JP2006283424A - Tip part structure of pile with rotary press-in type spiral blade - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a tip part structure of a pile with a rotary press-in type spiral blade allowing the spiral blade to smoothly bite into the ground while enlarging the side projecting dimension of the spiral blade to increase bearing power from the ground. <P>SOLUTION: The tip side outer peripheral part of a pile body 6 is provided with the spiral blade 5 projected to the side, and the spiral blade 5 is provided in such a form that its outer peripheral position goes away outward in a radial line direction in a gradually enlarged manner toward the base end side from the tip side of the pile body 6. The tip part of the pile body 6 is provided with a tapered cone part 4b on the tip side of a straight part 4a, and the spiral blade 5 is provided in a range from the outer peripheral part region of the straight part 4a to the outer peripheral part region of the tapered cone part 4b. Further, the inclination in the spiral direction of the spiral blade 5 is gradually enlarged toward the base end side from the tip side of the pile body 6. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a tip structure of a pile with a rotary press-fitting type spiral wing.

  As a rotary press-fitting type pile, as shown in FIG. 3 (a), a spiral wing 52 for expanding the bottom side is provided in one turn on the outer peripheral portion on the front end side of the pile body 51. A pile 54 with a spiral wing provided with a plurality of blades 53 for ground excavation disturbance on the tip surface portion has been conventionally provided.

Further, as shown in FIG. 3 (b), a disk 62 for expanding the bottom is provided on the outer periphery of the tip of the pile body 61 made of a steel pipe, and one circumferential direction of the disk 62 is provided. The swash plate portion 63 for earth and sand scooping and the swash plate portion 64 for earth and sand escape are provided there, and the tip opening of the pile body 61 is closed by a lid 65, and the lid 65 An expanded pile 67 provided with a plate blade 66 for excavation disturbance oriented in a direction perpendicular to the vertical direction is also provided.
JP-A-10-219682

  However, in the conventional piles 54 and 67 as described above, the larger the lateral projecting dimensions of the spiral blade 52 and the disc 62, the greater the supporting force from the ground. There is a problem that the 52 and the disc 62 are difficult to bite into the ground and difficult to enter, and it becomes difficult to drive the pile.

  In view of the above-described problems, the present invention is directed to spiral wings, and can increase the lateral projecting dimension of the spiral wings to increase the supporting force from the ground, and the spiral wings to the ground. It is an object of the present invention to provide a tip structure of a pile with a rotary press-fitting type spiral wing capable of smoothly biting and entering a wing.

The above-mentioned problem is provided with a spiral wing projecting laterally to the outer peripheral portion on the tip side of the pile body,
The pile with a rotary press-fit type spiral wing, wherein the spiral wing is provided in such a manner that the outer circumferential position gradually increases outward in the radial line direction from the distal end side to the proximal end side of the pile main body. This is solved by the tip structure (first invention).

  In this structure, the outer circumferential position of the spiral wing gradually increases away from the radial direction as it goes from the distal end side to the proximal end side of the pile body. The outer peripheral position of the pile is carried out from the side close to the pile body side, so that the spiral wing can be made to bite smoothly into the ground.

  In this way, by allowing the spiral wing to penetrate into the ground smoothly, the outer peripheral position of the spiral wing on the base end side of the pile body can be largely separated in the radial direction, and the spiral wing It is possible to increase the lateral overhang dimension of the and increase the supporting force from the ground.

In the first invention, the tip of the pile body comprises a tapered cone portion on the tip side of the straight portion,
The spiral blade may be provided in a range from the outer peripheral region of the straight portion to the outer peripheral region of the tapered cone portion.

  In this case, since the tip of the pile body has a tapered cone shape, the pile can smoothly advance into the ground, and the tapered cone portion is the ground surface at the start of driving the pile. The core can be held against the piles, and the piles can be prevented from wobbling. The inclination of the outer peripheral surface portion of the tapered cone portion may be set, for example, in the range of 45 to 75 ° with respect to the horizontal plane.

  In addition, since the spiral blade is provided in a range from the outer peripheral region of the straight portion to the outer peripheral region of the tapered cone portion, the spiral blade portion provided in the outer peripheral region of the tapered cone portion excavates and disturbs the earth and sand. Thus, the conventional dedicated blade for excavation disturbance can be omitted, and the efficiency of the excavation disturbance mechanism at the tip of the pile can be simplified.

  In the first and second inventions, the spiral wing may be provided in such a manner that the inclination in the spiral direction is gradually increased and / or gradually decreased from the distal end side to the proximal end side of the pile body.

  In this case, a change in the inclination of the spiral wing in the spiral direction acts to disturb the earth and sand around the spiral wing, and even if the soil is hard soil such as consolidated silt or gravel soil, Can be facilitated.

  Particularly, in combination with the second invention, the inclination of the spiral blade portion in the outer peripheral region of the tapered cone portion is gradually increased and / or gradually decreased from the distal end side to the proximal end side of the pile body. When it exists, the excavation disturbance action of the earth and sand in a pile main body front-end | tip part can be made more effective.

  Since the present invention is as described above, the lateral overhang dimension of the spiral wing can be increased to increase the supporting force from the ground, and the spiral wing can be sunk smoothly into the ground. You can enter.

  Next, the best mode for carrying out the present invention will be described with reference to the drawings.

  In the pile 1 of 1st Embodiment shown in FIG. 1, 2 is a steel pipe for piles, 3 is a pile tip part, The pile tip part 3 is laterally from the outer periphery of the pile core part 4 and the pile core part 4 It consists of a cast steel product that is integrally provided with a protruding spiral blade 5, and the base end of the pile core 4 is attached to the tip of the steel pipe 2 for pile by welding W or the like to constitute the pile 1, and the tip of the pile The pile main body 6 is comprised by the pile core part 4 of the components 3, and the steel pipe 2 for piles.

  And the pile core part 4 of the pile front-end | tip part 3 consists of what provided the taper cone part 4b in the front end side of the straight part 4a, and the spiral blade 5 is the taper cone part 4b from the outer peripheral part area | region of the straight part 4a. In the range up to the outer peripheral region, the outer peripheral position gradually increases outward in the radial line direction from the distal end side to the proximal end side of the pile body 6 as shown by auxiliary lines A and A in FIG. It is provided so that it may circulate around the pile core part 4 a plurality of times in a manner of leaving. Further, the spiral blade 5 is provided in such a manner that the inclination in the spiral direction gradually increases from the distal end side to the proximal end side of the pile body 6, that is, the pitch is in a relationship of p1 <. It has been.

  Further, the spiral wing portion 5a provided on the outer peripheral portion of the tapered cone portion 4b includes a spiral wing portion 5b whose outer peripheral position is located inward of the outer peripheral position of the straight portion 4a on the pile tip side. Yes.

  The lower surface side of the spiral blade 5 is provided with an outer peripheral ridge 7a that protrudes downward and extends in the spiral direction at an outer peripheral position or a position near the outer peripheral position, and an intermediate position between the outer peripheral position and the inner peripheral position. In addition, a single or a plurality of intermediate protrusions 7b that protrude downward and extend in the spiral direction are provided, and during the rotary press-fitting, the earth and sand on the lower surface side of the spiral blade diffuses outward from the outer peripheral position of the spiral blade 5. It is made to suppress going.

  In the above structure, since the outer peripheral position of the spiral blade 5 gradually increases away in the radial direction from the distal end side to the proximal end side of the pile body 6, the spiral blade 5 bites into the ground. The outer peripheral position of the spiral blade 5 is performed from the side close to the pile body 6 side, and therefore, the spiral blade 5 can be smoothly bitten into the ground. And, in this way, by allowing the spiral wing 5 to penetrate into the ground smoothly, the outer peripheral position of the spiral wing on the base end side of the pile body 6 can be greatly separated in the radial direction, The lateral projecting dimension of the spiral blade 5 can be increased, and the supporting force from the ground can be increased.

  Further, since the outer peripheral position of the spiral blade 5 is gradually increased outward in the radial direction from the distal end side to the proximal end side of the pile body 6, the spiral blade 5 exceeds one turn. When it is long in the spiral direction, especially when it has two or more turns, the supporting force from the ground acts on the outer peripheral side of the wing part located above the vertical direction in the overlapping part in the vertical direction of the wing. However, since the supporting force from the ground acts on the wing part directly below in the vertical direction on the inner periphery side, the supporting force from the ground becomes difficult to act, so that the wing part located above the vertical direction The support position of the pile can be increased by largely separating the outer peripheral position to the side, and the wing can be thinned, so that the spiral wing can be easily bited into the ground.

  Moreover, in this embodiment, since the tapered cone part 4b is provided in the front-end | tip part of the pile main body 6, the pile 1 can be advanced into the ground smoothly, and also when the driving | operation start of the pile 1 is started. , The tapered cone portion 4b performs a core holding action on the ground surface, and the pile 1 can be prevented from wobbling.

  In addition, since the spiral blade 5 is provided in the range from the outer peripheral region of the straight portion 4a to the outer peripheral region of the tapered cone portion 4b, the spiral blade portion 5a provided in the outer peripheral region of the tapered cone portion 4b. Works so as to excavate and disturb the earth and sand, and the conventional dedicated blade for excavation disturbance can be omitted, so that the efficiency of the excavation disturbance mechanism at the tip of the pile can be improved. In particular, the outer peripheral portion of the tapered cone portion 4b is provided with a spiral blade portion 5b in which the outer peripheral position of the spiral blade portion is located inward of the outer peripheral position of the straight portion 4a. The ground can be effectively excavated.

  Furthermore, since the spiral wing 5 is provided so that the spiral pitches p1 to p5 increase toward the base end side of the pile, the action causes the earth and sand around the spiral wing to be disturbed during driving, The pile can be driven easily even when the soil is hard soil such as consolidated silt or gravel soil. In particular, when the inclination of the spiral wing portion 5a in the outer peripheral region of the tapered cone portion 4b is gradually increased from the distal end side to the proximal end side of the pile body 6, the earth and sand at the distal end portion of the pile body The drilling disturbing action of can be made more effective.

  The structure of 2nd Embodiment shown in FIG. 2 is an aspect in which the inclination in the spiral direction of the spiral blade 5 becomes small gradually as it goes to the base end side from the front end side of the pile main body 6, ie, pitch is p1> ...> It is provided so that it may become the relationship of p5. Also in this case, it is possible to facilitate the driving of the pile even when the soil around the spiral blade is disturbed during driving and the soil is hard soil such as consolidated silt or gravel soil.

  Although the embodiment of the present invention has been described above, the present invention is not limited to this, and various modifications can be made without departing from the spirit of the invention. For example, the number of turns of the spiral blade is not limited, and for example, it is preferable that the number of turns of the spiral blade exceeds two turns or more, but it may be one turn or less.

  In the above embodiment, the tip of the pile body 6 is provided with the tapered cone portion 4b, and the spiral wing 5 is also provided in the region of the tapered cone portion 4b. It may be omitted from the portion and provided only in the straight portion, or the tapered cone portion 4b may be omitted.

  Moreover, in said embodiment, when the inclination in the spiral direction of the spiral wing | blade 5 is made to become large gradually as it goes to the base end side from the front end side of a pile main body, it is made to become small. Although it is shown about two cases, the inclination in the spiral direction of the spiral wing may gradually become smaller or larger as it goes from the distal end side to the proximal end side of the pile body, The inclination in the spiral direction of the spiral wing may be constant from the distal end side to the proximal end side of the pile body.

The pile front-end | tip part structure of 1st Embodiment is shown, A figure (I) is a perspective view and a figure (B) is a front view. The pile front-end | tip part structure of 2nd Embodiment is shown, A figure (I) is a perspective view and a figure (B) is a front view. Drawing (a) and figure (b) are front views which show the conventional pile tip part structure, respectively.

Explanation of symbols

4a ... Straight part 4b ... Tapered cone part 5 ... Spiral wing 6 ... Pile body

Claims (3)

A spiral wing projecting sideways is provided on the outer periphery of the tip of the pile body,
The pile with a rotary press-fit type spiral wing, wherein the spiral wing is provided in such a manner that the outer circumferential position gradually increases outward in the radial line direction from the distal end side to the proximal end side of the pile main body. Tip structure. The tip of the pile body comprises a tapered cone on the tip side of the straight part,
The tip structure of a pile with a rotary press-fit type spiral blade according to claim 1, wherein the spiral blade is provided in a range from the outer peripheral region of the straight portion to the outer peripheral region of the tapered cone portion.   The rotary press-fit spiral according to claim 1 or 2, wherein the spiral blade is provided in such a manner that the inclination in the spiral direction gradually increases and / or gradually decreases as the pile body moves from the distal end side to the proximal end side. Tip structure of a winged pile.

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