JP4341755B2 - Connection member for rotary press-fit pile - Google Patents

Description

  The present invention relates to a connection member used when a plurality of rotary press-fitting piles that support a foundation of a building or a civil engineering structure are connected in the press-fitting direction of the piles.

  Conventionally, rotary press-fit piles that support the foundations of buildings and civil engineering structures are constructed by applying a load to the pile head and pressing it into the ground while rotating the pile. The friction generated between the earth and sand in contact with the ground is increased, the pile is supported by this friction, and the pile is prevented from sinking into the ground by a load of a building or the like.

  When a rotary press-in pile that supports the foundation of a building or civil structure is pressed into a soft ground or a place where the support ground is deep, the rotary press-in pile is connected while sequentially connecting multiple piles in this press-fit direction. However, it is press-fitted until the support layer (supporting ground) having a large ground bearing strength that can sufficiently support the pile or until a sufficient supporting frictional force is obtained with the surrounding ground.

  As for the connection method between piles, when the pile is a steel pipe pile, the connection by welding is the most primitive means, but the welding in the field depends on the weather, and further, welding by skilled engineers is indispensable, In order to eliminate the need for on-site welding, a method of connecting using a connecting member (for example, see Patent Document 1) consisting of a pair of males and females mounted in advance on both upper and lower ends of a pile has spread.

  It is needless to say that the connection member is required to stably obtain a reliable connection strength, easy to connect, and require no skill. It clears the request.

  However, there are piles of various diameters that are driven by rotary press-fitting. For example, an outer diameter of about 114.3 mm or 139.8 mm used for supporting a foundation of a general house (foundation of a building or the like). In the case of a small-diameter pile whose outer diameter is about half of that of 267 mm, for example, the diameter of the connecting member is much larger than that of the pile and protrudes to the outside. When there is a tendency to cause press-fitting resistance at the time of formation, or a part of the ground that is not sufficiently consolidated is formed around the pile, preventing smooth progress of the rotary press-fitting work or insufficient control of the press-fitting work The concern that the stability of the supporting force after press fitting may not be sufficiently obtained cannot be eliminated.

  In addition, when there is an obstacle such as rubble or stone in the pile placement direction during rotary press-fitting, the pile is rotated forward and reverse to eliminate the obstacle. In addition to maintaining the connection strength with respect to the direction, the connection strength and its reliability must be sufficiently secured against rotation in the reverse direction.

JP 2000-199225 A (pages 1 to 5, FIGS. 1 to 8)

  In the present invention, the pile can be connected reliably and easily in spite of the simple structure of the connecting member, and the connecting member can be attached to both ends of the pile in advance in the factory, so that complicated welding work in the field Without damaging the merit that it is not necessary, it has sufficient strength against forward and reverse rotation during pile press-fitting and stably maintains the connection between piles over a long period of time Even if it is configured so that the connecting member does not protrude from the outer periphery of the pile and is used for connecting a small-diameter pile, the outer peripheral surface and the earth and sand in all of the piles and connecting members that are rotationally pressed into the ground It was made possible to provide a connecting member of a rotary press-fit pile that can generate stable friction between the two.

  In order to solve the above-described problems, the connection member of the rotary press-fitting pile according to the present invention is a connection member used when connecting a plurality of rotary press-fitting piles that support a foundation such as a building in the press-fitting direction of the pile. A male joint having an upper end portion attached to the lower end of the pile with respect to the press-fitting direction of the pile, and a female joint engaging the male joint having an attachment portion to the upper end portion of the pile at the lower end portion, The male joint has a small-diameter portion below the mounting portion to the pile, and has an engagement protrusion protruding radially on the outer peripheral surface of the small-diameter portion, and the female joint has an inner peripheral surface A first longitudinal groove portion that guides the engagement protrusion of the male joint from the upper end in the axial direction of the pile, a lateral groove portion that guides the circumferential direction of the pile following the first longitudinal groove portion, and the lateral groove portion. A second vertical groove portion for guiding in the axial direction of the pile, and an intersection portion of the second vertical groove portion and the horizontal groove portion And a window that communicates the inside and outside of the female joint, and the male and male joints are inserted through the window in a state in which these male and female joints are engaged, and the upper and lower sides of the engaging projections of the male joint in the second groove portion. It is configured with a retaining piece that regulates the movement in the direction.

  Further, the outer diameter of the female joint is configured to be equal to the outer diameter of the rotary press-fit pile to be connected.

  Furthermore, a through hole that penetrates the retaining piece and a through hole that communicates with the through hole when the retaining piece is inserted into the window of the female joint are also provided in the male joint, and a fixing pin is inserted into these through holes. Thus, the retaining piece can be prevented from falling off.

  Further, the lateral groove formed in the cylindrical portion of the female joint is inclined upward from the lower end of the first vertical groove to the upper end of the second vertical groove.

  Further, the small-diameter portion of the male joint is configured to have a tapered shape with a small diameter downward.

  According to the connecting member of the rotary press-fitting pile of the present invention, the engaging protrusion of the male joint is inserted into the first vertical groove portion of the female joint and rotated, whereby the engaging protrusion is guided to the lateral groove portion, and then the second Since it enters into the longitudinal groove, the engagement protrusion of the male joint can be easily and reliably set at the proper engagement position of the female joint.

  Therefore, in this state, the engagement of the engagement protrusion and the second vertical groove portion is already maintained with respect to the pile rotation direction and the placing direction (downward in the axial direction), and even if the pile is rotated in the forward and reverse directions, the male and female The connection between the joints is firmly maintained.

  And from the window formed in the female joint, by inserting the retaining piece into the upper part of the engagement protrusion that has entered the second longitudinal groove portion in the second longitudinal groove portion, the pile upward in the axial direction, that is, the direction in which the pile is pulled out. However, the connection state is maintained firmly, and the retaining piece is not subjected to stress in the direction of rotation of the pile, and the possibility of a decrease in connection strength due to breakage or dropout of the piece can be greatly reduced. It can be set as a high connection member.

  Moreover, since the engagement protrusions of the male joint are formed in the lower diameter portion of the lower part, when the piles are connected to each other, the outer peripheral surface of the pile and the outer peripheral surface of the connecting member are substantially flush with each other. Thickness can be reduced, so even when used to connect thin piles that support the foundations of ordinary houses, the outer peripheral surface of all piles and connecting members that are rotationally pressed into the ground and the earth and sand in the ground Can produce stable friction between them, and even if there are obstacles such as hard layers or rubble in the middle of the ground, it is unlikely that the connection members will be caught and hinder the press-in of the piles, and efficient piles Can be placed.

  Furthermore, in the case where the small diameter portion of the male joint is formed in a tapered shape, the male and female joints can be connected more easily, and can be suitably used particularly for connecting small diameter piles.

Hereinafter, the connecting member of the rotary press-fitting pile of the present invention will be described with reference to the accompanying drawings.
As shown in FIG. 1, the connecting member 1 includes a male joint 2 connected to the lower end of the pile, a female joint 3 connected to the upper end of the pile, and a retaining piece 4 fitted into the window 15 of the female joint 3. It is configured.

  The male joint 2 is provided with an engagement protrusion 6 having a rectangular cross-section projecting radially on the outer periphery of the lower small-diameter portion 5, and a pin through which an anchor pin 20 inserted through a through-hole 19 of a retaining piece 4 to be described later passes. It has the fitting small diameter part 8 which is a mounting part fitted to the through-hole 7 and the edge part opening of the pile which consists of a rotation press fit pile, ie, a steel pipe. This fitting small diameter part 8 is comprised so that it may insert in the inside, when a pile is a steel pipe pile.

  The small-diameter portion 5 is configured in a tapered shape having a diameter that decreases toward the lower side, and is configured to facilitate the engagement of the male and female joints 3 and 2. In some cases, it may be a straight cylinder.

  In the present embodiment, the engaging protrusions 6 are provided in two places that are different from each other by 180 degrees and in two stages, but the engaging protrusions 6 are different from each other by 120 degrees depending on the diameter of the pile to be attached, etc. In some cases, it may be provided in more than one place, or in one or three or more stages. In such a case, an engagement groove (first longitudinal groove portion, which guides the engagement protrusion 6 in the female joint 3 described later). The position and the number of the windows 15 into which the horizontal groove portion, the second vertical groove portion) and the retaining piece 4 are fitted are also made to correspond appropriately.

  Further, since the engaging protrusion 6 is formed at the same time as the molding of the male joint 2 and is integrally formed with the small diameter part 5, the strength of the base part in the engaging protrusion 6 can be sufficiently obtained.

  The female joint 3 is provided on the inner peripheral surface 11 of a cylindrical joint body 10 that guides the engaging protrusion 6 of the male joint 2 to a predetermined engaging portion (lower side in the second vertical groove portion 14). A window which is a through hole communicating from the outer peripheral surface of the joint main body 10 into which the engaging groove (first vertical groove portion 12, lateral groove portion 13, second vertical groove portion 14) and the retaining piece 4 are inserted into the second vertical groove portion 14. 15 and the fitting small diameter part 16 connected to the edge part opening of a pile, and when this pile is a steel pipe pile, this fitting small diameter part is formed so that it can be inserted in the inside.

  The retaining piece 4 has a through-hole 19 that penetrates in the same direction as the fitting direction of the female joint 3 to the window 15, and is inserted into the through-hole 19 so that the retaining piece 4 is inserted into the window 15 of the female joint 3. It has an anchor pin 20 for preventing it from falling off.

  Moreover, as shown in FIG. 2, the male joint 2 and the female joint 3 in the connecting member 1 are connected to the male joint 2 at the lower end opening (not shown) of the upper pile body 23 with respect to the press-fitting direction of the pile. The female joint 3 is firmly connected to the upper end opening (not shown) of the main body 23 by welding (welded portion 24). In addition, the code | symbol 9 in a figure shows the inclination part for comprising a welding allowance.

  At the time of welding, the small diameter part 5 of the male joint 2 and the fitting small diameter parts 8 and 16 (see FIG. 1) of the joint body 10 of the female joint 3 are respectively fitted into the openings at the upper and lower ends of the pile body 23. Positioning. This welding is not performed at the site where rotational press-fitting is performed, but is performed in advance so that sufficient connection strength is obtained in a stable environment in the factory.

  And in order to connect piles, it inserts in the opening 18 of the female joint 3 with which the male joint 2 with which the pile of the side to connect is attached to the pile of the side to be connected, and is rotated. 4, the engaging projection 6 of the male joint 2 enters the first vertical groove portion 12 of the female joint 3 (FIG. 4A), and proceeds downward in the first vertical groove portion 12 (FIG. 4 ( b)) Next, when the pile on which the male joint 2 is mounted is rotated in the rotational press-fitting direction, the engaging protrusion 6 advances through the lateral groove portion 13 following the first longitudinal groove portion 12 (FIG. 4C), It passes through the horizontal groove 13 and proceeds to the second vertical groove 14 following the horizontal groove 13 (FIG. 4D), and is set at the lower end of the second vertical groove 14 (FIG. 4E).

  When the engaging projection 6 of the male joint 2 is set in the second vertical groove portion 14 (FIG. 4E), the retaining piece 4 is fitted into the window 15 of the female joint 3, and the through-hole of the retaining piece 4 is inserted. An anchor pin 20 is driven into 19 so that the retaining piece 4 does not fall out of the window 15 of the female joint 3.

  FIG. 5 shows a state in which the anchor pin 20 is driven into the through hole 19 of the retaining piece 4 fitted into the window 15 of the female joint 3, and the anchor pin 20 is connected to the through hole 19 of the retaining piece 4. The cone 21 is driven in a state where the female joint 3 is inserted into the pin through hole 7 in the joint body 10, and the leg 22 opens outward by the driving of the cone 21, and the anchor pin 20 is fixed, and the retaining piece 4 is fixed. It is fixed in the window 15 of the female joint 3.

  From the above, the lower end, left side, and right side portions of the engaging projection 6 in the male joint 2 are surrounded by the lower end, left side, and right side portions of the second vertical groove portion 14 in the female joint 3. The movement in the direction is restricted, and the upper end portion of the engagement protrusion 6 in the male joint 2 is fitted into the window 15 of the female joint 3 and protrudes above the engagement protrusion 6 in the second vertical groove portion 14. Since the upward movement is restricted by the stop piece 4, the male joint 2 does not rotate in the circumferential direction of the pile with respect to the female joint 3 and does not come out in the axial direction of the pile.

  Therefore, a very large force related to the press-fitting of the pile generated at the lower end, left side, and right side of the engagement protrusion 6 in the male joint 2, that is, the rotation of the pile in the direction of the rotary press-in and the obstacle handling. The lower, left, and right sides of the second longitudinal groove portion 14 in the female joint 3 formed of a material having the same strength as the male joint 2 is applied to the vertically downward pile applied during reverse rotation and rotary press-fitting of the pile. Since each part of the three sides receives firmly, it is possible to stably receive the extremely large three-way force related to the rotary press-fitting of the pile.

  Thus, since the member thickness of the joint body 10 of the female joint 3 can be reduced, when the piles are connected to each other, the outer peripheral surface of the pile (pile body 23) and the connection member 1 (male joint 2, female joint 3). The diameter of the connecting member 1 can be configured to be substantially flush with the outer peripheral surface.

  In the above-described embodiment, the engaging protrusion 6 is formed in a so-called block shape having a rectangular cross section. However, in some cases, the engaging protrusion 6 may have a circular cross section as shown in FIG. The movement in the joint grooves 12a, 13a, and 14a can be made smoother.

  Further, the horizontal groove 13 may be inclined upward from the lower end of the first vertical groove 12a toward the upper end of the second vertical groove 14a, as in the horizontal groove 13a shown in FIG.

  Thus, the engaging protrusion 6a of the male joint 2 set in the second vertical groove portion 14a is formed by making the horizontal groove portion 13a incline upward from the lower end portion of the first vertical groove portion 12a toward the upper end portion of the second vertical groove portion 14a. Even if the retaining piece 4a fitted into the window 15a of the female joint 3 to be fixed should fall off, the engagement protrusion 6 can hardly move from the second longitudinal groove portion 14a to the lateral groove portion 13a, and therefore the retaining piece 4a has fallen off. It is possible to reduce the wobble and disengagement of the piles at the connection part that occurs when the machine is connected.

  Further, when the engagement protrusion 6 having a rectangular cross section is formed into an engagement protrusion 6a having a circular cross section as shown in FIG. 6, the lower end shape of the second vertical groove portion 14a is changed to the lower shape of the engagement protrusion 6a. In some cases, the retaining piece 4 may be shaped to follow the upper shape of the engaging protrusion 6a, such as the retaining piece 4a shown in FIG.

  FIG. 8 shows a state in which a plurality of piles are connected to each other by the connecting member 1 according to the present invention while being rotationally press-fitted from the ground surface 25 toward the underground 26. As can be seen from FIG. 2, since the outer peripheral surface of the female joint 3) and the outer peripheral surface of the pile (pile main body 23) are substantially flush with each other, a plurality of piles (pile main body 23) and the connecting member 1 ( The outer peripheral surfaces of the male joint 2 and the female joint 3) are in contact with the earth and sand of the underground 26, whereby the pile (pile body 23) and the connecting member 1 (male joint 2 and female joint 3) that are rotationally pressed into the underground 26 Stable friction is generated between the outer peripheral surface of the earth and the earth and sand in the ground.

  Although not shown in the embodiment, even when the pile passes through the hard layer in the underground 26, the outer surface of the pile (pile main body 23) and the connection member 1 (male joint 2, female joint 3) is almost the same. Since it is flush, the pile can pass through the hard layer of the underground 26 without being caught by the earth and sand or stones in this hard layer.

  Reference numeral 23a in FIG. 8 in the embodiment is an excavating blade disposed at the tip of the pile (pile main body 23).

The perspective view which shows the structure in the connection member of the rotary press-fit pile which concerns on this invention. The perspective view which shows the upper-lower-end part in the rotary press-fit pile in the state which welded the connection member. The perspective view which shows the state before welding which fitted the connection member to the upper-lower-end part of the rotation press fit pile. The figure which shows the engagement process of an engaging protrusion and each engaging groove. The longitudinal cross-sectional view of a connection member. The figure which shows the other example of an embodiment in an engagement protrusion and an engagement groove | channel. The figure which shows the other example of a form of a retaining piece. The figure which shows the use condition of the rotation press fit pile connected with the connection member which concerns on this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Connection member 2 Male joint 3 Female joint 4 Fall prevention piece 4a Fall prevention piece 5 Small diameter part 6 Engagement protrusion 6a Engagement protrusion 7 Pin through-hole 8 Fitting small diameter part 9 Inclination part 10 Joint main body 11 Inner peripheral surface 12 1st Vertical groove portion 12a First vertical groove portion 13 Horizontal groove portion 13a Horizontal groove portion 14 Second vertical groove portion 14a Second vertical groove portion 15 Window 15a Window 16 Fitting small diameter portion 17 Welded portion 18 Opening 19 Through hole 20 Anchor pin 21 Cone 22 Leg portion 23 Pile Main body 23a Excavation blade 24 Welded portion 25 Ground surface 26 Underground

Claims (5)

  It is a connecting member used when connecting multiple rotary press-fit piles that support the foundation of a building, etc. in the press-fit direction of the pile, and has a mounting portion on the lower end of the pile in the press-fit direction of the pile at the upper end. A male joint and a female joint that engages with the male joint; and a male joint having a small diameter portion below the pile mounting portion. The small-diameter portion has an engagement protrusion projecting in the radial direction on the outer peripheral surface, and the female joint guides the engagement protrusion of the male joint on the inner peripheral surface from the upper end to the axial direction of the pile. A groove portion, a horizontal groove portion that guides in the circumferential direction of the pile following the first vertical groove portion, a second vertical groove portion that guides in the axial direction of the pile following the horizontal groove portion, the second vertical groove portion and the horizontal groove A window that communicates the inside and outside of the female joint at the intersection of the male and female joints. And a retaining piece that is inserted through the window in a state in which these male and female joints are engaged and restricts the vertical movement of the engaging projection of the male joint in the second groove. Connection member for press-fit piles.   The connecting member of the rotary press-fit pile according to claim 1, wherein the outer diameter of the female joint is configured to be equal to the outer diameter of the rotary press-fit pile to be connected.   A through hole that penetrates the retaining piece and a through hole that communicates with the through hole when the retaining piece is inserted into the window of the female joint are also provided in the male joint, and a fixing pin is inserted into these through holes. The connecting member of the rotary press-fit pile according to claim 1, wherein the retaining piece can be prevented from falling off.   The connection of the rotary press-fit pile of Claim 1 which attaches an upward inclination from the lower end part of a 1st vertical groove part to the upper end part of a 2nd vertical groove part in the horizontal groove part formed in the cylinder part in the said female joint. Element.   The connecting member of the rotary press-fit pile according to claim 1, wherein the small-diameter portion of the male joint is formed in a tapered shape having a small diameter downward.

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