JP7612160B2 - Rubble dumping device - Google Patents

Description

The present invention relates to a device for dumping protective rubble onto, for example, a cable laid on the seabed.

Patent Document 1 discloses an underwater rubble dumping device that operates the crane of a crane ship to project a marker onto the sea surface from a chute platform installed on the seabed, and then operates the swinging arm and bucket of a rock-throwing bucket ship to dump rubble using the marker as a guide. This underwater rubble dumping device is used to create rubble mounds that serve as the foundations for breakwaters and revetments.

The riprap covering method, in which protective riprap is placed on top of cables, is known as a method for protecting undersea power transmission lines and communication cables (hereafter referred to as "cables") laid on the seabed. This riprap covering method is applied when burying cables in rocky areas or at great depths where burying them on the seabed is difficult. The following explanation assumes the application of the riprap covering method to an area with a water depth of 70 m and a tidal current speed of 7 kn.

Conventionally, a riprap covering method involves lowering a grab bucket holding riprap (crushed rock) to the seabed from a work vessel such as a grab dredger or crane ship, and then releasing the bucket on the cable. With this method, the amount of riprap dumped onto the cable in one cycle (from the start of lowering the grab bucket to the seabed, through dumping the riprap, to the completion of lifting the grab bucket) is small, resulting in low construction efficiency and long construction times.

On the other hand, with the rubble covering method using tremie pipes, it is difficult to accurately position the tremie pipes on the cable due to the influence of tidal currents, making construction precision an issue. In addition, tremie pipes that are extended to the seabed are at risk of being damaged by rocking.

Japanese Patent Application Publication No. 6-49846

The objective of the present invention is to provide a rubble dumping device that can streamline construction.

The riprap dumping device of the present invention is a riprap dumping device that dumps riprap onto a cable laid on the seabed, and is characterized in that it comprises a box-shaped bucket into which riprap is dumped, a movable plate provided within the bucket and dividing the interior of the bucket horizontally, a vertical plate provided within the bucket and arranged parallel to the movable plate, and a downwardly sloping plate extending at an angle from the lower edge of the vertical plate to the movable plate, a bulkhead that divides the space divided by the movable plate into adjacent chambers arranged side by side , and a lifting device provided on a ship and driving the movable plate in the vertical direction, and is arranged so that the lower end of each chamber is blocked by the movable plate and is opened sequentially as the lifting device raises the movable plate from the lower end position to the upper end position.

The present invention makes it possible to streamline construction using the rubble covering method.

FIG. 2 is a front view of the rubble dumping device according to the present embodiment. FIG. 2 is a right side view of the rubble dumping device according to the present embodiment. FIG. 2 is a plan view of the rubble dumping device according to the present embodiment. FIG. 2 is an explanatory diagram of the present embodiment, and is a front view conceptually showing the structure of the bucket. FIG. 2 is an explanatory diagram of the present embodiment, being a perspective view conceptually showing the structure of a bucket. FIG. 2 is a conceptual diagram of construction using the riprap dumping device according to this embodiment. FIG. 2 is an explanatory diagram of construction using the riprap dumping device according to this embodiment. FIG. 1 is a diagram showing the construction status and outfitting when the rubble covering method is applied.

An embodiment of the present invention will now be described with reference to the accompanying drawings.
Hereinafter, a description will be given of a riprap dumping device 1 that is applied to a riprap covering method for placing riprap 10 (crushed rock) on a cable 61 (submarine power transmission line, communication cable, etc., see FIG. 7) laid on the seabed 60. Here, a plane V1 in FIG. 3 is a symmetrical plane (hereinafter referred to as "vertical plane V1") that divides the inside of a bucket 2, which will be described later, symmetrically in the left-right direction. Also, a plane V2 in FIG. 3 is a symmetrical plane (hereinafter referred to as "vertical plane V2") that divides the inside of the bucket 2 symmetrically in the front-rear direction.

As shown in Figs. 1 to 3, the rubble dumping device 1 has a box-shaped bucket 2 that contains rubble 10 (see Fig. 7) dumped by a backhoe or the like. The bucket 2 has a frame 3 (frame structure) made of steel materials such as angle bars, pipes, and flat bars. At the four corners of the bottom 9 of the bucket 2, legs 19 are provided to support the bucket 2 at a certain height above the ground surface (the deck of a ship 55, the seabed 60, etc.). The four side walls of the bucket 2, i.e., the front wall 4, rear wall 5, left side wall 6, and right side wall 7, are made of expanded metal, which prevents the rubble from leaking out of the bucket 2 through the gaps in the frame 3 and allows the rubble 10 to be seen from the outside.

A pair of movable plates 11L, 11R are provided inside the bucket 2, facing each other with a gap in the left-right direction. The movable plates 11L, 11R are symmetrical with respect to the vertical plane V1 (see FIG. 3). The movable plates 11L, 11R are parallel to the vertical plane V1. The movable plates 11L, 11R are movable in the up-down direction, with their vertically extending edge portions on both the left and right sides guided by multiple pairs of guide rollers 30 provided on the front wall 4 and rear wall 5 of the bucket 2.

The upper ends 12L, 12R of the movable plates 11L, 11R are provided with protrusions 13L, 13R that protrude forward and backward. The movable plates 11L, 11R are suspended (hanging) by the frame 3 with each protrusion 13L, 13R engaged (hooked) with the opening periphery 8 on the upper end side of the bucket 2. Flat bars 14, 14 are installed between the opposing protrusions 13L, 13R between the movable plates 11L, 11R. In other words, the upper ends 12L, 12R of the movable plates 11L, 11R are connected by a pair of front and rear flat bars 14, 14 that extend in the left-right direction.

Bracket 15L, 15R is provided at the center in the front-rear direction of upper end 12L, 12R of movable plate 11L, 11R. Lower end of socket 17L, 17R is connected to bracket 15L, 15R via shaft member 16L, 16R extending in the front-rear direction. In other words, socket 17L, 17R can rotate around shaft member 16L, 16R. One end side of wire rope 18L, 18R is connected to the upper part of socket 17L, 17R. Then, movable plate 11L, 11R is pulled up by winding up the other end side of wire rope 18L, 18R by lifting device (driving device, not shown) provided on crane 56 (see FIG. 8) on ship 55.

Referring to Figures 1 to 5, a partition wall 25L (fixed plate) is provided between the movable plate 11L and the left side wall 6 of the bucket 2, dividing the space between the movable plate 11L and the left side wall 6 into a first chamber 21 on the outside (left side) and a second chamber 22 on the inside (right side). The partition wall 25L has a vertical plate 26L arranged parallel to the movable plate 11L and the left side wall 6 of the bucket 2, and an inclined plate 27L that extends from the lower edge of the vertical plate 26L to the movable plate 11L and inclines at an inclination of 45 degrees. As a result, the second chamber 22L is defined within the bucket 2 by the movable plate 11L, the partition wall 25L, the front side wall 4, and the rear side wall 5. Note that the inclination (inclination angle) of the inclined plate 27L is not limited to 45 degrees.

In the bucket 2, an inclined plate 29L is provided below the partition wall 25L and parallel to the inclined plate 27L. That is, the inclined plate 29L is inclined at an angle of 45 degrees. The inclined plate 29L extends from the left side wall 6 of the bucket 2 to the lower end of the movable plate 11L. As a result, a first chamber 21L is defined in the bucket 2 by the left side wall 6, partition wall 25L, inclined plate 29L, front wall 4, and rear wall 5.

A central partition 31 (fixed plate) is provided between the movable plates 11L and 11R, disposed on the vertical plane V1, i.e., parallel to the movable plates 11L and 11R. The central partition 31 extends from the upper end (opening periphery 8) of the bucket 2 to the middle position of the height of the bucket 2. The central partition 31 has a vertical plate 32 and an inclined plate 33L that extends from the lower edge of the vertical plate 32 to the movable plate 11L and inclines at an inclination of 45 degrees. As a result, the third chamber 23L is defined within the bucket 2 by the movable plate 11L, the central partition 31, the front wall 4, and the rear wall 5. The central partition 31 has an inclined plate 33R that extends from the lower edge of the vertical plate 32 to the movable plate 11R and inclines at an inclination of 45 degrees. That is, the cross section of the central partition 31 by the vertical plane V2 is formed in an inverted Y shape.

Here, the distance from the lower end edge of the inclined plate 29L to the lower end edge of the inclined plate 27L of the partition 25L, i.e., the opening height H1 (see FIG. 4) of the rubble discharge port 35L (lower end) of the first chamber 21L is set to be the same (H1=H2) as the distance from the lower end edge of the inclined plate 27L of the partition 25L to the lower end edge of the inclined plate 33L of the central partition 31, i.e., the opening height H2 (see FIG. 4) of the rubble discharge port 36L (lower end) of the second chamber 22L. Furthermore, the width W1 of the first chamber 21L, the width W2 of the second chamber 22L, and the width W3 of the third chamber 23L (all see FIG. 4) are also set to be approximately the same.

The first chamber 21L is provided with a first input amount adjustment means 41L for adjusting the capacity of the first chamber 21L to the capacity of the third chamber 23L. The first input amount adjustment means 41L has a pair of partitions 42, 42 arranged symmetrically with respect to the vertical plane V2 (see FIG. 3). The front partition 42 has an inclined plate 43 that slopes downward at 45 degrees from near the upper end of the front wall 4 of the bucket 2 toward the vertical plane V2, and a vertical plate 44 that extends from the lower edge of the inclined plate 43 to the inclined plate 29L. In order to avoid duplication, a description of the rear partition 42 will be omitted.

On the other hand, the second chamber 22L is provided with a second input amount adjustment means 45L for adjusting the capacity of the second chamber 22L to the capacity of the first chamber 21L and the third chamber 23L. The second input amount adjustment means 45L has a pair of partitions 46, 46 arranged to be symmetrical with respect to the vertical plane V2 (see FIG. 3). The front partition 46 has an inclined plate 47 that slopes downward at 45 degrees from near the upper end of the front wall 4 of the bucket 2 toward the vertical plane V2, and a vertical plate 48 that extends from the lower edge of the inclined plate 47 to the inclined plate 27L of the partition 25L. In order to avoid duplication, the description of the rear partition 46 is omitted.

The bucket 2 is configured symmetrically with respect to the vertical plane V1. Therefore, the configuration on the right side of the vertical plane V1 in the bucket 2 will only be given the reference numerals corresponding to those in the drawings, and duplicate explanations will be omitted.

Referring to FIG. 6, the frame 3 of the riprap dumping device 1 is provided with a transponder 51, four underwater lights 52 (only three are shown in FIG. 6) that illuminate the seabed 60, and two underwater cameras 53 (only one is shown in FIG. 6). The transponder 51 provides (transmits a signal) information on the position, course, speed, etc. of the riprap dumping device 1 to a receiving device (not shown) installed on the ship 55 (see FIG. 8). The image signal of the underwater camera 53 is output as an image to a monitor (not shown) installed on the ship.

One end of multiple wire ropes 20 (only two are shown in FIG. 6) is connected to the frame 3. The other end of the wire rope 20 is paid out by a lifting device (drive device, not shown) provided on a crane 56 (see FIG. 8) on the ship 55, thereby lowering the rubble dumping device 1, and the other end of the wire rope 20 is wound up by the lifting device, thereby lifting the rubble dumping device 1.

Next, a construction procedure for dumping riprap 10 (crushed stone) onto a cable 61 (see FIG. 7) laid on the seabed 60 using the riprap dumping device 1 will be described.
As shown in Fig. 8, a ship 55 that performs construction work in the sea area at the site is equipped with a crane 56. The ship 55 also carries a necessary amount (e.g., two days' worth) of riprap 10, a wheel loader 57, and a backhoe 58.

First, the backhoe 58 dumps the riprap 10 into each chamber of the bucket 2 of the riprap dumping device 1 placed on the deck of the ship 55, i.e., the first chambers 21L, 21R, the second chambers 22L, 22R, and the third chambers 23L, 23R. Next, the crane 56 lifts the riprap dumping device 1, and the wire rope 20 is paid out by a lifting device (not shown) mounted on the crane 56 to sink the riprap dumping device 1 to the seabed 60. Then, the riprap dumping device 1 is positioned at a first position (see FIG. 7) on the cable 61 of the seabed 60 using monitoring means such as the transponder 51, underwater camera 53, and ROV 59 (Remote Operated Vehicle). The legs 19 of the riprap dumping device 1 may be floating without being grounded on the seabed 60.

Next, while checking the situation with monitoring means such as the underwater camera 53 and ROV 59, the lifting device mounted on the crane 56 winds up the wire ropes 18L, 18R to raise the movable plates 11L, 11R to a certain height, and opens the rubble discharge ports 35L, 35R (lower end) of the first chambers 21L, 21R of the bucket 2. As a result, as shown in FIG. 7, the rubble 10 in the first chambers 21L, 21R is dumped onto the cable 61 from the rubble discharge ports 35L, 35R. After dumping is complete, the lifting device reels out the wire ropes 18L, 18R to pull the movable plates 11L, 11R down to the lower end position.

Next, while checking the situation using monitoring means such as the underwater camera 53 and ROV 59, the crane 56 is operated to position the riprap dumping device 1 at the second position (see FIG. 7). Here, the riprap dumping device 1 positioned at the second position is positioned so that it overlaps the riprap dumping device 1 positioned at the first position by a certain length (e.g., 0.5 m).

Next, while checking the situation with monitoring means such as an underwater camera 53 and an ROV 59, the wire ropes 18L, 18R are wound up by the lifting device mounted on the crane 56 to raise the movable plates 11L, 11R to a certain height, and the rubble discharge ports 36L, 36R (lower end) of the second chambers 22L, 22R of the bucket 2 are opened. As a result, as shown in FIG. 7, the rubble 10 in the second chambers 22L, 22R is dumped onto the cable 61 from the rubble discharge ports 36L, 36R. After dumping is complete, the wire ropes 18L, 18R are paid out by the lifting device to pull the movable plates 11L, 11R down to the lower end position.

Next, while checking the situation using monitoring means such as the underwater camera 53 and ROV 59, the crane 56 is operated to position the riprap dumping device 1 at the third position (see FIG. 7). Here, the riprap dumping device 1 positioned at the third position is positioned so that it overlaps the riprap dumping device 1 positioned at the second position by a certain length (e.g., 0.5 m).

Next, while checking the situation with monitoring means such as an underwater camera 53 and an ROV 59, the wire ropes 18L, 18R are wound up by the lifting device mounted on the crane 56 to pull up the movable plates 11L, 11R to the upper end position. As a result, the lower end of the third chamber 23L, 23R of the bucket 2 opens to the same height as the opening height H1 of the rubble discharge ports 35L, 35R of the first chambers 21L, 21R and the opening height H2 of the rubble discharge ports 36L, 36R of the second chambers 22L, 22R ("H1 = H2" in this embodiment), that is, the height H1 (H2) from the lower edge of the inclined plates 33L, 33R. As a result, the rubble 10 in the third chambers 23L, 23R is thrown onto the cable 61 from the rubble discharge ports 36L, 36R of the second chambers 22L, 22R via the second chambers 22L, 22R, as shown in FIG. 7.

After dumping is complete, the lifting device pays out the wire ropes 18L, 18R to lower the movable plates 11L, 11R to their lower end positions, and then the lifting device mounted on the crane 56 winds up the wire rope 20 to pull the rubble dumping device 1 up from the seabed 60. The rubble dumping device 1 pulled up from the seabed 60 is placed on the deck of the ship 55 by the crane 56, and the rubble 10 is dumped into each chamber of the bucket 2, i.e., the first chambers 21L, 21R, the second chambers 22L, 22R, and the third chambers 23L, 23R, by the backhoe 58.

Here, the problem with the conventional rubble covering method using a grab bucket is that the amount of rubble that can be dumped in one cycle (from the start of lowering the grab bucket to the seabed, through dumping the rubble, to the completion of lifting the grab bucket) is small, resulting in low construction efficiency and long construction periods.

In contrast, in this embodiment, a box-shaped bucket 2 for accommodating riprap 10, a pair of movable plates 11L, 11R for dividing the interior of the bucket 2 in the left-right direction, a partition wall 25L for dividing the space between the left side wall 6 of the bucket 2 and the movable plate 11L into a first chamber 21L and a second chamber 22L adjacent to each other in the left-right direction, a partition wall 25R for dividing the space between the right side wall 7 of the bucket 2 and the movable plate 11R into a first chamber 21R and a second chamber 22R adjacent to each other in the left-right direction, and a partition wall 25R for dividing the space between the opposing movable plates 11L, 11R in the left-right direction. The rubble dumping device 1 is configured to have a central partition 31 that divides the first chamber 21L, 21R, the second chamber 22L, 22R, and the third chamber 23L, 23R into adjacent chambers 23L and 23R, and to sequentially open the lower ends of the first chambers 21L, 21R, the second chambers 22L, 22R, and the third chambers 23L, 23R as the movable plates 11L, 11R move from the lower end position to the upper end position, thereby allowing the rubble dumping device 1 to be sequentially dumped onto the cable 61 on the seabed 60, the rubble 10 contained in the first chambers 21L, 21R, the second chambers 22L, 22R, and the third chambers 23L, 23R.
As a result, in this embodiment, after the riprap 10 in the first chambers 21L and 21R has been completely dumped, and after the riprap 10 in the second chambers 22L and 22R has been completely dumped, the riprap dumping device 1 can be moved along the cable 61 on the seabed 60 to dump the riprap 10 three times in one cycle (from the start of lowering the riprap dumping device 1 to the seabed 60, through dumping the riprap 10, to the completion of pulling the riprap dumping device 1 up from the seabed 60). In other words, the amount of riprap 10 that can be dumped in one cycle can be increased to three times that of the conventional method. As a result, it is possible to improve the construction efficiency of the riprap covering method, and to significantly shorten the construction period.
Furthermore, with the conventional riprap covering method using tremie pipes, it was difficult to accurately position the tremie pipes on the cable due to the influence of tidal currents, making construction accuracy an issue.
In contrast, in this embodiment, the riprap dumping device 1 is positioned while checking the situation using monitoring means such as an underwater camera 53 and an ROV 59, thereby improving the accuracy of construction.
Furthermore, in this embodiment, the operation of opening and closing the movable plates 11L, 11R is substantially the same as the operation of opening and closing a conventional grab bucket, so that an increase in the burden on the operator can be prevented.

1 Rubble stone feeding device, 2 Bucket, 11L, 11R Movable plate, 21L, 21R 1st chamber, 22L, 22R 2nd chamber, 23L, 23R 3rd chamber, 25L, 25R Partition wall (fixed plate), 31 Central partition wall (fixed plate) )

Claims (3)

A riprap dumping device for dumping riprap onto a cable laid on the seabed, comprising:
A box-shaped bucket into which rubble is dumped,
A movable plate provided in the bucket and dividing the inside of the bucket in a lateral direction;
a partition wall provided in the bucket, the partition wall having a vertical plate arranged parallel to the movable plate and a downwardly inclined plate extending from a lower end edge of the vertical plate to the movable plate, the partition wall dividing a space defined by the movable plate into adjacent chambers arranged side by side;
A lifting device is provided on the ship and drives the movable plate in a vertical direction.
A rubble dumping device characterized in that the lower end of each chamber is closed by the movable plate and is arranged to be opened sequentially as the lifting device raises the movable plate from the lower end position to the upper end position. 2. The rubble dumping device according to claim 1 , wherein the bucket is provided with a capacity adjustment plate for adjusting the capacity of rubble contained in each chamber to be the same. 3. The rubble dumping device according to claim 1 or 2 , further comprising a monitoring means for monitoring the construction status.

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