JP2012158978A - Steel pipe pile - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a steel pipe pile having high penetrating performance as well as excellent straight moving performance during penetration.SOLUTION: The steel pipe pile 61 includes a penetration promoting means formed at the tip. The tip of the steel pipe pile 61 is a tip opening 61a open at the lower end. Its pipe side face has side face holes 62 formed as the penetration promoting means via which the inside of a pipe is communicated with the outside thereof. Furthermore, a cover part 63 as a cover member is mounted in the pipe above the side face holes 62. Thus, when sediment is taken from the tip opening 61a into the pipe, part of the taken sediment and water content are discharged from the side face holes 62 to the outside to secure high penetrating performance.

Description

  The present invention relates to a steel pipe pile used for a foundation of a building such as a detached house.

  Conventionally, it is known to construct a pile foundation of a small-scale building such as a house by rotationally press-fitting a steel pipe pile into the ground. And in order to reduce the penetration resistance at the time of penetrating a steel pipe pile in this way, a penetration promotion means may be provided in the front-end | tip part of a steel pipe pile (refer patent documents 1-3 etc.).

  For example, in the steel pipe pile of patent document 1, while providing a helical protrusion around the pipe, the cutting edge is cut obliquely at an angle in one direction to form a cutting edge, and the penetration resistance to the ground is reduced. Yes.

  Moreover, in patent document 2, it is set as the penetration promotion means by forming the front-end | tip part of a steel pipe pile in a saw-tooth shape, and in patent document 3, the pile shoe in which the triangular-shaped cutting blade was formed is attached to the front-end | tip part of a steel pipe pile. This is a means of promoting penetration.

Japanese Utility Model Publication No. 4-41526 Japanese Unexamined Patent Publication No. 1-146011 Utility Model Registration No.3052267

  However, if the cutting edge is inclined in one direction as disclosed in Patent Document 1, the pressing pressure can be easily concentrated on the cutting edge, and the penetration performance can be improved. It becomes difficult to drive vertically into the ground because it is ahead.

  Moreover, when the pile is driven obliquely, the vertical support force may be reduced, and the pile may interfere with other adjacent piles, which may hinder the placement.

  In view of the above, an object of the present invention is to provide a steel pipe pile having high penetration performance and excellent straight running performance during penetration.

  In order to achieve the above object, a steel pipe pile according to the present invention is a steel pipe pile in which a penetration promoting means is formed at a distal end, and the distal end is opened at a lower end, and the penetration promotion is provided on a side surface of the pipe. As a means, a side hole for communicating the inside and outside of the pipe is formed.

  Here, it can be set as the structure by which a lid-like member is spanned in the pipe | tube above the said side hole.

  In the steel pipe pile of this invention comprised in this way, while the lower end of a front-end | tip part is opened, the side surface hole which connects the inside and outside of a pipe | tube is formed in the pipe side surface.

  For this reason, even if earth and sand are taken into the pipe from the opening at the tip, a part of the taken earth and sand and moisture are discharged to the outside from the side hole, so that high penetration performance can be ensured.

  Furthermore, since the earth and sand taken in from the opening is compressed by bridging the lid-like member in the pipe above the side hole, and the moisture is discharged from the side hole, the steel pipe pile is attached to the soft ground. Even when driven, high tip support force can be obtained by the compacted earth and sand.

It is explanatory drawing explaining the structure of the steel pipe pile of embodiment. It is a figure explaining the structure of the front-end | tip part of a steel pipe pile, Comprising: (a) is the front view seen in the AA arrow direction of FIG. 1, (b) is a perspective view. It is a figure explaining the structure of the front-end | tip part of the steel pipe pile of Example 1, Comprising: (a) is a side view, (b) is a bottom view. It is a figure explaining the structure of the front-end | tip part of the steel pipe pile of Example 1, Comprising: (a) is the front view seen in the BB arrow direction of Fig.3 (a), (b) is a perspective view. It is a figure explaining the structure of the front-end | tip part of the steel pipe pile of Example 2 of this invention, Comprising: (a) is a front view, (b) is a perspective view. It is explanatory drawing explaining an effect | action of the steel pipe pile of Example 2 of this invention. It is explanatory drawing explaining the structure of the steel pipe pile of Example 3. FIG. It is a figure explaining the structure of the front-end | tip part of the steel pipe pile of Example 3, Comprising: (a) is the front view seen in CC direction of FIG. 7, (b) is a perspective view.

  Embodiments for describing the present invention will be described below with reference to the drawings.

  First, the structure of the steel pipe pile 1 of this Embodiment is demonstrated, referring FIGS.

  The steel pipe pile 1 constitutes a pile foundation of a small-scale building such as a detached house, and is particularly suitable for application to a small-diameter pile having a diameter of about 70 mm to 140 mm, for example.

  The steel pipe pile 1 is formed with an oblique blade portion 2 as a penetration promoting means at the tip portion, and an oblique lid portion 3 as an inversely inclined surface portion inclined in a direction opposite to the inclination of the oblique blade portion 2 in the pipe. .

  As shown in FIG. 1, the inclined blade portion 2 is inclined in one direction intersecting the tube axis direction Z, and the inclined surface 2 a is inclined with respect to the tube axis orthogonal direction X orthogonal to the tube axis direction Z. Tilt at θ. The inclination angle θ can be set to about 10 degrees to 60 degrees. In FIG. 1, the inclination angle θ is set to 30 degrees.

  For example, if the oblique blade portion 2 is formed by cutting substantially the center of a cylindrical steel pipe at a predetermined inclination angle θ, the oblique blade portions of two steel pipe piles can be formed by one cutting.

  Further, as shown in the perspective view of FIG. 2B, the oblique lid portion 3 is formed of an elliptical steel plate that shields the inside of the tube obliquely in a lid shape. As shown in the side view of FIG. 1, the reversely inclined surface 3 a of the oblique lid portion 3 is inclined in the opposite direction intersecting with the inclined surface 2 a of the oblique blade portion 2.

  For example, the inversely inclined surface 3a is formed at an angle that is substantially line symmetric with the inclined surface 2a with respect to the symmetry axis S parallel to the tube axis orthogonal direction X intersecting the upper end 2c of the oblique blade portion 2. .

  Moreover, the front view seen in the AA arrow direction of FIG. 1 was shown to Fig.2 (a). As shown in FIGS. 2A and 1, the lower end 3 b of the oblique lid 3 is fixed to the inner surface of the tube above the upper end 2 c of the oblique blade 2 by welding or the like, and the upper end of the lower end 2 b of the oblique blade 2. The upper end 3c of the oblique lid 3 is fixed to the inner surface of the tube by welding or the like. Further, the oblique lid 3 is fixed to the inner surface of the pipe by welding or the like over the entire circumference.

  Next, the effect | action of the steel pipe pile 1 of this Embodiment is demonstrated.

  In the steel pipe pile 1 of this Embodiment comprised in this way, the diagonal blade part 2 which inclines in one direction at the front-end | tip part is formed. For this reason, when a load is applied to the pile head (not shown) of the steel pipe pile 1 in order to press-fit or rotationally press-fit the steel pipe pile 1, the load concentrates on the lower end 2b of the oblique blade part 2 and the oblique blade part on the ground. Since 2 will be buried, the steel pipe pile 1 can be easily penetrated into the ground. In particular, when the steel pipe pile 1 is placed on soft ground, the effect of improving the penetration performance by the oblique blade portion 2 is great.

  In addition, an oblique lid portion 3 having an inversely inclined surface 3a that is opposite to the inclined surface 2a of the inclined blade portion 2 is formed in the pipe. And when earth and sand are taken in from the front-end | tip opening 1a of the steel pipe pile 1, earth and sand will be collected in the pipe | tube between the diagonal cover part 3 and the inclined surface 2a, and will be compacted. Here, the space formed between the oblique lid 3 and the inclined surface 2a is the largest between the lower end 2b of the oblique blade 2 and the upper end 3c of the oblique lid 3, as shown in FIG. The narrowest portion is between the upper end 2c of the oblique blade portion 2 and the lower end 3b of the oblique lid portion 3.

  For this reason, a large resistance is received from the earth and sand taken in above the lower end 2b of the oblique blade part 2, and the earth and sand is hardly taken in at the upper end 2c of the oblique blade part 2, so the resistance becomes small. And the inclination to the lower end 2b side of the diagonal blade part 2 of the steel pipe pile 1 is suppressed by resistance of this taken-in earth and sand.

  That is, the posture of the steel pipe pile 1 can be controlled by adjusting the relative directional relationship between the inclination angle of the oblique lid portion 3 and the inclination direction of the inclined surface 2 a of the oblique blade portion 2.

  Moreover, the adjustment of the inclination angle and direction of the oblique lid portion 3 for posture control can also be performed for each soil type into which the steel pipe pile 1 is driven.

  And by providing the diagonal blade part 2 in this way, while being able to penetrate the steel pipe pile 1 in the ground easily, the inclination of the steel pipe pile 1 can be controlled by the diagonal cover part 3, Therefore The steel pipe pile 1 is straightened. Can be driven into the ground.

  Moreover, there is no part which protrudes from the steel pipe pile 1 in the pipe-axis orthogonal direction X like the diagonal blade part 2, and a helical protrusion, a spiral blade, etc. are provided in the pipe peripheral surface like the steel pipe pile 1 of this Embodiment. If not, adhesion between the ground and the circumferential surface of the steel pipe pile 1 can be secured over the entire length of the steel pipe pile 1.

  For this reason, when calculating the bearing capacity of the steel pipe pile 1, the peripheral frictional force of a ground and a pile surrounding surface can be added, and it can function as a friction pile. Moreover, if the bearing capacity can be calculated as a friction pile, the pile length of the steel pipe pile 1 can be shortened. If the ground is shallow and such a short pile penetrates, there are many soft grounds. The steel pipe pile 1 can be penetrated.

  Moreover, since the front-end | tip of the steel pipe pile 1 will be obstruct | occluded if the diagonal cover part 3 is a lid-like member which shields the inside of a pipe | tube, the contact area of a ground and a pile front-end | tip will become large. Here, since the tip support force of the steel pipe pile 1 is a product of the ground strength of the ground and the pile tip area, a large tip support force can be secured by providing the oblique lid portion 3.

  Furthermore, if the lower end 3b of the oblique lid 3 is provided above the upper end 2c of the oblique blade 2 and the upper end 3c of the oblique lid 3 is provided above the lower end 2b of the oblique blade 2, the oblique lid 3 is Positioning when mounting is easy. Moreover, if such alignment is performed, the reverse-gradient surface 3a which inclines in the direction exactly opposite to the inclination direction of the inclined surface 2a can be formed easily.

  Furthermore, if the inclination of the oblique blade part 2 and the inclination of the oblique cover part 3 are formed at an angle that is substantially line symmetric in side view, the steel pipe pile 1 that is excellent in straight running performance is likely to be obtained. Even when the desired straight-ahead performance cannot be obtained, the angle can be easily adjusted based on this angle.

  Hereinafter, Example 1 of a form different from the above-described embodiment will be described with reference to FIGS. The description of the same or equivalent parts as those described in the above embodiment will be given the same reference numerals.

  In the steel pipe pile 51 of the first embodiment, an oblique blade portion 52 is formed as a penetration promoting means at the tip portion, and an oblique band portion 53 as a reverse gradient surface portion inclined in a direction opposite to the inclination of the oblique blade portion 52 in the pipe. Is formed.

  The oblique blade portion 52 is inclined in one direction intersecting the tube axis direction Z as shown in FIG.

  Further, as shown in FIGS. 3B and 4, the oblique band portion 53 is formed of a strip-shaped steel plate that is obliquely bridged in the pipe. As shown in the side view of FIG. 3A, the reverse slope surface 53a of the oblique band portion 53 is inclined in the opposite direction intersecting with the inclined surface 52a of the oblique blade portion 52.

  For example, the reverse gradient surface 53a is formed at an angle that is substantially line symmetric with the inclined surface 52a with respect to the symmetry axis S parallel to the tube axis orthogonal direction X intersecting the upper end 52c of the oblique blade portion 52. .

  FIG. 4A shows a front view seen in the direction of arrows BB in FIG. 4A and 3A, the lower end 53b of the oblique band portion 53 is fixed to the pipe inner surface above the upper end 52c of the oblique blade portion 52 by welding or the like, and the lower end of the oblique blade portion 52 is secured. The upper end 53c of the slanted band portion 53 is fixed to the inner surface of the pipe above 52b by welding or the like.

  And the clearance gap connected to the front-end | tip opening 51a of the steel pipe pile 51 is formed in the both sides of the diagonal band part 53 attached in this way, as shown in FIG.3 (b) and FIG.4 (b). Sediment and groundwater entering the pipe from 51a can be taken into the pipe above the oblique band portion 53 through the gap.

  In the steel pipe pile 51 of the embodiment configured as described above, the slanted band portion 53 spanned in the pipe as a reverse slope surface portion is a band-shaped member, and therefore a part of the earth and sand taken from the tip opening 51a of the steel pipe pile 51 is used. Can be taken into the tube.

  For this reason, when penetrating the steel pipe pile 51, if earth and sand are taken in from the tip opening 51a and the penetration resistance is increased, a part of the taken earth and sand passes through the gaps on both sides of the oblique band portion 53 and is taken into the pipe. Therefore, penetration resistance can be reduced.

  The width of the slanted belt portion 53 and the size of the gap can be adjusted according to the soil quality such as the hardness and viscosity of the ground. For example, when the ground into which the steel pipe pile 51 is penetrated is hard, the penetration resistance is reduced by increasing the gap so that the compacted earth and sand are not easily accumulated at the tip of the pile. On the contrary, when the steel pipe pile 51 is penetrated into a soft and highly fluid ground, the compacted earth and sand are accumulated at the tip of the pile so as to obtain a high tip support force.

  Other configurations and functions and effects are substantially the same as those in the above-described embodiment, and thus description thereof is omitted.

  Hereinafter, Example 2 which is an embodiment of the present invention will be described with reference to FIGS. The description of the same or equivalent parts as those described in the above embodiment or Example 1 will be given the same reference numerals.

  The steel pipe pile 61 of the second embodiment is a tip opening 61a in which the lower end of the tip is opened. Further, a plurality of side holes 62,... Are formed on the pipe side surface of the tip portion as penetration promoting means.

  These side holes 62,... Are through holes that allow the inside and outside of the pipe to communicate with each other. In the second embodiment, the side holes 62 are formed at four locations at equal intervals in the circumferential direction of the pipe. Further, these side holes 62,... Have a left-right symmetrical arrangement in which another side hole 62 is provided at each facing position.

  Further, a lid 63 as a lid-like member is bridged in the pipe above the side holes 62. The lid 63 is formed of a circular steel plate having a diameter substantially the same as the inner diameter of the tube so as to shield the inside of the tube in the vertical direction. Moreover, this cover part 63 is fixed to the pipe inner surface of the steel pipe pile 61 by welding or the like.

  Moreover, the amount of earth and sand that can be accommodated in the pipe can be adjusted by adjusting the distance between the lid 63 and the tip opening 61a.

  The steel pipe pile 61 of Example 2 configured in this way is formed with a plurality of side holes 62,... That allow the inside and outside of the pipe to communicate with the pipe side surface while the lower end of the tip is opened as a tip opening 61a. ing.

  As shown in FIG. 6, when the steel pipe pile 61 is penetrated into the soft ground while rotating in the W direction, the earth and sand G containing a large amount of moisture is taken into the pipe from the tip opening 61a.

  When the earth and sand G is taken into the pipe in this way, a part of the earth and sand G and moisture M are discharged from the side holes 62 to the outside of the pipe, so that the penetration resistance is reduced and the high penetration performance is achieved. Can be secured.

  Moreover, the earth and sand G remaining in the pipe rises relatively with the penetration of the steel pipe pile 61 and is pressed against the lower surface of the lid portion 63. Further, the moisture M of the earth and sand G is discharged from the side holes 62 and 62 to the outside.

  As a result, the compacted earth and sand G from which moisture has been discharged is deposited below the lid portion 63, and the tip support force of the steel pipe pile 61 is increased by the large and compacted earth and sand G. .

  Moreover, the magnitude | size of this front-end | tip supporting force can be increased by increasing the quantity which can accommodate the compacted earth and sand (consolidated earth and sand) in a pipe | tube.

  Further, the side holes 62,... Are respectively provided at opposing positions, and the shape of the steel pipe pile 61 is bilaterally symmetric.

  Other configurations and functions and effects are substantially the same as those of the above-described embodiment or Example 1, and thus description thereof is omitted.

  Hereinafter, Example 3 of a form different from the above-described embodiment will be described with reference to FIGS. Note that the description of the same or equivalent parts as those described in the embodiment or other examples will be given with the same reference numerals.

  In the steel pipe pile 71 of this Example 3, the oblique blade portion 2 is formed as a penetration promoting means at the tip portion in the same manner as described in the above embodiment, and the inclination of the oblique blade portion 2 is opposite to that in the pipe. An oblique lid portion 3 is formed as an inversely inclined surface portion that is inclined in the direction.

  Moreover, this steel pipe pile 71 becomes the front-end | tip opening 71a by which the lower end of the front-end | tip part was opened, and several side surface holes 72 and 72 are formed in the pipe side surface of a front-end | tip part as penetration promotion means.

  The side holes 72 and 72 are through holes that allow the inside and outside of the pipe to communicate with each other. In the third embodiment, the side holes 72 and 72 are formed at two locations on the circumferential surface of the pipe that forms the oblique blade portion 2. The side holes 72 and 72 are located at a predetermined length above the inclined surface 2 a and are disposed closer to the inclined surface 2 a than the oblique lid portion 3.

  The steel pipe pile 71 of Example 3 configured in this way is formed with a tip opening 71a, an oblique blade portion 2 that is inclined in one direction, and side holes 72 and 72 that communicate the inside and outside of the pipe on the side of the pipe. Is formed.

  For this reason, it is possible to easily penetrate into the ground by the oblique blade portion 2, and even if the earth and sand G is taken into the pipe from the tip opening 71a, a part of the taken earth and sand G and moisture are exposed to the outside from the side holes 72 and 72. Since it is discharged, high penetration performance can be ensured.

  Furthermore, the inclination of the steel pipe pile 71 can be controlled by forming the oblique lid part 3 having an inclination opposite to the inclination of the oblique blade part 2 in the pipe above the side holes 72, 72. The pile 71 can be driven straight into the ground.

  Moreover, since the earth and sand taken in from the front-end | tip opening 71a is compressed by the diagonal cover part 3, and it is consolidated by moisture being discharged | emitted from the side holes 72 and 72, it is a case where the steel pipe pile 71 is driven into a soft ground. However, a high tip support force can be obtained by the compacted earth and sand.

  Other configurations and functions and effects are substantially the same as those of the above-described embodiment or other examples, and thus description thereof is omitted.

  The embodiment of the present invention has been described in detail above with reference to the drawings. However, the specific configuration is not limited to this embodiment or example, and the design changes are within the scope of the present invention. Are included in the present invention.

  For example, in the above-described embodiment or Example 1, a cylindrical steel pipe is processed and the oblique blade portions 2 and 52 are provided directly on the steel pipe piles 1 and 51. However, the present invention is not limited to this. A tip shoe in which the blade portion 2 is processed may be attached to the tip of a cylindrical steel pipe to form a tip portion.

  Moreover, in the said embodiment or the said Example 1, although the diagonal blade part 2, the diagonal cover part 3, or the diagonal blade part 52, and the diagonal strip | belt part 53 were formed in line symmetry with respect to the symmetry axis S, it is limited to this. It can adjust to the diagonal cover part 3 or the diagonal strip | belt part 53 of arbitrary angles and directions so that the rectilinear performance of the steel pipe piles 1 and 51 may improve.

  Moreover, in the said embodiment or the said Example 2, although the inside of a pipe | tube was shielded by the diagonal cover part 3 (or cover part 63), it is not limited to this, The diagonal cover part 3 (or cover part 63) is used. One or a plurality of through holes are provided, and earth and sand or groundwater entering from the tip opening 1a (61a) of the steel pipe pile 1 (61) can be taken into the pipe above the oblique lid portion 3 (or the lid portion 63). it can. By providing such a through hole, part of the earth and sand is taken into the pipe and the penetration resistance of the steel pipe pile 1 (61) is reduced, or the earth and sand taken from the tip opening 1a (61a) is dehydrated and the steel pipe pile. 1 (61) tip support force increases. In particular, when the steel pipe pile 1 (61) is placed on soft ground, the compaction effect (consolidation effect) by dehydration is large.

  Further, in the embodiment or the first embodiment, the lower ends 3b and 53b of the oblique lid portion 3 and the oblique band portion 53 are attached to the upper ends 2c and 52c of the oblique blade portions 2 and 52 with almost no gap. However, the present invention is not limited to this, and the lower ends 3 b and 53 b of the oblique lid portion 3 and the oblique band portion 53 may be located above the upper ends 2 c and 52 c of the oblique blade portions 2 and 52. Thus, the amount which accommodates the earth and sand compacted by the pressure at the time of penetration in the pipe by providing the slant lid part 3 and the slant band part 53 inside the steel pipe piles 1 and 51 apart from the tip openings 1a and 51a. The tip supporting force of the steel pipe piles 1 and 51 can be increased.

  Moreover, in the said embodiment or the said Example, although the steel pipe pile 1, 51, 61 without a protrusion in a pipe-axis orthogonal direction X was demonstrated, it is not limited to this, A helical protrusion is made into the steel pipe pile 1, It can also be provided on the peripheral surfaces of 51 and 61 so as to facilitate rotation penetration.

  Furthermore, in the said Example 3, although demonstrated about providing the side surface holes 72 and 72 in the pipe side surface of the steel pipe pile 71 provided with the diagonal blade part 2 and the diagonal cover part 3 similar to the said embodiment, it is limited to this. However, a side hole can be provided on the pipe side surface of the steel pipe pile 51 provided with the oblique blade portion 52 and the oblique band portion 53 described in the first embodiment. Moreover, you may provide a side hole in the pipe side surface of the steel pipe pile provided with the diagonal blade part 2 in which the diagonal cover part 3 and the diagonal strip | belt part 53 are not provided. Moreover, what provided the diagonal blade part in the front-end | tip part of the steel pipe pile 61 of the said Example 2 may be used.

Z Pipe axis direction X Pipe axis orthogonal direction S Target axis 1 Steel pipe pile 2 Diagonal blade (penetration promoting means)
2a Inclined surface 2b Lower end 2c Upper end 3 Slanted lid (reversely inclined surface)
3a Reverse slope surface 3b Lower end 3c Upper end 51 Steel pipe pile 52 Diagonal blade (penetration promoting means)
52a Inclined surface 52b Lower end 52c Upper end 53 Inclined belt portion (reversely inclined surface portion)
53a Reverse slope surface 53b Lower end 53c Upper end 61 Steel pipe pile 61a End opening (opening)
62 Side hole (penetration promoting means)
63 Lid (lid member)
71 Steel pipe pile 71a Tip opening (opening)
72 Side hole (penetration promotion means)

Claims (2)

A steel pipe pile with a penetration promoting means formed at the tip,
The steel pipe pile according to claim 1, wherein a lower end of the distal end portion is opened, and a side hole for communicating the inside and outside of the pipe is formed on the side surface of the pipe as the penetration promoting means. The steel pipe pile according to claim 1, wherein a lid-like member is bridged in the pipe above the side hole.