JP2021088855A - Caisson water injection control method and water injection control system - Google Patents

Abstract

To provide a caisson water injection control method and a water injection control system that can stably submerge a caisson to the water depth immediately before landing with simple water injection control.SOLUTION: Total water injection control, in which the average water level of each block 14 is calculated by averaging the water levels of the compartments 15 in the block 14 when a caisson 10 is in the desired posture, the relative water level difference between the average water levels of each block 14 is stored as a reference water level difference, and water is injected into each block 14 by a water injection pump 2 individually provided in each block 14, and correction control in which the relative water level difference between the average water levels in the blocks 14 is brought closer to the reference water level difference when the relative water level difference between the average water levels in any of the blocks 14 deviates from the reference water level difference by more than a preset allowable value are repeatedly executed until the caisson 10 moves downward to the water depth immediately before landing at a target position B.SELECTED DRAWING: Figure 1

Description

The present invention relates to a caisson water injection control method and a water injection control system, and more particularly to a caisson water injection control method and a water injection control system capable of stably submerging the caisson to a water depth immediately before landing. It is a thing.

The inner space of the caisson that forms a breakwater or the like is divided into a plurality of blocks that do not communicate with each other by a watertight partition wall. To land the caisson at the target position in the water, the caisson is submerged by injecting water into each block of the caisson floating on the water with a separate water injection pump. Immediately before landing, it is necessary to keep the caisson's posture substantially horizontal, so it is required that the caisson be sunk stably. However, it is difficult to keep the amount of water injected into each block uniform because of the influence of individual differences in the water injection pump and the length of the pipe. Therefore, simply operating each water injection pump to inject water will increase the water level difference between the blocks and increase the inclination of the caisson. Therefore, a caisson water injection control device that suppresses the inclination of the caisson has been proposed (see Patent Document 1).

In the caisson water injection control device described in Patent Document 1, the inclination angle of the caisson is measured by an inclinometer, and when the inclination angle exceeds the reference value, the caisson sinks downward based on the measurement result of the inclinometer. Stop pumping water to the side block to correct the caisson tilt. However, the caisson oscillates under the influence of waves, and the direction and angle of inclination of the caisson measured by the inclinometer change from moment to moment and are not stable. In addition, it takes some time for the amount of water injected by the water injection pump to be reflected in the inclination of the caisson. Therefore, in water injection control focusing on the measurement result of the inclinometer, it is necessary to control the timing of switching between the stopped state and the operating state of the water injection pump with high accuracy. There is room for improvement.

JP-A-2015-34373

An object of the present invention is to provide a caisson water injection control method and a water injection control system capable of stably submerging the caisson to a water depth immediately before landing with simple water injection control.

In order to achieve the above object, the caisson water injection control method of the present invention is to inject water into the caisson while floating the caisson having an inner space formed by a plurality of isolated chambers to a target position in water. In the caisson water injection control method for landing the caisson at the target position by further injecting water into the inner space after moving downward to the water depth immediately before landing on the bottom of the caisson, the inner space is further injected. Was divided into a plurality of blocks that were not communicated with each other in units of a single or a plurality of adjacent compartments, and the caisson was floated on water with the adjacent compartments communicating with each other in each block. In the initial stage, when water is injected into each of the blocks and the caisson is placed in a desired posture, the average water level obtained by averaging the water levels of the respective compartments constituting each of the blocks is calculated. The relative water level difference between the average water levels of each of the blocks is stored as a reference water level difference, and then water injection provided individually for each of the blocks is provided for the caisson in the state of the reference water level difference. The total water injection control in which water is injected into each of the blocks by a pump and the relative water level difference between the average water levels of any of the blocks deviate from the reference water level difference by exceeding a preset allowable value. In the case, the water injection by the water injection pump to the block whose average water level is relatively higher than the reference water level difference is stopped, and the relative water level difference between the average water levels of each of the blocks is changed to the reference water level difference. It is characterized in that the correction control to bring the caisson closer to the permissible value or less is repeatedly performed until the caisson is moved downward to the water depth immediately before landing at the target position.

The caisson water injection control system of the present invention includes a water injection pump that injects water into the inner air portion while a caisson having an inner air portion formed by a plurality of isolated chambers is floated on water, and a control device that controls the water injection pump. With the above, water is injected into the inner space by the water injection pump, and the caisson is moved downward to the water depth immediately before landing at the target position in the water to perform alignment, and then further water is injected into the inner space. In the water injection control system of the caisson that causes the caisson to land at the target position, the inner space is divided into a plurality of blocks that are not in communication with each other in units of a single or a plurality of adjacent compartments, and each of the above. In the block, the adjacent compartments are kept in communication with each other, and the water injection pump is individually provided for each of the blocks. In the initial stage when the caisson is floated on water, each of the blocks is provided with the water injection pump. On the other hand, when water is injected by the water injection pump and the caisson is placed in a desired posture, the average water level obtained by averaging the water levels of the respective compartments constituting each of the blocks is calculated by the control device, and each of them is calculated. The relative water level difference between the average water levels of the blocks is stored in the control device as a reference water level difference, and for the caisson in the state of the reference water level difference, the water injection pump is used for each of the blocks. When the relative water level difference between the average water level of any of the blocks and the total water injection control for injecting water deviates from the reference water level difference by exceeding a preset allowable value, the reference water level difference is relative to the reference water level difference. Then, the water injection by the water injection pump to the block having a relatively high average water level is stopped, and the relative water level difference between the average water levels of each of the blocks is brought close to the reference water level difference to be equal to or less than the permissible value. The correction control is characterized in that the caisson is repeatedly performed until the caisson is moved downward to the water depth immediately before landing at the target position.

According to the present invention, in the initial stage where the caisson is floated on water, water is injected into each block to put the caisson in a desired posture, and the relative water level difference between the average water levels of each block is used as a reference. Remember as a water level difference. Next, total water injection control that injects water into each block, and correction control that brings the relative water level difference between the average water levels of the blocks where the standard water level difference is varied due to the total water injection control closer to the reference water level difference. , Is repeated until the caisson moves downward to the water depth just before landing at the target position. In this way, by repeatedly executing the total water injection control and the correction control focusing on the average water level of the block, the caisson can be suppressed from becoming excessively inclined with respect to the desired posture by the simple water injection control. Can be stably submerged to the water depth just before landing at the target position.

It is explanatory drawing which illustrates the caisson to which the water injection control system of embodiment which concerns on this invention is applied in a vertical sectional view. It is explanatory drawing which illustrates the caisson of FIG. 1 in a plan view. It is a flow figure which illustrates the control flow of the water injection control method of this invention. It is explanatory drawing which illustrates the state in which the caisson was put into a desired posture by injecting water into each block of the caisson of FIG. 1 in a plan view. It is an explanatory diagram exemplifying in a plan view a state in which water is further injected into each block by total water injection control, and the relative water level difference between the average water levels of the blocks deviates from the reference water level difference by exceeding a preset allowable value. .. It is explanatory drawing which illustrates the state which brought the relative water level difference between the average water level of a block close to the reference water level difference by the correction control from the state of FIG.

Hereinafter, the caisson water injection control method and the water injection control system of the present invention will be described based on the embodiment shown in the figure. In the drawings, the width direction, the longitudinal direction, and the vertical direction of the caisson 10 in a plan view are indicated by arrows X, Y, and Z, respectively.

As illustrated in FIGS. 1 and 2, the water injection control system 1 of the present invention is used in a construction in which a caisson 10 floating on water W is installed at a target position B in water such as on the bottom of water or an underwater structure.
The caisson 10 includes a lid member 20 that covers the upper part of the caisson 10, a positioning device 21 that acquires position information of the caisson 10 from a global positioning system (GNSS), a light wave distance measuring instrument (total station), and the like, and a horizontal direction of the caisson 10. A winch 22, a power supply device 23 for supplying power to the water injection pump 2, the winch 22, and the like are installed. In the drawings other than FIG. 1, the lid member 20, the positioning device 21, the winch 22, and the power supply device 23 are omitted.

The caisson 10 is a concrete or steel structure having an inner space 11 formed by a plurality of compartments 15. As shown by the broken line square frame in FIG. 2, the inner space 11 is divided into a plurality of blocks 14 which are not connected to each other by an outer wall 10a and a watertight partition wall 12 in units of a single or a plurality of adjacent compartments 15. In this embodiment, the watertight partition wall 12 extending in the X direction and the watertight partition wall 12 extending in the Y direction provide a total of six blocks 14A in which the inner space 11 has two rows in the X direction and three rows in the Y direction. It is divided into ~ 14F.

In each block 14, adjacent compartments 15 are in communication with each other. In this embodiment, each block 14 is divided into four compartments 15 by a non-watertight partition wall 13 extending in the X direction and a non-watertight partition wall 13 extending in the Y direction. A communication hole 13a is provided in the lower part of the non-watertight partition wall 13.

In this embodiment, the rectangular parallelepiped caisson 10 is illustrated, but the caisson 10 may have other shapes such as a polygonal columnar shape and a columnar shape. Further, in the plan view, each block 14 is not limited to a square shape, and may have another shape such as a rectangular shape or a hook shape. The number and arrangement of the blocks 14 of the caisson 10 and the like, and the number and arrangement of the separated chambers 15 of each block 14 are not particularly limited.

The water injection control system 1 of the embodiment according to the present invention includes a water injection pump 2 that injects water into the inner space 11 of the caisson 10 and a control device 5 that controls the water injection pump 2. The water injection pump 2 is individually provided for each block 14. Each of the compartments 15 is provided with a water level gauge 3 for measuring the water level of the compartments 15. Further, the caisson 10 is provided with an inclinometer 4 for measuring the inclination angle of the caisson 10. Each water injection pump 2, each water level gauge 3, and an inclinometer 4 are communicably connected to the control device 5. In this embodiment, a management device 6 is further provided, which is communicably connected to the control device 5.

The water injection pump 2 injects water W in the water area where the caisson 10 is floating into the block 14. In this embodiment, one water injection pump 2 is provided for each block 14. In this embodiment, the water injection pump 2 is installed in one compartment 15 of each block 14, but if the configuration is such that water W can be injected into each block 14, the number and arrangement of the water injection pumps 2 can be changed. The configuration may be different from that of this embodiment.

When water is injected into one partition chamber 15 in the block 14 by the water injection pump 2, the water W flows into the other compartment 15 in the same block 14 through the communication hole 13a provided in the non-watertight partition wall 13. Therefore, by injecting water into one compartment 15 in the block 14, water W can be stored in all the compartments 15 in the same block 14.

The water level data of each of the compartments 15 measured by the water level gauge 3 is input to the control device 5 at any time. The inclinometer 4 measures the inclination angles of the caisson 10 in the X and Y directions, and the inclination data of the caisson 10 measured by the inclinometer 4 is input to the control device 5 at any time. As the control device 5, a computer or the like is used. The control device 5 controls each water injection pump 2. Details of water injection control by the control device 5 will be described later.

The management device 6 is provided for the operator to monitor the status of water injection control by the control device 5. As the management device 6, for example, a computer having a monitor or the like is used. The management device 6 relates to water injection control such as water level data of the compartment 15 by the water level gauge 3 input to the control device 5, tilt data of the caseon 10 by the tilt meter 4, and the control state of the water injection pump 2 by the control device 5. Various information is input from the control device 5 at any time. Various information input to the management device 6 is displayed on the monitor.

The management device 6 is arranged, for example, on land or a ship away from the caisson 10. The management device 6 may be arranged on the caisson 10, and in that case, for example, it may be a computer that also serves as the control device 5 and the management device 6.

When the caisson 10 is landed at the target position B in the water, the caisson 10 is transferred to the upper part of the target position B by a tugboat or the like. Next, the wire rope wound around the winch 22 installed in the caisson 10 is connected to a ship, an underwater structure, a sinker sunk in the bottom of the water, or the like existing around the caisson 10. Then, based on the position information of the caisson 10 acquired by the positioning device 21, the wire rope is wound or unwound by the winch 22 to align the caisson 10 with respect to the target position B in the horizontal direction.

Next, water is injected into the inside of each block 14 of the caisson 10 floating on the water W by the water injection pump 2, and the caisson 10 is moved downward to the water depth immediately before landing at the target position B. The water depth immediately before landing is, for example, about 0.5 m to 2.0 m above the target position B.

Next, in a state where the caisson 10 is located at the water depth immediately before landing at the target position B, the final alignment of the caisson 10 in the horizontal direction with respect to the target position B is performed by a winch 22 or the like. After that, the caisson 10 is landed at the target position B by further injecting water into each block 14 with the water injection pump 2 until the caisson 10 has landed at the target position B.

In the present invention, when the caisson 10 floating on the water W above the target position B described above is moved downward to the water depth immediately before landing on the target position B, the water injection control system 1 follows the control flow illustrated in FIG. Water injection control is performed based on this. 4 to 6 schematically illustrate a part of the management screen displayed on the monitor of the management device 6. Although some blocks 14 are shown in FIGS. 4 to 6, other blocks 14 that are not shown are also displayed on the management screen so that the entire situation of the caisson 10 in a plan view can be visually recognized. ing.

The numerical value surrounded by the thin solid square frame displayed in the center of each of the compartments 15 of FIGS. 4 to 6 indicates the water level (m) of each of the compartments 15. The numerical value surrounded by the thick solid square frame displayed slightly above the center of each block 14 indicates the average water level of each block 14 obtained by averaging the water levels of the compartments 15 constituting the block 14. .. The numerical value in parentheses surrounded by the square frame of the alternate long and short dash line displayed slightly below the center of each block 14 indicates the reference water level difference of each block 14 described later. Although a part of the caisson 10 is displayed on the management screen of the management device 6 in FIGS. 4 to 6, the entire caisson 10 is displayed on the management screen, and the water level difference between the adjacent compartments 15 and the caisson 10 are displayed. Tilt information, position information (horizontal position, water depth) of the caisson 10 acquired by the positioning device 21 and the like are also displayed.

Equipment such as a water injection pump 2, a water level gauge 3, an inclinometer 4, a control device 5, a lid member 20, a positioning device 21, a winch 22, and a power supply device 23 is installed in the caisson 10. Further, since there are individual differences in the caisson 10, the weight balance of the caisson 10 including the equipment is biased. Therefore, even if water is injected into each block 14 and all the blocks 14 have the same water level, the initial inclination of the caisson 10 is not corrected.

Therefore, in the water injection control method of the present invention, a step of storing the reference water level difference is performed before starting the control flow illustrated in FIG. As illustrated in FIG. 4, the control device 5 uses each water injection pump 2 based on the inclination data of the caisson 10 measured by the inclinometer 4 at the initial stage when the caisson 10 is floated on the water W. Water is injected into each block 14 (14A to 14F) to put the caisson 10 in a desired posture. At this stage, the amount of water injected into each block 14 is preferably the minimum necessary amount that allows the caisson 10 to be in a desired posture.

In this embodiment, the desired posture of the caisson 10 is set so that the caisson 10 is substantially horizontal. For example, the desired posture of the caisson 10 is set so that the caisson 10 is tilted by a predetermined angle with respect to the horizontal. You may. Since the caisson 10 floating on the water W fluctuates under the influence of waves, the inclination angle of the caisson 10 is such that the inclination of the caisson 10 measured in a predetermined cycle is averaged for a predetermined averaging period (for example, several seconds). It is preferable to use the moving average angle obtained by moving average.

Next, the control device 5 determines the water level of the compartments 15 constituting the block 14 from the water level of each compartment 15 measured by the water level gauge 3 when the caisson 10 is in the desired posture. Calculate the average average water level. Then, the relative water level difference between the average water levels of the calculated blocks 14 (14A to 14F) is stored as a reference water level difference.

Since the Kason 10 floating on the water W swings, the average water level of the block 14 is not limited to the one calculated by simple averaging, but the water level of the separated chamber 15 measured in a predetermined cycle is used for a predetermined averaging period. It is preferable to use the moving average water level that has been moved and averaged (for example, several seconds).

For example, when the caisson 10 is in the desired posture, the average water level of the blocks 14A, 14B, 14E, and 14F is 0.50 m, the average water level of the block 14C is 0.45 m, and the average water level of the block 14D is 0.55 m. Suppose. In this case, the reference water level difference is that the average water level of blocks 14B, 14E, and 14F is ± 0.00 m, the average water level of block 14C is -0.05 m, and the average water level of block 14D is +0 with respect to the average water level of block 14A. It will be 0.05m.

After performing the step of storing the reference water level difference described above, the control device 5 starts the control flow illustrated in FIG. 3, and the water depth immediately before the caisson 10 bottoms out at the target position B in the steps S1 to S7. Repeat until it moves down to.

In step S1, the control device 5 injects water into each block 14 by each water injection pump 2 with respect to the caisson 10 in which the relative average water level difference of each block 14 is the reference water level difference. Perform water injection control. Then, the process proceeds to step S2.

Even when the water injection pump 2 of the same standard is operated to inject water into each block 14, there are influences such as individual differences of the water injection pump 2 and the length of the pipe. It is difficult to keep the amount of water uniform. Therefore, when the total water injection control is executed, the relative water level difference between the average water levels of the blocks 14 gradually changes from the reference water level difference stored in advance. If the relative water level difference between the average water levels of the blocks 14 deviates significantly from the reference water level difference, there is a high risk that the caisson 10 will tilt significantly with respect to the desired posture.

Further, when water W is injected into the compartment 15 by the water injection pump 2, the water W flows into the other compartment 15 constituting the same block 14 through the communication hole 13a. However, when the amount of water injected per unit time by the water injection pump 2 exceeds the amount of water injected per unit time passing through the communication hole 13a, the relative water level difference between the compartments 15 in the block 14 is large. It may become. When the water level difference between adjacent compartments 15 becomes excessive, the water pressure applied to the watertight partition wall 12 and the non-watertight partition wall 13 partitioning the adjacent partition chamber 15 increases, and the watertight partition wall 12 and the non-watertight partition wall 13 are damaged. The risk is high.

Therefore, in step S2 of FIG. 3, the control device 5 sets the water level difference between the adjacent compartments 15 to be equal to or higher than the preset threshold value in order to prevent the water level difference between the adjacent compartments 15 from becoming excessive. Judge whether or not it is. This threshold value can be appropriately set according to the strength of the watertight partition wall 12 and the non-watertight partition wall 13, but is set to, for example, 1.00 m.

In step S2, when the control device 5 determines that the water level difference between all the adjacent compartments 15 is less than the preset threshold value (S2: NO), the state in which the total water injection control is being executed as it is. Proceed to step S4.

On the other hand, if it is determined in step S2 that the water level difference between the adjacent compartments 15 is equal to or greater than a preset threshold value (S2: YES), the process proceeds to step S3. From step S2, both when the water level difference between adjacent compartments 15 constituting the same block 14 is equal to or greater than the threshold value and when the water level difference between adjacent compartments 15 constituting different blocks 14 is equal to or greater than the threshold value. The process proceeds to step S3.

In step S3, the control device 5 comprises the partition chamber 15 having the highest water level and the compartment having the lowest water level constituting each block 14 so that the water level difference between the adjacent compartments 15 is less than a preset threshold value. Until the water level difference from 15 becomes equal to or less than the preset target value in all the blocks 14, the partition wall water level difference control for stopping the water injection by all the water injection pumps 2 is executed. This target value can be appropriately set as long as it is smaller than the threshold value of the water level difference between the adjacent compartments 15, but is set in the range of 0.05 m to 0.30 m, for example.

When the water injection by all the water injection pumps 2 is stopped by the partition wall water level difference control, water passes through the communication hole 13a from the partition chamber 15 having a relatively high water level to the compartment 15 having a relatively low water level in the same block 14. As W flows, the water level difference between the septums 15 in each block 14 becomes smaller. Along with this, the water level difference between adjacent compartments 15 constituting different blocks 14 also becomes smaller.

When the water level difference between the partition chamber 15 having the highest water level and the compartment 15 having the lowest water level in all the blocks 14 becomes equal to or less than the target value, the water level difference between all the adjacent compartments 15 becomes less than the threshold value. When the control device 5 determines that the water level difference between the compartment 15 having the highest water level and the compartment 15 having the lowest water level in all the blocks 14 is equal to or less than the target value, the control device 5 proceeds from step S3 to step S4.

In step S4, in order to prevent the caisson 10 from tilting significantly with respect to the desired posture, the relative water level difference between the average water levels of any of the blocks 14 is preset from the reference water level difference stored in advance. It is determined whether or not the deviation exceeds the permissible value. This permissible value can be appropriately set as long as it is a numerical value smaller than the above-mentioned threshold value, but is set in the range of 0.50 m to 0.90 m, for example. In this embodiment, the permissible value is set to 0.80 m.

In step S4, when the control device 5 determines that the relative water level difference between the average water levels of any of the blocks 14 does not deviate from the reference water level difference by more than the permissible value (S4: NO), step S4. Return to S1.

On the other hand, as in the state of FIG. 5, in step S4 of FIG. 3, the control device 5 causes the relative water level difference between the average water levels of any of the blocks 14 to deviate from the reference water level difference beyond the permissible value. If it is determined that the above is true (S4: YES), the process proceeds to step S5. In FIG. 5, the relative water level difference between the average water level of the block 14A and the average water level of the block 14D deviates from the reference water level difference by exceeding 0.80 m set as an allowable value. That is, based on the reference water level difference, when the average water level of the block 14A is 5.00 m, the average water level of the block 14D is preferably 5.05 m, which is 0.05 m higher than the average water level of the block 14A. The actual average water level of the block 14D, 4.24 m, deviates from 5.05 m by exceeding 0.80 m, which is set as an allowable value.

In step S5 of FIG. 3, the control device 5 stops water injection by the water injection pump 2 to the block 14 whose average water level is relatively high with respect to the reference water level difference, and the average water level of each block 14 is relative to each other. Correction control is performed to bring the water level difference closer to the reference water level difference and make it less than the permissible value. In the correction control, it is preferable that the relative water level difference between the average water levels of the blocks 14 is a value close to the reference water level difference (for example, the error with respect to the reference water level difference is within 0.20 m).

For example, when the average water level of the block 14A is relatively highest with respect to the reference water level difference, the control device 5 stops the water injection by the water injection pump 2 provided in the block 14A. Then, water is injected by the water injection pumps 2 provided in the blocks 14B to 14F until the average water level of the blocks 14B to 14F approaches the reference water level difference with respect to the average water level of the blocks 14A. Then, when the average water level approaches the reference water level difference with respect to the average water level of the block 14A, the water injection by the water injection pumps 2 provided in the blocks 14B to 14F having the reference water level difference is stopped.

When the correction control is completed from the state of FIG. 5, as illustrated in FIG. 6, the relative water level difference between the average water levels of the blocks 14 returns to a value close to the reference water level difference stored in advance, and all the water injection pumps 2 are used. Water injection is stopped. When the correction control in step S5 of FIG. 3 is completed, the process proceeds to step S6.

Basically, in step S5, by returning the relative water level difference between the average water levels of the blocks 14 to a value close to the reference water level difference, the inclination of the caisson 10 with respect to the desired posture becomes small, and the caisson 10 is generally desired. It will be in a state of returning to the posture of. However, the caisson 10 is desired even when the relative water level difference between the average water levels of the blocks 14 is set to a value close to the reference water level difference due to changes in the water depth where the caisson 10 is located and the amount of water stored in the block 14. It may be tilted with respect to the posture of. That is, in the process of submerging the caisson 10, the condition of an appropriate reference water level difference in which the caisson 10 is in a desired posture may change.

Therefore, in step S6, when the water level difference between the average water levels of the respective blocks 14 is brought close to the reference water level difference by the correction control, the inclination angle of the caisson 10 with respect to the desired posture of the caisson 10 is equal to or larger than the preset target angle. Determine if it exists. This target angle can be appropriately determined, but is set in the range of, for example, 1 ° to 5 °. Then, when the inclination angle of the caisson 10 with respect to the desired posture is less than the target angle (S6: NO), the process returns to step S1 as it is without changing the reference water level difference stored in advance.

On the other hand, if the inclination angle of the caisson 10 with respect to the desired posture of the caisson 10 is equal to or larger than the target angle (S6: YES), the process proceeds to step S7. In step S7, the control device 5 appropriately injects water into the block 14 by the water injection pump 2 so that the caisson 10 is in the desired posture, and the average water level of each block 14 when the caisson 10 is in the desired posture. The slope correction control that updates the water level difference as a new reference water level difference is executed. Then, the process returns to step S1.

The control device 5 repeatedly executes the above steps S1 to S7 until the caisson 10 is moved downward to the water depth immediately before landing at the target position B. When the control device 5 is located at the water depth immediately before the caisson 10 reaches the target position B, the control flow of FIG. 3 is terminated, and the water injection by all the water injection pumps 2 is stopped.

If a problem occurs in the process of performing automatic water injection control by the control device 5, the control device 6 inputs a command to the control device 5 to switch from automatic water injection control to artificial water injection control, respectively. The control of the water injection pump 2 is switched to an artificial operation by the management device 6.

Next, the operator uses a winch 22 or the like to finally align the caisson 10 with respect to the target position B. After that, the construction manager inputs the information that the final alignment of the caisson 10 is completed to the control device 5 by the management device 6. Then, the control device 5 starts water injection by all the water injection pumps 2 and executes control for continuously injecting water to all the blocks 14 until the caisson 10 reaches the target position B. By the above steps, the caisson 10 is in a state of landing at the target position B.

As described above, in the present invention, the reference water level difference, which is the relative water level difference between the average water levels of the respective blocks 14 when the caisson 10 floating on the water W is in the desired posture, is stored. Then, until the caisson 10 is moved downward to the water depth immediately before landing at the target position B, the relative of the average water levels of the blocks 14 in which the total water injection control and the total water injection control vary with respect to the reference water level difference. The correction control that brings the water level difference closer to the reference water level difference is repeatedly executed.

In the correction control, when the water injection pump 2 provided in the block 14 having the highest average water level relative to the reference water level difference is stopped, the relative water level difference between the average water levels of the respective blocks 14 is calculated. The target average water level of each block 14 for approaching the reference water level difference is determined. Therefore, the control device 5 may individually control the water injection pumps 2 provided in each block 14 so that the average water level of each block 14 becomes the target average water level.

In this way, by adopting the water injection control focusing on the average water level of the block 14, even when the caisson 10 is swinging, the inclination of the caisson 10 with respect to the desired posture becomes excessive by the simple water injection control. It is advantageous for the caisson 10 to be stably submerged to the water depth immediately before landing, while suppressing the caisson 10.

In the water injection control method for stopping the pump water injection to the block 14 on the side subducting downward based on the measurement result of the inclinometer 4 installed in the caisson 10 as in the invention described in Patent Document 1, for example, FIG. When adopted in a caisson 10 in which three or more blocks 14 are arranged in the X direction or the Y direction as illustrated in 2, the water injection control becomes relatively complicated. The reason is whether or not to stop the water injection pump 2 provided in the central block 14 when the central block 14 in which the caisson 10 is not arranged at the end in the inclined direction occurs. This is because it is difficult to set the judgment criteria for.

On the other hand, in the present invention, since the water injection pump 2 is controlled mainly by the water level difference between the average water levels of the blocks 14, the caisson 10 in which three or more blocks 14 are arranged in the X direction and the Y direction. However, the caisson 10 can be stably submerged by simple water injection control. Therefore, it is very versatile. Of course, the present invention can also be adopted for a caisson 10 in which the inner space 11 is divided into blocks 14 having less than six.

Basically, by repeatedly executing the total water injection control and the correction control, the caisson 10 can be stably submerged to the water depth immediately before landing. Furthermore, if the configuration is such that tilt correction control is performed as in this embodiment, the caisson 10 is tilted with respect to the desired posture by updating the caisson 10 to a more appropriate reference water level difference. Can be more reliably prevented from becoming large.

When the partition wall water level difference is controlled, it is possible to prevent the water level difference between the adjacent partition chambers 15 from becoming excessive, so that the risk of damage to the watertight partition wall 12 and the non-watertight partition wall 13 can be reduced. Further, when the water injection by all the water injection pumps 2 is stopped by the partition wall water level difference control, the water level difference between the high water level partition chamber 15 and the low water level partition chamber 15 constituting the same block 14 does not change, or If there is a block 14 that takes a long time until the water level difference becomes small, it can be seen that the communication hole 13a of the non-watertight partition wall 13 that partitions the block 14 may be clogged. Therefore, there is an advantage that a defect of the caisson 10 can be found by controlling the partition wall water level difference.

The permissible value in the correction control, the threshold value and the target value in the partition wall water level difference control are preferably set so as to satisfy the condition of the following equation (1).
"Threshold" ≥ "tolerance" + "target value" x α ... (1)
Here, α is the number of non-watertight partition walls 13 interposed between the compartment 15 in which the water injection pump 2 injects water W and the compartment 15 farthest from the compartment 15 in the block 14. is there. For example, in this embodiment, α is 2. By setting the permissible value, the threshold value, and the target value under the condition satisfying the equation (1), the water level difference between the compartments 15 in the block 14 becomes equal to or less than the target value regardless of the arrangement of the water injection pump 2. Therefore, it is possible to more reliably prevent a problem that the water level difference between adjacent compartments 15 having different blocks 14 becomes equal to or higher than the threshold value.

Providing water injection pumps 2 in all the compartments 15 is advantageous for shortening the water injection time and reducing the water level difference between the compartments 15. However, on the other hand, since the number of water injection pumps 2 installed in the caisson 10 is large, there is a demerit that it takes a lot of time to install the water injection pumps 2. Normally, the former requires more time than the work time required for installing the water injection pump 2 and the work time for injecting water W into the block 14. Therefore, if one water injection pump 2 is installed for each block 14 as in this embodiment, it is advantageous to shorten the total working time required for the installation work of the caisson 10. In the present invention, water injection control is performed focusing on the average water level of the blocks 14, so that even if the water injection pumps 2 are not provided in all the compartments 15, one water injection pump 2 can be installed in each block 14. , Caisson 10 can be sunk stably.

1 Water injection control system 2 Water injection pump 3 Water level gauge 4 Tiltmeter 5 Control device 6 Management device 10 Caisson 10a Outer wall 11 Inner space 12 Watertight partition 13 Non-watertight partition 13a Communication hole 14, 14A-14F Block 15 Separation room 20 Lid member 21 Positioning device 22 winch 23 power supply device B Target position W Water WL (outside the caisson) Water level position

Claims (6)

A caisson having an inner space formed by a plurality of compartments is moved downward to the water depth immediately before landing at a target position in the water by injecting water into the inner space while floating on water for alignment. After that, in the method of controlling water injection of the caisson, the caisson is landed at the target position by further injecting water into the inner space.
The caisson is divided into a plurality of blocks that are not communicated with each other in units of a single or a plurality of adjacent compartments, and the adjacent compartments are communicated with each other in each block. In the initial stage of floating on water, when water is injected into each of the blocks and the caisson is placed in a desired posture, the average water level obtained by averaging the water levels of the respective compartments constituting each of the blocks is averaged. Is calculated, and the relative water level difference between the average water levels of each of the blocks is stored as a reference water level difference.
Next, full water injection control in which water is injected into each of the blocks by a water injection pump individually provided for each of the blocks with respect to the caseon in the state of the reference water level difference, and one of the blocks When the relative water level difference between the average water levels deviates from the reference water level difference by exceeding a preset allowable value, the water injection to the block whose average water level is relatively higher than the reference water level difference. With the correction control of stopping the water injection by the pump and making the relative water level difference between the average water levels of each of the blocks closer to the reference water level difference to be equal to or less than the allowable value, the cason is landed at the target position. A cason water injection control method characterized in that the water injection is repeated until the water is moved downward to the water depth immediately before the pumping. When the relative water level difference between the average water levels of the blocks is brought closer to the reference water level difference by the correction control, the inclination angle of the caisson with respect to the desired posture of the caisson is equal to or larger than a preset target angle. In this case, before performing the total water injection control, water is injected into each of the blocks so that the caisson is in a desired posture, and when the caisson is in a desired posture, the block is described. The caisson water injection control method according to claim 1, wherein the inclination correction control is performed to update the relative water level difference between the average water levels as a new reference water level difference. When the water level difference between any of the adjacent caissons exceeds a preset threshold value, the water level difference between the caisson having the highest water level and the caisson having the lowest water level in each block. However, the caisson water injection control method according to claim 1 or 2, wherein the partition water level difference control is performed so that the water injection by all the water injection pumps is stopped until the value becomes equal to or less than the preset target value in all the blocks. .. The method for controlling water injection in Kason according to any one of claims 1 to 3, wherein a moving average water level obtained by moving and averaging the water level of the compartment measured in a predetermined cycle as the average water level of the block in a predetermined averaging period is used. The caisson water injection control method according to any one of claims 1 to 4, wherein one water injection pump is provided for each of the blocks. A caisson having an inner space formed by a plurality of compartments is provided with a water injection pump for injecting water into the inner space while floating on water, and a control device for controlling the water injection pump. After water is injected by the water injection pump and the caisson is moved downward to the water depth immediately before landing at the target position in the water to perform alignment, water is further injected into the inner space to land the caisson at the target position. In the bottoming caisson water injection control system
The inner space is divided into a plurality of blocks that are not communicated with each other in units of a single or a plurality of adjacent compartments, and the adjacent compartments are kept in communication with each other in each block, and the water injection is performed. When a pump is individually provided for each of the blocks and water is injected into each of the blocks by the water injection pump in the initial stage when the caisson is floated on water to bring the caisson into a desired posture. The average water level obtained by averaging the water levels of the caissons constituting each of the blocks is calculated by the control device, and the relative water level difference between the average water levels of the blocks is used as the reference water level difference. Stored in the control device
For the cason in the state of the reference water level difference, the total water injection control in which water is injected into each of the blocks by the water injection pump and the relative water level difference between the average water levels of any of the blocks are described. When the deviation from the reference water level difference exceeds a preset allowable value, the water injection by the water injection pump to the block whose average water level is relatively high with respect to the reference water level difference is stopped and the water injection of each of the blocks is stopped. The correction control that brings the relative water level difference between the average water levels closer to the reference water level difference and makes it equal to or less than the allowable value is repeated until the cason is moved downward to the water depth immediately before landing at the target position. Kason's water injection control system is characterized by its configuration.

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