JPH0236728B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an upper pile holding device for cutting steel pipe piles, which is used when cutting steel pipe piles as foundation piles of various offshore structures, etc. underwater.

Generally, large-diameter, thick-walled steel pipe piles are used as foundation piles for various offshore structures such as bridge foundations, dolphins, and oil drilling jackets. These steel pipe piles must be driven at the same level because the superstructures of the various marine structures mentioned above are connected to their upper parts. Often cut underwater. During this cutting, the upper pile, which is the side of the steel pipe pile that is to be separated, is gradually separated from the lower pile, which is the side that is left behind, as the cutting progresses. As a result, the upper pile gradually loses its restraining force at its lower end and begins to be swayed by waves and the like. As a result, the relative positions of the upper pile and the lower pile may change, and there is a fear that the underwater cutting machine that cuts them may become unusable or that the cutting tool may be damaged. Therefore, it is necessary to restrain the pile with some kind of holding device until the cutting of the steel pipe pile is completed. Therefore, conventionally, an upper pile holding device for cutting steel pipe piles (hereinafter abbreviated as holding device) as shown in Figs. 1 and 2 has been used.
is provided.

In Figures 1 and 2, reference numeral 1 indicates a steel pipe pile driven into the seabed, etc., and this steel pipe pile 1 is cut at a cut point 1a at a predetermined position above the seabed surface to form an upper pile 1b. It is separated from the lower pile 1c. For this reason, an underwater cutting machine 2 is installed inside the steel pipe pile 1 to cut the steel pipe pile 1 at the cut point 1a. This underwater cutting machine 2 includes a drive body 2b for driving a rotating shaft 2a, and a plurality of fixing jacks that are attached to the drive body 2b and fix the drive body 2b at predetermined locations on the inner wall surface of the steel pipe pile 1. 2c... is attached to the tip of the rotating shaft 2a, and the steel pipe pile 1
It is composed of a cutting tool 2d such as a grindstone type or a disk cutter type for cutting from the inner wall side of the cutter. In addition, the drive main body 2b and the fixed jack 2c...
... are driven by hydraulic pressure, for example. Therefore, in this underwater cutting machine 2, the fixed jack 2c... and the hydraulic hose 3 through which the pressure oil that is the drive source of the drive body 2b is guided are installed inside the steel pipe pile 1 from a work boat or the like at sea (not shown). It is connected via .

On the outside of this steel pipe pile 1, a holding device 4 consisting of a temporary receiving pile 4a and plate materials 4b, 4b is provided. The temporary receiving pile 4a is generally made of steel such as H steel, and is driven into the seabed to a required depth along the longitudinal direction of the steel pipe pile 1 while being in contact with the outer wall thereof. The upper end surface of this temporary receiving pile 4a is at approximately the same horizontal position as the upper end surface of the steel pipe pile 1,
The upper pile 1b of the steel pipe pile 1 is held by the temporary support pile 4a by passing plate materials 4b, 4b to the upper end surfaces of these partners and welding them, respectively.

In such a holding device 4, as described above, the steel pipe pile 1 is such that the upper pile 1b is attached to the temporary receiving pile 4 at its upper end surface.
While being held at position a, it is cut at the point to be cut 1a. After this cutting, the underwater cutting machine 2 is supported via the wire 5 by a floating crane or the like (not shown), and the pressure oil led from the hydraulic hose 3 is depressurized, so that the fixed jack 2c... Pile 1 is released from the inner wall, lifted up, and removed. Next, the plates 4b, 4b of the holding device 4 are removed while the cut upper pile 1b is supported by the above-mentioned crane, etc., and the upper pile 1b, which is no longer restrained, is lifted up. It will be removed. Subsequently, the temporary receiving pile 4a is removed, thereby completing the cutting work of the steel pipe pile 1.

However, such a holding device 4 has a disadvantage in that a large amount of construction cost and labor is required to drive the temporary receiving pile 4a.

In addition, in this holding device 4, the upper pile 1b of the steel pipe pile 1 is held only by its upper end surface, so when the weather conditions at sea deteriorate, the upper pile 1b may be cut off due to high waves caused by this. There was also a safety problem, as there was a risk of it shaking as it was being cut, making it impossible to carry out cutting work.

Moreover, in the holding device 4 using this temporary support pile 4a, if the location 1a of the steel pipe pile 1 to be cut is deep, the temporary support pile 4a becomes extremely long and does not sufficiently restrain the upper pile 1b. In addition, if the steel pipe pile 1 is a diagonal pile driven diagonally, one temporary support pile alone will not be able to hold it sufficiently, and the upper pile will begin to move as it is cut. There was a problem that both of them were unsuitable for use.

The present invention has been made in view of the above circumstances, and is an upper pile for cutting steel pipe piles that can easily and reliably prevent the pile from swinging and has excellent cutting work safety in cutting various steel pipe piles. The object is to provide a holding device.

The present invention will be explained below based on the drawings.

3 and 4 show an embodiment of the holding device of the present invention, and parts common to those shown in FIGS. 1 and 2 are given the same reference numerals to simplify the explanation. become

In FIG. 3, this holding device is generally designated by the reference numeral 6. This holding device 6 is attached to the inside of the upper pile 1b of the steel pipe pile 1 on the side to be cut off, and is attached to the steel pipe pile 1 at the cut point 1a of the steel pipe pile 1.
and a lower pile support 9 that is attached to the inside of the lower pile 1b on the side left after cutting and supports the underwater cutter 2 on the lower pile 1b. .

The underwater cutting machine 2, similar to the one shown in FIG. A cutting tool 2d is attached between the underwater cutting machine 2 of the shaft 10 and the lower pile support 9 to cut the steel pipe pile 1 from the inner wall surface thereof, and a cutting tool 2d is attached to the drive body 2b and is attached to the drive body 2.
In the underwater cutting machine 2 in this holding device 6, the above-mentioned rotating shaft 2a is further extended downward by a predetermined length. rotating shaft 1
0, and the lower part of this rotating shaft 10 is the lower pile support 9
It has a structure in which it is inserted into a bearing 7 which will be described later.

On the other hand, the lower pile support 9 includes a bearing 7 that is inserted into the outer periphery of the rotating shaft 10 of the underwater cutting machine 2 and supports this rotating shaft 10, and a bearing 7 that is attached to the bearing 7 and that supports the bearing 7 against the inner wall surface of the steel pipe pile. It is composed of a plurality of hydraulically actuated fixing jacks 8 for fixing.

The bearing 7 is a rolling bearing of an oil bath lubrication type, and is fixed at a predetermined position inside the lower pile 1c by the fixing jack 8 provided on its outer periphery. Therefore, the lower pile support 9
The fixed lower pile 1c and the fixed upper pile 1b of the underwater cutting machine 2 are respectively connected to the rotating shaft 1.
They are integrated through 0.

Here, each fixing jack 2c, which fixes the drive main body 2b and the bearing 7 to the inner wall surface of the steel pipe pile,
To supplement the explanation regarding 8, each of these fixing jacks 2c, 8 is installed along the radial direction of the steel pipe pile 1 in the axial direction of the steel pipe pile 1 in at least two stages, upper and lower, and They are arranged at intervals along the circumferential direction.

Further, an attachment 15 is provided at the tip of the rod of each of the fixing jacks 2c, 8 to make surface contact with the inner wall surface of the steel pipe pile 1. In addition, in this holding device 6, the hydraulic hose 3 to the drive body 2b of the underwater cutting machine 2, as well as the bearing 7 and fixing jack 8 of the lower pile support 9, are independently connected. A hydraulic hose 11 for supplying pressure oil is connected. The pressure oil guided into the drive body 2b by the hydraulic hose 11 passes through a pressure oil hole 10a provided at the center of the rotating shaft 10 through a seal and a rotatable joint (not shown), as shown in FIG. After that, the bearing 7 and the fixed jack 8 of the lower pile support 9 were used.

Such a holding device 6 includes an underwater cutting machine 2 and a lower pile support 9 that are integrated with the rotating shaft 10 in between.
are fixed to the upper pile 1b and the lower pile 1c by fixed jacks 2c..., 8..., respectively, and the cutting tool 2d attached to the rotating shaft 10 faces the part 1a of the steel pipe pile 1 to be cut. It is said to be a position where Therefore, during the cutting of the steel pipe pile 1, the holding device 6 always holds the upper pile 1b and the lower pile 1c of the steel pipe pile 1 as one body via its rotating shaft 10, so that it prevents the upper pile 1b from shifting. This will prevent the cut portion from being displaced. As shown in FIG. 4, since an arc-shaped attachment is attached to the tip of the fixed jack 8, the fixed jack 8 and the steel pipe pile 1 are fixed in surface contact. This has the effect of further enhancing the stable connection state. Moreover, in such a holding device 6, after the above-mentioned cutting operation, the separated upper pile 1b is first supported by a crane or the like (not shown). Next, the pressure oil from the hydraulic hose 11 to the lower pile support 9 is reduced, and the fixed jack 8
If ... is released from the lower pile 1c, the above upper pile 1b
This holding device 6 can also be lifted up integrally with the upper pile 1b by simply lifting the upper pile 1b, and these can be removed from the lower pile 1c at once.

In addition, in the description of the above-mentioned embodiment, the lower pile support 9
Although the bearing 7 is an oil bath lubricated rolling bearing, it is not limited to this, and may be an oil-free type or a sliding bearing type.In short, the upper pile 1b of the steel pipe pile 1 to be cut It may be of any type as long as it can sufficiently support the swinging motion of

As explained above, the upper pile holding device for cutting steel pipe piles of the present invention is an underwater cutting machine that is installed inside the upper pile on the side of the steel pipe pile to be cut and cuts the steel pipe pile at the part of the steel pipe pile to be cut. and a lower pile support that is attached to the inside of the lower pile on the side left by cutting and supports the underwater cutting machine on the lower pile, and the underwater cutting machine has a drive body and a drive body that a rotating shaft that is rotated and whose tip is connected to the lower pile support; a cutting tool that is attached between the drive body of the rotating shaft and the lower pile support for cutting the steel pipe pile from the inner wall side; and a plurality of fixing jacks attached to the drive body to fix the drive body to the inner wall surface of the steel pipe pile, while the lower pile support is inserted into the outer periphery of the rotating shaft of the underwater cutting machine. A bearing that supports this rotating shaft,
and a plurality of fixing jacks attached to the bearing to fix the bearing to the inner wall surface of the steel pipe pile, and each fixing jack fixing the drive body and the bearing to the inner wall surface of the steel pipe pile, They are installed along the radial direction of the steel pipe pile in at least two stages, upper and lower, in the axial direction of the steel pipe pile, and are arranged at intervals along the circumferential direction of the steel pipe pile. Since the rod tip is provided with an attachment that makes surface contact with the inner wall surface of the steel pipe pile, the following excellent effects can be achieved.

In the present invention, the fixing jacks 8 are installed on the inner wall surface of the upper pile on the side from which the steel pipe pile is to be separated, through fixed jacks 8 which are spaced apart along the circumferential direction of the steel pipe pile and arranged in two stages, upper and lower, along the axial direction. The drive body of the cutting machine was fixed, and on the inner wall surface of the lower pile on the side left by cutting, two stages were installed at intervals along the circumferential direction of the steel pipe pile and along the axial direction in two stages, one above and the other. Since the bearing that supports the rotating shaft of the underwater cutting machine is fixed via a fixed jack, the upper and lower piles that sandwich the section of the steel pipe pile to be cut are coaxially and circumferentially connected to the rotating shaft of the underwater cutting machine. It can be held movable relative to.

In particular, in the present invention, the drive body and the bearing that pivotally support the rotating shaft can be securely fixed to the inner wall surface of the steel pipe pile without swinging, by means of fixing jacks arranged in two stages, one above the other. The cutting tool can be held at the part to be cut not only during cutting of the steel pipe pile but also after the cutting, thereby preventing damage to the cutting tool and improving the safety of the cutting operation.

In addition, according to the present invention, after cutting the steel pipe pile, the upper and lower piles are in a state where they can rotate relative to each other around the rotation axis, so there is also an advantage that the completion of cutting of the steel pipe pile can be easily recognized.

Moreover, in the present invention, the rotating shaft of the underwater cutting machine is
Since it is configured to be rotatably supported by the bearing of the lower pile support, even if a rotational moment in the circumferential direction acts on the upper pile, the lower pile support will not receive force in the circumferential direction of the steel pipe pile due to the moment. There are some advantages to not having one. And with this,
After cutting a steel pipe pile, even if a force that causes the upper pile to rotate in the circumferential direction is applied due to waves, etc., the upper pile will rotate together with the rotation axis, so the entire holding device will be affected by the rotational moment of the upper pile. No unreasonable force will be applied. As a result, the steel pipe pile and the drive body and bearing fixed to the inner wall surface of the steel pipe pile via the fixing jack are reliably held, so that the separated upper pile can be lifted in a stable state.

In addition, in the present invention, when the rod of the fixing jack attached to the drive body is extended and the rod of the fixing jack attached to the bearing of the lower pile support is extended, the attachment that makes surface contact with the inner wall surface of the steel pipe pile will move into the inner wall of the steel pipe pile. Since it comes into contact with the wall surface and increases the contact area, it also has the advantage of stabilizing the state of restraint between the upper pile and the lower pile by the fixed jack.

In addition, with this holding device, the underwater cutting machine forms part of this holding device, so the device does not become complicated, and there is no need to drive temporary support piles as in the past, which reduces construction costs. Significant savings can be achieved.

Furthermore, this holding device can extremely easily perform cutting in deep water or cutting with a diagonal pile.

[Brief explanation of drawings]

Figures 1 and 2 show an example of a conventional upper pile holding device for cutting steel pipe piles. Figure 1 is a side configuration diagram, Figure 2 is a - line view of Figure 1, Figure 3 and FIG. 4 shows an embodiment of the upper pile holding device for cutting steel pipe piles of the present invention, FIG. 3 is a side configuration diagram, and FIG. 4 is a sectional view taken along the line -- of FIG. 3. 1...Steel pipe pile, 1a...Point to be cut, 1b...
Upper pile, 1c...lower pile, 2b...drive body, 2d...
...Cutting tool, 6... Holding device, 7... Bearing, 8...
Fixed jack, 9... Lower pile support, 10... Rotating shaft, 11... Hydraulic hose.

Claims (1)

[Claims] 1. An underwater cutting machine installed inside the upper pile on the side where the steel pipe pile is to be cut off to cut the steel pipe pile at the point to be cut, and an underwater cutting machine installed inside the lower pile on the side left behind by cutting. A lower pile supporter supports the underwater cutting machine on a lower pile, and the underwater cutting machine includes a drive body, a rotating shaft that is rotated by the drive body and whose tip is connected to the lower pile supporter. , a cutting tool that is attached between the drive body of the rotary shaft and the lower pile supporter to cut the steel pipe pile from its inner wall surface; and a cutting tool that is attached to the drive body and cuts the drive body against the inner wall surface of the steel pipe pile. It consists of a plurality of fixing jacks that fix the
The lower pile support body includes a bearing that is inserted into the outer circumference of the rotating shaft of the underwater cutting machine to support the rotating shaft, and a plurality of fixing jacks that are attached to the bearing and fix the bearing to the inner wall surface of the steel pipe pile. It consists of
The fixing jacks of the drive body and bearing are provided in at least two stages, upper and lower, in the axial direction of the steel pipe pile along the radial direction of the steel pipe pile, and spaced apart along the circumferential direction of the steel pipe pile. An upper pile holding device for cutting a steel pipe pile, further comprising an attachment that makes surface contact with the inner wall surface of the steel pipe pile at the tip of the rod of each of the fixing jacks.