JP7278858B2 - Pile head caps and building foundations - Google Patents

Description

The present invention relates to a pile head cap attached to the pile head of a steel pipe pile driven into the ground, and a building foundation using this pile head cap.

Conventionally, in order to prevent uneven subsidence of buildings on soft ground, a pile-shaped ground reinforcement method has been used in which cylindrical steel pipe piles are driven into the ground. In this pile-shaped ground reinforcement method, after driving the steel pipe piles, a pile head cap is attached to the pile head of the steel pipe pile by welding and backfilling is performed once. Digging up the soil and carrying out foundation work.

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 the method of welding a steel plate as a pile head cap to the pile head of a steel pipe pile on site, welding may not be possible due to weather.

In view of the above circumstances, an object of the present invention is to provide a pile head cap and a building foundation that can eliminate the need for work such as steel plate welding to the pile head on site.

In order to solve the above problems, the pile head cap of the present invention protrudes downward from the plate-shaped part and the lower surface side of the plate-shaped part, and covers the pile head of the steel pipe pile. A protruding portion facing at least one of the inner peripheral surface and the outer peripheral surface of the edge side is provided.

With the above configuration, the steel pipe pile can be mounted simply by covering the pile head with the pile head cap, which eliminates the need for on-site welding work. Then, even if an upward lifting force acts on the plate-shaped portion and the pile head cap separates from the pile head, it is not welded, so it can be installed simply by covering the pile head from above. . On the other hand, when a lateral force is applied to the plate-like portion, the protruding portion abuts against the peripheral surface of the upper edge of the pile head, so that the pile head cap is less likely to come off from the pile head and is less likely to be displaced. Furthermore, when an obliquely upward force is applied to the outer peripheral edge of the plate-like portion, the lower end side of the projecting portion can be brought into contact with the upper edge side peripheral surface of the pile head when the plate-like portion is inclined. It is possible to make it difficult for the pile head cap to come off from the pile head with respect to forces in directions other than the straight upward direction.

By the way, due to the improvement of the bearing capacity of the steel pipe piles, the diameter of the steel pipe piles is reduced and the driving pitch of the steel pipe piles is increased. A problem arises in that a large load is locally applied to the concrete. If the plate-like portion has an outer dimension larger than the outer dimension of the pile head of the steel pipe pile, the load locally applied to the foundation concrete can be reduced, and the performance of the steel pipe pile having high bearing capacity can be sufficiently improved. can be demonstrated.

As the projecting portion, a plurality of projecting portions facing the inner peripheral surface may be present in an interspersed manner, and a rib portion connected to the plurality of projecting portions may be provided. According to this, the strength of the pile head cap is improved by the rib portion, cracking and breakage can be reduced, the rigidity of the pile head cap is improved, deformation of the pile head cap is less likely to occur, and the building The load can be transmitted substantially uniformly to the steel pipe pile. In addition, it is possible to stack two pile head caps in a compact manner by facing each other with the protruding portions forming sides thereof and shifting the positions of the protruding portions, thereby contributing to a reduction in volume during transportation and the like.

Alternatively, as the protrusion, a protrusion facing the inner peripheral surface may be continuously formed in a wall shape. According to this, although it cannot contribute to the volume reduction as described above, the strength of the pile head cap can be improved, cracking and breakage can be reduced, the rigidity of the pile head cap is improved, and the pile head cap deformation is less likely to occur, and the building load can be transmitted substantially uniformly to the steel pipe pile.

As the projecting portion, a projecting portion facing the outer peripheral surface may be continuously formed in a wall shape. According to this, although it cannot contribute to the volume reduction as described above, the strength of the pile head cap can be improved, cracking and breakage can be reduced, the rigidity of the pile head cap is improved, and the pile head cap deformation is less likely to occur, and the building load can be transmitted substantially uniformly to the steel pipe pile.

The outer shape of the projecting portion facing the outer peripheral surface may form an oblique shape that becomes smaller toward the bottom. According to this, in a state in which the pile head cap is placed on the pile head of the steel pipe pile, the outer shape of the projecting portion facing the outer peripheral surface approaches the outer peripheral surface of the steel pipe pile toward the lower side. It is possible to minimize the amount of protrusion of the lower end surface of the protrusion from the outer peripheral surface of the steel pipe pile. As a result, it is possible to prevent the claws of the bucket of the heavy equipment from being caught in the pile head cap when digging up the soil around the steel pipe pile.

A recess for positioning may be formed on the upper surface of the plate-like portion. According to this, the surveying pole can be positioned using the concave portion, and light wave distance measurement for measuring pile misalignment after pile construction can be quickly performed.

In addition, the building foundation of the present invention is a building foundation comprising a steel pipe pile and a continuous foundation, and is directly on any of the pile head caps provided at the pile head of the steel pipe pile or via dump concrete. It is characterized in that the footing part of the continuous footing is positioned.

According to the present invention, it is possible to eliminate the need for on-site work such as steel plate welding to the pile head.

1 is a see-through perspective view showing a pile head cap and a steel pipe pile according to an embodiment of the present invention; FIG. 1(A) is a see-through perspective view of the pile head cap of FIG. 1 as seen from above, and FIG. 1(B) is a perspective view of the pile head cap of FIG. 1 as seen from below. FIG. 2 is a see-through perspective view showing a state in which two pile head caps of FIG. 1 are superimposed; It is an explanatory view showing a building foundation concerning an embodiment of the present invention. 5 is a plan view of the building foundation of FIG. 4; FIG. FIG. 6 is a see-through perspective view showing a pile head cap and a steel pipe pile according to another embodiment of the present invention; 7 is a see-through perspective view of the pile head cap of FIG. 6 as seen from below; FIG. 6(A) is a see-through perspective view of the pile head cap of FIG. 6 attached to the steel pipe pile, and FIG. 7(B) is a see-through side view thereof.

(Embodiment 1)
BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.
As shown in FIGS. 1, 2A, and 2B, the pile head cap 1 according to this embodiment includes, for example, a circular iron plate portion 11 having a flat upper surface, which is a plate-like portion, and the iron plate and a protruding portion 12 protruding downward from the lower surface side of the portion 11, and is attached to the pile head 51 so as to block the upper end opening of the cylindrical steel pipe pile 5 embedded in the ground. This pile head cap 1 is manufactured, for example, by casting.

The iron plate portion 11 has an outer dimension (diameter as an example) larger than the outer dimension (outer diameter as an example) of the steel pipe pile 5 . In addition, a circular thin-walled region 11a is formed at a portion of the lower surface (bottom surface) of the iron plate portion 11 that is not easily affected by the load, thereby reducing the weight. A positioning concave portion 11b is formed at the center of the upper surface (surface) of the iron plate portion 11. As shown in FIG. The concave portion 11b has, for example, an inverted cone shape.

The projecting portion 12 is positioned inside the pile head 51 in a state of being covered with the pile head 51 of the steel pipe pile 5 and faces the inner peripheral surface of the upper end side of the pile head 51 . In this embodiment, four protruding portions 12 are scattered around the center of the circular iron plate portion 1 at intervals of 90 degrees in the circumferential direction outside the thinned region 11a. A rib portion 13 is provided on the lower surface of the iron plate portion 11 to be connected to the protruding portion 12 to improve the rigidity and strength of the iron plate portion 1 . The rib portion 13 is lower in height than the projecting portion 12 and is formed so as to pass through the thin region 11a. In addition, although the amount of material for manufacturing the pile head cap 1 increases, the height of the rib portion 13 may be set to the same height as the protruding portion 12, and the thin portion 11a may not be formed. good too.

Moreover, the rib portion 13 connects the two projecting portions 12 facing each other, and is formed in a cross shape passing through the center side of the iron plate portion 11 . Of course, the number of the protruding portions 12 is not limited to four, and three protruding portions 12 may be arranged at intervals of 120 degrees in the circumferential direction to form the rib portion 13 in a three-forked shape. Two rib portions 13 may be arranged at intervals of 180 degrees to form a straight line. Alternatively, the number of protrusions 12 may be five or more.

4 and 5 show a building foundation 100 of this embodiment using the pile head cap 1 described above. In this building foundation 100, the pile head 51 of the steel pipe pile 5 is located at a location dug below the ground level GL, and the pile head cap 1 is mounted on the pile head 51. A footing portion 61 of the continuous foundation 6 is supported by the top of the pile head cap 1 via a sacrificial concrete 62 . It should be noted that a structure in which the footing portion 61 of the continuous foundation 6 is directly supported on the pile head cap 1 without interposing the dump concrete 62 may be employed.

The pile head cap 1 having the above configuration can be mounted by simply covering the pile head of the steel pipe pile 5 with the pile head cap 1, which eliminates the need for on-site welding work. Even if an upward lifting force acts on the iron plate portion 11 and the pile head cap 1 separates from the pile head 51, the pile head cap 1 is again placed over the pile head 51 because it is not welded. You can put it on by itself. On the other hand, when a lateral force is applied to the iron plate portion 11, the protruding portion 12 contacts the peripheral surface of the upper edge of the pile head 51, so the pile head cap 1 is difficult to come off from the pile head 51, and misalignment is prevented. Hard to come by. Further, when the iron plate portion 11 is obliquely tilted by applying a force in an obliquely upward direction to the outer peripheral edge of the iron plate portion 11, the lower end side of the projecting portion 12 contacts the upper edge side peripheral surface of the pile head 51. If the length of the protruding portion 12 and the gap between the protruding portion 12 and the inner peripheral surface of the pile head 51 are set, the pile head cap 1 is less likely to come off from the pile head 51 with respect to forces in directions other than the upward direction. can.

In addition, since the iron plate portion 11 having an outer dimension larger than the outer dimension of the steel pipe pile 5 is positioned on the pile head 51, the load locally applied to the foundation concrete can be reduced, and the performance of the steel pipe pile 5 having high bearing capacity. can be fully demonstrated. In addition, the outer dimensions of the iron plate portion 11 are not limited to being larger than the outer dimensions of the steel pipe piles 5 . The present invention includes a configuration in which the outer dimensions of the iron plate portion 11 are the same as the outer dimensions of the steel pipe pile 5 .

When a plurality of the protruding portions 12 are present in a scattered arrangement and a rib portion 13 connected to the plurality of protruding portions 12 is provided, the strength of the pile head cap 1 is improved by the rib portion 13, and cracks are prevented. Damage can be reduced, the rigidity of the pile head cap 1 is improved, deformation of the pile head cap 1 is less likely to occur, and the building load can be transmitted substantially uniformly to the steel pipe pile. Even if the pile head cap 1 is slightly deformed, by arranging the protruding portion 12 as close to the inner peripheral surface of the steel pipe pile 5 as possible, the pile head cap 1 is slightly deformed. The protruding portion 12 is crimped to the inner peripheral surface of the steel pipe pile 5 so that the deformation of the pile head cap 1 can be suppressed by the steel pipe pile 5 .

In addition, as shown in FIG. 3, two pile head caps 1 are compactly superimposed with their projecting portions 12 forming sides facing each other and the positions of the projecting portions 12 shifted to contribute to a reduction in volume during transportation and the like. is also possible.

When the concave portion 11b for positioning is formed on the upper surface of the iron plate portion 11, the surveying pole can be positioned and erected using the concave portion 11b, and the optical distance measurement for measuring the deviation of the pile center after pile construction. etc. can be performed quickly.

A square rib may be formed instead of the cross-shaped rib 13, and a triangular rib may be formed instead of the three-forked rib 13. Moreover, the iron plate portion 11 is not limited to a circular shape.

Moreover, although it is not possible to compactly stack the projections as described above, the projections may be continuously formed in a wall shape instead of the scattered arrangement. Even with such a configuration, the strength of the pile head cap is improved, cracking and breakage can be reduced, the rigidity of the pile head cap is improved, deformation of the pile head cap is less likely to occur, and the building load is reduced by the steel pipe. It can be transmitted to the pile substantially uniformly.

The degree of the outer dimension of the iron plate portion 11 with respect to the outer dimension of the steel pipe pile 5 is, for example, when the diameter of the iron plate portion 11 is R and the outer diameter of the steel pipe pile 5 is r, It is desirable to be in the range of 1.1r≤R≤1.3r. The same applies to the following embodiments.

(Embodiment 2)
Another embodiment of the present invention will now be described with reference to the accompanying drawings.
As shown in FIGS. 6, 7, 8(A) and 8(B), the pile head cap 2 according to this embodiment is a circular iron plate portion having outer dimensions larger than the outer dimensions of the steel pipe pile 5. A (plate-shaped portion) 21 protrudes downward from the lower surface side of the iron plate portion 21, and inwardly protrudes facing the inner peripheral surface of the upper edge side of the pile head 51 while being covered with the pile head 51 of the steel pipe pile 5. It has a portion 22 and an outer projecting portion 23 facing the outer peripheral surface. A positioning concave portion 21 a is formed at the center of the upper surface of the iron plate portion 21 .

There are four inner protruding portions 22, which are interspersed at intervals of 90 degrees in the circumferential direction around the center of the circular iron plate portion 21. As shown in FIG. On the other hand, the outer projecting portion 23 is formed continuously in a wall shape. The space between the inner protruding portion 22 and the outer protruding portion 23 is made wider than the thickness of the pile head 51, but the space between the inner protruding portion 22 and the outer protruding portion 23 is made as narrow as possible, and , the longer the protruding lengths of the inner protruding portion 22 and the outer protruding portion 23, the lower end sides of the protruding portions 22 and 23 are inclined to the upper edge side peripheral surface of the pile head 51 when the iron plate portion 21 is inclined. , the pile head cap 2 can be made difficult to come off from the pile head 51.例文帳に追加It should be noted that a pile head cap that does not include the inner protruding portion 22 may be used.

Further, the outer shape (outer diameter as an example) of the outer protruding portion 23 is not the same at the top and bottom, but has an oblique shape that becomes smaller toward the bottom. In other words, the outer side surface 23a of the outer protruding portion 23 is not vertical, but is inclined toward the center of the iron plate portion 21 toward the lower side.

In the oblique outer shape of the outer protruding portion 23, the angle α between the outer side surface 23a of the outer protruding portion 23 and the horizontal plane is, for example, greater than 45 degrees, preferably greater than 60 degrees. In addition, the outer shape of the upper end side of the oblique shape matches the outer shape of the iron plate portion 21 so that a step does not occur between the iron plate portion 21 and the lower end of the peripheral surface of the iron plate portion 21 . When the angle α becomes close to 90 degrees, the difference in size between the steel pipe pile 5 and the iron plate portion 21 becomes small, and the thickness of the outer projecting portion 23 becomes thin, so the angle α is 80 degrees. It is desirable that:

With the above configuration, the outer protruding portion 23 is formed in the shape of a wall. Therefore, even if there is no rib portion connecting the inner protruding portion 22, the strength of the pile head cap 2 is improved, and cracks are prevented. Damage can be reduced, the rigidity of the pile head cap 2 is improved, deformation of the pile head cap 2 is less likely to occur, and the building load can be transmitted substantially uniformly to the steel pipe pile.

In addition, when the outer shape of the outer protruding portion 23 has an oblique shape that decreases toward the lower side, the pile head cap covers the pile heads 51 of the two steel pipe piles 5, and the outer protruding portion 23 The outer surface 23a approaches the outer peripheral surface of the steel pipe pile 5 as it goes down. As a result, the horizontal projection amount p of the lower end surface of the outer projecting portion 23 from the outer peripheral surface of the steel pipe pile 5 can be minimized, and the weight of the bucket of the heavy equipment when excavating the soil around the steel pipe pile 5 can be minimized. It is possible to suppress the nail from being caught on the pile head cap.

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: Pile head cap 2: Pile head cap 5: Steel pipe pile 6: Laminated foundation 11: Iron plate part (plate-like part)
11a: thin region 11b: concave portion 12: projecting portion 13: rib portion 21: iron plate portion (plate-like portion)
21a: concave portion 22: inner protrusion (protrusion)
23: Outer protruding part (protruding part)
23a: outer surface 51: pile head 61: footing portion 62: discarded concrete 100: building foundation

Claims (5)

A plate-shaped portion and a projecting portion that projects downward from the lower surface side of the plate-shaped portion and faces at least the inner peripheral surface of the upper edge side of the pile head in a state where the pile head of the steel pipe pile is covered,
A plurality of the protrusions facing the inner peripheral surface are present in a scattered arrangement, and a rib connected to the plurality of protrusions is provided,
The pile head cap, wherein the rib portion is lower than the height of the projecting portion facing the inner peripheral surface. A plate-shaped portion, a protrusion that protrudes downward from the lower surface side of the plate-shaped portion and faces the outer peripheral surface of the upper edge side of the pile head in a state that it is covered with the pile head of the steel pipe pile , and the upper edge side of the pile head. It has a protruding part facing the inner peripheral surface ,
The protruding portion facing the outer peripheral surface is formed continuously in a wall shape, and the outer shape of the protruding portion facing the outer peripheral surface has an oblique shape that becomes smaller toward the lower side. The pile head cap is characterized in that the upper end side of the opposing projecting portion does not have a step with the lower end of the peripheral surface of the plate-like portion. 3. The pile head cap according to claim 1 or 2, wherein the plate-shaped part has an outer dimension larger than the outer dimension of the pile head of the steel pipe pile. The pile head cap according to any one of claims 1 to 3, wherein a recess for positioning is provided on the upper surface of the plate-like portion. A building foundation comprising a steel pipe pile and a continuous foundation, directly on the pile head cap according to any one of claims 1 to 4 provided at the pile head of the steel pipe pile, or dump concrete A building foundation characterized in that the footing part of the continuous foundation is positioned through.

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