JPH10252060A - Joint for underground piping - Google Patents

Abstract

PROBLEM TO BE SOLVED: To dispense with on-site machining such as welding by providing a circular groove on the outer periphery of the tip section of a male screw side joint piece provided on one pile end, and inserting a fixing means coupled with the circular groove of the male screw side joint piece into a female side joint piece provided on the other pile end from the outside. SOLUTION: The male screw 10 of the male screw side joint piece 5 of a pile to be added is screwed and connected to the female screw 4 of a female screw side joint piece 3 so that the female screw side joint piece 3 is located at the apex of a pile driven in advance. The added pile is held, rotated, screwed, and connected by the pile hold section of a pile driver. The shoulder section 5b of the male screw side joint piece 5 is kept in contact with the opening end 3b of the joint piece 3, they are aligned for connection, multiple hook pins 15 fitted in advance are deeply screwed into fixing screw holes 8 respectively, and their tip hook sections 15 a are coupled with a circular groove on the male screw 10 side. No on-site aligning work is required, and the connecting work can be conducted in a short time.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a threaded joint of a steel pipe pile mainly embedded in the ground for the purpose of foundation pile or earth retaining, and more particularly to a method of pushing a steel pipe pile into the ground. The present invention relates to a joint for an underground pipe which is capable of reliably transmitting a high torque by forward and reverse rotation operations at a threaded joint portion of a steel pipe pile.

[0002]

2. Description of the Related Art Conventionally, steel pipe piles have been used instead of concrete piles for piles driven into the ground to reinforce the ground, such as foundation piles for structures in civil engineering work and earth retaining work to prevent landslides. More. In this case, when piles are driven deeper, the piles can be easily added, which is advantageous for a construction method that requires piles driven deep into the ground as compared with concrete piles. Piles used in such construction methods
Since the driving length becomes as long as 40 m, a length convenient for transportation (for example, 6 m in length) is transported to a construction site and driven into the ground, and piles are sequentially added and used. For this reason, as a connection joint of the piles, a method is adopted in which the ends are connected to each other by forming a fitting structure at the ends and welding them on site. Also, when driving this pile into the ground, in order to avoid environmental pollution such as noise and vibration,
A method has been adopted in which a pile is pushed by applying a rotating force.

[0003]

However, in the conventional connection method using a joint of piles, welding is performed on site,
Since it is a so-called on-site work, the number of work steps is inevitably increased and the work cost is increased. Therefore, attempts have been made to adopt a threaded joint as a joint for this pile. However, this threaded joint method has a problem that it is not yet satisfactory to use the pushing propulsion and the rotational force to drive the pile.

[0004] In connection of piles with this threaded joint, when a rotational force is used to drive the piles, the rotational direction is sometimes reversed in order to reduce the resistance applied to the tip of the piles. In this case, loosening occurs in the screw portion. For this reason, means for preventing loosening at the joint is required, and welding is performed at the joint to which the screw connection is unavoidably performed so that the joint does not come off. As a result, workability is improved as compared with a conventional joint using only welding, but workability is inevitably impaired due to the necessity of field welding.

In the present invention, in order to solve such a problem, when connecting piles at a steel pipe pile driving work site, a set part prepared in advance is used without requiring on-site processing such as welding. It is an object of the present invention to provide a joint for a pile configured to transmit a high torque of a forward / reverse rotation operation without loosening just by assembling.

[0006]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention relates to a joint portion of a steel pipe pile having a threaded joint structure, wherein a tip portion of a male screw side joint piece provided at one pile end is provided. An annular groove is provided on the outer periphery, and a fixing means for engaging with the annular groove of the male screw side joint piece is externally fitted into the female screw side joint piece provided at the other pile end. It is assumed that.

In the present invention, the fixing means includes an outer peripheral portion of the female screw side joint piece, which is axially oriented at a plurality of positions at positions corresponding to the annular groove of the male screw joint piece to be screwed with the female screw. A locking pin insertion hole is provided, and the locking pin is irremovably inserted from the locking pin insertion hole to engage with the annular groove of the male screw side joint piece, so that the connection ends of the two joint pieces are in a tightly connected state. It is preferred that Further, as the fixing means, an annular groove is formed in the fitting peripheral surface so as to extend over a fitting portion between the straight portion in the stepped hole of the female screw side joint piece and the tip side straight portion of the male screw portion in the male screw side joint piece,
It is possible to prevent loosening of the screw connection by filling a large number of steel balls into the annular groove and screwing it into the annular groove after screw connection from the ball insertion hole drilled on the outer periphery of the female screw side joint piece and communicating with the annular groove. Good.

The underground pipe joint according to the present invention is constructed as described above. When a pile is added at a pile driving site, the male screw side joint piece is screwed to the female screw side joint piece, and then the male screw side joint piece is connected. The tip of the locking pin is engaged with the annular groove of the female thread side joint piece from the outside of the female screw side joint piece through the pin insertion hole, and the locking pin is simply fixed, or the annular groove on the outer circumference of the female screw side joint piece By simply filling a large number of steel balls into the pile, the screw joint is securely fixed, so even if the pile is turned forward or reverse during the pile driving operation, the rotational torque from the driving Will be communicated. Therefore, the on-site work is significantly simplified, and the work efficiency is further improved.

[0009]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a joint for an underground pipe according to the present invention. The figure shows an example of a joint of a steel pipe pile used for a foundation pile.

FIG. 1 shows a joint portion 1 of a steel pipe pile, and a female screw side joint piece in which a female screw 4 having a required diameter with a coaxial center is integrated with one end of a steel pipe constituting a pile body 2 by welding. 3, a male screw side joint piece 5 provided with a male screw 10 of a size coaxial with the female screw 4 and coaxially integrated with the other end of the pile body 2 by welding, and the female screw 4 and the male screw 10 are screwed together. And fixing means 14 which is fixed after the fixing.

The female screw side joint piece 3 is a cylindrical body having a required length with an outer diameter matching the outer diameter of the steel pipe constituting the pile body 2. A female screw 4 is formed, and a portion from the inner end of the female screw 4 to the step portion 6 ′ is formed as a straight portion 7 having an inner diameter slightly smaller than the diameter of the female screw 4. Then, as shown in FIG. 2, around the stepped hole 6 corresponding to the straight portion 7,
Plural radially from axis (depending on pile diameter, but 4
(About 6 pieces) of fixing screw holes 8 are provided. The end 3a opposite to the side on which the female screw is formed has an inner side recessed to form an annular portion 3a 'in order to ensure welding with the steel pipe, and a groove for welding is formed on the outer periphery of the annular portion 3a'. Is formed.

The external thread side joint piece 5 is a cylindrical body having a required length according to the outer diameter of the steel pipe (pile body 2), similarly to the female thread side joint piece 3, and a steel pipe (pile body 2) An annular portion 5a that can be reliably welded with the female screw 4 is formed at the front portion.
And a male screw 10 of a size screwed with the male screw 1
The leading end of the female screw side joint piece 3 is fitted to the straight portion 7 of the stepped hole 6 of the female screw side joint piece 3. An annular groove 12 is engraved in the peripheral surface of the distal end portion 11 so as to correspond to the position of the fixing screw hole 8 provided in the female screw side joint piece 3 in a state of being joined as a joint.

The female screw side joint piece 3 and the male screw side joint piece 5
As the fixing means 14, a screw portion 15 b screwed into a plurality of fixing screw holes 8 provided in the female screw side joint piece 3.
A locking pin 15 having a diameter and having a diameter that can fit into the annular groove 12 formed in the male screw side joint piece 5 and having a distal end portion is used. The locking pin 15 is provided with, for example, a hexagonal wrench hole 15c in the head, and is inserted into the fixing screw hole 8 of the female screw side joint piece 3 before shipment. The relationship between the above-described annular groove 12 and the distal end locking portion 15a of the locking pin 15 is such that the annular groove 1
It is preferable that the setting is made such that the distal end locking portion 15a of the locking pin 15 comes into contact with the peripheral side surface of the second pin 2.

The female screw side joint piece 3 and the male screw side joint piece 5 thus formed are respectively provided with rear annular portions 3a ', 5a.
a is matched with the end of the steel pipe to be the pile 2 and is integrally joined by welding. In such a state, it is factory-produced and supplied to the construction work site.

At the pile driving site, as shown in FIG.
Leader 21 by known means by known pile driver 20
The pile A is gripped by the pile gripper 23 attached to the drive unit 22 that is driven to rotate while applying a pressing force to the pile along
The pile is driven while the required pressing force is applied. If it is necessary to add the pile A, the pile A separately suspended by a crane or the like by the suspension holding means 24 attached to the top of the leader 21 is suspended in an upright state, and a joint attached to the lower end of the pile A is provided. The piece is connected with the joint piece at the top end of the pile into which the piece has been driven. The refilling at the joint portion 1 is performed such that the female screw side joint piece 3 of the pile to be replenished is positioned such that the female screw side joint piece 3 is located at the top of the pile A previously driven in advance. The male screw 10 is screwed into the female screw 4 and connected. At this time, the pile A to be added is a pile driver 2
It is gripped and rotated by the pile holding portion 23 of No. 0 and screwed and connected.

When the male thread 10 of the male thread side joint piece 5 is screwed into the female thread 4 of the female thread side joint piece 3, the male thread side joint piece 5
The shoulder 5b of the female screw side joint piece 3 comes into contact with the opening end 3b of the female screw side joint 3 so that the two are joined to each other. The distal end locking portion 15a is formed in the annular groove 12 on the male screw 10 side.
To be engaged. By doing so, the head of the locking pin 15 does not protrude from the outer peripheral surface of the joint piece, and the screwed position of the screwed male screw 10 and female screw 4 is fixed. Accordingly, in the process of continuing the pushing operation while rotating the pile A by the operation of the pile driver 20, the propulsion resistance increases and a reverse rotation force is applied to the pile, and the torque in the loosening direction of the male screw 10 with respect to the female screw 4 acts. However, as described above, the locking pin 15 engages with the annular groove 12 in the screw threaded portion, and the reverse rotation of the male screw 10 side is prevented by the plurality of locking pins 15, and the loosening in the joint portion 1 is prevented. Does not occur, and the rotational force can be reliably transmitted to the underground pile 2 and propelled.

In the above specific example, a description has been given of a case where the fixing means 14 in the joint portion 1 uses the screw-type locking pin 15. However, as another fixing means 14A, FIG. As shown in the figure, a locking pin 15A having a partially cut distal end locking portion 15a 'is used, and the locking pin 15A is inserted through a plurality of straight locking pin insertion holes 16 provided in the female screw side joint piece 3 respectively. The distal end locking portion 15a 'is inserted into and engaged with the annular groove 12' of the distal end portion 11 'of the male screw side joint piece 5, and as shown in FIG. 4 (b), the rear end of the locking pin 15A. May be partially cut out so as to be prevented from coming off by the set screw 15d.

By doing so, the male screw 10 and the female screw 4
When the plurality of locking pins 15 </ b> A are all in the distal locking portion 15 a ′, the annular groove 1 of the male screw side joint piece 5 is screwed.
Since the front end locking portion 15a 'of the locking pin 15A is engaged with the 2' at the surface contact, a larger locking force can be obtained than the locking by the point contact as in the above specific example, and a high torque can be obtained. The transmission ability of is obtained. In the case of this method, the locking pin 15A is attached at the time of pile joining work on site. If necessary, it is also possible to use the above-mentioned screw-type locking pin 15 in combination with the fixing means 14A using the locking pin 15A per surface.

FIG. 5 shows another embodiment of the joint, as a fixing means 14B for fixing the female screw side joint piece 3B and the male screw side joint piece 5B in the stepped hole 6B of the female screw side joint piece 3B. An annular groove 17 is formed in each peripheral surface so as to straddle the straight portion 7B having an inner diameter slightly smaller than the diameter of the female screw 4 and the fitting portion of the male screw side joint piece 5B with the distal straight portion 10b of the male screw 10 portion. A ball insertion hole 18 is formed in the outer periphery of the female screw side joint piece 3B at at least one place, and the male and female joint pieces 3B, 5B are screwed and connected from the ball insertion hole 18. A number of steel balls 19 are inserted into the grooves 17, and the ball insertion holes 18 are sealed with plugs 18A.

According to this structure, in the joint portion 1 of the pile, the male screw side joint piece 5B and the female screw side joint piece 3B are made of a large number of steel pieces inserted into the annular groove 17 in the threaded portion of both. Even if the pile is rotated forward and backward by the interposition of the ball 19, the pile is no longer immovable at the screwed portion, and even if a rotational force is applied to the pile in either the forward or reverse direction, the joint 1 integrally forms. When connected, the rotational force applied at the top of the pile is reliably transmitted to the underground pile, and the driving operation can be performed without difficulty. And, in this type of joint structure, when performing a refilling work at a pile driving site,
The objective can be achieved simply by inserting the steel balls 19 into the annular groove 17 provided in the connection portion, the operation can be simplified, and the high torque transmitting force acting on the pile by the large number of steel balls 19 can be achieved. Is obtained.

In the above embodiment, the pile corresponding to the driving of the foundation pile has been described.
The same configuration can be adopted as a joint for other underground pipes (steel pipe piles).

[0022]

As described above, the underground pipe joint according to the present invention performs all processing in the steel pipe pile manufacturing process at the factory by adding a simple fixing mechanism to the threaded joint structure. At the stakeout site, after the screw connection of the joints is performed, the rotation torque applied to the connected piles can be reliably transmitted by applying fixing means such as locking pins or inserting steel balls. This makes it possible to perform connection work in a short period of time without the need for so-called on-site adjustment work, thereby achieving rationalization such as a reduction in construction costs and a reduction in pile production costs.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a specific example of a joint for an underground pipe according to the present invention.

FIG. 2 is a sectional view taken along line II-II of FIG.

FIG. 3 is a schematic diagram showing a driving mode of a steel pipe pile provided with the joint according to the present invention.

FIG. 4 shows another embodiment of the joint for an underground pipe according to the present invention, wherein (a) is a cross-sectional view and (b) is a bb view of FIG. (A). is there.

FIG. 5 is a sectional view showing another embodiment of the joint for an underground pipe according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Joint part 2 Pile 3,3B Female thread side joint piece 4 Female thread 5,5B Male thread side joint piece 6,6B Stepped hole part 7,7B Straight part of stepped hole 8 Fixing screw hole 10 Male screw 11,11 'Male screw Tip portion of side joint piece 12, 12 'Annular groove 14, 14A, 14B Fixing means 15, 15A Locking pin 15a15a' Tip locking portion of locking pin 16 Locking pin insertion hole 17 Ring groove 18 Ball insertion hole 19 wrecking ball

Claims (3)

[Claims] In a joint portion of a steel pipe pile having a screw joint structure, an annular groove is provided on an outer periphery of a tip portion of a male screw side joint piece provided at one pile end, and a female screw side joint piece provided at the other pile end is provided. An underground pipe joint characterized in that fixing means for engaging with the annular groove of the male screw side joint piece is inserted from the outside. 2. As the fixing means, locking pins are inserted into the outer peripheral portion of the female screw side joint piece at a plurality of positions in the axial direction at positions corresponding to the annular groove of the male screw joint piece screwed with the female screw. A hole is provided, and a locking pin is irremovably inserted from the locking pin insertion hole to engage with the annular groove of the male screw side joint piece, so that the connection ends of both joint pieces are brought into a close connection state. The joint for an underground pipe according to claim 1, wherein: 3. As the fixing means, an annular groove is formed in the fitting peripheral surface so as to extend over a fitting portion between a straight portion of the stepped hole of the female screw side joint piece and a tip side straight portion of the male screw portion of the male screw side joint piece. 2. The method according to claim 1, wherein a number of steel balls are filled in the annular groove after being screwed from a ball insertion hole drilled on the outer periphery of the female screw side joint piece and communicating with the annular groove, and confined. Underground pipe fittings.