JP2009057692A - End member - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce cost while securing enough fitting strength between a spiral blade part and a straight pipe-like part by integrally forming the spiral blade part and the straight pipe-like part to eliminate the need of welding work. <P>SOLUTION: This end member 50 fitted to a pile is formed by including the cylindrical straight pipe-like part 51 and the spiral blade part provided at the ground side of the straight pipe-like part, and integrally casing the straight pipe-like part and the spiral blade part 52. The spiral blade part 52 is extended in the inside and outside directions of the straight pipe-like part 51, and in the inside of the straight pipe-like part 51, an opening is reduced to be half-blocked. The vicinity of the end on the opposite side to the blade part in the straight pipe-like part is provided with a plurality of through holes 55, and a connector is inserted in the through holes 55 and a through hole provided in the pile to make connection. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a propulsion member (referred to as a tip member) that is connected to an end of the foundation pile on the bottom side and propels the foundation pile into the ground, and in particular, the straight pipe portion and the spiral wing portion are integrally formed by casting. It relates to the formed tip member.

Conventionally, when a low-rise building is built on soft ground, a steel foundation pile (steel pipe pile) is used as a foundation for supporting the building. This foundation pile is buried in the ground, and the foundation and concrete slab that support the building are integrally formed at the pile head.
The foundation pile generally consists of an upper pile that is integrally connected to the base of the building, and a lower pile, and when this is buried in the ground, a spiral wing member gives rotational force to the lower pile attached to the tip, The spiral wing member propels it into the ground. When the lower pile is buried to a certain depth, a new pile material is added to the upper end of the lower pile, and the propulsion is started again by applying a rotational force to the added pile material. This operation is repeated until the pile reaches the support layer.

The shape of the tip formed at the tip of this foundation pile affects the ease of penetration of this foundation pile into the ground and the support capacity of the foundation pile after penetration. Proposed.
For example, a steel pipe pile having a tip portion in which a spiral blade is attached to the outer periphery of a bottomed steel pipe is known (see Patent Document 1).

  The steel pipe pile described in Patent Document 1 is a bottomed steel pipe, and a spiral blade (referred to as a wing part in the present invention) is fixed to the outer periphery of the steel pipe. I cannot dig. In addition, depending on the diameter and ground of the steel pipe, the resistance of the earth and sand (penetration resistance) to the penetration direction on the bottom surface of the steel pipe is very large. Sometimes it happens. Even if the penetration is advanced little by little while spinning around, the supporting force of the steel pipe pile after penetration is reduced because the spiral blades are disturbed in the earth and sand around the steel pipe.

Therefore, foundation piles in which spiral blades with drilling blades on the bottom surface are formed at the end of the open metal pipe are used for steel pipes with larger diameters and increased resistance to earth and sand (Patent Literature). 2).
When this foundation pile is rotated and penetrated into the ground, the ground is excavated by the excavating blade provided on this spiral blade, and the excavated soil is taken into the hollow part of the metal pipe, so that The resistance is small and the penetration proceeds smoothly.
However, in the foundation pile described in Patent Document 2, when the penetration is finished, the ground at the tip of the foundation pile is disturbed by the excavating blade provided on the spiral blade, and the foundation pile Since the pile is formed of a completely open-ended metal tube, the resistance to the earth and sand in the axial direction is small, and there is a possibility that sufficient axial supporting force cannot be obtained.

Then, in order to solve the problem of penetration resistance and the problem of supporting force at the same time, a rotary press-fit steel pipe pile in which a spiral blade is fixed to the tip of a spirally cut steel pipe pile is used (see Patent Document 3). ).
This spiral blade also extends radially inward of the steel pipe pile, and the tip of the steel pipe pile is in a semi-closed state by this helical blade.
According to this rotary press-fit steel pipe pile, it is possible to reduce the resistance of the earth and sand against the tip of the steel pipe pile at the time of intrusion by rotating and penetrating while appropriately taking excavated soil from the semi-closed tip to the inside of the pile. The steel pipe pile can be penetrated into the ground, and after penetration, the spiral blade formed at the tip of the steel pipe pile can receive the resistance of the earth and sand against the tip of the steel pipe pile and ensure the axial support force. it can.

This rotary press-fit steel pipe pile is manufactured by cutting the tip portion of the steel pipe into a spiral shape and welding a spiral blade that matches the tip surface to the cut surface. However, in addition to the cutting process of the tip of the steel pipe, there is a problem that a great deal of labor and cost are required for the manufacture of the blade member that is thicker than the steel pipe in order to receive a large penetration resistance and welding the blade member to the steel pipe.
JP 59-85028 A JP 2002-221948 A JP 2004-316421 A

  The present invention has been made in order to solve the above-described problems. The object of the present invention is to integrally form a spiral wing portion and a straight pipe portion so that a welding operation is unnecessary, and the spiral wing portion and the straight pipe portion are formed. It is to reduce the cost while ensuring sufficient attachment strength with the part.

The invention of claim 1 is a tip member that can be attached to a pile, and includes a cylindrical straight pipe portion, and a spiral wing provided on the bottom side of the straight pipe portion, and the straight pipe portion The spiral wing is integrally cast.
According to a second aspect of the present invention, in the tip member according to the first aspect, the wing portion extends in the inner and outer diameter directions of the straight pipe portion at the bottom side end portion of the straight pipe portion, and extends in the inner diameter direction. The wing part has a width that forms a spiral opening of a predetermined diameter inside the straight pipe part.
According to a third aspect of the present invention, in the tip member according to the first or second aspect, the wing portion leaves a predetermined gap between the start end and the end of the wing portion when the tip member is viewed from below. In this case, the straight pipe portion is formed so as to go around the bottom side end portion.
According to a fourth aspect of the present invention, in the tip member according to any one of the first to third aspects, a through hole is provided in the vicinity of the end portion of the straight pipe portion opposite to the wing portion, and the through hole And a connecting tool is inserted into and connected to the through hole provided in the pile.
According to a fifth aspect of the present invention, in the tip member according to the fourth aspect, the tip of the coupling tool is substantially equal to or larger in diameter than the inner end of the wing when the tip member is viewed in plan from below. It is located outside in the direction.
According to a sixth aspect of the present invention, in the tip member according to the fourth or fifth aspect, the connector includes a cylindrical sleeve and a pin inserted into the cylindrical sleeve. It has a tip portion that expands at the tip portion of the pin when the pin is inserted, and is prevented from coming off from the through hole by the tip portion that expands the diameter.

According to the present invention, since the spiral wing portion and the straight pipe portion are integrally formed by casting, the helical wing portion is not welded to the straight pipe portion as in the prior art, so that the number of processing steps and costs are reduced. Can do.
In addition, a complicated shape of the wing portion can be easily formed by casting, and sufficient strength can be ensured because the wing portion and the straight pipe portion are integrally formed.

Hereinafter, the foundation pile which concerns on embodiment of this invention is demonstrated, referring attached drawing.
FIG. 1 is a front view showing a foundation pile according to the present embodiment.
As shown in the drawing, the foundation pile 1 according to the present embodiment is an upper pile 10 located on the ground side of the foundation pile 1 (the rear end side in the traveling direction of the pile when the foundation pile 1 is buried in the ground), The lower pile 40 located on the bottom side (the tip side in the traveling direction of the pile when the foundation pile 1 is buried in the ground), the tip member 50 attached to the tip of the lower pile 40, the upper pile 10, the lower pile 40, and It consists of a connecting tool 70 that fixes the lower pile 40 and the tip member 50 in a connected state.

  The foundation pile 1 is assumed to have a maximum diameter of about 30 to 70 cm capable of supporting a relatively low-rise building or the like. When this foundation pile 1 is buried, first, cement milk is poured into the position where the foundation pile 1 is buried with an earth auger or the like while excavating holes to the depth of the support layer, and the excavated soil and cement milk are mixed and ground. A soil cement pillar is formed inside. Next, the lower pile 40 having the tip member 50 attached to the soil cement pillar is rotated and penetrated. When the lower pile 40 has been penetrated, the lower pile 40 is fixed and the upper pile 10 is added to the upper end portion thereof. Then, it is fixed by the connecting tool 70, and is similarly embedded by being rotated and penetrated into the ground.

Next, the upper pile 10 which is an element which comprises the foundation pile 1 shown in FIG. 1 is demonstrated.
FIG. 2 is a view showing the upper pile 10 constituting the foundation pile 1 according to the present embodiment, FIG. 2A is a plan view of the upper pile 10, and FIG. 2B is a front view showing a part of the upper pile 10 in a longitudinal section. is there.
As shown in FIG. 2B, the upper pile 10 has a predetermined length with a flange 11 provided integrally on the ground side of the upper pile 10 for attaching a reinforcing bar integrated with a concrete slab or the like placed on the upper pile 10. A straight tubular pile body 21, a lower end portion 23 formed in a straight tubular shape with the same diameter as the pile body 21, and a connecting portion 31 connecting between the flange 11 and the pile body 21, which are molten molten cast iron Is poured into a mold that rotates at high speed in cooling water, for example, and cast while being subjected to centrifugal force to be integrally formed. Then, it heat-processes and makes ductile cast iron.

  The flange 11 has a ring shape with a predetermined thickness. As shown in FIG. 2A, through holes 12 formed at the time of casting are arranged at equal intervals on the flange surface. As shown in FIG. 2B, a threaded rebar 13 having a thread groove formed at the end portion is inserted, and is fastened from both sides of the flange 11 with nuts 14a and 14b so as to sandwich the flange 11 therebetween. . When the reinforcing bars are freely arranged at the construction site or the like, the through hole 12 may be appropriately formed by a drilling means such as a drill without depending on casting.

  The inner diameter of the flange 11 is formed to be slightly larger than the inner diameter of the pile main body 21, and as will be described later, a lid receiving portion 32 is formed between the diameter of the pile main body 21 (on the left side of FIG. 2B). (See cross-sectional view). That is, a lid receiving portion 32 is formed on the inner peripheral surface of the intermediate portion between the bottom side end portion and the ground side end portion of the connecting portion 31, and the lid receiving portion 32 has a concrete slab on the upper pile 10. A drop lid 33 is installed to prevent the concrete from falling into the pile when the concrete is placed in order to form the like. The drop lid 33 is formed in a disk shape whose outer diameter is substantially the same as the inner diameter of the connecting portion 31 on the ground side. In FIG. 2, the lid receiving portion 32 has a stepped shape, but is not limited thereto, and may be any shape as long as the drop lid 33 can be installed, such as a tapered shape.

In this embodiment, the outer peripheral surface shape of the connecting portion 31 has a large diameter continuing from the tapered surface 34 and the upper side thereof corresponding to the lid receiving portion 32 on the inner peripheral surface, as shown in FIG. Since it is formed in the cylindrical surface 35 and the outer peripheral surface shape allows the connecting portion 31 to be formed thicker than the pile main body 21, not only is cracking or breakage difficult, but also the flanges are formed via the reinforcing bars 13. 11 can resist the load acting on the pile 11, and can smoothly transmit the load to the pile body 21.
In addition, the outer peripheral surface shape of the connecting portion 31 is not limited to the above-described embodiment, and may be configured by a tapered surface 34 as shown in FIG. 2D or may be formed only by the cylindrical surface 35 as shown in FIG. 2E. Also good.

A bottom end portion 23 (referring to an overlapping portion of the pile main body 21 and the large diameter portion 41) is formed at the bottom end of the pile main body 21 so as to be inserted into and connected to the large diameter portion 41 of the lower pile 40. .
As shown in FIG. 2B, through the peripheral surface of the lower end portion 23, the through-holes opposed to each other in the radial direction for inserting a connection tool 70 (see FIG. 5) to be described later used for connecting the upper pile 10 and the lower pile 40. Two pairs of holes 22 (a pair in the horizontal direction and a pair in the depth direction in the drawing) are formed at predetermined intervals in the axial direction. However, the position where the through hole 22 is formed may be other than this.
In addition, after inserting the upper pile 10 in the lower pile 40, this through-hole 22 is formed by arbitrary drilling means, such as a drill. Alternatively, the through hole 22 is formed in advance in a state where the lower end portion 23 is positioned so as to be aligned with the through hole 44 formed on the peripheral surface of the large diameter portion 41 when the lower end portion 23 is inserted into the large diameter portion 41. Also good.

  As described above, since the upper pile 10 is cast, it has a complicated shape such as the through hole 12 of the flange 11, the lid receiving portion 32 and the enlarged diameter portion 35 formed in the connecting portion 31, and the tapered surface 34. The structure can also be easily formed. Moreover, since the flange 11 is formed in the upper pile 10 at one end, and it is comprised in the shape used as the straight tubular pile main body 21 smaller diameter than the flange 11 through the connection part 31, it casts in a factory. After the removal, the upper pile 10 can be easily taken out by pulling it out from the flange 11 side.

  Moreover, since the threaded reinforcing bar 13 is attached to the flange 11 only by inserting the threaded reinforcing bar 13 into the through hole 12 of the flange and screwing the nuts 14a and 14b into the thread grooves, the welding is performed. The quality can be kept constant regardless of the weather and the skill of the engineer as in the case of performing.

Next, the lower pile 40 which is an element which comprises the foundation pile 1 shown in FIG. 1 is demonstrated.
FIG. 3 is a front view showing a part of the lower pile 40 in a longitudinal section.
As shown in the figure, the lower pile 40 includes a pile main body 43 formed in a straight tube having a predetermined length, a lower end portion 48 formed in a straight tube having the same diameter as the pile main body 43, and a cylindrical large diameter portion 41. And a connecting portion 42 that connects between the large diameter portion 41 and the pile main body 43, and is integrally molded by casting similar to the upper pile 10 and then heat-treated to obtain ductile cast iron.
In addition, the lower pile 40 has a smaller influence on the horizontal load applied to the concrete slab formed on the foundation pile 1 than the upper pile 10 shown in FIG. It is formed thinner overall than the thickness of the pile 10.

A large-diameter portion 41 is integrally formed with a predetermined length in the longitudinal direction at the end of the pile body 43 on the ground side. The inner diameter of the large-diameter portion 41 is formed to be slightly larger than the outer diameter of the lower end portion 23 so that the lower end portion 23 can be fitted when connected to the upper pile 10. Moreover, the step part 45 of the boundary part of the internal diameter of the large diameter part 41 and the internal diameter of the pile main body 43 becomes a support part which receives the lower end part 23 of the upper pile 10 fitted, and the large diameter part 41 is the upper pile as a whole. 10 is formed.
On the peripheral surface of the large-diameter portion 41, through holes 44 opposed to each other in the radial direction for inserting a connecting tool 70 to be described later used for connecting the upper pile 10 and the lower pile 40 are located on the ground side from the step portion 45. Two pairs (a pair in the horizontal direction and a pair in the depth direction on the paper surface) are formed with a predetermined interval in the axial direction. However, the position where the through hole 44 is formed may be other than this.
In addition, after inserting the upper pile 10 in the lower pile 40, this through-hole 44 is formed by arbitrary drilling means, such as a drill. Alternatively, the through hole 44 may be formed in advance in a state where the lower end 23 is positioned so as to be aligned with the through hole 22 formed on the peripheral surface of the lower end 23 when the lower end 23 is inserted into the large diameter portion 41. Good.

  The connecting portion 42 is formed integrally with the ground-side end portion of the large-diameter portion 41 at the ground-side end portion, and has an outer peripheral surface that is a tapered surface. A step 45 is formed by the difference in size between the inner diameter of 42 and the inner diameter of the large-diameter portion 41. When the lower end portion 23 of the upper pile 10 shown in FIG. 2 is fitted to the large diameter portion 41 of the lower pile 40, the stepped portion 45 comes into contact with the bottom end portion of the lower end portion 23, and the lower end portion 23. And receiving the downward load from the upper pile connected to the top.

A lower end portion 48 that is inserted into and connected to a receiving port 54 (see FIG. 4) of the tip member 50 described later (refers to an overlapping portion of the pile main body 43 and the receiving port 54) at the bottom side end of the pile main body 43. Is formed.
As shown in FIG. 3, two pairs of through-holes 46 facing each other in the radial direction for inserting a connecting tool 70 (described later) used for connecting the lower pile 40 and the tip member 50 are provided on the peripheral surface of the lower end 48. A pair in the horizontal direction and a pair in the depth direction on the paper) are formed at predetermined intervals in the axial direction. However, the position where the through hole 46 is formed may be other than this.
The through hole 46 is formed by any drilling means such as a drill after the lower pile 40 is inserted into the tip member 50. Alternatively, the through hole 46 may be formed in advance in a state where the lower end portion 48 is positioned so as to be aligned with the through hole 55 formed on the peripheral surface of the receiving port 54 when the lower end portion 48 is inserted into the receiving port 54. .

As described above, the lower pile 40 is continuously integrally formed from the large-diameter portion 41 through the connecting portion 42 to the pile main body 43 by casting. Therefore, when connecting with each member constituting the foundation pile 1 There is no need to use a separate connecting member or to perform, for example, a diameter expansion process for forming the large diameter portion. By not manufacturing or processing the connecting member, the manufacturing cost can be reduced and stable quality can be obtained.
Moreover, since the lower pile 40 forms the large-diameter portion 41 and the pile main body 43 having a smaller diameter than the large-diameter portion 41 connected by the connecting portion 42, when the lower pile 40 is taken out from the mold after being cast in the factory, The lower pile 40 can be easily taken out by pulling it out from the diameter part 41 side.

Next, the tip member 50 which is an element which comprises the foundation pile 1 shown in FIG. 1 is demonstrated.
4 is a view showing the tip member 50, FIG. 4A is a plan view of the tip member 50, FIG. 4B is a side view of the tip member 50, and FIG. 4C is a cross-sectional view of the tip member 50.
As shown in FIG. 4B, the tip member 50 includes a cylindrical straight pipe portion 51, a straight tubular receiving port 54 formed at the ground-side end of the straight pipe portion 51, and the underground side of the straight pipe portion 51. Like the upper pile 10 and the lower pile 40, it is cast and integrally molded and then heat treated to form ductile cast iron.

A receiving port 54 is integrally formed with a predetermined length in the longitudinal direction at the end of the straight pipe portion 51 on the ground side. The inner diameter of the receiving port 54 is larger than the inner diameter of the straight pipe portion 51 and is slightly larger than the outer diameter of the lower end portion 48 so that the lower end portion 48 can be fitted when connected to the lower pile 40. . Further, the inner diameter of the straight pipe portion 51 is substantially the same as the inner diameter of the lower end portion 48 of the lower pile 40.
The step portion 53 formed at the boundary portion by the size difference between the inner diameter of the receiving port 54 and the inner diameter of the straight pipe portion 51 positions the lower end portion 48 of the lower pile 40 fitted to the receiving port 54, and The load from the lower pile 40 connected to the upper side is received.

Further, on the peripheral surface of the straight pipe portion 51, through holes 55 opposed to each other in a radial direction for inserting a connecting tool 70 to be described later used for connecting the lower pile 40 and the tip member 50, than the step portion 53. Two pairs are formed on the ground side (a pair in the horizontal direction and a pair in the depth direction on the paper) with a predetermined interval in the axial direction. However, the position where the through hole 55 is formed may be other than this.
In addition, after inserting the lower pile 40 in the front-end | tip member 50, this through-hole 55 is formed by arbitrary drilling means, such as a drill. Alternatively, the through hole 55 may be formed in advance in a state where the lower end portion 48 is positioned so as to be aligned with the through hole 46 formed on the peripheral surface of the lower end portion 48 when the lower end portion 48 is inserted into the receiving port 54. .

  The bottom end of the straight pipe portion 51 is formed in a spiral shape. That is, the ground side where the axial length from the ground side end a point (starting point) having the shortest axial length to the ground side end and the ground side end is the longest in the axial direction from the ground side end to the ground side end. Up to the end b point (end point), the bottom side end of the straight pipe portion 51 is formed to change spirally.

  Further, a wing portion 52 is integrally formed at the bottom side end portion of the straight pipe portion 51. The wing portion 52 extends inward and outward in the radial direction of the straight pipe portion 51, and its width is set in a semi-closed state in which the inside of the straight pipe portion 51 is narrowed by a spiral opening having a predetermined diameter. Each of the straight pipe portions 51 has a width approximately half the radius of the straight pipe portion 51 in the direction, and is formed in a spiral shape along the bottom end of the straight pipe portion 51.

  As explained above, since the wing part 52 has put the bottom end of the straight pipe part 51 in a semi-closed state, when embedding the foundation pile 1, earth and sand cement (hereinafter referred to as earth and sand) are used. It penetrates while taking an appropriate amount inside the pile, does not disturb the flow of earth and sand, reduces the resistance of earth and sand to the pile at the time of penetration, and can secure the supporting force in the axial direction of the foundation pile 1 after construction . That is, the penetration resistance can be reduced as compared with the structure in which the tip is closed, and the support force can be ensured because the support area is large compared to the structure in which the tip is opened.

  Furthermore, as shown in FIG. 4A, the wing part 52 almost circles the bottom side end part of the straight pipe part 51 leaving a slight gap G in plan view between the spiral start end 52a and the terminal end 52b. In FIG. 4B, the straight line connecting the points a and b is inclined so as to form a predetermined angle with respect to the center line of the tip member 50. Due to the gap G and the inclination, it is easy to remove the mold after molding.

Next, the coupler which mutually connects each pile and tip member which comprise the foundation pile 1 is demonstrated.
FIG. 5 is an enlarged cross-sectional view of the connector 70. As shown in FIG. 5, the connector 70 includes a cylindrical sleeve 71 and a pin 72 that is inserted into the cylinder formed by the sleeve 71. The sleeve 71 and the pin 72 are made of a steel material such as chrome molybdenum steel.

The sleeve 71 is formed in a cylindrical shape having an outer diameter corresponding to the inner diameter of the through-hole formed in the peripheral surface of the upper pile 10 described above, and the rear end side (when the pin 72 is inserted into the sleeve 71). A flange portion 73 is integrally formed on the outer periphery on the rear end side in the insertion direction, and the thickness is on the inner periphery on the front end side (the front end side in the insertion direction when the pin 72 is inserted into the sleeve 71). An annular protrusion 74 whose tip is formed at an acute angle is formed by a tapered surface 79 that gradually becomes thinner toward the side.
In addition, slits 75 parallel to the axial direction are formed at a plurality of positions along the circumferential direction at the distal end of the sleeve 71 so as to have a predetermined length from the distal end surface of the sleeve 71.

  The pin 72 has a cylindrical shape having an outer diameter corresponding to the inner diameter of the sleeve 71, can be penetrated into the sleeve 71, and a flange portion 76 is integrally formed on the outer periphery of the rear end thereof. A tapered surface 77 is formed. On the outer peripheral surface of the pin 72, an annular groove 78 having a rectangular cross section is formed at a position away from the tapered surface 77 in the axial direction.

6 to 8 are views for explaining a procedure for connecting the upper pile 10 and the lower pile 40 by using the connecting tool 70.
6A shows a state where through holes are formed in each pile, and FIG. 6B shows a state where sleeves 71 are inserted into the through holes of each pile.
7A shows a state in which the pin 72 is inserted into the sleeve 71 inserted into the through hole, and FIG. 7B shows a state in which the diameter of the tip of the sleeve 71 is increased by inserting the pin 72 into the sleeve 71. .
8A shows a state in which the pull-out force is applied to the pin 72 completely inserted into the sleeve 71, and FIG. 8B shows a state in which the projection 74 is fitted in the groove 78. FIG.

  First, as shown in FIG. 6A, the lower end portion 23 of the upper pile 10 is inserted into the large-diameter portion 41 of the lower pile 40, and a through hole 44 is penetrated into the lower pile 40 by a drilling means such as a drill. Hole 22 is formed. Next, as shown in FIG. 6B, the sleeve 71 is inserted from the outside of the through hole 44 of the large-diameter portion 41 of the lower pile 40 and fitted until the flange portion 73 contacts the outer peripheral surface of the large-diameter portion 41. Thereby, the part in which the protrusion 74 and the slit 75 at the tip of the sleeve 71 are formed is projected from the through hole 22 of the lower end 23 into the upper pile 10.

Next, as shown in FIG. 7A, the tip of the pin 72 is aligned with the cylindrical inlet of the sleeve 71, and the pin 72 is driven into the sleeve 71. Then, as shown in FIG. 7B, the tip end portion of the pin 72 passes through the protrusion 74 while deforming the protrusion 74 of the sleeve 71 so as to spread outward in the radial direction. At this time, since the slits 75 are formed in the sleeve 71, the sleeve 71 is easily deformed in the portion where the projection 74 is formed. Further, as described above, since the tip of the protrusion 74 is formed on the tapered surface 79, the tapered surface 79 abuts on the tapered surface 77 formed on the tip of the pin 72, and the force between the tapered surfaces is reduced. By the transmission, the tapered surface 77 of the pin 72 pushes the tip of the sleeve 71 easily and reliably.
A diameter-expanded portion 80 is formed at the tip of the sleeve 71 pushed and spread by the pin 72, and the diameter-expanded portion 80 prevents the connecting tool 70 from coming out of the through holes 22 and 44.
The length of the connector 70 is such that the tip of the pin 72 is more radial than the inner end 52d of the wing portion 52 of the tip member 50 so that the resistance of earth and sand applied to the connector 70 is reduced by the penetration of the pile. It is desirable to form the length so as to be located outside.

Further, when a pull-out force from the sleeve 71 acts on the pin 72 of the connector 70 inserted into the through holes 22 and 44, that is, a pin in which the groove 78 protrudes from the sleeve 71 as shown in FIG. 8A. When a force in the direction indicated by the arrow X in FIG. 8 is applied to the pin 72, the pin 72 is displaced toward the rear end side with respect to the sleeve 71 as shown in FIG. 8B, but when the groove 78 reaches the position of the protrusion 74, 74 springs back and fits into the groove 78. As a result, the pin 72 can be prevented from coming off from the sleeve 71 completely.
As shown in FIG. 9, the length relationship between the pin 72 and the sleeve 71 is such that when the pin 72 is driven until the flange portion 76 abuts on the flange portion 73 of the sleeve 71, the protrusion 74 is inserted into the groove 78. It can be configured to fit.

Next, the position of the tip of the connector 70 (the length of the pin 72) will be described.
FIG. 10 is a cross-sectional view showing a state in which the lower pile 40 is inserted into the tip member 50 and connected by the connecting tool 70, and FIG. 10A shows that the position of the tip of the connecting tool 70 is substantially the same as the position of the inner end 52 d of the wing part 52. FIG. 10B shows a state where the tip of the connector 70 is located radially outside the inner end 52d of the wing portion 52. FIG.
As shown in FIG. 10A, the lower end 48 of the lower pile 40 is inserted into the receiving port 54 of the tip member 50, and a through hole 55 and a through hole 46 are provided by a drilling means such as a drill, and a sleeve 71 is provided there. The lower pile 40 and the tip member 50 are connected by inserting the pin 72 into the sleeve 71.

  As already explained, in the tip member 50 constituting the foundation pile 1 according to the present embodiment, the spiral wing part 52 has the bottom end of the straight pipe part 51 in a semi-closed state (see FIG. 4). ) When the foundation pile 1 is buried in the ground, the soil cement is pushed into the pile while being taken into the pile from the semi-closed bottom end. When soil cement taken into the inside of the pile comes into contact with a portion protruding into the pile of the connecting tool 70 when the connecting tool 70 is inserted into each through hole, the resistance when the foundation pile 1 is propelled into the ground. Therefore, it is necessary to adjust the amount of protrusion of the connector 70 into the pile, that is, the length of the connector 70.

In this embodiment, the length of the connector 70 is formed so that the position of the tip of the pin 72 is substantially equal to the position of the inner end 52d of the wing 52 (in the drawing, the tip of the pin 72 is the inner end 52d). Slightly more radially inward). That is, the position of the tip of the connector 70 is substantially equal to the position of the inner end 52d of the wing portion 52 when the tip member 50 is viewed from below.
However, the coupling tool 70 is such that the tip of the pin 72 is positioned radially outward from the inner end 52d of the wing portion 52 of the tip member 50 so that the resistance of earth and sand applied to the coupling tool 70 is reduced by the penetration of the pile. It is desirable to form a shorter length.

As described above, since this connecting tool 70 can connect and integrate the piles by simply driving the pin 72 into the sleeve 71 inserted into the through hole, the time required for the connecting work is short, Further, the pin 72 is driven into the sleeve 71 to increase the diameter of the tip of the sleeve 71, and the protrusion 74 at the tip of the sleeve 71 fits into the groove 78 of the pin 72 when a pull-out force acts on the pin 72. 71 and the pin 72 do not come out of the through hole of the pile.
In addition, by shortening the length of the connecting tool 70 corresponding to the wing portion 52 of the tip member 50, earth and sand taken into the pile when the foundation pile 1 penetrates into the ground contacted the connecting tool 70. It is possible to reduce resistance caused by earth and sand against the rotation and penetration of the foundation pile 1.

Since the foundation pile 1 comprised from the upper pile 10, the lower pile 40, the front-end | tip member 50, and the connection tool 70 demonstrated above was formed by casting even if it was a complicated shape part, an engineer's In addition to on-site welding whose quality depends on workmanship, weather, etc., welding work at the factory is also unnecessary, so that the entire foundation pile 1 can always maintain a constant quality.
Also, in the on-site connection work etc., all other structures such as through holes for attaching reinforcing bars are formed at the factory simply by drilling the through hole for inserting the connector. Since the work can be minimized and the connecting work can be quickly performed by the connecting tool 70, it is possible to reduce the construction man-hours and the construction time on site.
In addition, the material which forms the foundation pile 1 is not restricted to ductile cast iron, For example, other cast iron, cast steel, etc. may be sufficient.

  Although the foundation pile 1 which concerns on this embodiment is formed from the upper pile 10, the lower pile 40, and the front-end | tip member 50, it is not restricted to this, For example, the upper pile 10 and the front-end | tip member 50, or the upper pile 10 and several lower piles You may form from the pile 40 and the front-end | tip member 50, The combination is arbitrary. Therefore, the length of the foundation pile 1 can be adjusted and the foundation pile 1 suitable for the support layer depth of the field can be formed.

  Although the foundation pile 1 demonstrated above is comprised by the upper pile 10, the lower pile 40, and the front-end | tip member 50, the intermediate member 150 of the substantially same shape as the front-end | tip member 50 is connected with the lower pile 140 and the upper pile 10 further. By installing it between the parts, it is possible to arrange a spiral wing part in the middle part of the foundation pile 1, so that the propulsive force at the time of pile embedding can be increased and the construction efficiency can be improved. The wing portion becomes a resistance against a vertical load, and the vertical supporting force of the foundation pile 1 can be improved.

The structure will be described below.
FIG. 11 is a diagram illustrating a state in which the intermediate member 150 is interposed between the connecting portions of the lower pile 140 and the upper pile 10.
As shown in FIG. 11, the shape of the intermediate member 150 is substantially the same as that of the tip member 50 shown in FIG. 4, but the wing portion 152 of the intermediate member 150 extends only in the radially outward direction of the straight pipe portion 151. Thus, the straight pipe portion 151 does not exist in the inner diameter direction. Further, the inner diameter of the straight pipe portion 151 is formed to be slightly larger than the outer diameter of the lower end portion 23 so that the lower end portion 23 can be fitted when connected to the upper pile 10. Is formed in a size slightly smaller than the inner diameter of the large-diameter portion 141 so that it can be inserted into the large-diameter portion 141 when connecting to the lower pile 140.
The other configuration is the same as that of the tip member 50 shown in FIG. 4 and is integrally cast.

  At the time of attachment, with the wing portion 152 of the intermediate member 150 facing the ground side, the straight pipe portion 151 is inserted into the large diameter portion 141 of the lower pile 140, and further, the inside of the straight pipe portion 151 of the intermediate member 150 After inserting the lower end portion 23 of the upper pile 10 into the through hole 144, 155, 22 by any drilling means such as a drill, and inserting the connecting tool 70 here, The intermediate member 150 is attached to the connecting portion with the pile 140.

  12 is a cross-sectional view showing a state in which the intermediate member 150 is interposed between the lower pile 140 and the upper pile 10. FIG. 12A shows a case where the outer peripheral surface of the intermediate member 150 is linear, and FIG. The case where the outer peripheral surface of the member 150 is a taper shape is shown. In particular, as shown in FIG. 12B, the inner surface of the large-diameter portion 141 and the outer surface of the intermediate member 150 are formed in a mutually complementary tapered shape in which the inner surface of the large-diameter portion 141 and the outer surface of the intermediate member 150 open toward the ground side. It is possible to suppress the occurrence of backlash at the connecting portion during and after construction.

  In the above description, the intermediate member 150 is interposed in the connection portion between the upper pile 10 and the lower pile 140. However, the intermediate member 150 is not limited thereto, and is interposed in the connection portion with the pile or the tip member constituting the other foundation pile 1. The combination may be arbitrary.

Moreover, in the foundation pile 1 already demonstrated, since the through-hole 12 which attaches a reinforcing bar to the flange 11 of the upper pile 10 by casting is formed in a factory beforehand, the attachment position of the reinforcing bar is preset. Therefore, it is not easy to change the rebar attachment position.
Therefore, the rebar can be attached to the upper portion of the flange 11 by welding as in the past, and the degree of freedom of the rebar attachment position can be increased.

FIG. 13 is a diagram illustrating a pile head portion of the upper pile 10, FIG. 13A is a plan view of the upper pile 10, and FIG. 13B is a cross-sectional view.
13B, an iron plate 91 having the same shape as the flange 11 is placed on the upper surface of the flange 11, and is fixed with bolts 92 and nuts 93 so as to sandwich the flange 11 and the iron plate 91.
As shown in FIG. 13A, the iron plate 91 is provided with through holes 94 for inserting a plurality of bolts 92 (four in the figure) along the circumference thereof. Furthermore, the lower end portions of a plurality of (four in the figure) reinforcing bars 13 are fixed to the surface of the iron plate 91 by, for example, stud welding.

  Since the foundation pile 1 demonstrated above attaches the steel plate 91 to the upper surface of the flange 11, since the reinforcing bar 13 can be attached anywhere on the iron plate 91, for example, at the construction site of the foundation pile 1, etc. When it is necessary to change the mounting position, it is possible to quickly respond.

It is a front view which shows the foundation pile which concerns on this embodiment. It is a figure which shows the upper pile which comprises a foundation pile, FIG. 2A is a top view of an upper pile, FIG. 2B is a front view which shows a part of upper pile in a longitudinal section, FIG. 2C is an expanded sectional view of the pile head of an upper pile FIG. 2D is an enlarged cross-sectional view of the pile head of the upper pile in which the connecting portion is formed only by the tapered surface, and FIG. 2E is an enlarged cross-sectional view of the pile head of the upper pile in which the connecting portion is formed only by the cylindrical surface. It is a front view which shows a part of lower pile in a longitudinal cross section. 4A is a plan view of the tip member, FIG. 4B is a side view of the tip member, and FIG. 4C is a cross-sectional view of the tip member. It is an expanded sectional view of a connector. It is a figure explaining the procedure which connects an upper pile and a lower pile using a connecting tool, FIG. 6A shows the state which formed the through-hole in each pile, FIG. 6B inserted the sleeve 71 in the through-hole of each pile. Indicates the state. It is a figure explaining the procedure which connects an upper pile and a lower pile using a connector, and Drawing 7A shows the state which inserts a pin in the inside of a sleeve inserted in a penetration hole, and Drawing 7B inserts a pin in a sleeve Thus, the state where the tip of the sleeve is expanded is shown. It is a figure explaining the procedure which connects an upper pile and a lower pile using a connection tool, and Drawing 8A shows the state where the withdrawal force acted on the pin completely inserted in the sleeve, and Drawing 8B has a projection stuck in a slot It shows the state. It is a figure which shows the state which connected the upper pile and the lower pile using the coupling tool which changed the length of the pin. It is sectional drawing which shows the state which inserted the lower pile into the front-end | tip member, and was connected with the coupling tool, FIG. 10A is a state in which the position of the front-end | tip of a coupling tool is substantially equal to the position of the inner end of a wing | blade part, FIG. It is a figure which shows the state which the front-end | tip of was located in the radial direction outer side of the inner side end of a wing | blade part. It is a perspective view which shows the state which interposes an intermediate member between the connection parts of a lower pile and an upper pile. It is sectional drawing which shows the state which interposed the intermediate member between the connection parts of a lower pile and an upper pile. It is a figure which shows the pile head part of an upper pile, FIG. 13A has shown the top view of the upper pile, and FIG. 13B has shown sectional drawing.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Foundation pile, 10 ... Upper pile, 11 ... Flange, 12, 22, 44, 46, 55, 94, 144, 155 ... Through-hole, 13 ... Rebar, 14a, 14b ... Nuts, 21, 43 ... Pile main body, 23, 48 ... Lower end, 31, 42, 142 ... Connection part, 32 ... Lid receiving part, 45, 53 ... Step Part, 33 ... drop lid, 34 ... tapered surface, 35 ... cylindrical surface, 40 ... lower pile, 41, 141 ... large diameter part, 50 ... tip member, 51, 151 ... Straight pipe part, 52, 152 ... Wing part, 52a ... Start end, 52b ... Termination, 52c ... Outer end, 52d ... Inner end, 70 ... Connecting tool, 71 ... Sleeve, 72 ... Pin, 73 ... Flange, 74 ... Projection, 75 ... Slit, 76 ... Flange, 7 ... Tapered surface, 78 ... groove, 79 ... tapered surface, 80 ... diameter enlarged portion, 91 ... iron plate, 92 ... bolt, 93 ... nut, 140 ... bottom Pile, 150 ... Intermediate member.

Claims (6)

  It is a tip member that can be attached to a pile, and has a cylindrical straight pipe part and a spiral wing provided on the bottom side of the straight pipe part, and the straight pipe part and the spiral wing part are integrated. A tip member cast into The tip member according to claim 1,
The wing portion extends in the inner and outer radial directions of the straight pipe portion at the bottom end of the straight pipe portion, and the wing portion extending in the inner diameter direction forms a spiral opening with a predetermined diameter inside the straight pipe portion. A tip member characterized by having a width. In the tip member according to claim 1 or 2,
The wing portion is formed so as to make one round of the bottom side end portion of the straight pipe portion leaving a predetermined gap between the start end and the end end of the wing portion when the tip member is viewed from below. A tip member characterized by that. The tip member according to any one of claims 1 to 3,
A through hole is provided in the vicinity of the end portion of the straight pipe portion opposite to the wing portion, and a connecting tool is inserted into and connected to the through hole and the through hole provided in the pile. Element. The tip member according to claim 4,
The distal end of the connector is substantially equal to the inner end of the wing portion when the distal end member is viewed in plan view from below, or is positioned more radially outward of the straight pipe portion. Element. In the tip member according to claim 4 or 5,
The connector comprises a cylindrical sleeve and a pin inserted into the cylindrical sleeve, and the cylindrical sleeve has a tip portion that expands at the tip of the pin when the pin is inserted. A tip member that is prevented from coming off from the through hole by the tip portion that expands in diameter.

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