JP2005155108A - Core sampling method of sea bottom ground - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a safe and efficient core sampling method of the sea bottom ground for reducing a piloting burden and cost. <P>SOLUTION: This core sampling method comprises a process of seating and arranging a sea bottom core sampling device on the sea bottom by suspending the device, a process of separating the sea bottom core sampling device from a rope of a work ship by releasing the connection with the rope by releasing a connecting mechanism, a process of gathering a sample by excavating the sea bottom ground by the sea bottom core sampling device, a process of stopping the work ship on the sea of the point by specifying a position of an ultrasonic transceiver after finishing the sample gathering process, and a process of suspending and recovering the sea bottom core sampling device by suspending an intermediate part of the rope attached with the ultrasonic transceiver by a rope holding mechanism installed on the tip of the rope delivered from the work shape while confirming the position of the ultrasonic transceiver by transmitting an ultrasonic wave from the work ship. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a core sampling method for submarine ground.

As the conventional core sampling method for the seabed ground, the following three methods filed by the present applicant are known.
The first conventional method is to hang a submarine core sampling device on a cable fed from a work ship and install it on the sea bottom to collect a sample of the seabed ground. At the tip of the cable fed from the work ship, A suspension device is provided which can automatically attach and detach the seabed core sampling device. This method includes a step of holding a submarine core sampling device in a suspension device, suspending it with a cable, and installing the suspension device at a sampling point on the seabed. The process of disconnecting from the cable and disconnecting from the cable, the process of excavating the seabed ground with the seabed core sampling device in this state, collecting the sample, and taking the sample of the seabed ground and then hanging it on the seabed core sampling device The method includes sampling the seabed ground by connecting the devices and lifting the cable with a cable and collecting the seabed core sampling device.

  In the second conventional method, a buoyancy body and a weight attached so as to be automatically detachable are provided, and a detachable suspension device is provided at the tip of a cable fed from a work ship. Hold the submarine core sampling device on the suspension device, suspend it with a cable, and install it at the sampling point on the seabed. After the core sampling device is seated at the sampling point, the suspension device is disconnected from the core sampling device and disconnected from the cable, and in this state, the seabed ground is excavated by the core sampling device to collect the sample. After taking a sample of the seabed ground, the weight attached to the core sampling device can be separated automatically, and the core sampling device is lifted by the buoyancy of the buoyant body attached to the core sampling device and collected. ing.

In the third conventional method, the submarine core sampling device has a buoyant body and a weight attached so as to be separable. In this state, the submarine core sampling device is inserted into the sea from the ship, and when it reaches the seabed, it is installed in the submarine. The manipulator is held and seated at a predetermined position. After that, the seabed ground is excavated by the core sampling device and the sample is collected. After the seabed ground sample is collected, the weight attached to the core sampling device is detachable, and the core sampling device is lifted and collected by the buoyancy of the buoyant body attached to the core sampling device.
JP 7-217351 A JP-A-7-217361 JP 7-293182 A

However, such conventional techniques have the following problems.
In the first conventional method, the submarine core sampling device is gripped by the suspension device attached to the tip of the cable of the work ship and installed and recovered on the suspended seabed. In addition, the suspension device that automatically attaches and detaches the submarine core sampling device is heavy and large, and the cables and the cable feeding equipment become heavy and large.

  In the second conventional method, the weight attached to the seabed core sampling device is automatically cut off, and the seafloor core sampling device is levitated by the buoyancy of the buoyant body attached to the seabed core sampling device. Will be facilitated, maneuvering burden will be reduced and recovery will be improved. However, as with the first conventional method, the seabed core sampling device is gripped by the suspension device attached to the tip of the cable of the work ship and suspended and installed on the seabed. Not only does it take time to operate, but also the suspension device that automatically attaches and detaches the submarine core sampling device is heavy and the cables and cable feeding facilities become heavy and the ship handling equipment costs increase accordingly. Not improved. In addition, since the weight is discarded on the seabed every time sampling is performed, the automatic discarding device and the operation thereof are complicated, and the cost thereof is further increased.

  In the third conventional method, without using the ship's cable equipment (both for the automatic suspension device) in the first and second conventional methods, the submarine core sampling device is placed from the ship into the sea when the submarine core sampling device is installed in the seabed. When it reaches the bottom of the sea, it is held by a manipulator equipped on the submarine and seated at a predetermined position. When the submarine core sampling device is collected, the weight is automatically separated from the submarine core sampling device, and the submarine core sampling device is lifted by the buoyancy of the buoyant body attached to the submarine core sampling device. This facilitates the installation and recovery of the submarine core sampling device and reduces the vessel handling burden on the vessel. However, since a submarine equipped with a manipulator is used when the submarine core sampling device is installed on the seabed, the maneuvering burden on the submarine is heavy. In addition, the automatic discarding apparatus and the operation for discarding the weight on the seabed every sampling are complicated, and there is a disadvantage that the cost of adding them is increased.

  In order to solve these problems, the object of the present invention is to simplify the installation and recovery of the submarine core sampling device, and to install a plurality of submarine sampling devices on the sea floor with one work ship, which reduces the maneuvering burden and cost. It is to provide a core sampling method for submarine ground that is reduced, safe and efficient.

  In order to achieve the above object, the core sampling method of the submarine ground according to the first aspect of the present invention is to suspend a submarine core sampling device on a rope fed from a work ship and install it on the sea floor to collect a sample of the submarine ground. In the core sampling method, one end of a rope having a predetermined length is connected to the upper part of the submarine core sampling device, a weight is attached to the other end of the rope, a buoyant body and an ultrasonic transceiver are attached to the middle part, A step of being attached to the tip of a rope fed out from a work ship, and suspending and installing the seabed core sampling device on the seabed by a connecting mechanism for detachably connecting the intermediate part or weight of the rope; and Releasing the connection mechanism to release the connection to the rope and separating the seabed core sampling device from the work ship rope; A step of excavating the seabed ground by the step of collecting a sample, a step of identifying the position of the ultrasonic transmitter / receiver after the completion of the sampling step, and stopping the work ship on the sea at the point; And confirming the position of the ultrasonic transmitter / receiver while holding the intermediate portion of the rope to which the ultrasonic transmitter / receiver is attached by the rope holding mechanism attached to the tip of the rope fed out from the work ship. And a step of lifting and collecting the submarine core sampling device.

  The invention according to claim 2 is the core sampling method of the seabed ground according to claim 1, wherein a plurality of the seabed core sampling devices are provided, and a series of steps from installation to collection of the seabed core sampling device. By repeating this process in sequence, a plurality of submarine core sampling devices are sequentially installed at a plurality of locations on the seabed by at least one work boat, and samples are collected from each submarine ground.

  Further, the invention according to claim 3 is the core sampling method of the seabed ground according to claim 1 or 2, wherein the sampling step includes time delay means such as a timer built in the seabed core sampling device or It is automatically performed by remote operation control means via a command signal from the work ship to the submarine core sampling device.

  According to the invention of claim 1, a cable or a rope fed from a conventional work ship is connected to the seabed core sampling device while the seabed ground is excavated by the seabed core sampling device and the sample is collected. It is not necessary to stop the work boat against the wind or current so that the work boat is located directly above the submarine core sampling device. Therefore, it is not always necessary to provide the work ship with a fixed position maintaining function such as DPS, and the burden of maneuvering can be reduced. Even if the weather conditions deteriorate, the seabed core sampling device can be left on the seabed so that only the work ship can be easily evacuated and the seabed core sampling device can be recovered after the weather conditions improve. Moreover, when the work ship is washed away as in the conventional case, the submarine core sampling device is pulled by the cable and falls or drags, so that there is no accident that the excavation and sampling work cannot be performed. Thus, according to the first aspect of the invention, the safety and reliability in submarine core sampling is improved.

  In addition, the connecting mechanism for detachably connecting the middle part of the rope or the weight is simpler and smaller and lighter than the conventional suspension system that directly grips the submarine core sampling device. Equipment is reduced in size and weight. Furthermore, it is not necessary to discard the weight as in the prior art when collecting the submarine core sampling device, and the installation and collection operation of the submarine core sampling device is simplified, so that the cost including the ship maneuvering equipment is reduced.

  According to the invention of claim 2, in addition to the same effects as those of the invention of claim 1, a plurality of submarine core sampling devices are sequentially installed at a plurality of submarine sampling points on a single work ship to collect samples. Therefore, the efficiency and profitability in submarine core sampling is improved.

  According to the invention of claim 3, in addition to having the same effects as those of the inventions of claim 1 and claim 2, the sampling process of the submarine ground is carried out from the time delay means incorporated in the seabed core sampling device or the work ship. Since it is automatically performed by remote control, the burden of maneuvering is reduced and the efficiency of core sampling of the submarine ground is further improved.

  Hereinafter, the core sampling method for submarine ground according to the present invention will be described in detail with reference to the illustrated embodiments.

1 and 2 show a submarine core sampling device installation step in the core sampling method of the submarine ground according to one embodiment, and the submarine core sampling device 10 has the following configuration.
That is, one end of a rope 12 having a predetermined length is connected to the upper portion of the seabed core sampling device body 11. The rope 12 is attached with a weight 13 at the other end and an ultrasonic transmitter / receiver 14 and a buoyancy body 15 at the middle.

  Since the well-known technique can be applied as the submarine core sampling apparatus 10, detailed description is omitted, but the core of the submarine G is bored by using one or more rotary core tubes having a bit at the tip. Even if it is a marine drill type | system | group sampling apparatus extract | collected by (1), it may be a gun type sampling apparatus which inject | emits a sampler and extract | collects a core, and is not specifically limited.

  The rope 12 has a predetermined length such that the weight 13 at the tip of the rope 12 sinks and sits on the seabed G in a state where the seabed core sampling device 10 to which the rope 12 is connected is installed on the seabed G, and transmits and receives ultrasonic waves. It is desirable to make the length as short as possible so that the vessel 14 and the buoyancy body 15 are attached and the middle portion of the rope 12 is floated in a state of being bent convexly upward (see FIG. 3).

  The buoyancy body 15 can be a known structure such as a glass sphere, a syntactic foam, an aluminum or plastic buoy, and is preferably attached individually or integrally in the vicinity of the ultrasonic transceiver 14. This is because the position of the rope 12 is specified by ultrasonic waves from the work ship 20 when the submarine core sampling device 10 to be described later is collected by floating the ultrasonic transmitter / receiver 14 above the intermediate portion of the rope 12 that is bent into a convex shape. This is to make it easier to confirm and lock and hold. Further, in such a state, the buoyancy body 15 serves as a stabilization buoy for the seabed core sampling device 10 in a series of steps in seabed core sampling described later in the sea. The buoyancy of the buoyancy body 15 is set to be smaller than the weight of the submarine core sampling device main body 11 and the weight 13 and larger than the weight of the ultrasonic transceiver 14 and the rope 12 in the sea.

  The weight 13 is a relatively small shape having a weight that balances the undersea core sampling device main body 11, the ultrasonic transmitter / receiver 14 and the buoyant body 15 through the rope holding mechanism 24 in the middle of the rope 12 in the sea. Can be. This is because the buoyancy of the buoyancy body 15 can be set so that the weight of the submarine core sampling device body 11 and the ultrasonic transmitter / receiver 14 is considerably reduced in the sea. Thereby, the lifting force of the rope 22 of the work boat 20 can be minimized.

In the present invention, the submarine core sampling apparatus 10 configured as described above is hung on a rope 22 fed from a rope feeding facility 21a provided on a hull 21 of a work ship 20 and installed on a seabed G, and a sample of the seabed ground is provided. This is a submarine core sampling method for collecting seawater, which is performed in the following steps.
As shown in FIGS. 1 and 2, a gripping mechanism 23 as a connecting mechanism for gripping the weight 13 of the rope 12 is attached to the tip of the rope 22 fed out from the work boat 20, and the weight 13 is attached to the gripping mechanism 23. The seabed core sampling device 10 is suspended by being held, and is seated and installed at the sampling point of the seabed G (seabed core sampling device installation step).

  As the gripping mechanism 23 serving as the coupling mechanism, for example, a toggle mechanism having at least two claws 23a and 23b that can be automatically opened and closed that grips the small weight 13 can be applied. For this reason, it can be set as a simple small and lightweight structure compared with the suspending apparatus which hold | grips the conventional submarine core sampling apparatus directly. In connection with this, downsizing of the weight 13 and minimizing the lifting force of the rope 22 of the work boat 20 (see paragraph 0021), the rope feeding facility 21a of the work boat 20 is reduced in size and weight, and the cost of maneuvering equipment is reduced. The

  FIG. 3 shows a step of separating the seabed core sampling device subsequent to FIG. In this step, after the submarine core sampling device body 11 is seated on the seabed, the gripping of the weight 13 of the gripping mechanism 23 is automatically released by remote control from the work boat, whereby the submarine core sampling device 10 is attached to the work boat 20. Separate from the rope 22. At this time, as shown in FIG. 3, the weight 12 of the tip of the rope 12 is seated on the seabed G, and the intermediate portion of the rope 12 to which the ultrasonic transceiver 14 and the buoyant body 15 are attached is the buoyant body 15. Due to the buoyancy, it is bent upward and is in a floating state.

At this time, as shown in FIG. 1, the submarine core sampling device 10 is suspended, and before the submarine core sampling device main body 11 is seated on the seabed (the submarine core sampling device installation step), the gripping mechanism is positioned at an appropriate depth. It is also possible to put the seabed core sampling device 10 into the sea by releasing the gripping of the weights 23, and to sink and set the seabed core sampling device 10 on the seabed. In this case, the buoyancy body 15 of the rope 12 serves as a stabilization buoy that prevents the submarine core sampling device 10 from falling due to the buoyancy.
This method is easy to apply especially when the ocean current is not violent, and since the seabed core sampling device 10 is separated before being seated on the seabed G, the installation work time of the seabed core sampling device 10 can be shortened. .

  FIG. 4 shows the submarine core sampling process following FIG. In this process, in the state where the seabed core sampling device 10 is installed on the seabed G, the seabed ground is excavated by the seabed core sampling device 10 and the sample is collected.

  The submarine core sampling process can be automatically performed by a time delay means such as a timer built in the submarine core sampling apparatus 10 or a remote operation control means via a command signal from the work ship to the submarine core sampling apparatus. Thereby, the marine vessel handling burden can be reduced and the efficiency in submarine core sampling can be further improved.

  As described above, the cable or rope 22 suspended from the work ship 20 is not connected to the seabed core sampling apparatus 10 while the seabed ground is excavated by the seabed core sampling apparatus 10 and the sample is collected. It is not necessary to stop the work boat 20 against the wind or tide so that the work boat 20 is positioned directly above the submarine core sampling apparatus 10. Therefore, it is not always necessary to equip the work boat 20 with a fixed position maintenance function such as DPS, and the burden of maneuvering can be reduced. Even when the weather conditions deteriorate, the seabed core sampling device 10 can be left on the seabed G, so that only the work ship 20 can be easily evacuated, and the seabed core sampling device 10 can be recovered after the weather conditions improve. Moreover, when the work ship 20 is washed away, there is no accident that the submarine core sampling device 10 is pulled by the cable and falls or dragged, and excavation and sampling operations cannot be performed. Thus, safety and reliability in submarine core sampling are improved.

  In addition, the gripping mechanism 23 that grips the weight 13 of the rope 12 and the rope holding mechanism 24 that suspends the intermediate portion of the rope 12 have a simpler structure and are smaller and lighter than a conventional suspension device that directly grips the submarine core sampling device. As a result, the rope feeding equipment 21a of the work boat 20 is reduced in size and weight, and accordingly, the cost of maneuvering equipment is reduced.

  FIG. 5 shows a submarine core sampling point position specifying step subsequent to FIG. In this process, after the submarine core sampling process is completed, the work ship 20 is run again in the vicinity of the submarine core sampling point, and the ultrasonic transceiver 14 of the rope 12 is used by an ultrasonic detection system or a dynamic positioning system (DPS) not shown. And locate the ship at sea at that point.

FIG. 6 shows the submarine core sampling device recovery process following FIG. In this process, following the submarine core sampling device position confirmation process, the ultrasonic wave is transmitted from the work ship 20 while transmitting the ultrasonic wave 25 from the ultrasonic detection system of the work ship 20 and confirming the position of the ultrasonic transmitter / receiver 14 of the rope 12. The intermediate portion of the rope 12 to which the ultrasonic transmitter / receiver 14 whose position has been confirmed is attached from below by a rope holding mechanism 24 such as a hook means having a hook portion 24a newly attached to the tip of the rope 22 The seabed core sampling device 10 is lifted and collected by being hooked and held on the hook portion 24a.
At this time, as described in the paragraph 0020 and the like, the intermediate portion to which the ultrasonic transmitter / receiver 14 of the rope 12 that is bent and floated upward by the buoyancy of the buoyancy body 15 is attached is pulled to the hook portion 24a. It is easy to hang.

  For the rope holding mechanism 24, for example, a known technique such as hook means having a plurality of hook portions 24 a can be applied. For this reason, it can be set as a simple small and lightweight structure compared with the heavy and long suspension device which directly grasps the conventional submarine core sampling device. In connection with this, downsizing of the weight 13 and minimization of the lifting force of the rope 22 of the work boat 20, the rope feeding facility 21 a of the work boat 20 is reduced in size and weight, and the cost of maneuvering equipment is reduced.

  In the submarine core sampling device installation step, the rope holding mechanism 24 used in the submarine core sampling device recovery step is used in place of the gripping mechanism 23, and as shown in FIG. The submarine core sampling device 10 can be suspended by being hung on the ground, and can be seated and installed at a sampling point on the seabed G. After the seabed core sampling device 10 is seated on the seabed G, the rope 22 of the work boat 20 is further fed out and the rope holding mechanism 24 is further lowered to easily remove the hook portion 24a from the lower side of the intermediate portion of the rope 12. Conversely, when the seabed core sampling device 10 is lifted and collected, the seabed core sampling device 10 can be easily lifted by suspending the middle portion of the rope 12 from below and hooking the hook portion 24a.

According to such a method, there is a merit that the rope holding mechanism and its operation in the submarine core sampling device installation and recovery process are simplified.
Moreover, monitoring means such as a video camera (not shown) may be attached to the rope holding mechanism 24 to arbitrarily monitor the recovery or installation state of the seabed core sampling device 10.

  Furthermore, in the submarine core sampling method, there are a plurality of submarine core sampling devices 10, and by repeating a series of steps from the submarine core sampling device installation step to the submarine core sampling device recovery step, at least one work is performed. A plurality of submarine core sampling devices 10 can be sequentially installed at a plurality of submarine G sampling points on the ship 20 and samples can be collected from those grounds.

  As described above, since a plurality of submarine core sampling devices 10 can be sequentially installed at a plurality of sampling points of the seabed G by one work ship 20, the efficiency and profitability in submarine core sampling can be improved. improves.

  In the above invention, a plurality of submarine core sampling devices can be sequentially installed at a plurality of submarine sampling points on a single work ship, and sampling of a plurality of submarine grounds is particularly necessary. In this case, both efficiency and profitability can be satisfactorily applied.

It is explanatory drawing which shows the start state of the seabed core sampling apparatus installation process in the core sampling method of the seabed ground of one Example which concerns on this invention. It is a submarine core sampling apparatus installation process figure following FIG. It is a seabed core sampling device separation process figure following FIG. It is a submarine core sampling process figure following FIG. It is a submarine core sampling point position specific process figure following FIG. FIG. 6 is a seabed core sampling device recovery process diagram following FIG. 5.

Explanation of symbols

10 Submarine Core Sampling Device 11 Submarine Core Sampling Device Body 12 Rope 13 Weight 14 Ultrasonic Transceiver 15 Buoyant Body (Stable Buoy)
DESCRIPTION OF SYMBOLS 20 Work ship 21 Hull 21a Rope delivery equipment 22 Lifting rope 23 Grip mechanism 23a, 23b Claw 24 Rope holding mechanism 24a Hook part 25 Ultrasonic wave G Submarine

Claims (3)

A core sampling method in which a seabed core sampling device is hung on a rope drawn from a work ship and installed on the seabed, and a sample of the seabed ground is collected.
In the submarine core sampling device, one end of a rope of a predetermined length is connected to the upper part, a weight is attached to the other end of the rope, a buoyant body and an ultrasonic transceiver are attached to the middle part,
A step of attaching a submarine core sampling device to a bottom of the seabed by a connecting mechanism that is attached to the tip of a rope fed from the work ship and detachably connects an intermediate portion or weight of the rope; and ,
Disconnecting the seabed core sampling device from the rope of the work ship by releasing the connection by releasing the connection mechanism;
A process of excavating the seabed with a seabed core sampling device and collecting a sample;
After completion of the sampling process, identifying the position of the ultrasonic transceiver, and stopping the work ship on the sea at that point;
The middle part of the rope to which the ultrasonic transmitter / receiver is attached by the rope holding mechanism attached to the tip of the rope fed from the work ship while transmitting the ultrasonic wave from the work ship to confirm the position of the ultrasonic transmitter / receiver And a step of lifting and collecting the submarine core sampling apparatus while holding the core. A plurality of the submarine core sampling devices,
By sequentially repeating a series of steps from installation to collection of the submarine core sampling device, a plurality of submarine core sampling devices are sequentially installed at a plurality of locations on the seabed using at least one ship, and samples are collected from each submarine ground. The core sampling method for submarine ground according to claim 1, wherein the sampling is performed.   The sampling step is automatically performed by time delay means such as a timer built in the seafloor core sampling device or remote operation control means via a command signal from the work ship to the seafloor core sampling device. The core sampling method for submarine ground according to claim 1 or claim 2.

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