JP2024041545A - Suction bucket foundation construction method and construction management system - Google Patents

Abstract

An object of the present invention is to provide a suction bucket foundation construction method and a construction management system that do not obstruct the penetration of the suction bucket and can easily manage suction bucket foundation construction.
[Solution] The bottoming state of the suction bucket 1 (first detection point, second detection point, third detection point, fourth detection point The suction bucket 1 is adjusted horizontally based on the detected bottoming state of the suction bucket 1. Optical fiber sensors S1, S2, S3, and S4 do not require waterproofing, so management of suction bucket foundation construction is easy. Furthermore, since the optical fiber sensors S1, S2, S3, and S4 have an outer diameter of approximately several mm, they do not obstruct the penetration of the suction bucket 1.
[Selection diagram] Figure 2

Description

The present invention relates to a suction bucket foundation construction method and a construction management system that are applied to foundation construction for fixed-type offshore wind power generation facilities, etc.

The suction bucket foundation construction method, which is applied to foundation construction for ground-mounted offshore wind power generation facilities, drains the inside of a cylindrical suction bucket that is anchored to the bottom of the water, and lowers the pressure inside the suction bucket to below hydrostatic pressure. This is a method in which the suction bucket penetrates into the seabed by lowering the suction bucket (for example, see Patent Document 1).

JP2021-147937A

In this type of suction bucket foundation method, the suction bucket needs to be placed horizontally on the bottom to maintain the verticality of the body and prevent the occurrence of piping phenomena during construction. With conventional suction bucket foundation methods, the bottom placement of the suction bucket was confirmed by video footage from a camera attached to an underwater drone or by visual inspection by a diver, but confirmation becomes difficult when visibility is reduced due to turbidity, etc.

On the other hand, there is a method in which multiple (for example, 3) pressure sensors are installed at the lower end of the suction bucket at intervals in the circumferential direction, and the suction bucket is adjusted horizontally based on the electrical signals from these pressure sensors. There is a possibility that the pressure sensor protruding from the side wall of the bucket becomes a resistance and obstructs the penetration of the suction bucket. Furthermore, since pressure sensors use electrical signals, they require waterproofing, making them complicated to handle.

SUMMARY OF THE INVENTION An object of the present invention is to provide a suction bucket foundation construction method and a construction management system that do not impede the penetration of the suction bucket and can easily manage suction bucket foundation construction.

The suction bucket foundation construction method of the present invention is a suction bucket foundation construction method in which a covered cylindrical suction bucket is placed on the underwater ground and sunk, and includes an installation step of attaching one side of an optical fiber sensor to the suction bucket, and a crane. a settling step of sinking the suction bucket suspended toward the underwater ground; a calculation step of calculating a landing state of the suction bucket based on the detection signal of the optical fiber sensor; and a calculation step of calculating the landing state of the suction bucket based on the detection signal of the optical fiber sensor. The present invention is characterized in that it includes a display step of displaying a floor condition on a display, and an operation step of operating the suction bucket while checking in real time the landing condition of the suction bucket displayed on the display.
The construction management system of the present invention is a construction management system applied to a suction bucket foundation construction method in which a covered cylindrical suction bucket is placed on the underwater ground and sunk, and one side of the construction management system includes an optical fiber sensor attached to the suction bucket. The present invention is characterized by comprising: a control device that calculates a landing state of the suction bucket based on a detection signal of the optical fiber sensor; and a display that displays the calculated landing state of the suction bucket.

According to the present invention, it is possible to provide a suction bucket foundation construction method and a construction management system that do not impede the penetration of the suction bucket and can easily manage the construction of the suction bucket foundation.

It is an explanatory diagram of the suction bucket foundation. It is an explanatory view of this embodiment, and is a figure showing arrangement of a 1st optical fiber sensor. It is an explanatory view of this embodiment, and is a figure showing arrangement of a 2nd optical fiber sensor. It is an explanatory view of this embodiment, and is a figure showing arrangement of a 3rd optical fiber sensor. FIG. 1 is an explanatory diagram of an embodiment of the present invention, showing a concept of a construction management system. It is an explanatory view of this embodiment, and is a flowchart of the suction bucket foundation construction method. FIG. 2 is an explanatory diagram of the present embodiment, showing a state in which the suction bucket has landed on the bottom of the water. FIG. 3 is an explanatory diagram of the present embodiment, showing a state in which the inside of the suction bucket is drained.

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to the accompanying drawings.
In this embodiment, a suction bucket foundation construction method applied to foundation construction of a bottom-mounted offshore power generation facility will be described as an example. For convenience, the vertical direction in FIG. 1 is simply referred to as the vertical direction. As shown in FIG. 1, the suction bucket 1 is formed into a cylindrical shape with a lid. The suction bucket 1 has a cylindrical side wall 3 and a top wall 6 that closes the upper end opening of the side wall 3. Note that a tower 8 is erected at the center of the upper surface of the ceiling wall 6.

A construction management system 10 (see FIG. 5) that manages suction bucket foundation construction is applied to the suction bucket foundation construction method according to the present embodiment. As shown in FIG. 2 or 5, the construction management system 10 includes a plurality of (four in this embodiment) optical fiber sensors S1, S2, S3, and S4 (first optical fiber sensors). One side of the optical fiber sensors S1, S2, S3, and S4 is attached to the outer peripheral surface 3 of the side wall 2 of the suction bucket 1. Further, one side of the optical fiber sensors S1, S2, S3, and S4 is attached along the generatrix of the side wall 2 of the suction bucket 1 (the generatrix of the cylinder including the outer peripheral surface 3). Furthermore, one side of the optical fiber sensors S1, S2, and S3 are arranged at equal intervals in the circumferential direction of the outer peripheral surface 3 of the side wall 2 of the suction bucket 1. Although the optical fiber sensors S1, S2, S3, and S4 are not shown at regular intervals in FIG. 2 for convenience, they are actually spaced at 90° intervals around the center line of the suction bucket 1.

One end of the optical fiber sensors S1, S2, S3, and S4 protrudes downward beyond the lower end surface 5 (lower end position) of the suction bucket 1. At the ends of the optical fiber sensors S1, S2, S3, S4, sensor parts s1, s2, s3, s4 (detection points) consisting of diffraction gratings (FBG: Fiber Bragg Gratings) are provided. Hereinafter, as needed, the sensor part s1 of the optical fiber sensor S1 is the first detection point of the suction bucket 1, the sensor part s2 of the optical fiber sensor S2 is the second detection point of the suction bucket 1, and the sensor part of the optical fiber sensor S3 is s3 will be referred to as the third detection point of the suction bucket 1, and the sensor section s4 of the optical fiber sensor S4 will be referred to as the fourth detection point of the suction bucket 1. Note that the other ends of the optical fiber sensors S1, S2, S3, and S4 are connected to the optical fiber measuring instrument 11 via optical connectors (not shown).

As shown in FIG. 3 or 5, the construction management system 10 includes a plurality of (n) optical fiber sensors P1, P2, P3...Pn (second optical fiber sensors). One side of the optical fiber sensors P1, P2, P3, . . . Pn is attached to the outer peripheral surface 3 of the side wall 2 of the suction bucket 1. Further, one side of the optical fiber sensors P1, P2, P3, . Furthermore, one side of the optical fiber sensors P1, P2, P3, . . . Pn are arranged at regular intervals in the circumferential direction of the side wall 2 of the suction bucket 1. The other ends of the optical fiber sensors P1, P2, P3, . . . Pn are connected to the optical fiber measuring device 12 via optical connectors (not shown).

The distance from the lower end surface 5 (lower end position) of the suction bucket 1 on one side of the optical fiber sensors P1, P2, P3...Pn is the shortest for the optical fiber sensor P1; The length increases by a certain distance in the order of P3...Pn. Note that one side of the optical fiber sensor P1 is arranged above the lower end surface 5 (lower end position) of the suction bucket 1. At the ends of the optical fiber sensors P1, P2, P3, . . . Pn, sensor parts p1, p2, p3, . In other words, the distance of the sensor parts p1, p2, p3...pn of the optical fiber sensors P1, P2, P3...Pn from the lower end surface 5 (lower end position) of the suction bucket 1 is p1 is the shortest, and the sensor parts p1, p2, p3, . . . pn become longer by a certain distance in this order.

As shown in FIG. 4 or 5, the construction management system 10 includes a plurality of (n) optical fiber sensors Q1, Q2, Q3...Qn (third optical fiber sensors). One side of the optical fiber sensors Q1, Q2, Q3...Qn is attached to the inner peripheral surface 4 of the side wall 2 of the suction bucket 1. Further, one side of the optical fiber sensors Q1, Q2, Q3, . Further, one side of the optical fiber sensors Q1, Q2, Q3, . . . Qn are arranged at regular intervals in the circumferential direction of the side wall 2 of the suction bucket 1. Note that the optical fiber sensors Q1, Q2, Q3...Qn extend to the outside of the suction bucket 1 by penetrating the top wall 6 of the suction bucket 1, and the other end thereof is connected via an optical connector (not shown). It is connected to the optical fiber measuring device 13.

The distance from the lower end surface 5 (lower end position) of the suction bucket 1 on one side of the optical fiber sensors Q1, Q2, Q3...Qn is the shortest for the optical fiber sensor Q1; The length increases by a certain distance in the order of Q3...Qn. Note that one side of the optical fiber sensor Q1 is arranged above the lower end surface 5 (lower end position) of the suction bucket 1. Sensor sections q1, q2, q3...qn (detection points) each consisting of a diffraction grating (FBG) are provided at the ends of the optical fiber sensors Q1, Q2, Q3...Qn. In other words, the distance of the sensor parts q1, q2, q3...qn of the optical fiber sensors Q1, Q2, Q3...Qn from the lower end surface 5 (lower end position) of the suction bucket 1 is The sensor section q1 is the shortest, and the sensor sections q1, q2, q3, . . . , qn become longer by a certain distance in this order.

As shown in FIG. 5, the optical fiber measuring device 11 detects the optical fibers based on the changes in the wavelength of the light of the sensor parts s1, s2, s3, s4 (detection points) of the optical fiber sensors S1, S2, S3, S4. Distortion occurring in sensor parts s1, s2, s3, s4 of sensors S1, S2, S3, S4 is measured, and a distortion detection signal as a measurement result is transmitted to control device 15 via an interface (not shown). The control device 15 calculates the bottoming state (landing state) of the suction bucket 1 that has landed on the bottom surface 21 based on the strain detection signal transmitted from the optical fiber measuring device 11, and displays the calculation result in numerical values on the display 16. Or display it as an image.

Further, the optical fiber measuring instrument 12 detects the optical fiber sensor P1 based on the change in the wavelength of the light of the sensor portions p1, p2, p3...pn (detection points) of the optical fiber sensors P1, P2, P3...Pn. , P2, P3...Pn, the distortion occurring in the sensor parts p1, p2, p3...pn is measured, and a distortion detection signal as a measurement result is transmitted to the control device 15 via an interface (not shown). . The control device 15 calculates the penetration depth D1 of the suction bucket 1 into the underwater ground 20 based on the underwater bottom surface 21 based on the strain detection signal (detection point position) transmitted from the optical fiber measuring device 12, The calculation results are displayed on the display 16 as numerical values or images.

Further, the optical fiber measuring instrument 13 detects the optical fiber sensor Q1 based on the change in the wavelength of the light of the sensor parts q1, q2, q3...qn (detection points) of the optical fiber sensor Q1, Q2, Q3...Qn. , Q2, Q3...Qn's sensor units q1, q2, q3...qn, and transmits a distortion detection signal as a measurement result to the control device 15 via an interface (not shown). . The control device 15 calculates the height H1 of the internal ground 22 of the suction bucket 1 with the lower end surface 5 of the suction bucket 1 as the base point based on the strain detection signal (detection point position) transmitted from the optical fiber measuring device 13. do. Furthermore, the control device 15 calculates the amount of rise H2 (H1-D1) of the internal ground 22 of the suction bucket 1 based on the water bottom surface 21 from the penetration depth D1 of the suction bucket 1 and the height H1 of the internal ground 22. The calculation results are displayed on the display 16 as numerical values or images.

Next, the steps of the suction bucket foundation construction method using the construction management system 10 described above will be explained based on the flowchart shown in FIG.
(Installation step)
First, optical fiber sensors S1, S2, S3, and S4 (first optical fiber sensors) are attached to the suction bucket 1.
(sedimentation step)
Next, the suction bucket 1 is lifted by a crane (not shown) installed on the hoist and landed on the water, and the suction bucket 1 is lowered toward a predetermined landing position ("Step 1" in FIG. 6). Note that the landing position of the water bottom surface 21 is leveled horizontally in advance.
During the settling of the suction bucket 1, at least one of the sensor parts s1, s2, s3, s4 of the optical fiber sensors S1, S2, S3, S4 detects a strain, that is, the first detection point, the second detection point of the suction bucket 1, When at least one of the detection point, the third detection point, and the fourth detection point reaches the bottom of the water bottom 20, the suction bucket 1 is stopped from sinking (movement) ("Step 2" in FIG. 6).
(calculation step, display step)
After stopping the suction bucket 1 from settling, the bottoming (landing state) of the first detection point, second detection point, and third detection point of the suction bucket 1 is calculated, and the calculation results are displayed on the display 16.
(operation step)
While checking the bottomed state of the suction bucket 1 on the display 16, the lower end surface 5 of the suction bucket 1 is adjusted horizontally as shown in FIG. 7 ("Step 3" in FIG. 6).
Next, while keeping the lower end surface 5 of the suction bucket 1 horizontal, a part of the suction bucket 1 (the lower end of the side wall 2) is penetrated into the underwater ground 20 by the weight of the suction bucket 1 (step 4 in FIG. ”).
Next, as shown in FIG. 8, a pump (not shown) is operated to drain the inside of the suction bucket 1, and the internal pressure of the suction bucket 1 is made lower than the hydrostatic pressure, so that the suction bucket 1 is moved to the bottom of the water. It is made to penetrate into the ground 20 ("Step 5" in FIG. 6).
During the penetration of the suction bucket 1, the operator can check the penetration depth D1 of the suction bucket 1 and the heave amount H2 (landing state) of the internal ground 22 of the suction bucket 1 on the display 16 in real time.

By the way, in the suction bucket foundation construction method, it is necessary to place the suction bucket horizontally on the bottom in order to maintain the verticality of the main body and to prevent piping from occurring during construction. In the conventional suction bucket foundation construction method, the state of the suction bucket landing on the bottom (landing state) was confirmed by images from a camera attached to an underwater drone or visually by a diver, but confirmation was difficult when visibility decreased due to turbidity, etc. It becomes difficult.
In contrast, in this embodiment, the bottoming state of the suction bucket 1 (first detection point, second detection point, third detection point Since the suction bucket 1 is adjusted horizontally based on the detected bottoming state of the suction bucket 1, the suction bucket foundation is not affected by water turbidity, etc. can be constructed efficiently.

In addition, in the conventional suction bucket foundation construction method, the bottoming state of the suction bucket was detected based on the electrical signal of the pressure sensor attached to the suction bucket, but there was a risk that the pressure sensor would create resistance and prevent the suction bucket from penetrating. there were. Furthermore, since pressure sensors use electrical signals, they require waterproofing and are complicated to handle.
On the other hand, in the present embodiment, the optical fiber sensors S1, S2, S3, and S4 have a diameter of about several mm, so they cannot provide resistance that would obstruct the penetration of the suction bucket 1. Further, the detection signals of the sensor sections s1, s2, s3, s4 of the optical fiber sensors S1, S2, S3, S4 are optical signals, not electrical signals, and therefore easy to handle.
Furthermore, since the tips of the optical fiber sensors S1, S2, S3, and S4 protrude beyond the suction bucket 1, it is possible to easily grasp the situation in which the bucket body hits the bottom even before the bucket body hits the bottom. Can be done.

In addition, in the conventional suction bucket foundation construction method, for example, a displacement meter (contact type sensor) was used to measure the amount of swell of the ground inside the suction bucket. There is a risk that it may get caught and cause malfunction. Furthermore, like the pressure sensor, the displacement meter requires waterproofing because it uses an electric signal, making it complicated to handle.
In contrast, in this embodiment, the suction bucket 1 penetrates into the underwater ground 20 based on the detection signals of the optical fiber sensors P1, P2, P3, ... Pn attached to the outer peripheral surface 3 of the side wall 2 of the suction bucket 1. The depth D1 is calculated, and the lower end surface 5 of the suction bucket 1 is set as a base point based on the detection signals of the optical fiber sensors Q1, Q2, Q3...Qn attached to the inner peripheral surface 4 of the side wall 2 of the suction bucket 1. The height H1 of the internal ground 22 of the suction bucket 1 is calculated from the penetration height D1 of the suction bucket 1 and the height H1 of the internal ground 22, and the amount H2 of the internal ground 22 of the suction bucket 1 is calculated. Since the calculation result is displayed on the display 16, the amount of heave H2 of the internal ground 22 of the suction bucket 1 can be measured with high accuracy and reliability.

1 Suction bucket, 16 Display, S1, S2, S3, S4 Optical fiber sensor

Claims (8)

A suction bucket foundation construction method in which a covered cylindrical suction bucket is placed on the underwater ground and sunk,
an attachment step of attaching one side of the optical fiber sensor to the suction bucket;
a settling step of settling the suction bucket suspended by a crane toward the underwater ground;
a calculation step of calculating the landing state of the suction bucket based on the detection signal of the optical fiber sensor;
a display step of displaying the calculated implantation state of the suction bucket on a display;
an operation step of operating the suction bucket while checking the landing state of the suction bucket displayed on the display in real time;
A suction bucket foundation construction method characterized by including. The suction bucket foundation construction method according to claim 1,
In the attaching step, a plurality of first optical fiber sensors are attached to the suction bucket, and sensor portions of the plurality of first optical fiber sensors are positioned at a lower end position of the suction bucket and in a circumferential direction of the suction bucket. placed at equal intervals,
In the calculation step, the bottoming state of the suction bucket is calculated based on the detection signals of the plurality of first optical fiber sensors,
The suction bucket foundation construction method is characterized in that, in the operation step, the suction bucket is adjusted horizontally while checking the bottoming state of the suction bucket displayed on the display in real time. The suction bucket foundation construction method according to claim 1 or 2,
In the mounting step, a plurality of second optical fiber sensors are mounted on an outer peripheral surface of the suction bucket, and sensor portions of the plurality of second optical fiber sensors are disposed at different distances from a lower end position of the suction bucket as a base point;
A suction bucket foundation construction method, characterized in that in the calculation step, a penetration depth of the suction bucket is calculated based on detection signals of the plurality of second optical fiber sensors. The suction bucket foundation construction method according to claim 3,
In the attaching step, a plurality of third optical fiber sensors are attached to the inner peripheral surface of the suction bucket, and the sensor portions of the plurality of third optical fiber sensors have a distance from the lower end position of the suction bucket as a base point. established to be different,
In the calculation step, the height of the internal ground of the suction bucket based on the lower end position of the suction bucket is calculated based on the detection signals of the plurality of third optical fiber sensors, and the depth of penetration of the suction bucket is calculated. A suction bucket foundation construction method, characterized in that the amount of swell of the ground inside the suction bucket is calculated from the height of the ground inside the suction bucket. A construction management system applied to a suction bucket foundation construction method in which a covered cylindrical suction bucket is placed on the underwater ground and sunk,
a fiber optic sensor with one side attached to the suction bucket;
a control device that calculates a landing state of the suction bucket based on a detection signal of the optical fiber sensor;
a display that displays the calculated landing state of the suction bucket;
A construction management system characterized by comprising: The construction management system according to claim 5,
The optical fiber sensor includes a plurality of first optical fiber sensors,
The sensor portions of the plurality of first optical fiber sensors are provided at the lower end position of the suction bucket and at equal intervals in the circumferential direction of the suction bucket,
The construction management system is characterized in that the control device calculates a bottoming state of the suction bucket based on detection signals from the plurality of first optical fiber sensors. The construction management system according to claim 5 or 6,
The optical fiber sensor includes a plurality of second optical fiber sensors provided on the outer peripheral surface of the suction bucket,
The sensor portions of the plurality of second optical fiber sensors are provided at different distances from the lower end position of the suction bucket,
The construction management system is characterized in that the control device calculates the penetration depth of the suction bucket based on the detection signals of the plurality of second optical fiber sensors. The construction management system according to claim 7,
The optical fiber sensor includes a plurality of third optical fiber sensors provided on the inner peripheral surface of the suction bucket,
The sensor portions of the plurality of third optical fiber sensors are provided at different distances from the lower end position of the suction bucket,
The control device calculates the height of the internal ground of the suction bucket based on the lower end position of the suction bucket based on the detection signals of the plurality of third optical fiber sensors, and also calculates the penetration depth of the suction bucket. A construction management system characterized in that the amount of swell of the ground inside the suction bucket is calculated from the height of the ground inside the suction bucket.

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