JP2023151845A - Excavation support system of water bottom ground - Google Patents

Abstract

To provide an excavation support system of a water bottom ground that can support efficient excavation by grasping states of a ground and a water flow of a water bottom in a planned range of excavation.SOLUTION: An excavation support system 1 comprises: an underwater sonar 4 that emits sound waves to a ground surface 12 to grasp a state of a water bottom in a predetermined range; a GPS 5 that is a positioning system that can grasp a position of a heavy excavation machine 2 on water; a machine guidance function 6 that can grasp a position of an attachment 21 of the heavy excavation machine 2; a flow velocity measurement portion 7 that can grasp a flow velocity in a construction water area; a display portion 8 that can display various information; and a control portion 9 that performs information processing. The control portion 9 can display a water depth of a measurement range 13, the position of the attachment 21 of the heavy excavation machine 2, and the flow velocity and a flow direction 16, on the display portion 8.SELECTED DRAWING: Figure 1

Description

The present invention relates to an underwater excavation support system.

Conventionally, as a construction management method when excavating the ground under water, data obtained from 3D sonar etc. is used to display the underwater bottom and its surroundings in 3D images, and work is carried out while visually checking the images at all times. There is a method (for example, see Patent Document 1). Furthermore, a method has been proposed in which water depth information and backhoe posture information are acquired and the operating state of the backhoe is displayed superimposed on the underwater topography (for example, see Patent Document 2).

Patent No. 5565957 JP2003-278158A

Conventional methods make it possible to monitor the bottom of the water during excavation in real time and manage the finished product, but they do not take into account the flow speed and direction of the water. The flow speed and direction of water change depending on the installation status of structures such as pier foundations, water gates, quay walls, and cofferdam steel pipe sheet piles, the distance from the structures, the progress of excavation, etc., and are greatly affected by the movement of earth and sand during excavation. .

The present invention has been made in view of the above-mentioned problems, and its purpose is to support efficient excavation by understanding the conditions of the water bottom ground and water flow in the area to be excavated. It is about providing a support system.

In order to achieve the above-mentioned object, the present invention is an underwater ground excavation support system, which includes an underwater sonar that emits sound waves on the ground surface to grasp the condition of the water bottom in a predetermined range, and an underwater sonar that grasps the position of heavy excavation equipment on the water. A possible positioning system, a machine guidance function that can determine the attachment position of the heavy excavation equipment, a flow velocity measurement unit that can determine the flow velocity in the construction water area, a display unit that can display various information, and a control that performs information processing. An excavation support system for underwater ground, characterized in that the control unit is capable of displaying the water depth of the measurement range, the attachment position of the excavation heavy equipment, the flow velocity, and the flow direction on the display unit. It is.

According to the present invention, since the control unit processes various information and displays it on the display unit, the state of the ground at the bottom of the water, the flow velocity and direction of the water flow, and the attachment position of the heavy excavation machine can be grasped in real time. As a result, the order of excavation of the planned excavation range can be determined in consideration of the flow velocity and direction of the water flow so that the excavation can be carried out efficiently.

It is preferable that the control unit is capable of setting an excavation amount of the ground to be excavated at one time according to the flow velocity measured by the flow velocity measurement unit, and displaying the amount on the display unit.
This allows excavation with an appropriate amount of excavation depending on the flow velocity, thereby preventing unexcavation and spillage from the bucket.

It is preferable that the control unit is capable of identifying the type of object at each position on the water bottom from the reflected intensity of the sound wave of the underwater sonar, and displaying the object type on the display unit. In this case, the control section may be able to determine whether excavation is possible based on the type and size of the object, and display information on whether excavation is possible on the display section.
If the type of object can be displayed on the display, the presence of objects other than sand and earth can be detected in real time. Furthermore, by displaying information on whether or not the object can be excavated on the display section, it is possible to select the most suitable attachment for the object removal work.

The control unit can determine a scour prediction area and a sedimentation prediction area in the ground by comparing the flow velocity, flow direction, and water bottom condition with preset scour conditions and sedimentation conditions, and display the results on the display unit. It is desirable that there be.
Thereby, the order of excavation in the planned excavation range can be appropriately determined in consideration of the movement of earth and sand by water flow.

The underwater sonar is a multi-beam sonar, and it is desirable that the measurement waves can be switched depending on the degree of turbidity of the construction area.
This makes it possible to improve measurement accuracy depending on the turbidity.

During construction on a river, it is desirable that the control unit be able to predict future water level changes by acquiring the amount of precipitation upstream of the river and comparing it with pre-stored conditions.
This makes it possible to grasp changes in water depth in advance and decide whether or not to continue construction.

According to the present invention, it is possible to provide an underwater ground excavation support system that can support efficient excavation by grasping the conditions of the underwater ground and water flow in the area to be excavated.

1 is a diagram showing the configuration of an excavation support system 1. FIG. FIG. 2 is a block diagram showing the functions of the excavation support system 1. FIG. (a) is a plan view showing information on the state of the ground surface 12, water flow, and the position of the attachment 21, and (b) is a sectional view taken along line AA in (a). FIG. 3 is a plan view showing information about the object 15; FIG. 3 is a plan view showing information on predicted deformation of water flow and ground surface 12 in each part. FIG. 9 is a diagram showing an example of information processing by the control unit 9. FIG. (a) is a plan view of the vicinity of the excavated location 14, and (b) is a sectional view taken along line BB in (a). (a) is a plan view of the vicinity of the excavated location 14, and (b) is a sectional view taken along line CC in (a). (a) is an elevational view of the vicinity of the flow velocity measuring section 7a, and (b) is a diagram showing an example of the display on the display section 8. (a) is a diagram showing a self-supporting submerged levee 23a, and (b) is a diagram showing a self-supporting submerged levee 23b.

Hereinafter, embodiments of the present invention will be described in detail based on the drawings.
FIG. 1 is a diagram showing the configuration of the excavation support system 1, and FIG. 2 is a block diagram showing the functions of the excavation support system 1.

As shown in FIG. 1, the excavation support system 1 is used, for example, when carrying out dredging work on the ground 3 at the bottom of a river or the like using heavy excavation equipment 2 installed on a barge 22. The excavation support system 1 includes an underwater sonar 4, a GPS 5 which is a positioning system, a machine guidance function 6, a flow velocity measurement section 7, a display section 8, a control section 9, and the like.

The underwater sonar 4 emits sound waves to the ground surface 12 to ascertain the state of the water bottom in the measurement range 13. The underwater sonar 4 is a multi-beam sonar having a horizontal and vertical oscillation mechanism. It is desirable that the underwater sonar 4 be able to switch measurement waves between CW waves and FM chirp waves depending on the degree of turbidity of the construction water area. Normally, CW waves are used, but if a highly turbid water mass exists, FM chirp waves can be used to measure distances with high accuracy. Furthermore, if the flow velocity of the underwater 11 does not exceed 1 knot (approximately 0.5 m/sec) and it is possible to control the position of the underwater drone using a thruster, an underwater acoustic camera mounted on the underwater drone may be used as the underwater sonar 4. . This makes it possible to accurately measure relatively local underwater topography. Whether or not the underwater drone can be used is determined using the actual measurement value of the flow velocity by the flow velocity measurement unit 7, which will be described later.

The GPS 5 can determine the position of the heavy excavation machine 2 on the water. Note that the positioning system is not limited to GPS5, but may be other satellite positioning systems (GNSS), total stations, or the like. By installing multiple total stations (surveying instruments) at points on land where the coordinates are known and installing an automatic tracking mirror on the barge 22 side (moving object), it is possible to grasp the position and direction of the heavy excavation machine 2. .

The machine guidance function 6 consists of a plurality of inclinometers 61 attached to the boom 23, and is capable of grasping the position of the attachment 21 of the heavy excavation machine 2. The attachment 21 is attached to the tip of the boom 23 and can be replaced depending on the application. When excavating ordinary earth and sand, the bucket shown in Fig. 1 is attached to the boom 23 as an attachment 21, but when crushing concrete, it is attached to a breaker, when processing sunken wood, it is attached to a gripping machine, and when excavating rock, it is attached to a loader. Replaced with header or drum cutter.

The flow rate measurement unit 7 is capable of determining the flow rate in the construction water area. The construction water area is the entire underwater area 11 above the planned excavation area of the ground 3, and the flow velocity measurement unit 7 is arranged at at least one location in the construction water area. The flow velocity measuring section 7 is attached to, for example, a support section 71 that reaches the ground surface 12, and measures the flow velocity near the ground surface 12. The flow rate measurement unit 7 is not limited to the illustrated example, and may be installed separately from the barge 22, or may directly measure the flow rate of water using various sensors, or may directly measure the flow rate of water. The flow rate may be measured and converted into a flow rate. The support portion 71 is, for example, in the shape of a hollow pipe, and a current meter or sensor cord may be placed inside. Further, the turbidity of the water 11 may be measured by disposing an ultra-small submersible pump (water sampling pump or hose for measuring turbidity near the bottom of the water) inside the support part 71. From the flow velocity data obtained by the flow velocity measurement unit 7 and the turbidity data obtained by the ultra-compact submersible pump, it can be determined whether the above-mentioned underwater drone or other precision current meter can be used. Note that the support portion 71 is also used for measuring water depth.

As shown in FIG. 2, the control unit 9 is connected by wire or wirelessly to the underwater sonar 4, GPS 5, machine guidance function 6, and current velocity measurement unit 7, and acquires information from each device and processes it. The control unit 9 causes the display unit 8 to display information on the water depth of the measurement range 13, the position of the attachment 21 of the heavy excavation machine 2, and the flow velocity and direction. The display unit 8 and the control unit 9 may be integrated like the PC 10, or may be separate units connected by wire or wirelessly. The display section 8 may be provided at a plurality of locations, and the display contents may be confirmed within the cabin of the heavy excavation machine 2. Note that the data acquired from each device and the data processed by the control unit 9 are stored in a cloud server (not shown) via on-site Wi-Fi, and can be checked even from outside the site.

3 to 5 are diagrams showing display examples of the display unit 8, and FIG. 6 is a diagram showing an example of information processing by the control unit 9. When excavating the ground 3 on the water bottom with heavy excavation equipment 2 , in the excavation support system 1 , the control unit 9 receives information on the state of the ground 3 on the water bottom in the measurement range 13 from the underwater sonar 4 and the water flow from the flow velocity measurement unit 7 . and the position information of the attachment 21 from the GPS 5 and the machine guidance function 6 (S101). Based on this information, the display unit 8 displays the water depth of the ground surface 12 in the measurement range 13, the flow velocity and flow direction 16 at the position of the flow velocity measuring unit 7, and the position of the attachment 21 (S102, Fig. 3). In addition, when the water depth at the position of the current velocity measurement part 7 is measured by the support part 71, the control part 9 may compare the water depth obtained from the information of the underwater sonar 4 with the measurement value by the support part 71, and correct|amend it. Furthermore, the method of displaying the water depth of the ground surface 12 is not limited to the example shown in FIG. 3, but may also be color-coded to indicate the water depth, or a bird's-eye view or the like to three-dimensionally display the shape of the ground surface 12. In addition, the flow direction is not limited to the two-dimensional flow direction; for example, the direction of the flow in the depth direction can also be displayed, for example by using a bird's-eye map or by displaying upflow or downflow above a certain level using colors. It's okay.

After S101, the control unit 9 identifies the types of objects such as concrete lumps, gravel, cobblestones, sunken wood, and driftwood existing on the ground surface 12 from the information on the reflection intensity of the sound waves from the underwater sonar 4, and displays these on the display unit 8. The type of object 15 and whether excavation is possible may be displayed (S103, FIG. 4). Note that the method of displaying the type of object 15 is not limited to the example shown in FIG. It's okay. Further, the size, specific gravity, etc. of the object 15 may be displayed.

After S101, the control unit 9 may estimate the flow velocity and flow direction 16a of each part of the construction water area from the state of the ground 3 at the bottom of the water and information on the flow velocity and flow direction 16, and display it on the display unit 8 (S102', Fig. 5). In S102', for example, the flow velocity and flow direction 16 at the position of the flow velocity measurement unit 7 are input as representative values of water flow into the condition of the ground 3 at the bottom of the water, and the flow velocity and flow direction 16 in each part of the construction water area near the ground surface 12 are measured using FEM or the like. Calculate the flow direction 16a. If the flow velocity and flow direction 16a are calculated and displayed in detail, it is possible to estimate upward and downward flows in each part and the occurrence of vortices and the like.

After S102 or S102', the control unit 9 may set the amount of excavation of the ground 3 to be excavated at one time with the bucket, and display it on the display unit 8 (S104). The amount of excavation of the ground 3 is set according to the flow velocity and flow direction 16 at the position of the flow velocity measurement unit 7 and the estimated flow velocity and flow direction 16a at each part. When the flow velocity is high, it is possible to prevent the excavated soil from spilling from the bucket by setting a small amount of excavation at one time. Alternatively, the direction of the cutting edge of the bucket may be set according to the flow direction, and the excavation direction may be set in a direction in which spillage from the bucket is less likely to occur.

After S102 or S102', the control unit 9 performs preset washing based on information such as the condition of the ground 3 at the bottom of the water, the flow velocity and flow direction 16 at the position of the flow velocity measurement unit 7, and the estimated flow velocity and flow direction 16a at each part. The scour prediction unit 17 and the accumulation prediction unit 18 in the ground 3 may be determined by comparing with the excavation conditions and the deposition conditions and displayed on the display unit 8 (S105, FIG. 5). In S105, for example, simulations using several water flows are performed in advance to set conditions (flow velocity and flow direction) under which the occurrence of scouring and sedimentation is predicted as scouring conditions and deposition conditions, and the various conditions described above are set. The scour prediction unit 17 and the accumulation prediction unit 18 compare the flow velocity and flow direction at the location where scour and accumulation occur, which are calculated from the information. Alternatively, water flow conditions in eddy current generating areas where scour is likely to occur or stagnation generating areas where sedimentation is likely to occur are set as scour conditions and deposition conditions, and compared with the above various information, the scour prediction unit 17 The deposition prediction unit 18 may determine that. Furthermore, depending on the shape and size of the object 15, the possibility of occurrence of scour or accumulation in response to various water flows is made into a matrix, and parts that meet the conditions are determined as the scour prediction unit 17 or the accumulation prediction unit 18. good.

When excavating the ground 3 using the excavation support system 1, in S101 and S102, information on the state of the ground 3 at the bottom of the water, the flow velocity, and the flow direction 16 is grasped in real time, and the order of excavation in the planned excavation range is determined. When S102' and S105 are performed, the flow velocity and direction 16a of each part shown in FIG. 5 and the positions of the scour prediction section 17 and the deposition prediction section 18 are also taken into consideration. At the time of excavation, information on whether or not the object 15 can be excavated (S103) and the amount of excavation to be excavated at one time (S104) are also referred to. For example, if sand and cobbles coexist on the ground surface 12, by stirring at the bottom of the water after excavation, the sand with light specific gravity flows downstream and only the cobblestones with heavy specific gravity remain, so the amount of soil to be lifted can be reduced.

FIGS. 7 and 8 are diagrams showing changes in water flow and the bottom of the water. When the excavation point 14 is set parallel to the water flow as shown in FIG. 7(a), if the excavation point 14 is excavated in a groove shape as shown in FIG. Because of the high flow rate, scour portions 17a are generated on both sides of the groove, and deposited portions 18a are generated at the bottom of the groove. In addition, when the excavation point 14 is set perpendicular to the water flow as shown in FIG. 8(a), if the excavation point 14 is excavated in a groove shape as shown in FIG. 8(b), the upstream side of the groove A scour section 17a is generated, and an accumulation section 18a is generated on the downstream side of the bottom of the groove, and a scour section 17a, which is smaller than the upstream side, is generated on the downstream side of the groove, and the soil is washed downstream. It will be done.

When determining the order of excavation in the planned excavation range, knowledge regarding water flow and water bottom changes as shown in FIGS. 7 and 8 is also taken into consideration. This enables efficient excavation using water flow, such as excavating while scouring, excavating without backfilling, and excavating while accumulating. For example, excavated soil is usually lifted above the water surface, but if the excavated area 14 is perpendicular to the water flow as shown in Figure 8, excavation should be done from upstream to downstream to scour the downstream side. By flushing away the earth and sand in the portion 17a, the amount of soil to be lifted can be reduced.

The state of the water bottom ground 3, the flow velocity, and the flow direction 16 grasped in S101 and S102 may be fed back to the simulation and used for calculations to predict the future water flow and the state of the water bottom ground 3 when excavation continues. . In this case, the excavation work is performed while understanding both the predicted state of the ground 3 and the actual state of the ground 3. In other words, the actual ground conditions are constantly updated using underwater sonar, and predictions of future ground changes and optimal excavation conditions are updated accordingly.

During excavation of the ground 3 using the excavation support system 1, the control unit 9 may be able to obtain the amount of precipitation upstream of the river. The control unit 9 compares the amount of precipitation upstream of the river with pre-stored conditions to predict future changes in water level in the construction area. This makes it possible to make decisions such as stopping excavation in advance if signs of dangerous water level changes are seen several hours later.

In this way, in the excavation support system 1 of the first embodiment, by using information from the underwater sonar 4, GPS 5, and machine guidance function 6, it is possible to determine the actual state of the ground 3 at the bottom of the water ( Since the water depth, the presence of objects 15 other than sand) and the position of the attachment 21 can be displayed on the display unit 8 in real time, the operator can check these information while excavating. Furthermore, by displaying the type and excavation availability information when the presence of the object 15 is recognized, the attachment 21 most suitable for removing each object 15 can be selected.

In the excavation support system 1, by using the information from the flow velocity measuring section 7, the flow velocity and flow direction 16 of the water flow can be displayed on the display section 8 in real time while excavating the ground. Therefore, changes in the flow velocity and flow direction 16 due to the installation status of various structures, the distance to the structures, deformation of the ground surface 12 due to the progress of excavation, etc., along with the state of the ground 3 during excavation can be grasped and efficiently The excavation order of the planned excavation area can be determined so that the excavation can be carried out. Further, by setting the amount of excavation of the ground 3 to be excavated at one time according to the state of water flow, it is possible to set an appropriate amount of excavation and prevent unexcavation and spillage from the bucket.

In the excavation support system 1, the scour prediction unit 17 and the deposition prediction unit 18 in the ground 3 can be determined from the flow velocity and direction 16 and the state of the ground 3 at the bottom of the water, and can be displayed on the display unit. Thereby, the order of excavation can be appropriately determined in consideration of the movement of earth and sand.

In addition, in the example shown in FIG. 1, the flow velocity measurement part 7 was installed only in the vicinity of the ground surface 12, but the arrangement of the flow velocity measurement part 7 is not limited to this. FIG. 9 is a diagram showing an example in which a plurality of flow velocity measurement units 7a are arranged. The construction water area shown in FIG. 9 has severe conditions in which the water is turbid 19 and there is backflow from the offshore side to the upstream side due to swells and the like. Under such conditions, a plurality of flow velocity measurement units 7a may be arranged and a plurality of flow velocity and flow directions 16 may be displayed on the display unit 8. In the example shown in FIG. 9, three flow velocity measuring units 7a-1, 7a-2, and 7a-3 are arranged near the ground surface 12, near the center of the water depth, and near the water surface, respectively. Then, the control unit 9 acquires information on the water flow at three locations in the depth direction, and displays the flow velocity and flow directions 16-1, 16-2, and 16-3 on the display unit 8. The control unit 9 may calculate the flow velocity distribution and display it on the display unit 8.

The flow rate measurement section 7a is configured, for example, with an extensible section 73 connected to a support section 71, and a sphere 72 connected to the tip of the extensible section 73. The support portion 71 is suspended by a hanging member 76, and heavy snowshoes 74 are provided at the lower end to prevent movement due to water flow. The connecting portion between the snowshoes 74 and the support portion 71 has a structure that can follow the inclination of the underwater topography to some extent. As an alternative to the snowshoes 74, a disc-shaped member may be provided near the lower end of the support part 71 like a ski pole, and the lower side of the disc-shaped member may penetrate into the ground 3 at the bottom of the water to prevent movement due to water flow. . In addition, by providing the GPS 75 at the top end, even when water level fluctuations are large, the absolute coordinates of the ground surface 12 are measured from the length of the support 71 and the position information of the GPS 75, and the water depth can be grasped at any time. It can be compared with the measured value.

The specific gravity of the sphere 72 is adjusted to be approximately equal to the turbid water in the construction area. The extensible portion 73 is made of rubber, a spring, or the like whose relationship between flow velocity and elongation amount has been calibrated in advance, and has durability and restorability. The flow velocity measurement unit 7a measures the flow velocity and flow direction 16 of the water flow from the amount and direction of elongation of the expandable portion 73 when the sphere 72 moves due to the water flow. The flow rate measuring section 7a is inexpensive and easy to replace in case of failure. Note that the flow rate measurement unit 7a can be used in both freshwater and seawater by adjusting the specific gravity of the sphere 72 to match the water in the construction area. Note that the method for measuring the flow velocity and flow direction for each water depth is not particularly limited.

In addition, if the flow velocity conditions in the construction area are expected to be severe over the long term and the operating rate of underwater excavation work is expected to decrease significantly, a self-supporting submerged embankment structure may be temporarily installed on the ground 3. . FIG. 10 is a diagram showing an example of a self-supporting submerged embankment. The self-supporting submersible 23a shown in FIG. 10(a) has a perforated membrane 25 like a silt fence between the floating pipe 24 and the H steel 26, and is similar to the self-supporting submersible 23a shown in FIG. 10(b). 23b is a frame body 29 provided with a perforated plate 28. By installing the self-supporting submerged embankments 23a and 23b on the upstream side of the water flow near the ground surface 12 of the construction water area, the water flow passes through the perforated membrane 25 and perforated plate 28 and flows into the construction water area in a decelerated state. Work becomes easier. The self-supporting submersible banks 23a and 23b have a hanging rope 27 and a hanging hook 30, and are installed or removed by a lifting device (not shown). If the hanging hook 30 is attached to a floating body and is placed above the water surface, the self-supporting submerged banks 23a and 23b can be easily removed after the excavation work is completed.

Although preferred embodiments of the present invention have been described above with reference to the accompanying drawings, the present invention is not limited to such examples. It is clear that those skilled in the art can come up with various changes or modifications within the scope of the technical idea disclosed in this application, and these naturally fall within the technical scope of the present invention. Understood.

For example, in the embodiment, the dredging work of the riverbed ground 3 is used as an example of the waterbed, but the excavation support system 1 can also be used to support excavation of waterbed ground other than the riverbed. The installation location of the heavy excavation machine 2 is not limited to the barge 22.

1...Drilling support system 2...Drilling heavy equipment 3...Ground 4...Underwater sonar 5, 75...GPS
6...Machine guidance function 7, 7a, 7a-1, 7a-2, 7a-3...Flow velocity measuring section 8...Display section 9...Control section 10...PC
11...Underwater 12...Ground surface 13...Measurement range 14...Excavation location 15...Object 16, 16-1, 16-2, 16-3, 16a...Flow velocity and flow direction 17 ......Scouring prediction part 17a...Scouring part 18...Deposition prediction part 18a...Deposition part 19......Turbidity 21......Attachment 22......Barge 23......Self-supporting submerged embankment 24... Floating pipe 25... Perforated membrane 26... H steel 27... Hanging rope 28... Perforated plate 29... Frame body 30... Hanging hook 61...... Inclinometer 71... Supporting part 72... Sphere 73... Expandable part 74... Snowshoes 76... Hanging member

Claims (7)

An underwater ground excavation support system,
Underwater sonar, which emit sound waves on the ground surface to determine the condition of the water bottom in a predetermined range;
A positioning system that can determine the location of heavy excavation equipment on water,
a machine guidance function that can grasp the attachment position of the heavy excavation machine;
A flow velocity measurement unit that can determine the flow velocity in the construction water area;
A display section that can display various information;
A control unit that performs information processing;
Equipped with
The underwater excavation support system, wherein the control unit is capable of displaying the water depth of the measurement range, the attachment position of the excavation heavy equipment, the flow velocity, and the flow direction on the display unit. The underwater ground according to claim 1, wherein the control unit is capable of setting an excavation amount of the ground to be excavated at one time according to the flow velocity measured by the flow velocity measurement unit, and displaying the amount on the display unit. excavation support system. The underwater bottom according to claim 1, wherein the control unit is capable of identifying the type of object at each position on the underwater bottom from the reflected intensity of the sound wave of the underwater sonar, and displaying the object type on the display unit. Ground excavation support system. 4. The underwater ground excavation support system according to claim 3, wherein the control unit is capable of determining whether excavation is possible based on the type and size of the object, and displaying information on whether excavation is possible on the display unit. The control unit can determine a scour prediction area and a sedimentation prediction area in the ground by comparing the flow velocity, flow direction, and water bottom condition with preset scour conditions and sedimentation conditions, and display the results on the display unit. 2. The underwater ground excavation support system according to claim 1. 2. The underwater ground excavation support system according to claim 1, wherein the underwater sonar is a multi-beam sonar, and measurement waves can be switched depending on the degree of turbidity of the construction area. Claim 1: During construction in a river, the control unit is capable of predicting future changes in water level by acquiring the amount of precipitation upstream of the river and comparing it with pre-stored conditions. The underwater underground excavation support system described above.

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