JP2008274723A - Steel pipe pile driver used in conjunction with auger and method of driving steel pipe pile - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide improved technology for driving an oscillating pile which is used in conjunction with an earth auger, which eliminates the need for a crane used exclusively for an auger, and which can strongly intrude a steel pipe pile into the ground. <P>SOLUTION: A leader 12 is erected, and a hanger 14 of an oscillating pile driver which is supported and guided by the leader can be moved up and down. The auger 16 is supported and guided, and can be moved up and down by the leader. The screw 17 of the auger is inserted into the steel pipe pile 7, and earth and sand can be excavated by the auger. The chuck 15 for the steel pipe pile of the oscillating pile driver is rotary-driven about the axis with respect to a vibration generator 13. Then the performance of the steel pipe pile for intrusion into the ground can be greatly improved by the rotation of the steel pipe pile 7 about the axis. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  TECHNICAL FIELD The present invention relates to a technique for assisting subsidence of a steel pipe pile by excavating the ground by inserting an auger screw into the steel pipe pile when a steel pipe pile is placed on a relatively hard ground. .

When driving resistance into a relatively hard ground, water jet and auger combination are known as means for assisting the penetration of the pile into the ground.
The ground structure is remarkably diverse, and the specifications for pile driving work are also diverse. In addition, the environmental conditions around the pile driving site are not uniform.
From such a situation, it is desirable that various pile driving assistance means can be arbitrarily selected from the viewpoint of a person who designs and designs pile driving work.
The above water jet method is also extremely effective in some cases, but its use is often limited, and therefore, an improvement in the auger combined method is expected.

JP-A-2001-329535 “Auger combined press-fitting method and auger device and sheet pile” listed in Patent Document 1 is known as a technique for using an auger in pile driving.
FIG. 4 is a schematic plan view illustrating an embodiment of the above-mentioned auger combined press-fitting method, in which an auger device 2 is disposed in a concave portion of the U-shaped steel sheet pile 1 (a circle 2 in the figure represents an auger casing). ing).

The auger device 2 is supported by the U-shaped steel sheet pile 1 via the contact seat 3. An engaging member 5 is provided so as to protrude from the flange of the U-shaped steel sheet pile, and a guide member 4 for restricting the fitting relationship between these members is provided. It has been reported that when configured in this way, the U-shaped steel sheet pile 1 can be easily penetrated into the hard ground, and the relative position between the auger and the U-shaped steel sheet pile can be regulated.
However, the application of this known invention is limited to U-shaped steel sheet piles and cannot be applied to steel pipe piles.

As a known technique applicable to steel pipe piles, there is JP-A-2001-182062 “Pile press-in system and pile press-in method using the same” cited as Patent Document 2.
FIG. 5 is a schematic diagram illustrating an embodiment of the above-described pile press-fitting system. A steel pipe sheet pile 7 lifted by the first crane 6 is gripped by a press-fitting / pulling machine 8 and press-fitted into the ground for placement. At the same time, the screw 17 of the auger 10 lifted by the second crane 9 is suspended and inserted into the steel pipe sheet pile 7.

According to the pile press-in system according to the above-mentioned known technique, it has been reported that the screw of the auger is stably supported.
However, the application range of the pile press-fitting system according to this known technique is limited to a press-fitting pile punching machine, and cannot be applied to a vibration pile driver.
Moreover, it is natural to use the first crane 6 for work preparation, but the second crane 9 is required during the period when the pile is being driven. For this reason, the equipment cost corresponding to the second crane 9 is increased, and construction in a narrow place is difficult.
JP 2001-329535 A JP 2001-182062 A

Many pile drivers are often called pile punchers because they can also pull piles.
However, the use of the auger is generally at the time of pile driving, and the pile removal work with the auger is rare and an exception.
The press-fitting type and vibration type, which are the two mainstreams of pile punching machines, are both long and short, both of which are necessary and important. As a general tendency, the press-fitting method is advantageous particularly when quietness is required, and the vibration method must be relied upon when it is necessary to force the hard ground.
For both the construction design engineer and the construction site engineer, both the press-fitting pile punching machine and the vibration pile punching machine are necessary and important.
For this reason, the above-mentioned known technology limited to the press-fitting type is not satisfactory.

The present invention has been made in view of the above circumstances, and its purpose is as follows.
I. It can be applied to steel pipe pile driving by vibration pile punching machine,
B. No need for an auger crane throughout the pile driving period
C. It is to provide a pile driving machine and a pile driving method having a powerful pile driving performance that cannot be expected by the prior art.

Just because a technique that uses an auger in combination with the press-fitting of a U-shaped steel sheet pile is known, this cannot be immediately applied to vibration pile driving of a steel pipe pile.
In the vibration pile driving machine that penetrates the pile into the ground by the principle different from the press-fitting, the mechanisms such as “vibration transmission”, “vibration isolation” and “vibration isolation support” which are not in the press-fitting pile driving machine are necessary. This is because the auger must work together.

The basic principle of the present invention created to achieve the above object will be described below with reference to the drawings corresponding to the embodiments. This is an explanation of the principle and does not describe the essential components of the present invention.
(See Fig. 2) To avoid the need for an auger crane,
The leader 12 is set up to guide the auger 16 and the hanger 14 of the vibrator 13.
(See FIG. 1) The exciter 13 is indispensable for application to a vibration pile driver, and the auger insertion hole 14a is necessary to use the auger together.
The vibrator 13 and the steel pipe pile chuck 15 drawn with a broken line are components of a vibration system, and the hanger 14 drawn with a solid line is a component of a stationary system. In the present invention, a hook 19 for engaging with the leader is fixed to the hanger 14 which is a stationary member.
The vibration system and the stationary system are isolated from vibration by a coil spring 18 that is a buffer member.
(See Fig. 3) In order to obtain stronger pile driving performance,
A ring gear 21 is provided on the hanger 14, and a pinion 23 is provided on the steel pipe pile chuck 15, and the steel pipe pile chuck 15 is rotated around the Z axis with respect to the hanger 14. Thereby, the steel pipe pile 7 gripped by the chuck is rotated around the Z axis and easily penetrates into the ground.

The construction of the auger combined steel pipe pile driving machine according to the present invention created based on the principle described above will be described below with reference to the drawings corresponding to the embodiment.
In this [Means for Solving the Problems] column, reference numerals of the drawings are added in parentheses to facilitate comparison with the drawings. However, the attached notes do not limit the configuration of the present invention as shown in the drawings.

The structure of the auger combined steel pipe pile driver according to the invention of claim 1 is:
(See FIG. 1) An exciter (13) suspended by a hanger (14) having an auger insertion hole (14a) via a buffer member (for example, a coil spring 18),
In the auger combined steel pipe pile driving machine comprising the steel pipe pile chuck (15) attached to the vibrator,
A hook member (19) slidably engaged with the leader is fixed to the hanger,
And the drive means (refer FIG. 3) which rotates the chuck | zipper for steel pipe piles around the axis (Z) of a steel pipe pile with respect to the said vibrator is characterized by the above-mentioned.

The structure of the auger combined steel pipe pile driving machine according to claim 2 is in addition to the structure of the invention of claim 1,
The rotation driving means of the steel pipe pile chuck has a structure for continuously rotating the steel pipe pile so that it can be rotated forward and backward.
Moreover, the structure of the auger combined use steel pipe pile driving machine which concerns on Claim 3 is a structure which reciprocates continuously the said steel pipe pile at an angle within 180 degrees similarly.

The structure of the auger combined steel pipe pile driver according to claim 4 is:
An auger combined steel pipe that excavates the ground by inserting an auger screw into the steel pipe pile while attaching a vibration exciter to the steel pipe pile via a chuck, causing the steel pipe pile to vibrate and penetrating into the ground. In the pile driving method,
The steel pipe pile is rotated around its axis according to the degree of hardness of the ground.

Applying the auger combined steel pipe pile driver of claim 1,
I. Since it is equipped with a leader, the exciter and auger can be supported and guided by the leader, and steel pipe piles can be driven, without a dedicated auger crane,
B. Since the vibrator is attached to the reader via the buffer member, the reader is not subjected to vibration,
C. Since the steel pipe pile is driven to rotate around the axis, a tremendous penetration force is exhibited as compared with the conventional example.
What should be noted here is that it is not necessary to newly install the buffer member described in the paragraph (b), and that the vibration pile driver inherently has a buffer member (for example, a coil spring, a rubber joint, etc.), And, it is an increase in the penetration force by rotating the steel pipe pile in the section C.

When the invention of claim 2 is applied to the invention of claim 1 and the steel pipe pile is continuously rotated, or the invention of claim 3 is applied to the invention of claim 1 and the steel pipe pile is reciprocally rotated. Depending on the condition of the ground, the maximum pile penetration input can be demonstrated. Depending on the condition of the ground, continuous rotation may be better, and reciprocating rotation may be better, so it is desirable to prepare for selective use.
Focusing on the mechanical device, continuous rotation (Claim 2) is easier to control, and reciprocating rotation (Claim 3) requires a simpler actuator structure.

When the auger combined steel pipe pile driving method according to claim 4 is applied, a significantly stronger underground penetration performance is exhibited compared to the conventional auger combined pile driving method, and the construction cost reduction effect due to the improvement of work efficiency is achieved. Play.
Not only will the construction period be shortened by improving efficiency, but also the operating time of the pile driving machine will be shortened, so the occurrence of vibration and noise pollution will be reduced in time.

Hereinafter, embodiments of the present invention will be described with reference to FIGS. 1 to 3.
FIG. 2 is a schematic diagram depicting a form in which the auger combined steel pipe pile driving method according to the present invention is implemented using the auger combined steel pipe pile driving machine according to the present invention. The front view which shows a whole view, (B) is the side view which extracted and showed the principal part.
A reader 12 is mounted as a front attachment of the vehicle construction machine 11, and this reader is erected vertically on the ground of the work site.

The external structure of the vibration pile driving machine in the present embodiment includes an exciter 13 that is a generation source of vibration energy, and a steel pipe pile chuck 15 that is attached in vibration connection to the exciter. The hanger 14 that is vibrationally insulated from and attached to the vibrator is the main part.
Of the above three parts, the vibrator 13 and the steel pipe pile chuck 15 are not in contact with the leader 12, and the hanger 14 is engaged with the leader 12 so as to be able to slide up and down (details of structure). Will be described next with reference to FIG. 1).

Drawing 1 shows the appearance of the vibration pile driver in this embodiment, (A) is a top view and (B) is a front view.
In FIG. 1, a vibration system device including a vibrator 13 as a vibration source and a steel pipe pile chuck 15 that is vibrationally connected to the vibrator is drawn by a broken line, and the vibrator A stationary apparatus having a hanger 14 that is vibrationally insulated as a main component is drawn with a solid line. The vibration insulating member interposed between the two is a coil spring 18 made of an elastic material, which is drawn with a chain line.
Although not shown, the coil spring 18 can be replaced with a rubber joint.

Reference numeral 19 denotes a leader engaging hook which is fixed to a hanger 14 which is a stationary member.
The engaging hook 19 is engaged with the reader 12 (FIG. 2), the hanger 14 is supported and guided so as to be lifted and lowered by the wire rope W.
(See FIG. 2) With the above-described configuration, the vibration pile driver is supported by the leader without transmitting vibration to the leader 12 and the vehicle construction machine 11.
The auger 16 is supported and guided by the reader 12 and is moved up and down by the wire rope W. Accordingly, the auger can be supported and moved up and down without providing a crane dedicated to the auger.

As shown in FIG. 1 (A), when the auger insertion hole 14a is provided in the hanger 14 and the exciters 13 are arranged on both sides of the auger insertion hole, the exciters on both sides are synchronized with each other to cooperate. It is necessary to work.
Since the technology for controlling the vibrators provided on both sides of the auger insertion hole in synchronization with each other is disclosed in Japanese Patent Application Laid-Open No. 2006-207354 “Pumping Machine Exciter with Adjustable Vibration Force” What is necessary is just to apply this technique.

FIG. 3 is a partial cross-sectional view schematically drawn for explaining a connection structure between the steel pipe pile chuck 15 and the vibration generator 13. It is not a realistic projection because it is modeled so that the structural functions can be easily understood.
This cross-sectional view is drawn by cutting the right half and the left half of the center line Z along two planes that are perpendicular to each other, with the vibrator 13 appearing on the left half, The exciter does not appear in the half.
The exciter 13 is mounted on an exciter base 21 and is suspended by a hanger (not shown) via a coil spring 18.

  An upper end portion of the steel pipe pile chuck 15 is formed in a large-diameter cylindrical shape, and is rotatably connected to the vibrator base 21 by a bearing 22. In the figure, the bearing 22 is depicted as small, but since it is a member that transmits the vibration energy generated by the vibrator to the chuck for steel pipe piles, a heavy load bearing having a particularly large thrust load is used. . Accordingly, the steel pipe pile chuck 15 is supported so as to be rotatable around the axis Z of the gripped steel pipe pile 7.

A ring gear 23 is formed on the inner periphery of the cylindrical portion at the upper end of the steel pipe pile chuck 15 described above.
On the other hand, a pinion 25 that is supported by a drive mechanism 24 installed on the exciter base 21 and rotated is engaged with the ring gear 23.
Thereby, the steel pipe pile chuck 15 holding the steel pipe pile 7 is rotated around the axis Z of the steel pipe pile 7.

The power source of the drive mechanism 24 may be a hydraulic motor or an electric motor, but it is equipped with a control mechanism (not shown) so that rotation start / stop / rotation acceleration / deceleration and forward / reverse can be operated arbitrarily. It has become.
As an embodiment different from the above, a hydraulic cylinder can be used as a power source without using a hydraulic motor or an electric motor. If a hydraulic cylinder is installed as an actuator (not shown), it is not necessary to provide a ring gear, so that the structure is simplified. However, it cannot be continuously rotated, and is reciprocally rotated at a rotation angle of 180 degrees or less.

Next, an example of carrying out the auger combined pile driving method according to the present invention using the auger combined steel pipe pile driving machine configured as described above will be described.
As shown in FIG. 2, a leader 12 is attached as a front attachment of the vehicle construction machine 11, self-propelled to the steel pipe pile placement site, and the leader 12 is set up at the placement point.
The auger 16, the screw 17, the vibration pile driving machine, and the steel pipe pile 7 are carried into the work site by appropriate means.
In order to cooperate with work preparation, a mobile crane (not shown) is placed at the work site.

The hanger 14 of the vibration pile driver is attached to the reader 12 and the wire W is attached to make it possible to move up and down.
The steel pipe pile 7 is gripped by the steel pipe pile chuck 15 of the vibration pile driving machine. Since the steel pipe pile 7 is a heavy member, it requires appropriate skill and the cooperation of a crane not shown. However, since this operation is also performed in the general prior art, detailed description is omitted. Also in the following description, detailed description of the same work as that of the prior art is omitted.

When the leader 12 supports the vibration pile driving machine that holds the steel pipe pile 7 so that it can be moved up and down, if it is not hard ground, the steel pipe pile is penetrated into the ground as usual and placed. Can do.
However, a ground survey is always conducted prior to the pile driving work. As a result of the survey, the auger combined construction method is adopted on the assumption that it is difficult to place steel pipe piles by simple vibration pile driving alone.
Therefore, the auger 16 is attached to the reader 12 in advance, and the wire W is hung so that it can be moved up and down.

The ground usually has a layered structure called a stratum, and when the pile driving operation is expressed in an extremely simplified manner, it is completed by breaking through the soft stratum and biting the lower end of the pile into the hard stratum. Of course, it will be installed according to the specifications based on the construction design.
Because of this situation, pile driving is generally performed through various strata.
When the preparation is completed as described above, first, the vibration pile driving operation of the steel pipe pile is performed without using the auger together.

When the lower end of the steel pipe pile 7 reaches a slightly hard formation, the settlement speed of the steel pipe pile becomes slow. When the subsidence speed of the steel pipe pile is slowed, the combined use of the auger is started as follows.
When carrying out the method of the present invention, if sinking is difficult from the beginning, an auger may be used together from the beginning. The same applies to cases where the surface layer is found to be hard by ground survey.
In order to use the auger together, a screw 17 is attached to the auger 16 and the screw is suspended in the steel pipe pile 7 and rotated.

If the steel pipe pile 7 starts to sink smoothly due to the combined use of the auger, the operation is continued as it is.
When the subsidence of the steel pipe pile is not expected even when the auger is used together, and when the subsidence of the steel pipe pile that has subsided due to the combined use of the auger stagnate, the drive mechanism 24 described with reference to FIG. Rotate around the axis.
When the steel pipe pile 7 rotates, the “friction resistance between the outer peripheral surface of the pile and the earth and sand” that hinders the penetration of the pile changes from a static friction state to a dynamic friction state, and the friction coefficient decreases accordingly. Begins to sink.

As understood from the principle of “acceleration of settlement by rotation of steel pipe piles” described above, the rotation around the axis of the steel pipe piles is normal regardless of whether the rotation is one-way continuous rotation or one-way intermittent rotation. Even repetition of reverse rotation is effective.
When the cycle is extremely shortened for forward and reverse iterations, reciprocal rotation is performed.
The settlement of the steel pipe pile can also be promoted by continuous reciprocating rotation.
On the other hand, the structure of the ground is complex, and depending on the state of the ground structure, one-way continuous rotation may be most effective, and forward / reverse rotation may be most effective, but any rotation method is effective. is there. According to the inventors' experimental study, even a non-optimal rotation method is not invalid. The difference between the effect of the best rotation method and the result of the worst rotation method is relatively small.

  As to what kind of rotation form should be taken in response to the ground structure and other various working conditions, we must expect to accumulate empirical knowledge in the future. It is desirable to prepare equipment capable of rotating operation and to secure the degree of freedom of construction design that can be arbitrarily selected and used according to the situation.

  FIG. 2 is a two-sided view schematically showing the main part of an auger combined steel pipe pile driving machine that is a grandchild of the present invention, in which a vibration system device is drawn with a broken line and a stationary system device is drawn with a solid line.   BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 shows an embodiment of the present invention, in which (A) is a front view of the overall appearance, and (B) is a side view of a main part extracted.   FIG. 2 is a partial cross-sectional view showing a vibration system device according to an embodiment of the present invention, in which the cut surface on the right side and the cut surface on the left side of the center line Z intersect at approximately 90 degrees.   (A) is a top view which shows the well-known example of an auger combined use press-fitting apparatus, (B) is an external appearance front view in a well-known example different from the above.   It is the schematic diagram which drew the pile driving construction of the prior art example.

Explanation of symbols

1 ... U-shaped sheet pile 2 ... Auger device (auger casing)
DESCRIPTION OF SYMBOLS 3 ... Contact seat 4 ... Guide member 5 ... Engagement member 6 ... 1st crane 7 ... Steel pipe sheet pile (steel pipe pile)
DESCRIPTION OF SYMBOLS 8 ... Press fit pulling machine 9 ... 2nd crane 10 ... Auger 11 ... Vehicle system construction machine 12 ... Leader 13 ... Exciter 14 ... Hanger 15 ... Steel pipe pile chuck 16 ... Auger 17 ... Auger screw 18 ... Coil spring 19 ... Leader engaging hook 20 ... pulley 21 ... exciter base 22 ... bearing 23 ... ring gear 24 ... drive mechanism 25 ... pinion W ... wire rope

Claims (4)

With a hanger having an auger insertion hole, a vibrator suspended through a buffer member;
In the auger combined steel pipe pile driving machine comprising the steel pipe pile chuck attached to the vibrator,
Hook member slidably engaged with the leader is fixed to the hanger, and the driving means for rotating the chuck for the steel pipe pile around the axis of the steel pipe pile with respect to the exciter An auger combined use steel pipe pile driving machine characterized in that is provided.   The auger combined steel pipe pile driving machine according to claim 1, wherein the rotation driving means of the chuck for steel pipe piles has a structure for continuously rotating the steel pipe piles so as to be forward and reverse.   The auger combined steel pipe pile driving machine according to claim 1, wherein the rotation driving means of the steel pipe pile chuck is configured to continuously reciprocate the steel pipe pile at an angle of 180 degrees or less. . An auger combined steel pipe that excavates the ground by inserting an auger screw into the steel pipe pile while attaching a vibration exciter to the steel pipe pile via a chuck, causing the steel pipe pile to vibrate and penetrating into the ground. In the pile driving method,
An auger combined steel pipe pile driving method, characterized in that the steel pipe pile is rotated around its axis according to the hardness of the ground.

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