JP2011127347A - Steel pipe pile - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a steel pipe pile in which, when welding the engaging piece of the steel pipe pile in contact with a plier to a steel pipe pile body, the engaging piece is welded to the pile body with a sufficient strength, without welding the portion of the engaging piece in contact with the plier. <P>SOLUTION: In the steel pipe pile, the plate-shaped engaging piece 11 to be engaged with the plier is provided on the inner or outer circumferential surface of the steel pipe pile body 1. The rotation of the plier is transmitted to the steel pipe pile through the engaging piece 11, allowing the pile to be driven into the ground while being rotated. Slits 14 with the circumferential direction of the steel pipe pile body 1 as the longitudinal direction is formed in the engaging piece 11. The engaging piece 11 is slot-welded to the inner or outer circumferential surface of the steel pipe pile body 1 at the portion of the slits 14. Thereby, welded metal caused by welding is eliminated on the axial direction side 12 of the engaging piece 11 in contact with the plier, or on the side edge in the axial direction of the steel pipe pile body 1 of the engaging piece 11, also eliminating the need for scraping the welded metal at the portion in contact with the plier, with improved work efficiency and a cost reduction. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a steel pipe pile that is a civil engineering and building foundation member, and relates to a steel pipe pile including an engagement piece that engages with a rotational force transmission member that transmits a rotational force from a construction apparatus to the steel pipe pile.

  One method of building a steel pipe pile in the ground while rotating the steel pipe pile is a rotary penetrating steel pipe pile method using a construction device such as an all-around rotating machine (for example, see Patent Document 1). Rotating penetrating steel pipe pile construction method applies a rotational force to a pile with blades (blades) at the tip, and rotates the entire pile to build the steel pipe pile without generating excavation residual soil with low vibration and low noise. It is a waste. As another method of building a steel pipe pile into the ground while rotating it, there is a medium digging pile method in which an auger is installed in the steel pipe pile and the auger and the steel pipe pile are rotated together to excavate the ground.

  When there is an underground floor in the upper structure, the top end position of the steel pipe pile is below the ground surface (hereinafter sometimes referred to as GL). The construction procedure in that case is to attach the Yatsuko (rotational force transmission member) to the upper part of the steel pipe pile and rotate the Yatco to rotate the steel pipe pile. As a result, G. L. A steel pipe pile is built up to a deeper depth, and only the Yatco is removed after reaching a predetermined depth (see, for example, Patent Documents 2 and 3).

An example of the form of engagement between the steel pipe pile and the Yatco 2 will be described with reference to FIGS. A steel engagement piece 3 is attached to the inner peripheral surface (or outer peripheral surface) of the steel pipe pile main body 1, and the engagement groove 4 of the Yatco 2 and the engagement piece 3 are fitted together. As a result, the rotation of the yatco 2 is transmitted to the steel pipe pile through the engagement portion between the engagement groove 4 and the engagement piece 3.
As shown in FIG. 7, the engagement piece 3 is attached to the steel pipe pile main body 1 by welding four sides on the outer periphery of the engagement piece 3. In FIG. 7, reference numeral 5 denotes a weld metal. The Yatco 2 is made of, for example, a steel pipe, and connects the upper end of the steel pipe pile and the rotating part of the construction device. When the engagement piece 3 is on the inner periphery of the steel pipe pile main body 1, the Yatco 2 An engagement groove (concave portion) 4 is formed along the axial direction on the outer peripheral surface of the lower end portion of 2, and the engagement piece 3 is engaged with the upper end portion thereof. In addition, the upper end part engaged with the engagement piece 3 of the engagement groove 4 is formed slightly long in the circumferential direction, and the engagement groove 4 is substantially T-shaped. The engaging groove may be generally L-shaped.

  6 and 7 are schematic views. In FIG. 6, the yatco 2 is depicted in a plan view, but actually, the engaging groove 4 is formed in the cylindrical yatco 2. Moreover, in FIG. 7, although the engagement piece 3 is drawn in flat form, the engagement piece 3 is actually fixed to the inner peripheral surface or outer peripheral surface of the cylindrical steel pipe pile main body 1. Yes, it is a plate-like member curved in an arc shape along the circumferential direction of the steel pipe pile main body 1.

Japanese Patent No. 4232743 JP 2004-19238 A Japanese Patent Laid-Open No. 11-158867

Here, the weld metal 5 is from the side (the side corresponding to part c in FIG. 7; hereinafter referred to as the axial side because it is the side along the axial direction of the steel pipe pile main body 1) with which the Yatco 2 comes into contact. If it protrudes, the Yatco 2 will come into contact with the engaging piece 3 and the surface pressure will increase locally, which may damage the contact surface of the Yatco 2 or the engaging piece 3. Therefore, the contact surface of the Yatco 2 and the engagement piece 3 needs to be smoothed by scraping the weld metal 5 with a grinder or the like (see FIG. 7B (cross-sectional view along bb ′ in FIG. 7A)). ). There is a problem that the cutting work of the weld metal 5 takes a considerable amount of time and leads to an increase in manufacturing cost. In particular, when the engagement piece 3 is attached to the inner surface of the steel pipe pile main body 1, the work efficiency is significantly deteriorated. .
In order to avoid such a problem, two sides that do not come into contact with the Yatco 2 (sides other than the c portion in FIG. 7; hereinafter, they are also sides along the circumferential direction of the steel pipe pile body 1 are also referred to as circumferential sides). It is also possible to weld only. However, the construction using the YATCO 2 is basically in the vicinity of stopping the steel pipe pile to the support layer, and when the YATCO 2 is used, the rotational force (torque) from the construction device may be the largest. There is a possibility that the shear strength of the welded portion may be insufficient in welding with only two sides.

  The present invention was made in view of such circumstances, in welding to the steel pipe pile body of the engagement piece of the steel pipe pile that contacts the Yatco (rotational force transmission member), without cutting the weld metal part, An object of the present invention is to provide a steel pipe pile that prevents the weld metal portion from coming into contact with the Yatco and that can weld the engagement piece to the steel pipe pile body with sufficient strength.

  In order to solve the above-mentioned problem, the steel pipe pile according to claim 1 is provided with a plate-like engagement piece that engages with the rotation transmission member on the inner peripheral surface or the outer peripheral surface of the steel pipe pile main body. The rotation of the rotation transmission member is transmitted through a piece, and is a steel pipe pile that is built in the ground while rotating, and a slit having a longitudinal direction in the circumferential direction of the steel pipe pile body is formed in the engagement piece, The engagement piece is welded to the inner peripheral surface or the outer peripheral surface of the steel pipe pile main body by the slit.

  In the first aspect of the invention, not the outer peripheral edge of the engagement piece but the inner peripheral edge of the slit is welded by, for example, groove welding (slot welding) or the like. When transmitting the rotation of the rotation transmission member via the engagement piece, the rotation transmission member side comes into contact with the peripheral edge of the engagement piece. In the present invention, the welded metal is engaged. Since it exists in the inside of a piece, even if a rotation transmission member contacts an engagement piece, a rotation transmission member does not contact a welding metal.

Therefore, it is not necessary to cut the weld metal as in the prior art, and labor saving can be achieved in the manufacture of the steel pipe pile, that is, the work efficiency can be improved and the cost can be reduced.
In addition, by making the dimensions such as the length of the slit, the number, the amount of weld metal in the slit portion, etc. sufficient, the shear strength of the engagement piece can be improved, and the rotation transmission member can be removed from the construction device. Even if a large rotational torque acts on the steel pipe pile, it is possible to obtain a sufficient shear strength in the welded portion of the engagement piece within the range of the assumption of a general steel pipe pile.

  The steel pipe pile according to claim 2 is characterized in that, in the invention according to claim 1, the slit is filled with a weld metal by welding at a thickness of half or more of the thickness of the engagement piece. To do.

  In the invention according to claim 2, since the weld metal is filled in the slit so as to be more than half of the thickness of the engagement piece, in the welded portion (welded metal portion) of the engagement piece to the steel pipe pile body Smooth stress transmission can be promoted, resulting in a stable structure.

  The steel pipe pile according to claim 3 is the abbreviation of the steel pipe pile main body according to claim 1 or 2, wherein the engagement piece is engaged with the rotation transmission member to transmit a rotational force. A pair of axial side edges along the axial direction, and a pair of circumferential side edges along the circumferential direction of the steel pipe pile main body to which the rotational force is not transmitted, the circumferential side of the engagement piece An edge portion is welded to the steel pipe pile main body.

  The steel pipe pile according to claim 4 is characterized in that, in the invention according to claim 3, the axial side edge of the engagement piece is welded to the steel pipe pile body in a range not contacting the rotation transmission member. To do.

  In the invention according to claim 3 and claim 4, in addition to being welded to the steel pipe pile main body by the slit, the engagement piece is also welded to the steel pipe pile main body even at the peripheral portion within a range not contacting the rotation transmission member. Therefore, a large shear strength can be obtained at the weld. Therefore, for example, when an all-round rotating machine with a large torque output is used as a construction device, such as when the diameter of the steel pipe pile is large or when the steel pipe pile is built on a solid ground, it is very solid and intrusive. It is very effective when constructing steel pipe piles (rotary intrusion steel pipe piles) in poor ground, with repeated forward and reverse rotation.

  According to the present invention, when welding the engagement piece that engages with the steel pipe pile unit to the steel pipe pile main body, the welding metal is prevented from being provided in the contact portion with the engagement piece unit. Sufficient shear strength can be ensured at the joint portion of the steel pipe pile body of the engagement piece. Therefore, when the engagement piece is welded to the steel pipe pile main body, it is not necessary to cut the weld metal in the portion that comes into contact with the yatco, so that the work efficiency can be improved and the cost can be reduced.

It is the schematic which shows the engagement piece which concerns on 1st Embodiment of this invention, Comprising: (a) is a side view, (b) is bb 'sectional drawing of (a), (c) is It is aa 'sectional drawing of (a). It is the schematic which shows the steel pipe pile concerning 1st Embodiment of this invention, Comprising: (a) is a side view, (b) is bb 'sectional drawing of (a), (c) is ( It is aa 'sectional drawing of a). It is the schematic which shows the steel pipe pile concerning 2nd Embodiment of this invention, Comprising: (a) is a side view, (b) is bb 'sectional drawing of (a), (c) is ( It is aa 'sectional drawing of a). It is a figure which shows the steel pipe pile which concerns on 3rd Embodiment of this invention, Comprising: (a) is a side view, (b) is bb 'sectional drawing of (a), (c) is (a It is aa 'sectional drawing of). It is a figure which shows the steel pipe pile which concerns on 4th Embodiment of this invention, Comprising: (a) is a side view, (b) is bb 'sectional drawing of (a), (c) is (a It is aa 'sectional drawing of). It is the schematic which shows a steel pipe pile provided with the conventional engagement piece, and a Yatco. It is the schematic which shows the conventional steel pipe pile, Comprising: (a) is a side view, (b) is bb 'sectional drawing of (a), (c) is aa' of (a). It is sectional drawing.

DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, a first embodiment of the invention will be described with reference to the drawings.
As shown in FIG. 1 and FIG. 2, the steel pipe pile of this example is built in the ground while rotating in the same manner as in the past, and the rotational force is transmitted from the construction device via the yatco (rotational force transmission member). Communicated. In this steel pipe pile, an engagement piece 11 that is engaged with the inner peripheral surface or the outer peripheral surface of the steel pipe pile main body 1 so as to be able to transmit a rotational force to the yatco is fixed by welding.
And the steel pipe pile of this example has the structure similar to the former except that the way of welding the engagement piece 11 to the steel pipe pile main body 1 is different from the conventional one.

  The engagement piece 11 is fixed to the inner peripheral surface or the outer peripheral surface of the cylindrical steel pipe pile main body 1, and is a plate-like member curved in an arc shape along the circumferential direction of the steel pipe pile main body 1. A pair of axial sides (axial side edges) 12 along the axial direction of the steel pipe pile main body 1, and a pair of circumferential sides (circumferential side edges) 13 along the circumferential direction of the steel pipe pile main body 1, It has. In FIG. 1 and FIG. 2, the engagement piece 11 is illustrated in a flat plate shape so that the description of the drawings does not become complicated. 3 to 5 to be described later, the locking pieces 21, 31, 41 are illustrated in a flat plate shape, but similarly, are actually plate-shaped.

  The engagement piece 11 is formed with two slits 14 extending in two circumferential directions and spaced apart from each other. The upper slits 14 are arranged with an interval between the upper circumferential side 13 and the lower slit 14. Further, the lower slit 14 is disposed with a space between the lower circumferential side 13 and the upper slit 14. Further, the distance between the upper slit 14 and the upper circumferential side 13, and the lower slit 14 and the lower circumferential side 13 than the distance between the upper slit 14 and the lower slit 14. The distance between and is slightly wider.

Here, the engagement piece 11 has a width W along the circumferential direction of the steel pipe pile main body 1, a length L along the axial direction of the steel pipe pile main body 1, and a steel sheet having a thickness t and a width W ₁ × length L. ₁ has a slit 14 having a size of ₁ . For example, when the number of the slits 14 is two, the centroid of each slit 14 is at a position where the length L is equally divided into three in the axial direction and at a position where the width W is equally divided in the circumferential direction. The engagement piece 11 is welded to the steel pipe pile main body 1 by groove welding (slot welding) in these slits 14.

Moreover, the dimension of the width W of the engagement piece 11, the length L, and the number of the engagement pieces 11 welded to a steel pipe pile main body are set according to the pile diameter of the steel pipe pile main body 1, the yat used, etc. .
Moreover, the dimension of the width W ₁ and the length L ₁ of the slit 14 and the number of the slits 14 are the joining of the engagement piece 11 to the steel pipe pile body 1 with respect to the rotational force (torque) transmitted from the construction apparatus. What is necessary is just to set so that the welding amount which the shear strength of a part exceeds can be ensured.

Further, it is difficult to have welding width W ₁ smaller slit 14, it is more likely to have defects such as poor penetration occurs. Width _{W 1} is preferably set to thickness t + 8 mm or more. On the other hand, if the size and number of the slits 14 are excessive, the shear strength of the engagement piece 11 itself is reduced due to a cross-sectional defect due to the slits 14, so that the appropriate size and number of the slits 14 are determined in consideration of these.

As a preferable example of the shape of the engagement piece determined in this way, in the case of a steel pipe pile diameter of 1200 mm, the engagement piece 11 is (W = 350 mm) × (L = 350 mm) × (t = 40 mm) _No. 14 includes two (W ₁ = 170 mm) × (L ₁ = 150). In addition, this is an example and may change also with conditions other than the pile diameter of a steel pipe pile.

Further, the height h of slot welding, that is, the height from the inner peripheral surface or outer peripheral surface of the steel pipe pile body of the weld metal filled in the slit 14 by welding promotes smooth stress transmission and provides a stable structure. In order to ensure, it is preferable that it is 1/2 or more of the plate thickness t and further 16 mm or more. However, when the plate thickness t is 16 mm or less, the thickness is preferably the same as the plate thickness. On the other hand, even if the height h is further set to W ₁ × 0.5 or more (note that the width W ₁ is the plate thickness t + 8 mm or more as described above), it hardly contributes to the improvement of the shear strength of the slot welded portion.

  According to the steel pipe pile having such an engagement piece 11, there is no weld metal on the outer peripheral edge of the engagement piece 11, and the yat that engages with the engagement piece 11 does not contact the weld metal. Therefore, since the Yatsuko contacts the weld metal, the engagement portion with the engagement piece of the Yattco and the engagement piece 11 are not damaged, so there is no need to cut the weld metal portion, The work efficiency can be improved and the cost can be reduced. Moreover, the welding part of the engagement piece 11 shall have sufficient shear strength in the construction of a normal steel pipe pile.

Next, 2nd Embodiment of this invention is described based on drawing.
Whereas the engagement piece 11 of the steel pipe pile of the first embodiment is welded only at the slit 14 portion, in the steel pipe pile of the second embodiment shown in FIG. The steel pipe pile body 1 is welded. Therefore, the engagement piece 21 of the second embodiment has the same slit 14 as the engagement piece 11 of the first embodiment, and the engagement piece 21 is a steel pipe pile main body in the slit 14 portion as in the first embodiment. 1 is welded to the outer peripheral surface or the inner peripheral surface.

  In the first embodiment, the end surfaces of the engagement pieces 21 at the axial side 12 and the circumferential side 23 that are the four sides of the engagement piece 11 are substantially orthogonal to the inner peripheral surface or the outer peripheral surface of the steel pipe pile body 1. In contrast, in the second embodiment, the end surface that becomes the circumferential side 23 of the engagement piece 21 is grooved, and the end surface that becomes the circumferential side 23 is inclined. It has become.

  As in the case of the first embodiment, the engaging piece 21 is slot welded to the inner peripheral surface or the outer peripheral surface of the steel pipe pile main body 1 at the slit 14. In addition to this, the grooved portion of the portion that becomes the circumferential side 23 of the engagement piece 21 is groove-welded to the inner peripheral surface or the outer peripheral surface of the steel pipe pile body 1. In addition, in FIG. 3, the code | symbol 25 is the welding metal of the said groove weld part. In the second embodiment, welding at the circumferential side 23 of the engagement piece 21 is groove welding. However, depending on the required shear strength of the welded portion and the clearance between the engagement piece 21 and the engagement groove of the Yatco. In some cases, fillet welding may be performed without providing a groove.

According to such a steel pipe pile of the second embodiment, the engagement piece 21 is welded to the steel pipe pile body 1 not only in the slit 14 portion but also in the circumferential side 23, so that the steel pipe pile of the first embodiment is used. The shear strength of the joint part of the engagement piece 21 to the steel pipe pile main body 1 is improved.
Here, when the diameter of the steel pipe is large or when the steel pipe pile is built on a solid ground, an all-around rotating machine having a large torque output is used. In that case, as in the first embodiment, there is a possibility that the shear strength of the joint portion of the engagement piece 11 to the steel pipe pile body 1 may be insufficient just by slot welding the slit 14 portion. Therefore, in the second embodiment, by using welding at the circumferential side 23 that does not require welding metal cutting, shear strength is improved, and a large shear stress acts on the engagement piece 21 in the above-described situation. Even when doing so, it can be made available.

Next, 3rd Embodiment of this invention is described based on drawing.
In the steel pipe pile of the second embodiment, the circumferential side 23 of the engagement piece 21 is welded to the inner peripheral surface or the outer peripheral surface of the steel pipe pile main body 1, whereas in the steel pipe pile of the third embodiment, Also in the axial side 22 of the engagement piece 31, the engagement piece 31 is welded to the inner peripheral surface or the outer peripheral surface of the steel pipe pile body 1.
However, the end surface which becomes the side 22 in the axial direction of the engagement piece 31 is a surface that comes into contact with the Yatsuko, where there is a weld metal by welding, and the contacted portion has a shape that cannot be smoothly contacted by surface contact or the like. There is a possibility that the Yatco or the engagement piece 31 may be damaged, and it is necessary to cut the weld metal portion into a flat shape, for example.

  Therefore, in the third embodiment, the size of the welded portion (welded metal 26) on the axial side 22 of the engagement piece 31 is smaller than the welded portion (welded metal 25) formed on the circumferential side 23. By doing so, the welded portion (welded metal 26) of the axial side 22 is prevented from contacting the Yatco. More specifically, the weld metal 26 fits in the clearance between the portion of the engagement piece 31 of the YATCO that contacts the end surface on the side 22 in the axial direction and the inner peripheral surface or the outer peripheral surface of the steel pipe pile body 1. It is about the size. Therefore, the weld metal 26 is disposed within a range close to the inner peripheral surface or the outer peripheral surface of the steel pipe pile main body 1.

  A small groove is provided on the steel pipe pile body 1 side of the end face of the axial side 22 of the engagement piece 31, and groove welding is performed so that the welded portion becomes small as described above. Therefore, although the size of the weld metals 25 and 26 is different between the circumferential side 23 and the axial side 22, the weld metal 25 and 26 are welded over the entire circumference of the outer peripheral portion of the engagement piece 31.

  Here, when a rotary penetrating steel pipe pile is to be built on a ground that is very solid and has poor penetrability, it may be constructed while repeating forward and reverse rotations. In such a situation, there is a concern that a repeated load acts on the welded portion between the engagement piece 31 and the steel pipe pile main body 1 to cause a crack due to low cycle fatigue. Since a crack in the welded portion usually occurs from the toe portion, in the engagement piece 21 of the second embodiment, if a crack occurs in the welded portion, the starting point is the welding of the circumferential side 23 that becomes the outer circumferential welded portion. There is a high possibility of becoming an end portion (stopped portion) of the portion (welded metal 25).

Therefore, in the third embodiment, as described above, the welding of the outer peripheral portion of the engagement piece 31 is continuous (closed cross section) over the entire circumference of the engagement piece 31 to eliminate the toe portion, The possibility of cracking in the weld is reduced.
Therefore, according to the steel pipe pile of the third embodiment, it is possible to obtain a steel pipe pile that can be surely applied even when the rotary penetration steel pipe pile is built on the ground that is very solid and has poor penetration.

Next, 4th Embodiment of this invention is described based on drawing.
The welding of the engagement piece 41 of the steel pipe pile of the fourth embodiment is basically the same as that of the third embodiment, but the welding of the slit 14 portion is not slot welding but fillet welding. By setting it as such a structure, the workability of welding of the slit 14 part can be improved. However, in the welding of the slit 14 portion, slot welding is superior to fillet welding from the viewpoint of the yield strength.

  In each of the above embodiments, the number of slits 14 is two. However, the number, size, etc. of the slits 14 can be changed according to various conditions. May be.

1 Steel pipe pile body 2 Yatco (rotation transmission member)
11 Engagement piece 12 Axial side (Axial side edge)
13 circumferential side (circumferential side edge)
14 Slit 15 Weld Metal 21 Engagement Piece 31 Engagement Piece 41 Engagement Piece

Claims (4)

A plate-like engagement piece that engages with the rotation transmission member is provided on the inner peripheral surface or outer peripheral surface of the steel pipe pile main body, and the rotation of the rotation transmission member is transmitted through the engagement piece, and the ground is rotated. A steel pipe pile built in
The engagement piece is formed with a slit whose longitudinal direction is the circumferential direction of the steel pipe pile main body, and the engagement piece is welded to the inner peripheral surface or the outer peripheral surface of the steel pipe pile main body. Steel pipe pile to be.   2. The steel pipe pile according to claim 1, wherein a weld metal by the welding is filled in the slit with a thickness of half or more of the thickness of the engagement piece. The engaging pieces are a pair of axial side edges along the substantially axial direction of the steel pipe pile main body to which the rotational force is transmitted by being engaged with the rotation transmission member, and the steel pipe pile to which the rotational force is not transmitted. A pair of circumferential side edges along the circumferential direction of the main body,
The steel pipe pile according to claim 1 or 2, wherein the circumferential side edge of the engagement piece is welded to the steel pipe pile main body.   The steel pipe pile according to claim 3, wherein the axial side edge portion of the engagement piece is welded to the steel pipe pile main body within a range not contacting the rotation transmission member.

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