JP2003055967A - Penetration method of steel pipe pile - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a smooth penetration method capable of properly and easily controlling the pushing force and pushing rate of a steel pipe pile, and surely preventing the falling or breakage of the steel pipe pile generated in penetration. SOLUTION: Required pushing force F and pushing rate V by a pushing and returning cylinder to be worked on the steel pipe pile in penetration are preliminarily calculated from the geology, penetration depth, diameter of steel pipe pile and the like every penetration scheduled position of steel pipe piles. The pressure of oil acting on the rod side of the pushing and returning cylinder is adjusted to work the pushing force F onto the steel pipe pile, and the oil flow rate on the head side of the pushing and returning cylinder is adjusted to set the pushing rate of the steel pipe pile to the above pushing rate V.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention uses a steel pipe pile penetrating device having a function of holding and rotating a steel pipe pile having a spiral blade at the tip for use in foundation works in construction and civil engineering. Then, the present invention relates to the penetration method for penetrating a plurality of steel pipe piles into the ground.

[0002]

2. Description of the Related Art An apparatus for penetrating a steel pipe pile, which grips the steel pipe pile and then pushes it while rotating it, is disclosed in, for example, Japanese Patent Laid-Open No. 2000-2000.
No. 226849 is disclosed. A method for penetrating a steel pipe pile in this apparatus will be described below with reference to FIG.

A steel pipe pile 2 arranged in the central portion of the steel pipe pile penetration device 1 is gripped by a chuck member 3 which is a gripping means, and then the steel pipe pile 2 is driven by a hydraulic motor 5 which is one of rotating means. After the chuck member 3 is rotated and the steel pipe pile 2 is rotated and pushed by the pushing / returning cylinder 4 which is a pushing / returning means, the steel pipe pile 2
The chuck member 3 gripping is released, and then the chuck member 3 is returned to the next gripping portion of the steel pipe pile 2 by the pressing / returning cylinder 4 which is the pressing / returning means. By repeating the above steps, the steel pipe pile penetrates deep into the ground.

Here, when the steel pipe pile having the shape of the steel pipe pile has a spiral blade at its tip, the steel pipe pile is
When it is rotated, earth and sand are excavated at the tip of the blade with a spiral shape, and the earth and sand excavated at the upper surface of the blade are pushed up as the blade rotates, and thrust in the intrusion direction (hereinafter thrust) generated by the reaction force of the ground. Called)) is penetrated into the ground. In the above-mentioned penetration, since the ground is generally homogeneous and the ground has a strength capable of supporting the thrust of the blades, the steel pipe pile is rotated by the chuck member and pushed by the pushing / returning cylinder 4 and pushing speed. And synchronized,
Due to the screw action of the spiral shaped blade,
Only one pitch of the blade is embedded in the ground, and the steel pipe pile can be normally penetrated.

However, in the actual penetration work, at the beginning of the penetration of the steel pipe pile,
When the steel pipe pile is penetrated at the pitch / rotation penetration speed because the steel pipe pile does not have the strength to support the steel pipe pile and the steel pipe pile is not self-supporting and easily falls, the steel pipe pile to be penetrated collapses, and many corrections are required for the collapse. If the geology in the intermediate layer during the intrusion, which requires a long process and time, is hard, when the steel pipe pile is penetrated at the above-mentioned pitch / rotation penetration speed, the steel pipe pile will generate an uneven reaction force from the ground. There is a problem that it may be damaged when received.

Therefore, in the above cases, it is necessary to reduce the pushing speed of the steel pipe pile and gradually perform the penetration. Furthermore, at the beginning of the penetration of the steel pipe pile, since the self-weight of the steel pipe pile is light and the thrust from the ground is small, it is necessary to appropriately apply a pushing force to penetrate the steel pipe pile. In the case where the geology in the intermediate layer is hard, the self-weight of the steel pipe pile is slightly increased as compared with the beginning of the penetration, but similarly, it is necessary to apply an appropriate pushing force to penetrate the steel pipe pile. There is also a problem. .

Therefore, in the above cases, it is necessary to increase the pushing force of the steel pipe pile to penetrate it.

On the other hand, although the shape is not the bladed pile,
For a steel pipe pile having a bit for excavation at the tip, as a method of controlling the weight of the steel pipe pile at the time of penetration for the purpose of preventing wear of the bit, for example, Japanese Patent No. 2908682.
It is disclosed in the publication.

The outline will be described below with reference to FIGS. 4 and 5.

The outline of this technique is as follows.
The throttle valve 21 and the relief valve 24 are arranged in a circuit branched from the head side of the above, whereby the hydraulic pressure does not act on the rod side of the pressing / returning cylinder 4 and the relief valve 24 is not used, as shown in FIG. As described above, the steel pipe pile is penetrated while the self-weight of the steel pipe pile is directly applied as the pushing force.

On the other hand, when the relief valve is used, that is, as an example, when the penetration depth of the steel pipe pile becomes deep, the self-weight of the steel pipe pile becomes large and this large self-weight acts on the bit, so that Greater wear. A method of reducing this acting force is disclosed in FIG. This is because the back pressure due to the set pressure of the relief valve 24 acting on the head side of the pressing / returning cylinder 4 is subtracted from the self-weight of the steel pipe pile when the steel pipe pile is inserted, and the back pressure is applied as the pushing force. To do.

[0012]

However, when the method for penetrating a steel pipe pile disclosed in Japanese Patent No. 2908682 is applied to a steel pipe pile having a spiral blade at the tip which is the subject of the present invention, As described above, the following problems arise due to the unique circumstances of having the blade portion.

That is, in the method of penetrating a steel pipe pile disclosed in Japanese Patent No. 2908682, when a steel pipe pile having a spiral blade at the tip is penetrated, the diameter of the steel pipe pile is small and the pile length is small. When it is short, or when the geology of the intermediate layer during the penetration is hard, the weight of the steel pipe pile becomes light, and the necessary pushing force cannot be secured when the steel pipe pile penetrates.

Therefore, as shown in FIG. 6, it is necessary to adjust the hydraulic pressure supplied to the rod side of the pressing / returning cylinder 4 to switch to the normal pressing method for ensuring the necessary pressing force each time.

However, in this state, when the pushing force acts on the pressing / returning cylinder 4 by the thrust of the blades, the hydraulic pressure on the head side of the pressing / returning cylinder 4 rises. When this pressure exceeds the set pressure of the counter balance valve 27, the oil on the head side of the pressing / returning cylinder 4 will pass through the counter balance valve 27 and flow into the tank 28 without controlling the flow rate. The moving speed of 4 becomes out of control. As a result, the steel pipe pile is in a so-called "pre-running state" in which the steel pipe pile is penetrated at a speed higher than a predetermined pushing speed. At this time, if the steel pipe pile collapses at the beginning of penetration of the steel pipe pile or if a hard layer exists in the middle of the ground, the steel pipe pile will be damaged. Therefore, in order to prevent the "pre-running state", it is necessary to switch to the method shown in FIG. 4 or 5.

As described above, in the switching work, in the series of penetration work, the thrust force that causes the switching work is greatly influenced by the viscosity and hardness of the geology targeted for the penetration, the diameter of the steel pipe pile and the like. It is extremely complicated because it increases and decreases,
As a result, the penetration work efficiency of the steel pipe pile is significantly reduced.

In view of the above problems, it is an object of the present invention to solve the above problems, and more specifically, to the viscosity, hardness, diameter, etc. of the geology that act when the steel pipe pile with vanes penetrates. Thrust unique to a steel pipe pile with blades that greatly varies and increases / decreases, and its own weight that changes due to the diameter of the steel pipe pile, the penetration depth, etc.
It is possible to properly and easily control the pushing force and pushing speed of the steel pipe pile by preventing the influence of the pushing force and pushing speed of the steel pipe pile, and to reliably prevent the steel pipe pile from collapsing and breaking during penetration. , To provide a smooth penetration method.

[0018]

In order to solve the above-mentioned problems, the present invention provides a first step of gripping a steel pipe pile having a spiral blade at its tip by a gripping means, following the first step, A third step of releasing the grip of the steel pipe pile, following the second step and the second step of pushing the steel pipe pile by the pressing / returning cylinder while rotating the steel pipe pile by the rotation of the gripping means by the rotating means. And the third step, and the fourth step of returning the gripping means to the next gripping point by the pressing / returning cylinder. By repeating the above steps, the steel pipe pile is penetrated into the ground. In the steel pipe pile penetration method, the oil is supplied to the rod side of the pressing / returning cylinder in the first step, and the oil is supplied to the head side of the pressing / returning cylinder in the third step. Press and return shirin And the required pushing force F and pushing speed V by the pressing / returning cylinder to be applied to the steel pipe pile at the time of penetration from the geology, the penetration depth, the diameter of the steel pipe pile, etc. Is calculated in advance, and in the second step, the pressure of the oil acting on the rod side of the pressing / returning cylinder is adjusted to adjust the pushing force F to the steel pipe pile.
And the flow rate of oil on the head side of the pressing / returning cylinder is adjusted to set the pushing speed of the steel pipe pile to the pushing speed V.

Further, in the present invention, in the second step, the pressure of the oil acting on the rod side of the pressing / returning cylinder is adjusted so that the pushing force F acts on the steel pipe pile and the pressing / returning is performed. The pushing speed of the steel pipe pile can be set to the pushing speed V by adjusting the flow rate of oil acting on the rod side of the cylinder.

Further, in the present invention, the required pushing force F and pushing velocity V calculated in advance are input to the control device for each of the planned penetration points of the steel pipe pile, and the steel pipe pile is penetrated based on the input values. You can also do it.

[0021]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described in detail below with reference to embodiments shown in the drawings.

<First Embodiment> FIG. 1 is a hydraulic circuit diagram for driving a pressing / returning cylinder according to a first embodiment of the present invention. In the figure, solid arrows indicate the flow direction of the entire hydraulic oil in the hydraulic circuit when the steel pipe pile penetrates into the ground. Chuck member 3 which is a gripping means for gripping the steel pipe pile
The flow direction of the entire hydraulic oil when (see FIG. 3) returns to the original position is indicated by a dotted arrow.

In the figure, when high-pressure oil from the hydraulic pump 9 is supplied to the rod side of the pressing / returning cylinder 4, the pressing / returning cylinder 4 is pulled in, and accordingly, the steel pipe pile is pressed in. Be done.

Reference numeral 7 is an electromagnetic switching valve for supplying high-pressure oil from the hydraulic pump 9 to the rod side of the pressing / returning cylinder 4, and 6 is an electromagnetic proportional valve, which is a main structure when the present invention is carried out. This is a flow control system, the opening degree of which is arbitrarily controlled by a command from a control device (not shown), and the flow rate of the oil that is going to return from the head side of the pressing / returning cylinder 4 to the tank 13 is adjusted. By adjusting the flow rate, the moving speed of the pressing / returning cylinder 4 is controlled, and as a result, the pressing speed of the steel pipe pile can be controlled.

A check valve 10 allows high-pressure oil from the hydraulic pump 9 to pass through when it is supplied to the head side of the pressing / returning cylinder 4. On the other hand, 8 is an electromagnetic proportional relief valve which is another main configuration when the present invention is carried out,
The hydraulic pump 9 is instructed by a command from a control device (not shown).
Adjust the supply pressure of high-pressure oil from the. By adjusting the supply pressure, the pressure for operating the pressing / returning cylinder 4 is controlled, and as a result, the pushing force of the steel pipe pile can be controlled.

In the hydraulic circuit diagram for driving the pressing / returning cylinder having the above structure, an appropriate control method for the case of actually penetrating a steel pipe pile will be described.

As described above, this method solves the problems of the prior art such as the collapse of the steel pipe pile at the beginning of the penetration of the steel pipe pile and the damage of the steel pipe pile during the penetration when the geology is hard. The pitch / rotation penetration rate,
Instead of penetrating the steel pipe pile, the steel pipe pile is gradually penetrated. The procedure for the actual penetration work of the steel pipe pile will be described in detail below. Procedure 1: Geology, depth of penetration,
The required pushing force F and pushing speed V to be applied to the steel pipe pile at the time of penetration are calculated in advance from the diameter of the steel pipe pile and the like. As described above, as a method for calculating the pushing force F and the pushing speed V, the rotation which is normally performed by the chuck member and the pushing force f and the pushing speed v by the pushing / returning cylinder 4 are synchronized to form a spiral. The pushing force F = (2-5) × f and the pushing speed V = (0.2-0. 5) It is better to set so that it becomes xv.

Step 2: In order to set the pushing speed of the steel pipe pile to the required pushing speed V calculated above, the hydraulic flow rate on the head side of the pushing / returning cylinder is set by adjusting the opening of the electromagnetic proportional flow control valve 6.

Step 3: In order to apply the calculated required pushing force F to the steel pipe pile, electromagnetic proportionality is applied so that the force due to the hydraulic pressure acting on the rod side of the pushing / returning cylinder becomes F. Set the pressure of the relief valve.

The above procedure 2.3 has the same operation and effect in the reverse order.

According to the above-mentioned penetration method, in the actual penetration work of a steel pipe pile, when the geology during the penetration is hard, it is generated by the blade of the steel pipe pile when the penetration is slower than the pitch / rotation penetration speed. Even if the thrust force that acts on the pressing / returning cylinder acts as a pushing force, the hydraulic pressure flow rate on the head side of the pressing / returning cylinder is adjusted to the pushing speed of the steel pipe pile by adjusting the opening of the electromagnetic proportional flow controller 6. Since the calculated required pushing speed V is set, it is possible to slowly penetrate the steel pipe pile,
Thereby, the steel pipe pile is not damaged.

Further, even when the steel pipe pile starts to penetrate and the pile length is short, or the diameter of the steel pipe pile is small, the hydraulic pressure on the rod side of the pressing / returning cylinder is controlled by the electromagnetic proportional relief valve. Therefore, it is possible to slowly penetrate the steel pipe pile with a required pushing force and pushing speed, so that the steel pipe pile does not fall.

In the above embodiment, the hydraulic pump 9 is of fixed discharge type, but a variable discharge type hydraulic pump is used, and the pressure side of the rod side of the pressing / returning cylinder corresponding to the preset required pushing speed is used. If it is set a little higher than the oil flow rate, the oil pressure loss decreases and the power loss can be reduced.

<Second Embodiment> FIG. 2 is a hydraulic circuit diagram for driving a pressing / returning cylinder according to a second embodiment of the present invention.
In the figure, solid arrows indicate the flow direction of the entire hydraulic oil in the hydraulic circuit when the steel pipe pile penetrates into the ground. Chuck member 3 which is a gripping means for gripping the steel pipe pile
The flow direction of the entire hydraulic oil when (see FIG. 3) returns to the original position is indicated by a dotted arrow.

In the figure, the same parts as those in the first embodiment shown in FIG. 1 are designated by the same reference numerals, and only the differences from the first embodiment will be described below.

The difference from the first embodiment is that a counterbalance valve 11 is provided in place of the electromagnetic proportional flow controller 6, and a variable discharge hydraulic pump 12 is provided in place of the fixed discharge hydraulic pump 9. It is a point.

With the above construction, in the actual penetrating work of the steel pipe pile with vanes, the flow rate of the oil supplied to the rod side of the pressing / returning cylinder 4 can be varied even if the thrust by the vanes acts during the penetration. As described above, if the vehicle is controlled by the hydraulic pump 12 of the variable discharge type hydraulic pump 12, the hydraulic pressure on the rod side of the pressing / returning cylinder 4 is reduced when the vehicle is going ahead of the pushing speed corresponding to the flow rate supplied by the variable discharge hydraulic pump 12, as described above. The balance valve 11 is closed to prevent the front run,
Moreover, as described above, even if the weight of the steel pipe pile is small, the pressure on the rod side of the pressing / returning cylinder 4 is proportional to the electromagnetic proportional relief valve 8.
Therefore, because it is controlled, for each planned penetration location of the steel pipe pile, from the geology, the penetration depth, the diameter of the steel pipe pile, etc., at the required pushing force F and pushing speed V to act on the steel pipe pile at the time of penetration, The steel pipe pile can be penetrated.

[0038]

According to the present invention, when a vaned steel pipe pile is penetrated, the thrust unique to the vaned steel pipe is increased and decreased greatly depending on the viscosity and hardness of the geology to be penetrated, the diameter of the steel pipe pile, and the like. The self-weight that changes depending on the diameter and penetration depth of the steel pipe pile,
It is surely prevented from affecting the control of the pushing force and the pushing speed of the steel pipe pile, the pushing force and the pushing speed of the steel pipe pile can be appropriately and easily controlled, and the falling and damage of the steel pipe pile occurring at the time of penetration can be surely performed. It is possible to prevent and provide a smooth penetration method.

[Brief description of drawings]

FIG. 1 is a hydraulic circuit diagram for driving a pressing / returning cylinder according to a first embodiment of the present invention.

FIG. 2 is a hydraulic circuit diagram for driving a pressing / returning cylinder in a second embodiment of the present invention.

FIG. 3 is a side view showing an outline of a conventional steel pipe pile penetration device.

FIG. 4 is a hydraulic circuit diagram for driving a conventional pressing / returning cylinder.

FIG. 5 is a hydraulic circuit diagram for driving a conventional pressing / returning cylinder.

FIG. 6 shows a hydraulic circuit diagram for driving a conventional pressing / returning cylinder.

[Explanation of symbols]

1. Penetration device for steel pipe piles 2. Steel pipe pile 3. Chuck member 4. Pressing / return cylinder 5. Hydraulic motor 6. Electromagnetic proportional flow controller 7. Solenoid switching valve 8. Electromagnetic proportional relief valve 9.
Hydraulic pump 10. Check valve 11. Counter balance valve 12. Variable discharge pump 13. Tank 14.
Hydraulic pump 15. Relief valve for compression 16. Solenoid valve 1
7. Relief valve 18. Solenoid valve 19. Check valve 20.
Solenoid valve 21. Throttle valve 22. Check valve 23. Solenoid valve 24. Relief valve 25. Pilot check valve
26. Check valve 27. Counter balance valve 28. tank

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Akashi Tetsushi             46-59 Nakahara, Tobata-ku, Kitakyushu             Into Design Co., Ltd. (72) Inventor Tetsuji Anan             46-59 Nakahara, Tobata-ku, Kitakyushu             Into Design Co., Ltd. F-term (reference) 2D050 AA06 BB02 CB22 CB23 FF02

Claims (3)

[Claims] 1. A first step of gripping a steel pipe pile having spiral blades at its tip by a gripping means, and subsequent to the first step, the steel pipe pile is rotated by rotating the gripping means by a rotating means. A second step of pushing the steel pipe pile by the pressing / returning cylinder, a third step of releasing the grip of the steel pipe pile after the second step, and a third step of the third step of releasing the grip of the steel pipe pile by the pressing / returning cylinder. A fourth step of returning the gripping means to the next gripping point, which is a penetration method of a steel pipe pile for penetrating the steel pipe pile into the ground by repeating the above-mentioned steps, wherein the pressing / pressing in the first step is performed. Oil is supplied to the rod side of the return cylinder, and in the third step, oil is supplied to the head side of the pressing / returning cylinder to operate the pressing / returning cylinders, and at each planned penetration point of the steel pipe pile. , Geology, Nyufuka of the press-to be applied to steel pipe piles from diameter of the steel pipe pile at penetration
A required pushing force F and a pushing velocity V by the return cylinder are calculated in advance, and in the second step, the pressure of the oil acting on the rod side of the pushing / return cylinder is adjusted to push the pushing force into the steel pipe pile. A method for penetrating a steel pipe pile, wherein F is applied and the flow rate of oil on the head side of the pressing / returning cylinder is adjusted to set the pushing speed of the steel pipe pile to the pushing speed V. 2. In the second step, the pressure of the oil acting on the rod side of the pressing / returning cylinder is adjusted so that the pushing force F acts on the steel pipe pile and the rod side of the pressing / returning cylinder. The method for penetrating a steel pipe pile according to claim 1, wherein the pushing speed of the steel pipe pile is set to the pushing speed V by adjusting the flow rate of oil that acts on the steel pipe pile. 3. The required pushing force F and pushing velocity V calculated in advance are input to a control device for each planned location of penetration of the steel pipe pile, and the steel pipe pile is penetrated based on the input values. The method for penetrating a steel pipe pile according to claim 1 or 2.