JP2023050898A - Pile head cap and building foundation - Google Patents

Abstract

To provide a pile head cap and a building foundation which facilitate fitting the pile head cap to a pile head of a steel pipe pile even when the pile head of the steel pipe pile is somewhat deformed.SOLUTION: A pile head cap 1 comprises an iron plate portion 11, a plurality of protrusions 12 protruding downward from a lower surface side of the iron plate portion 11 in a state of covering a pile head 51 of a steel pipe pile 5 and facing the inner peripheral surface of an upper edge side of the pile head 51. Horizontal width of a tip portion 12a of the protrusion 12 in the state of covering the pile head 51 is narrower than horizontal width of a non-tip portion 12b of the protrusion 12.SELECTED DRAWING: Figure 1

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.

On the other hand, Patent Literature 1 discloses a pile head cap that can be used simply by covering the pile head of a steel pipe pile, and that can eliminate the need for work such as iron plate welding to the pile head on site.

Japanese Patent Application Laid-Open No. 2020-180510

However, as shown in FIG. 3(B), the conventional pile head cap has a deformed portion 501a in the pile head 501 of the steel pipe pile. The projecting portion 120 hits the deformed portion 501a of the pile head 501, and the work of fitting the pile head cap to the pile head 501 sometimes takes time.

In view of the above circumstances, the present invention provides a pile head cap and a building foundation that make it easy to fit the pile head cap onto the pile head of a steel pipe pile even if the pile head of the steel pipe pile is slightly deformed. The task is to provide

In order to solve the above problems, the pile head cap of the present invention protrudes downward from the lower surface side of the plate-shaped part in a state of being covered with the plate-shaped part and the pile head of the steel pipe pile. and a projecting portion facing the inner peripheral surface of the edge side, and the horizontal width of the tip portion of the projecting portion in the state of being covered with the pile head is narrower than the horizontal width of the non-tip portion of the projecting portion. It is characterized by being

With the above configuration, the horizontal width of the tip portion of the protrusion in the state of being covered with the pile head is narrower than the horizontal width of the non-tip portion of the protrusion, so deformation that occurs in the pile head The rate at which the protrusion hits the location is reduced. As a result, even if the pile head of the steel pipe pile is slightly deformed, the pile head cap can be easily fitted to the pile head, and the work efficiency of fitting the pile head cap is improved.

In a state in which the pile head cap is placed on the pile head, the tip portion of the protruding portion may be in line contact with the inner peripheral surface with a single vertical line. According to this, the rate at which the protrusion hits the deformed portion of the pile head is further reduced compared to when the tip portion faces the inner peripheral surface.

A horizontal cross-sectional shape of the tip of the projecting portion in a state where the pile head cap is placed on the pile head may be arcuate. According to this, compared with the case where the cross-sectional shape of the tip portion is triangular, chipping or the like at the tip portion is less likely to occur.

A portion below the tip portion of the projecting portion may have an inclined lower surface that is downwardly inclined toward the center of the steel pipe pile in a state where the pile head is covered with the pile head cap. According to this, even if the pile head of the steel pipe pile is slightly deformed, the inclined lower surface serves as a trigger for fitting the pile head cap into the pile head, and the workability of fitting the pile head cap. improves. Even when the pile head cap is tapped to fit into the pile head, the presence of the trigger facilitates the fitting.

A horizontal width of the inclined lower surface in a state where the pile head cap is placed on the pile head may be narrower than a horizontal width of the non-tip portion. According to this, when the inclined lower surface creates a trigger for fitting the pile head cap, the rate of contact of the inclined lower surface with the deformed portion generated in the pile head is reduced, so the workability of fitting the pile head cap is improved. .

A horizontal cross-sectional shape of the inclined lower surface in a state where the pile head cap is placed on the pile head may be arcuate. According to this, compared with the case where the cross-sectional shape of the inclined lower surface is triangular, for example, chipping or the like of the inclined lower surface is less likely to occur.

In these pile head caps,
From the state where the tip of a part of the protrusion is in contact with the inner peripheral surface on the upper edge side of the pile head, the pile head cap is tilted about the point where the plate-shaped part hits the upper end surface of the pile head as a fulcrum. when
In a vertical plane parallel to the vertical plane passing through the fulcrum and the center of the pile head cap, the tip portion of the protrusion located below the portion of the plate-shaped portion that rises at this inclination The lower end portion closest to the inner peripheral surface may contact the inner peripheral surface before reaching the highest position on the upper edge side of the pile head with the inclination.

Here, as described above, when the horizontal width of the tip portion of the protrusion in the state of being covered with the pile head is narrower than the horizontal width of the non-tip portion of the protrusion, some When the pile head cap inclines from a state where the tip of the protruding portion of is in contact with the inner peripheral surface of the upper edge of the pile head, the pile head cap is easily removed from the pile head. If the lower end portion closest to the inner peripheral surface comes into contact with the inner peripheral surface before reaching the uppermost position on the upper edge side of the pile head with the inclination, it is possible to prevent the coming-off.

In addition, the building foundation of the present invention is a building foundation comprising a steel pipe pile and a foundation, wherein the footing of the foundation is directly on any of the pile head caps provided on the pile head or via dump concrete. A part is located.

ADVANTAGE OF THE INVENTION If it is this invention, even when some deformation|transformation has arisen in the pile head of a steel pipe pile, there exists an effect that it becomes easy to engage|insert the said pile head cap in the pile head of a steel pipe pile.

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. 1(A) is an explanatory plan view showing the tip of the protrusion of the pile head cap in FIG. 1 and the deformed portion of the pile head, and FIG. 1(B) shows the tip for comparison. It is explanatory drawing of the planar view which showed the deformation|transformation part of the protrusion part which does not have, and a pile head. FIG. 2 is a side view explanatory diagram showing the tip portion of the protrusion of the pile head cap of FIG. 1 , the inclined lower surface, and the upper end of the pile head; FIG. 2 is an explanatory view of the pile head cap of FIG. 1 when tilted on the pile head; 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; 9 is a see-through perspective view of the pile head cap of FIG. 8 as seen from below; FIG. 8A is a see-through perspective view of a state in which the pile head cap of FIG. 8 is attached to the steel pipe pile, and FIG. 7B 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 mounted on 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.

Further, 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 11 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 projecting portion 12 to improve the rigidity and strength of the iron plate portion 11 . 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.

The horizontal width W1 of the tip portion 12a of the projecting portion 12 in the state where the pile head cap 1 is placed on the pile head 51 of the steel pipe pile 5 is the non-tip portion 12b of the projecting portion 12, as shown in FIG. is narrower than the horizontal width W2 of . In the form in which the horizontal width W1 is the narrowest, the tip portion 12a of the projecting portion 12 can be in line contact with the inner peripheral surface with a single vertical line. The horizontal cross-sectional shape of the tip portion 12a that is in line contact is, for example, a pointed triangular shape. In this embodiment, the tip portion 12a of the projecting portion 12 has an arcuate horizontal cross-sectional shape when the pile head cap 1 is placed over the pile head 51. As shown in FIG. The curvature of this arc is smaller than the radius of curvature of the inner peripheral surface of the pile head 51 .

In addition, as shown in FIG. 4, the pile head cap 1 is placed on the lower side of the tip portion 12a of the projecting portion 12, and the pile head 51 is covered with the pile head cap 1. It has an inclined lower surface 12c that slopes downward in a straight line or a concave curve toward the center. The horizontal width W3 of the inclined lower surface 12c is narrower than the horizontal width W2 of the non-tip portion 12b. The horizontal width W3 is, for example, equal to the horizontal width W1. In this embodiment, when the pile head cap is placed on the pile head 51, the inclined lower surface 12c has an arcuate horizontal cross-sectional shape.

The pile head cap 1 having the above configuration can be mounted by simply covering the pile head 51 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 abuts against 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 also occurs. Hard to come by.

In addition, since the horizontal width W1 of the tip portion 12a of the protrusion 12 facing the inner peripheral surface is narrower than the horizontal width W2 of the non-tip portion 12b of the protrusion 12, as shown in FIG. As described above, the rate at which the projecting portion 12 hits the deformed portion 51a of the pile head 51 of the steel pipe pile 5 is reduced. As a result, even when the pile head 51 of the steel pipe pile 5 is somewhat deformed, the pile head cap 1 can be easily fitted to the pile head 51, improving the efficiency of the pile head cap fitting work.

With the pile head cap 1 covered on the pile head 51, when the tip portion 12a of the protruding portion 12 is in line contact with the inner peripheral surface with a single vertical line, the tip portion 12a is brought into contact with the inner peripheral surface. Compared to facing each other face-to-face, the rate at which the protrusion 12 contacts the deformed portion 51a of the pile head 51 is further reduced.

When the horizontal cross-sectional shape of the tip portion 12a of the protrusion 12 in the state where the pile head cap 1 is placed on the pile head 51 is arc-shaped, compared to the case where the cross-sectional shape of the tip portion 12a is triangular Therefore, chipping or the like of the tip portion 12a is less likely to occur.

The pile head cap 1 is provided at a portion below the tip portion 12a of the projecting portion 12, and the inclined lower surface 12c is inclined downward toward the center of the steel pipe pile 5 in a state where the pile head cap 1 is covered with the pile head 51. , even if the pile head 51 of the steel pipe pile 5 is slightly deformed, the inclined lower surface 12c serves as a trigger for fitting the pile head cap 1 into the pile head 51, and this pile head cap 1 workability of fitting is improved.

When the horizontal width W3 of the inclined lower surface 12c with the pile head cap 1 covering the pile head 51 is narrower than the horizontal width W2 of the portion above the inclined lower surface 12c, the inclined lower surface 12c is Since the ratio of the inclined lower surface 12c coming into contact with the deformed portion 51a of the pile head 51 is reduced when the pile head cap 1 is triggered to be fitted, the workability of fitting the pile head cap 1 is improved.

When the horizontal cross-sectional shape of the inclined lower surface 12c in the state in which the pile head cap 1 is placed on the pile head 51 is arc-shaped, the inclined lower surface 12c is larger than the case where the cross-sectional shape of the inclined lower surface 12c is triangular. chipping etc. becomes difficult to occur.

Here, when an obliquely upward force is applied to the outer peripheral edge of the iron plate portion 11 and the iron plate portion 11 becomes oblique, the lower end side of the protruding portion 12 contacts the upper edge side peripheral surface of the pile head 51. If the height (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 will not move against the force in directions other than the upward direction. It can be made difficult to come off from the head 51 .

However, as described above, since the horizontal width W1 of the tip portion 12a of the protrusion 12 facing the inner peripheral surface is made narrower than the horizontal width W2 of the non-tip portion 12b of the protrusion 12, the inclination condition Depending on the situation, the pile head cap 1 becomes easily detached from the pile head 51 . Therefore, by increasing the height of the protruding portion 12, the iron plate portion 11 is made difficult to come off from the pile head 51. As shown in FIG.

For example, as shown in FIG. 5, in the pile head cap 1, the tip portions 12a of some (two adjacent) protrusions 12 are in contact with the inner peripheral surface of the upper edge of the pile head 51 (this contact is the contact point Y), the pile head cap 1 is most likely to come off from the pile head 51 when the iron plate portion 11 inclines around the point where it hits the upper end surface of the pile head 51 as a fulcrum.

Therefore, for the tip portion 12a of the other protruding portion 12 located below the portion of the iron plate portion 11 that rises due to the inclination, the vertical plane S passing through the fulcrum and the center of the pile head cap 1 is parallel. By contacting the inner peripheral surface before the lower end portion P of the portion closest to the inner peripheral surface in the vertical plane reaches the uppermost position on the upper edge side of the pile head 51 with the inclination, the pile head cap 1 prevent it from coming off.

In this embodiment, the position where the vertical plane parallel to the vertical plane S and passing through the lower end portion P contacts the inner peripheral surface of the pile head 51 is the steel pipe interference position I, and the steel pipe interference position I is parallel to the vertical plane S. Let C be the horizontal distance between IY in the vertical plane passing through the contact point Y, and B be the distance between the lower end portion P and the contact point Y. This is a condition for preventing the pile head cap 1 from coming off due to the inclination.

6 and 7 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, for example, a 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. In addition, not only a continuous foundation but also a raft foundation may be used.

(Embodiment 2)
Another embodiment of the present invention will now be described with reference to the accompanying drawings.
As shown in FIGS. 8, 9, 10(A) and 10(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. (plate-like portion) 21, and a protruding portion that protrudes downward from the lower surface side of the iron plate portion 21 and faces 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. 22, and a ring-shaped 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 projecting portions 22, which are scattered about the center of the circular iron plate portion 21 in the circumferential direction at intervals of 90 degrees. On the other hand, the ring-shaped portion 23 is formed continuously like a wall. The distance between the projecting portion 22 and the ring-shaped portion 23 is made wider than the thickness of the pile head 51, but the distance between the projecting portion 22 and the ring-shaped portion 23 is made as narrow as possible, and As the projecting lengths of the projecting portion 22 and the ring-shaped portion 23 are increased, the lower end sides of the projecting portion 22 and the ring-shaped portion 23 become larger than 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

Also in the pile head cap 2 according to this embodiment, similarly to the pile head cap 1, the pile head cap 2 faces the inner peripheral surface of the pile head 51 in the state where the pile head 51 of the steel pipe pile 5 is covered. The horizontal width of the tip portion 22a of the protruding portion 22 is narrower than the horizontal width of the non-tip portion 22b of the protruding portion 22. As shown in FIG.

Further, the outer shape (outer diameter as an example) of the ring-shaped 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 surface 23a of the ring-shaped portion 23 is not vertical, but is inclined toward the center of the iron plate portion 21 as it goes down.

With the above configuration, since the ring-shaped portion 23 is formed in a wall shape, the strength of the pile head cap 2 is improved even without a rib portion connecting the projecting portion 22, and cracks and breakages occur. In addition, 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 to the steel pipe pile 5 substantially uniformly.

In addition, if the outer shape of the ring-shaped portion 23 has an oblique shape that decreases toward the bottom, the pile head cap 2 is placed on the pile head 51 of the steel pipe pile 5, and the ring-shaped 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 amount of horizontal projection of the lower end surface of the ring-shaped portion 23 from the outer peripheral surface of the steel pipe pile 5 can be minimized, and when the soil around the steel pipe pile 5 is excavated, the claws of the bucket of the heavy machinery can be reduced. can be suppressed from being caught on the pile head cap 2.

Since the horizontal width of the tip portion 22a of the protruding portion 22 facing the inner peripheral surface of the pile head 51 is narrower than the horizontal width of the non-tip portion 22b of the protruding portion 22, the pile head of the steel pipe pile 5 The rate at which the protruding portion 22 hits the deformed portion 51 is reduced. As a result, even when the pile head 51 of the steel pipe pile 5 is slightly deformed, the pile head cap 2 can be easily fitted to the pile head 51, improving work efficiency. In addition, since the pile head cap 2 has the ring-shaped portion 23, the pile head cap 2 is prevented from coming off even if the height of the projecting portion 22 is not made too high.

Note that the tip portion 22a of the pile head cap 2 of this embodiment does not have the inclined lower surface 12c provided in the pile head cap 1 of the previous embodiment, but has an inclined lower surface like the pile head cap 1. is also good.

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-shaped part)
11a: thin region 11b: concave portion 12: projecting portion 12a: tip portion 12b: non-tip portion 12c: inclined lower surface 13: rib portion 21: iron plate portion (plate-shaped portion)
21a: concave portion 22: protruding portion 22a: tip portion 22b: non-tip portion 23: ring-shaped portion 23a: outer surface 51: pile head 51a: deformed portion 61: footing portion 62: discarded concrete 100: building foundation GL: ground level I : Steel pipe interference position S : Vertical plane P : Lower end portion W1 : Horizontal width W2 : Horizontal width W3 : Horizontal width Y : Contact point

Claims (8)

a plate-like portion;
a protruding portion that protrudes downward from the lower surface side of the plate-shaped portion while being covered with the pile head of the steel pipe pile and faces the inner peripheral surface of the upper edge side of the pile head;
and
The pile head cap is characterized in that a horizontal width of a tip portion of the projecting portion in a state of being covered with the pile head is narrower than a horizontal width of a non-tip portion of the projecting portion. 2. In the pile head cap according to claim 1, in a state in which the pile head cap is put on the pile head, the tip portion of the projecting portion is in line contact with the inner peripheral surface with a single vertical line. A pile head cap characterized by a 3. The pile head cap according to claim 2, wherein the horizontal cross-sectional shape of the tip portion of the projecting portion in a state where the pile head cap is placed over the pile head is an arc shape. . The pile head cap according to any one of claims 1 to 3, wherein the steel pipe pile is placed under the tip portion of the projecting portion while the pile head cap is placed over the pile head. A pile head cap characterized by having a sloped lower surface that slopes downward toward the center of the pile head cap. 5. The pile head cap according to claim 4, wherein the horizontal width of the inclined lower surface when the pile head cap is placed over the pile head is narrower than the horizontal width of the non-tip portion. pile head cap. 6. The pile head cap according to claim 5, wherein the horizontal cross-sectional shape of the inclined lower surface when the pile head cap is placed over the pile head is arcuate. In the pile head cap according to any one of claims 1 to 6,
From the state where the tip of a part of the protrusion is in contact with the inner peripheral surface on the upper edge side of the pile head, the pile head cap is tilted about the point where the plate-shaped part hits the upper end surface of the pile head as a fulcrum. when
In a vertical plane parallel to the vertical plane passing through the fulcrum and the center of the pile head cap, the tip portion of the protrusion located below the portion of the plate-shaped portion that rises at this inclination A pile head cap, wherein a lower end portion closest to the inner peripheral surface contacts the inner peripheral surface before reaching the uppermost position on the upper edge side of the pile head with the inclination. A building foundation comprising a steel pipe pile and a foundation, directly on the pile head cap according to any one of claims 1 to 7 provided at the pile head, or through dump concrete. A building foundation characterized in that a footing portion of is located.

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