JP2005076415A - Steel pipe pile, and method of connecting the steel pipe piles - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a steel pipe pile which is small in parts count, produced in a labor saving manner, and improved in connection strength, and to provide a method of connecting the steel pipe piles, which facilitates connection of the steel pipe piles. <P>SOLUTION: According to the method, a second steel pipe pile 11 spliced to a first steel pipe pile 1 is integrally formed of a long cylindrical upper pile body 12, a constricted portion 13 having a taper surface 16 which is formed by constricting an outer surface at a tip of the upper pile body 12 in the tip direction, and a short cylindrical pile joint portion 14 extended from the tip of the constricted portion 13, so that axial lines of the respective component parts are aligned with each other. Then the pile joint portion 14 of the second steel pipe pile 11 is fitted into the first steel pipe pile 1 to arrange the second steel pipe pile 11 above the first steel pipe pile 1, and a V-grooved outward open portion 17 is defined by an upper end face 15 of the first steel pipe pile 1 and the taper surface 16 of the second steel pipe pile 11, followed by welding the piles to each other so as to fill the groove, to thereby connect the fist and second steel pipe piles 1, 11 together. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a steel pipe pile buried in a building ground as a foundation pile, and a method for connecting a steel pipe pile using the steel pipe pile.

  Conventionally, steel pipe piles embedded in building ground as foundation piles have pile diameters and pile lengths that ensure appropriate bearing capacity according to various ground conditions such as depth and softness of the support layer. Has been determined. Therefore, depending on various conditions of the ground, a long steel pipe pile exceeding 10 m may be required. In such a case, in order to improve the handleability and reduce the labor for transporting to the site, a steel pipe pile formed in a short length of about 5 to 6 m in advance is used, and a plurality of these piles are added at the site to obtain the required pile length. It is generally done to get it. Therefore, in embedding a steel pipe pile, after embedding a short steel pipe pile, a method of driving further after connecting another short steel pipe pile by welding above the steel pipe pile is widely adopted.

  Moreover, it is known from the general structure of the ground that a vertical load is more strongly applied to the foundation pile of a building on the tip side and a horizontal load is more strongly applied to the base end side. In order to obtain foundation piles with appropriate pressure resistance against such uneven load distribution, steel pipe piles with different diameters that are thicker and stronger than the buried steel pipe piles can be connected by welding. Widely done. Here, “different diameter” means that only the inner diameters of the upper and lower piles are different. Usually, the outer diameters of the upper and lower piles are formed equally from the viewpoint of easy driving.

  When connecting such steel pipe piles by welding, it is necessary that the axial direction of the upper and lower steel pipe piles match with each other with high accuracy, so that the inner diameter of the buried steel pipe pile is slightly smaller than the inner diameter of the steel pipe pile. A method in which an inscribed pipe with a flat width is inserted and temporarily fixed (partially welded), and the inside of another steel pipe pile added to the upper part of the inscribed pipe is externally fitted, and the two upper and lower steel pipe piles are welded. Is adopted. In addition, if the upper and lower steel pipe piles are welded in a completely joined state, the strength of the joint portion is lowered, and therefore, as shown in FIG. 3, several spacers S and S are provided between the upper and lower steel pipe piles P1 and P2. ····················································································

Moreover, it can connect simply like the joint structure of the steel pipe pile provided with the steel pipe pile in which the taper surface was formed in the patent document 1, and the joint pipe which has the fitting part in which the taper surface was formed. Technology may also be used.
JP-A-7-150553

  However, in the conventional method of connecting steel pipe piles shown in FIG. 3, since a separate inscribed pipe is temporarily fixed to the steel pipe pile, it takes time to adjust the axial alignment of the upper and lower steel pipe piles P1 and P2, and During the welding, it was necessary to keep holding the several spacers S, S... Between the steel pipe piles P1, P2, and this work was very troublesome. In addition, when connecting steel pipe piles with different diameters via an inscribed pipe, the shape of the inscribed pipe must also be changed according to the inner diameter of the steel pipe pile, which complicates the shape of the connecting jig. It was. Further, the joint structure described in Patent Document 1 has a problem that a groove portion for welding cannot be formed, and the bonding strength is weakened.

  In view of these problems, the present invention eliminates the need for a separate connecting jig such as an inscribed pipe, reduces the number of parts and saves labor, and further improves the connection strength and facilitates the steel pipe pile. It is in providing the connection method which can be connected to. Moreover, it is providing the steel pipe pile which can be used suitably for such a connection method.

  In order to solve the above-mentioned problem, a steel pipe pile according to the invention of claim 1 includes a long cylindrical pile body, and a narrowed portion having a tapered surface narrowed in the distal direction on the outer surface at the tip of the pile body. The short cylindrical pile connecting portion provided continuously at the tip of the narrowing portion is integrally formed so that the respective axes coincide with each other.

  The steel pipe pile according to the invention of claim 2 is configured such that the narrowed portion and the pile connecting portion are formed by cutting out the outer surface at the tip of the pile body.

  The connection method of the steel pipe pile by invention of Claim 3 is a connection method of the steel pipe pile for connecting a 2nd steel pipe pile on the upper side of the 1st steel pipe pile buried in the ground, Comprising: As a steel pipe pile according to claim 1 or 2, a pile connection part of the second steel pipe pile is inserted into the first steel pipe pile, and an upper end surface of the first steel pipe pile and the second steel pipe pile. The groove part which consists of a taper surface is welded.

  According to the invention of claim 1, since the narrowed portion and the pile connecting portion are integrally formed at the tip of the pile body, a separate connecting jig is not required when connecting to another steel pipe pile, and the component to be used The score can be reduced. Moreover, since it formed so that each axis of a pile main body, a narrowing-down part, and a pile connection part might correspond, an upper and lower steel pipe pile can be matched easily with high precision.

  According to invention of Claim 2, since the outer surface at the front-end | tip of a pile main body was carved out and the narrowing part and the pile connection part were formed, it can manufacture cheaply and easily.

  According to invention of Claim 3, since a groove part can be formed with the upper end surface of the 1st steel pipe pile, and the taper surface of the 2nd steel pipe pile, the effort which forms a groove part with another member can be saved, Work time for on-site welding can be shortened, and connection work becomes easy. Moreover, it can weld so that the groove | channel of a groove part may be filled, and high connection strength can be obtained.

  Hereinafter, an embodiment of a steel pipe pile according to the present invention and a connection method thereof will be described in detail based on the drawings. FIG. 1 (a) is a side view showing a pile that is driven first into the ground, that is, a first steel pipe pile, and FIG. 1 (b) shows a pile that is added to the first steel pipe pile, that is, a second steel pipe pile. FIG.

  A first steel pipe pile (hereinafter referred to as “lower pile”) 1 is configured as a so-called feathered steel pipe pile by a lower pile body 2, a bite 3, and a spiral blade 4. The lower pile body 2 is made of iron and has a cylindrical shape (cylinder thickness t1 = approximately 6.0 mm) having an outer diameter φA1 (= about 165.4 mm), an inner diameter φB1 (= about 153.4 mm), and a length L1 (= about 6 m). ). And at the front-end | tip of the lower pile main body 2, the two byte | pieces 3 and 3 made from iron and square pillar shape (width about 20mm, thickness about 12mm) are attached (it welds to the inner wall of the lower pile main body 2). It is in the state which protruded from the front-end | tip of the lower pile main body 2 about 20 mm. The tips of the cutting tools 3 and 3 are pointed at the center.

  In addition, a spiral blade 4 made of an iron plate having a thickness of about 6.0 mm is integrally attached to a portion of the lower pile main body 2 at the front end by welding into a circular flange shape having an outer diameter of about 265 mm. The spiral wing 4 winds the outer periphery of the lower pile main body 2 at an interval of about 150 mm in the right direction (that is, in a direction rotating in the right direction from the upper end to the lower end when viewed from above). It is in the state.

  Next, the 2nd steel pipe pile (henceforth "upper pile") 11 integrally forms the upper pile main body 12, the narrowing-down part 13, and the pile connection part 14 so that each axis line may correspond. It is configured as follows. The upper pile body 12 is made of, for example, the same iron as the lower pile body 2 and is a cylinder having an outer diameter φA2 (= about 165.4 mm), an inner diameter φB2 (= about 143.4 mm), and a length L2 (= about 6.0 m). (Cylinder thickness t2 = about 11.0 mm). The upper pile body 12 is formed thick so that the strength is higher than that of the lower pile body 2. Hereinafter, as in the case of the lower pile 1 and the upper pile 11, it is assumed that the outer diameters of the piles are equal and the inner diameters are different from each other.

  The narrowing portion 13 is formed by cutting out the tip outer surface of the upper pile main body 13 by a cutting means such as a cutting device so as to have a tapered surface 16 that narrows the outer surface of the upper pile main body 12 in the tip direction. . Further, a short cylindrical pile connection portion 14 is continuously provided at the distal end of the narrowing portion 13 by cutting with the same cutting means as the narrowing portion 13. The pile connecting portion 14 has an outer diameter φA3 that is slightly smaller than an inner diameter φB1 of the first steel pipe pile, an inner diameter φB3 that is equal to the inner diameter φB2 of the upper pile main body 12, and a cylinder length L3.

  Moreover, since the narrowing-down part 13 is formed so that the front-end | tip of the upper pile main body 12 and the base end of the pile connection part 14 may be connected, the circle | round | yen of the same diameter as the outer diameter (phi) A2 of the upper pile main body 12 is used. The top surface is a circular truncated cone having the same diameter as the outer diameter φA2 of the pile connecting portion 14 and the bottom surface is a truncated cone having a height h (= about 5.0 mm). It becomes.

  Hereinafter, the connection method of the said lower pile and the upper piles 1 and 11 is demonstrated according to a figure. FIG. 2 is an enlarged cross-sectional view of the joint portion showing a state in which the upper pile 11 is connected to the lower pile 1.

  When the upper pile 11 is connected above the lower pile 1 buried in the ground by rotation penetration, the pile connection portion 14 of the upper pile 11 is inserted into the lower pile 1 (the outer surface of the pile connection portion 14 is The upper pile 11 is disposed above the lower pile 1 by being fitted so as to be joined to the inner surface of the lower pile 1. By arranging the upper pile 11 in such a manner, a V-shaped groove-like groove portion 17 is formed on the entire circumference by the upper end surface 15 of the lower pile 1 and the tapered surface 16 of the upper pile 11. Using a burner, two or three spots of the groove portion 17 are temporarily fixed and then welded sufficiently over the entire circumference so as to fill the groove of the groove portion 17. The connection with the pile 11 is completed.

  According to the steel pipe pile such as the upper pile 11, since the narrowed portion 13 and the pile connecting portion 14 are integrally formed at the tip of the upper pile body 12, it is connected to a steel pipe pile having a different diameter such as the lower pile 1. In this case, a separate connecting jig as in the prior art becomes unnecessary, and the number of parts used for the connecting work can be reduced. Moreover, since it formed so that each axis of the upper pile main body 12, the narrowing-down part 13, and the pile connection part 14 might correspond, the lower pile 1 and the upper pile 11 can be matched easily with high precision.

  Moreover, since the narrowing part 13 and the pile connection part 14 were formed by carving out the outer surface at the front-end | tip of the upper pile main body 12, the precision of the coaxiality of the outer diameter and inner diameter with which the upper pile main body 12 is equipped is narrowed down. It can be reflected also in the part 13 and the pile connection part 14. Therefore, when manufacturing the upper pile 11, the matching process of each axis of the upper pile main body 12, the narrowing-down part 13, and the pile connection part 14 can be omitted, and the manufacturing process can be simplified. Furthermore, in this case, it can be manufactured easily and inexpensively using a general cutting machine tool.

  On the other hand, according to the connection method of the lower pile 1 and the upper pile 11 as described above, the upper and lower piles 1 and 11 are connected very easily so that the longitudinal direction is matched (so as not to be bent into a square shape). can do. Moreover, since the groove part 17 can be formed by the upper end surface 15 of the lower pile 1 and the taper surface 16 of the upper pile 11 only by fitting operation of the upper pile 11 with respect to the lower pile 1, the effort which forms a groove part with another member. Can be omitted, the work time for on-site welding can be shortened, and the connection work becomes easy. Moreover, it can weld so that the groove | channel of a groove part may be filled, and high connection strength can be obtained.

The present invention is not limited to the above-described embodiment, and can be implemented by appropriately changing the shape and configuration of each part without departing from the spirit of the present invention, as exemplified below. .
(1) The steel pipe pile which concerns on this invention may form the upper pile main body 12, the narrowing-down part 13, and the pile connection part 14 in a different body, and make each axis line agree | coincide. This steel pipe pile also eliminates the need for a conventional connection jig, and can reduce the number of parts used for connection work.
(2) The present invention is not limited to steel pipe piles with different diameters, but can also be applied to connections between steel pipe piles with the same diameter. In this case, the upper pile 11 is formed, for example, by separately forming a pile connection portion 14 formed to be slightly smaller in diameter than the inner diameter of the lower pile 1, and a narrowing portion 13 formed separately at the tip of the lower pile body 2. It can be considered that they are connected via Also in this steel pipe pile, the same effect as the case of a different diameter can be obtained.
(3) The present invention can be used not only for the rotary press-fitting method but also for other foundation pile methods such as a driving method.
(4) The lower pile 1 is not limited to a winged steel pipe pile, and may be a steel pipe pile having a form such as a driving method such as a simple cylindrical pile from which spiral wings are removed.
(5) The upper pile 11 is not only configured using an outer diameter of the upper pile body 12 that is substantially the same as that of the lower pile body 2, but also has a smaller or larger diameter than the lower pile body 2. It can also be configured using.
(6) The steel pipe pile according to the present invention can be applied not only to the lower pile 1 and the upper pile 11 but also to a plurality of connection methods such as three or four. For example, the third steel pipe pile connected to the upper side of the upper pile 11, like the upper pile 11, has a long cylindrical pile body and a narrowed surface having a tapered surface narrowed in the distal direction on the outer surface of the pile body. The inserting portion and the short cylindrical pile connecting portion provided continuously at the tip of the narrowing portion are integrally formed so that the respective axes coincide with each other. The pile connection portion of the third steel pipe pile is formed so as to be fitted into the upper pile 11. And the connection using this 3rd steel pipe pile inserts and arrange | positions a 3rd steel pipe pile above the upper pile 11 so that an axis line may correspond. By arranging in this way, a V-shaped groove-shaped groove portion is formed on the entire circumference by the upper end surface of the upper pile 11 and the tapered surface of the third steel pipe pile, and the groove portion is welded to complete the connection. To do. The same effect as the connection method of the lower pile 1 and the upper pile 11 can also be obtained by the connection method of the third steel pipe pile and the upper pile 11 in this case.
(7) The pile connection portion 14 of the upper pile 11 is not only formed so that the tip end surface thereof is orthogonal to the cylinder axis as shown in FIGS. You may form in. In this case, it becomes easy to insert the pile connection part 14 of the upper pile 11 inside the lower pile 1.

An embodiment of the steel pipe pile concerning the present invention is shown, (a) is a side view of the 1st steel pipe pile, and (b) is a side view of the 2nd steel pipe pile. It is structure explanatory drawing which shows one Embodiment of the connection method of the steel pipe pile which concerns on this invention. It is explanatory drawing which shows the connection method of the conventional steel pipe pile.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Lower pile as 1st steel pipe pile 2 Lower pile main body 3 Bite 4 Spiral wing 5 Upper end part 11 Upper pile as 2nd steel pipe pile 12 Upper pile main body 13 Narrowing part 14 Pile connection part 16 Tapered surface 17 Groove part

Claims (3)

A long cylindrical pile body,
A narrowed portion having a tapered surface narrowed in the distal direction on the outer surface at the tip of the pile body;
A short cylindrical pile connecting portion provided continuously at the tip of the narrowing portion;
Steel pipe piles that are integrally formed so that their axes match. The steel pipe pile according to claim 1, wherein the narrowed-down portion and the pile connecting portion are formed by cutting out the outer peripheral surface of the tip end of the pile body. A steel pipe pile connection method for connecting a second steel pipe pile on the upper side of the first steel pipe pile buried in the ground,
The second steel pipe pile as a steel pipe pile according to claim 1 or claim 2,
The pile connection part of the second steel pipe pile is inserted into the first steel pipe pile,
Welding a groove formed by an upper end surface of the first steel pipe pile and a tapered surface of the second steel pipe pile;
Steel pipe pile connection method.

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