 11 may be formed in a cylindrical shape like a frustum. In addition, when stacking a plurality of partition frames 1 and the like, the stacking volume can be reduced.

Although the embodiments of the present invention have been described above with reference to the drawings, the present invention is not limited to the illustrated embodiments. Various modifications and variations can be made to the illustrated embodiment within the same scope as the present invention or within an equivalent scope.

1: Partition frame 1A: Partition frame 1B: Partition frame 1C: Partition frame 2: Pile-shaped ground reinforcement 3: Grooving section 4: Crushed stone 5: Formwork 6: Building foundation 11: Rising wall 11a: Lower wall section 11b : Upper wall portion 12 : Outer protruding portion 12a : Through hole portion 13 : Rib portion 14 : Nail-like object (fixing member)
15: Nail-like object 16: Resin convex portion (fixing member mounting portion)
21: Pile head 31: Pile head space 41: Soil 61: Footing part 62: Rising part 63: Pile head concrete part 100: Partition frame

Claims (6)

A partition frame that forms a space above the pile head for concrete placing above the pile head of the pile-shaped ground reinforcement driven into the ground,
a continuous rising wall that prevents crushed stone laid on the peripheral side of the pile head from entering into the pile head side and prevents concrete placed on the pile head from flowing toward the crushed stone side; and the rising wall. and an outer protruding portion that protrudes outward from the lower edge of the partition frame and is pressed by the crushed stone to suppress the lifting of the partition frame. 2. The partition frame according to claim 1, further comprising a rib portion connected to said rising wall and said outer projecting portion. A partition frame that forms a space above the pile head for concrete placing above the pile head of the pile-shaped ground reinforcement driven into the ground,
A continuous rising wall that prevents the crushed stone laid on the peripheral side of the pile head from entering the pile head side and prevents the concrete that is placed on the pile head from flowing to the crushed stone side , and the partition frame. A partition frame , comprising a fixing portion for fixing to the ground or a fixing member mounting portion for mounting a fixing member for fixing the partition frame to the ground. Rise to stop the crushed stone laid around the pile head of the pile-shaped ground reinforcement driven into the ground from entering the pile head side and to stop the concrete cast on the pile head from flowing to the crushed stone side The outer shape of the upper portion of the rising wall is smaller than the inner shape of the lower portion of the rising wall, and the upper portion of the rising wall is formed by the rising of another partition frame. A partition frame that fits within the lower side of a wall . The step of exposing the pile head of the pile-shaped ground reinforcing body driven into the ground, and forming a pile head space for concrete placing above the pile head, according to any one of claims 1 to 4. A step of arranging the ready-made partition frame described above, a step of laying crushed stone around the partition frame and compacting it, a step of providing a building foundation formwork in an area including the above-mentioned pile overhead space, and a step of forming the formwork and a step of placing concrete in the space above the pile head . 6. The method of constructing a building foundation according to claim 5, wherein the inner peripheral portion of the partition frame is separated from the peripheral edge of the pile head.

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