JP3108802B2 - Sheet laying method and sheet laying device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for laying a sand barrier sheet for preventing earth and sand from leaking through a foundation such as a landfill seawall or a breakwater.

[0002]

2. Description of the Related Art For example, when reclaiming the ocean, a caisson is generally installed continuously on a foundation mound built on the seabed to form a seawall, and sediment is dumped into an inner sea area (inland sea) surrounded by the seawall, and seawater is sequentially discharged. The replacement method is adopted. In such a landfill method, the foundation mound is often made of a so-called rubble mound, which is formed by dumping crushed stones on the seabed. When landfill sediment is dumped into the inland sea, the landfill sediment leaks from the inland sea to the open sea through the rubble layer due to the flow of seawater generated by ebb and tide. Therefore, conventionally, a sand control sheet has been laid on the inland sea side surface, particularly the slope of the rubble mound, and landfill sand has been dumped on the sand control sheet. The rubble mound is also used when constructing a breakwater.For example, when a rubble mound is formed on sandy ground, the lower layer of sand leaks through the rubble layer as described above. It is necessary to lay a sand control sheet on the planned site.

[0003] Conventionally, the laying of the above sandproof sheet is performed by:
Generally, a method is used in which a sandproof sheet is floated on the surface of the water using a float and then spread, then the float is removed and the sheet is submerged by the weight or load of the sheet itself. There is a problem that it is extremely difficult to sink uniformly and the construction efficiency is poor.

Therefore, recently, a sheet roll formed by winding a sand-proof sheet around a shaft member in a roll shape is suspended by a crane and lowered to the bottom of the water, and the sheet roll is rolled using the inclination of the slope of the rubble mound or the movement of the crane. In many cases, a construction method of laying is adopted (for example,
No. 127034).

[0005]

However, according to the above-mentioned method using a sheet roll, it is difficult to smoothly roll the sheet roll in a certain direction, so that the assistance of a diver is required. Since the sheet roll does not roll when the laying surface is rough, for example, it is necessary to level the slope of the rubble mound as a sheet laying surface in advance by a diver, and in any case, troublesome diving The application to a deep water area where the water depth exceeds 20 m due to the necessity of the work was in a situation where it had to be practically abandoned.

The conventional general-purpose sand-proofing sheet has a low elongation characteristic (elongation of 20 to 30%). Therefore, when it is laid on a sheet laying surface having a large unevenness, the elongation limit is exceeded by the subsequent load on the landfill. Although the above-mentioned leveling work was necessary from this aspect, recently, the use of a sheet having a high elongation property (elongation of 50% or more) as a sandproof sheet has caused a large unevenness. Development of a construction method for preventing the above-mentioned breakage from occurring even when laid directly on a surface, thereby eliminating the need for leveling work of rubble has been promoted. However, when the unevenness is large, since the sheet roll does not roll as described above, it is practically impossible to lay the sandproof sheet, and there is also a problem that the precious construction method cannot be utilized.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned conventional problems, and an object of the present invention is to make it possible to lay a sandproof sheet reliably and easily on a sheet laying surface having large unevenness. It is another object of the present invention to provide a sheet laying method and a sheet laying apparatus which do not require a special diving operation such as rubble leveling and can be applied to a deep water area.

[0008]

Means for Solving the Problems In order to solve the above-mentioned problems, a sheet laying method according to the present invention provides a method in which a sheet member formed by winding a sandproof sheet in a roll shape on a shaft member is rotatably supported by a hanging tool. After lowering the hanger into the water by the work machine on the work boat, the position of the hanger is checked on the work boat by a global positioning system (GPS) and an ultrasonic surveying system, and the hanger is placed on the sheet laying surface. Moving the sand roll sheet from the sheet roll, and rotating the sheet roll by the braking means provided on the hanging member.
It is characterized by feeding out while controlling the speed .

According to the sheet laying method configured as described above, the position of the work boat is obtained by the GPS, and the relative position between the work boat and the hanger is obtained by the ultrasonic surveying system. It is possible to determine the absolute position of the hangers with high accuracy.Therefore, if the shape of the sheet laying surface is known in advance, the hangers can be laid while confirming the position of the hangers with respect to the sheet laying surface. It can be accurately moved along the surface, and the sandproof sheet can be laid without being affected by the size of the unevenness.

In the method of the present invention, based on data received by a GPS fixed station installed at a known point on land,
Correcting the position data of the lifting gear enables more accurate positioning of the lifting gear.
Position can be obtained. In addition, this method allows the user to control the movement of the work machine and the work boat by remote control while moving the hanger along the sheet laying surface while checking the position of the hanger on the monitor on the work boat. Can,
In this case, construction management can be performed in real time.

The type of sandproofing sheet used in the present method is optional, but since there is no fear of breaking even if it is laid directly on the sheet laying surface with large unevenness (± 70 cm), it has a high elongation property (elongation of 50% or more). ) Is desirably used. Further, it is desirable to add a weight member to the sandproof sheet to increase the sheet weight.

[0012] An apparatus for performing the sheet laying method includes a hanger having, at both ends, a rotating shaft that supports a shaft member obtained by winding a sandproof sheet into a roll, and a crane that hung and supports the hanger. A work boat mounted thereon, positioning means for determining the position of the hanger by means of a GPS and an ultrasonic surveying system, a display for displaying position data of the hanger obtained by the positioning means , Control the rotation speed of the rotating shaft
Controlling the braking means and detecting the amount of rotation of the rotating shaft of the lifting device.
Rotation amount detector, and the detection result by the rotation amount detector.
Control means for controlling the operation of the braking means on the basis of the control means .

[0013] In the above-mentioned hanging tool, the hanging tool is a lifting wire of a crane.
Of the long body frame with hooks
A rotating shaft may be provided at an end portion at a variable distance from each other , and both ends of a shaft member wound with a sandproof sheet may be detachably connected to the rotating shaft .

[0014]

Embodiments of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 shows the overall implementation of a sheet laying method according to the present invention. In the figure,
Reference numeral 1 denotes a revetment revetment separating an intended reclaimed sea area (inland sea) A from the open sea B. A rubble mound 2 formed on the seabed ground and a caisson 3 continuously installed on the top end 2a of the rubble mound 2.
It consists of This construction method automatically lays a sand-prevention sheet 4 on a part of the top end 2a of the rubble mound 2 constituting the landfill revetment 1 and a slope 2b continuing from the top 2a. Here, the sheet laying surface) is finished without special leveling, and has a large unevenness H (about ± 70 cm) as shown in FIG.

On the other hand, as the sandproof sheet 4 to be laid here, a high-stretch sheet having high stretch characteristics is used. The high-stretch sheet is made of a woven or non-woven fabric made of polyester-based synthetic fiber so as to have high elongation in both the vertical and horizontal directions.
It is commercially available under the trade name of -600. This SD-600
Since the sheet has an elongation characteristic of about 110%, the sheet is laid on the rubble mound 2 having the above-mentioned large unevenness H (± 70 cm), and the landfill soil is discarded thereon, as shown in FIG. Thus, the sandproof sheet 4 receives the weight of the landfill earth and sand 5 and extends into the recess 6 of the rubble mound 2 and sticks to the bottom of the recess, so that the sandproof sheet 4 is not broken by the overload.

In this embodiment, the sandproof sheet 4
4 and 5, a weight chain (weight member) 7 for increasing the weight of the seat is attached. The weight chains 7 are placed vertically and horizontally on one surface of the sand-proof sheet 4 in a grid-like manner, and their intersections are connected to the sand-proof sheet 4 by binding wires 8. Sandproof sheet 4 provided with this weight chain 7
Is wound on a shaft member 9 (FIGS. 8 and 9), which will be described later, in a roll shape and provided as a sheet roll 10. The sandproof sheet 4 has a width W10 to 15 as an example.
m and a length of 20 to 30 m, and the weight chains 7 are arranged at a pitch P of 1.5 to 3 m as an example with respect to the sandproof sheet 4 of the above-described size.

In the present sheet laying method, the sheet roll 10 is rotatably supported by a hanger 11 to be described later, and a crane 13 on a work boat 12 floating on an inland sea B surrounded by the landfill revetment 1. Hanging wire 14 extending from
The hanging tool 11 is suspended and supported, and the sheet roll 10 is lowered into the water together with the hanging tool 11 by the movement of the crane 13. As shown in FIG. 1, the position of the work boat 12 is arbitrarily changed by winding the other end of the rope 15 having one end fixed to the caisson 3 and an anchor (not shown) around a winch 16. ing. In order to detect the position of the hanger 11 lowered from the work boat 12 into the water, that is, the position of the sheet roll 10, this embodiment uses the following positioning means.

That is, the positioning means includes a global positioning system (GPS) and an ultrasonic surveying system. As shown in FIGS. 6 and 7, a GPS mobile station 17 installed on a work boat 12 and And a GPS fixed station 18 installed at a known point of
It includes three ultrasonic transmitters 19, three ultrasonic receivers 20 provided on the work boat 12, and an arithmetic processing unit 21.
Each of the GPS mobile station 17 and the GPS fixed station 18 has a GPS receiving antenna 23, 24 for receiving GPS signals transmitted from at least four satellites 22.
S receivers 25 and 26 are provided. A wireless transmitter 27 for wirelessly transmitting a signal received by a GPS receiver 26 is provided in the GPS fixed station 18, and a wireless receiver 28 for receiving a signal transmitted from the wireless transmitter 27 is provided in the GPS mobile station 17. Are provided respectively.

The arithmetic processing unit 21 includes the GPS mobile station 1
It has a function of calculating the current position of the work boat 12 based on a signal taken from the GPS receiver 25 in 7. In this case, the value calculated from the signal transmitted from the satellite 22 includes some errors, and the GPS signal received by the GPS receiver 26 in the GPS fixed station 18 which is a known point is transmitted to the radio transmitter / receiver. 27, 28 to the arithmetic processing unit 21,
The current position of the work boat 12 is corrected. The positional accuracy of the work boat 12 obtained in this manner is in a range of ± 2 cm. The arithmetic processing unit 21 also instructs the ultrasonic transmitter 19 via the signal line 31 (FIG. 7) for transmission timing, and receives a signal from the ultrasonic receiver 20 to
And a function for determining the relative distance between the hanging tool 11 and the hanging tool 11. Then, the arithmetic processing unit 21 calculates the position (absolute position) of the hanging tool 11 from the current position of the working boat 12 obtained as described above and the relative distance between the working boat 12 and the hanging tool 11, and as a result, Is output to a display 29 including a CRT and a printer. The work boat 12 is provided with a gyroscope 30 for detecting the direction of the ship and a trim heel meter 31 for detecting the inclination of the ship in front, rear, left and right.
Numeral 1 corrects the operation result based on the signals from these, and sends the corrected position data to the display 29.

Here, as shown in FIGS. 9 to 11, the hanging tool 11 includes a long main body frame 33 having a hook 32 on which the hanging wire 14 of the crane 13 is hooked, and two ends of the main body frame 33. Support units 34 and 35 are provided to face each other and rotatably support the shaft member 9 of the sheet roll 10. Each of the support units 34 and 35 includes a support frame 36 fixed to the lower surface of the main body frame 33 so as to extend in a direction perpendicular to the main frame 33, and a pair of left and right support legs vertically lowered from the lower surface of the support frame 36. 37, a roller frame 39 composed of two plates disposed between the support legs 37 and connected to the support legs 37 via joints 38, and mounted on the roller frame 39 in a concentric manner. A plurality of rollers 40, and a rotating shaft 41 rotatably supported by the plurality of rollers 40.

The roller frame 39 has an octagonal shape as shown in FIG. 12, and has a circular hole 39a for inserting the rotary shaft 41 in the center thereof, and a roller 40 for mounting the roller 40 around the hole 39a. (In this case, eight) are provided. The mounting hole 39b
Are many on the lower side (here, 6
) Are provided so as to be displaced, so that the rollers 40 are displaced downward so that a large number of rollers 40 are displaced.
9 will be attached. This is to make it possible to more stably support the heavy sheet roll 10. The roller 40 is configured as a grooved roller having an annular groove 40a as shown in FIG.
Bearings 42 are fitted into both ends of the shaft hole 40b. The bearing 42 is prevented from being pulled out by a plate 43 fixed to the end face of the roller 40 with bolts, and a shaft (not shown) inserted through the bearing 42 is pressed into the mounting hole 39b of the roller frame 39. become.

On the other hand, as shown in FIG. 14, the rotary shaft 41 has a flange 44 at one end thereof which is connected to an end flange 9a (FIG. 9) of the shaft member 9 of the sheet roll 10, and has an axial direction. An annular rail 45 that can be fitted into the annular groove 40a of the roller 40 is provided on an intermediate outer periphery.
The rotating shaft 41 is attached to each roller frame 39 with its flanges 44 facing each other between the supporting units 34 and 35 facing each other. As shown in FIG. 9, the sheet roll 10 has an end flange 9 of the shaft member 9.
a is fitted between the two rotating shafts 41 by being connected to the flange 44 of the rotating shaft 41 with bolts (not shown).

In this embodiment, one support unit 35 is connected to the main body frame 3 via a slide unit 46.
3 is suspended and supported. This slide unit 46
9 and 11, a slide plate 47 fixed to the upper surface of the support frame 36 and slidably fitted to the lower flange 33a of the main frame 33 sandwiches the web 33b of the main frame 33. A rack 48 provided integrally on the upper surface of the slide plate 47 at a position, and a pinion 5 attached to both ends of a shaft 49 through the web 33b of the main body frame 33 so as to mesh with the rack 48.
It consists of 0.

Both ends of the shaft 49 of the pinion 50 are formed in a square shape (for example, a square shape). On the other hand, an L-shaped operation arm 51 (which has a socket portion 51a at the tip end engageable with the square end portion) is provided. 9 and 11) are prepared. When the operation arm 51 is extended from the easy-to-operate side of the both sides of the main body frame 33, the socket portion 51 a is engaged with the shaft 49, and the pinion 50 is rotated, the rotation movement is performed by the slide plate via the rack 48. It is converted into 47 linear motions. That is, by operating the slide unit 46 to adjust the interval between the two support units 34 and 35, the variation in the length of the shaft member 9 of the sheet roll 10 can be absorbed, and the sheet The roll 45 can be reliably supported.

A brake unit 52 for controlling the rotation speed of the rotating shaft 41 is provided on one of the support units 35. As shown in FIG. 11, the braking unit 52 includes a ring-shaped disk 53 attached to the other end of the rotating shaft 41 and a pair of shoes 54 pressed against the outer peripheral surface of the disk 53. . The shoes 54 are provided at the lower ends of a pair of swing arms 56 and 57 that are swingably attached to the roller frame 39 using pins 55. The pair of swing arms 56 and 57 are connected by a synchronization bar 58 so as to open and close with each other, and one of the swing arms 57 is operatively connected to an output shaft of a cylinder 59 mounted on the roller frame 39. Have been. The pair of swing arms 56 and 57 operate to close the shoe 54 in accordance with the extension of the cylinder 59, and press the shoe 54 against the outer peripheral surface of the disk 53 to brake the rotary shaft 41. A spring 60 is interposed between the base end of the other swing arm 55 and the roller frame 39, and the pair of swing arms 56 and 57 are normally driven by the biasing force of the spring 60. It operates in a direction to open the 54 side.

The brake unit 52 can be replaced with, for example, a disk brake 61 exemplified on the other support unit 34 side. As shown in FIGS. 9 and 10, the disc brake 61 is configured as an opposed piston type, and is attached to the roller frame 39 in the support unit 34 and attached to the other end of the rotating shaft 41. 62, and a predetermined braking force is generated.

The underwater cameras 63 are attached to both ends of the body frame 33 of the hanging tool 11. A dog 6 projecting from the peripheral surface of the rotating shaft 41 at a predetermined pitch is provided on the roller frame 39 of the one support unit 35.
A rotation amount detector 65 that detects the rotation amount of the rotation shaft 41 by detecting the rotation number 4 and an ultrasonic sounding device 66 that measures the distance between the jig 11 and the sheet laying surface are attached (FIG. 9). ).

In order to support the sheet roll 10 on the hanging member 11, as shown in FIGS. 15 and 16, a pair of roll support tables 70 for supporting the shaft member 9 of the sheet roll 10 with both ends are prepared. Are installed on the work boat 12 at predetermined intervals. The roll support 70 includes a pair of right and left columns 7.
A support block 73 having a V-shaped groove 72 formed on the upper surface thereof is attached to the upper end of 1, and the shaft member 9 of the sheet roll 10 is placed in the V-shaped groove 72 so that the sheet roll 10 can be stably supported. Has become. Then, the hanging tool 1 hung by the crane 13 approaches the sheet roll 10 supported by the roll support table 70, and the shaft member 9 is positioned between the rotating shafts 41 in the support units 34 and 35 at both ends. Then, if the flange 44 of the rotating shaft 41 and the end flange 9a of the shaft member 9 are joined together and fastened with bolts, the sheet roll 10 can be easily integrated with the hanging tool 11. At this time, it goes without saying that one support unit 35 is moved by operating the slide unit 46 in accordance with the length of the shaft member 9 of the sheet roll 10.

On the other hand, after the sheet roll 10 is supported by the hanging tool 11 as described above, the hanging tool 11 is
It is desirable to put on the hanging support 75 and wait for the start of construction. The hanger support base 75 includes a pair of right and left columns 77 having a support portion 76 at the upper end on which both ends of the support frame 36 constituting the support units 34 and 35 of the hanger 11 are placed. In this case, a pair of right and left columns 77
Are installed at a sufficient interval so as not to interfere with the main parts of the support units 34 and 35 including the roller frame 39 and the rotating shaft 41.

When laying the sandproof sheet 4, the top surface shape of the slope 2b of the rubble mound on which the sandproof sheet 4 is to be laid is measured in advance and stored in a storage unit (not shown) of the arithmetic processing unit 21. , The surface locus is displayed on the CRT of the display 29. Then, the work boat 12 floating on the inland sea A surrounded by the revetment 1 is moored at an appropriate place close to the slope 2 b of the rubble mound 2. Next, the hanging tool 11 previously supported on the sheet roll 10 and placed on the hanging tool support 75 (FIGS. 17 and 18) is hung on a hanging wire 13 extending from the crane 13, and first, the top end of the rubble mound 2 The hanging tool 11 is lowered to a position immediately above 2a, the sandproof sheet 4 is slightly pulled out from one end of the sheet roll 10, and the end is fixed to the top end 2a by an appropriate fixing means such as a weight or a wire.

Then, the position of the hanging tool 11 is determined by the positioning means including the GPS and the ultrasonic surveying system, and the hanging tool 11 is moved in the CRT of the display 29 while the hanging tool 11 is rubble-mounded. Along the slope 2b. Thereby, the sandproof sheet 4 is gradually pulled out from the sheet roll 10 and laid on the slope 2b. At this time, the rotation amount of the rotation shaft 41 is detected by the rotation amount detector 65, and based on the detection result, the rotation shaft 41 is not rotated more than necessary, that is, the feeding amount of the sand preventive sheet 4 is adjusted appropriately. , The hydraulic pressure supplied to the cylinder 59 or the disc brake 61 of the braking unit 52 is controlled. Also,
While monitoring the laying state with the underwater camera 63 provided on the hanging tool 11, the distance between the hanging tool 11 and the slope 2b is confirmed by the ultrasonic sounding device 66 provided on the hanging tool 11, and if there is any abnormality,
Stop work immediately.

As described above, the sand preventive sheet 4 passes over the large unevenness H (FIG. 2) of the rubble mound 2 (FIG. 2) and the slope 2b thereof.
Is laid uniformly. When the entire amount of the sandproof sheet 4 wound on the sheet roll 10 is laid, the lifting tool 11 is raised on the work boat 12, and the shaft member 9 is cut off on the roll support base 70 (FIGS. 15 and 16). The sheet roll 10 set in advance on the tool support 75 is supported by the hanging tool 11 and wrapped by a predetermined amount on the sandproof sheet 4 previously laid in the above-described manner (the wrap margin is about 2 to 3 m). The sandproof sheet 4 is laid, and this is sequentially repeated, and the top end 2a of the rubble mound 2
And a sandproof sheet 4 is laid on the entire surface of the slope 2b.

After the sand protection sheet 4 is laid, the upper surface of the sand protection sheet 4 is scanned by using, for example, a narrow multi-beam sonar 80 as shown in FIG. It is desirable to manage the finished form from the pattern of the chain 7. In this case, as the working frequency of the narrow multi-beam sonar 80, for example, about 455 kHz is selected, the beam angle θ is about 1.5 degrees, and the scanning range α is 90 degrees.

[0035]

As described above in detail, according to the sheet laying method and apparatus according to the present invention, the sandproof sheet can be laid reliably and easily on the sheet laying surface having large unevenness. This eliminates the need for special diving work such as rubble leveling, and is suitable for application to deep water.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an implementation state of a sheet laying method according to the present invention.

FIG. 2 is a cross-sectional view schematically illustrating a laying state of a sandproof sheet in the sheet laying method.

FIG. 3 is a cross-sectional view schematically illustrating a deformed state of a sandproof sheet used in the present sheet laying method.

FIG. 4 is a plan view schematically showing an arrangement of a sandproof sheet used in the present sheet laying method and a weight chain attached thereon.

FIG. 5 is a perspective view showing an attachment state of a weight chain to a sandproof sheet.

FIG. 6 is a perspective view schematically showing positioning means in the sheet laying method.

FIG. 7 is a block diagram showing a structure of a positioning means.

FIG. 8 is a front view showing the entire structure of the hanger of the sheet laying device.

FIG. 9 is a front view showing a main part of the hanging tool partially opened.

FIG. 10 is an enlarged side view of one side showing a main part of the hanging tool.

FIG. 11 is an enlarged side view showing the main part of the hanging tool on the opposite side.

FIG. 12 is a front view showing a shape of a roller frame which is a part of the hanging tool.

FIG. 13 is a cross-sectional view illustrating a structure of a roller that is a part of the hanging tool.

FIG. 14 is a cross-sectional view showing a structure of a rotating shaft which is a part of the hanging tool.

FIG. 15 is a front view showing the structure of a roll support table that supports a sheet roll.

FIG. 16 is a side view showing the structure of a roll support table that supports a sheet roll.

FIG. 17 is a front view showing a structure of a hanging tool support for supporting the hanging tool.

FIG. 18 is a side view showing a structure of a hanging tool support for supporting the hanging tool.

FIG. 19 is a schematic diagram showing a narrow multi-beam sonar used for finished product management and its use mode.

FIG. 20 is a schematic diagram showing a state of a weight chain to which the work management is applied.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Landfill revetment 2 Ripstone mound 3 Caisson 4 Sandproof sheet 8 Weight chain (weight member) 9 Shaft member 10 Sheet roll 11 Hanging tool 12 Work boat 13 Crane (Work machine) 16 Winch 17 GPS mobile station 18 GPS fixed station 19 Ultrasonic transmission Device 20 ultrasonic receiver 21 arithmetic processing unit 23 GPS receiving antenna 24 GPS receiving antenna 27 wireless transmitter 28 wireless receiver 29 display 33 body frame 34 support unit 35 support unit 41 rotation axis 52 braking unit 61 disk brake 65 rotation amount Detector

Continued on the front page (72) Keita Tomizawa, Inventor 4-1-1, Komyobashi, Chuo-ku, Osaka-shi, Osaka Toyo Construction Co., Ltd. (72) Eiichi Makino 4-1-1, Komashibashi, Chuo-ku, Osaka-shi, Osaka Toyo Construction Co., Ltd. (72) Inventor Seiichi Goto 4-1-1 Komyobashi, Chuo-ku, Osaka-shi, Osaka Prefecture Toyo Construction Co., Ltd. (72) Inventor Kenshi Morita 4-1-1 Komurobashi, Chuo-ku, Osaka-shi, Osaka No. Toyo Construction Co., Ltd. (72) Inventor Atsushi Sugimoto 4-1-1 Koraibashi, Chuo-ku, Osaka-shi, Osaka Prefecture Toyo Construction Co., Ltd. (72) Yoshio Nishino 1058 Nakao Uozumi-cho, Akashi-shi, Hyogo Shibata Kogyo (56) References JP-A-7-127034 (JP, A) JP-A-7-230597 (JP, A) JP-A-6-80388 (JP, A) (58) Fields investigated (Int. Cl. ^7, DB name) E02B 3 / 06.3 / 12,3 / 18 B66C 13/22 E02F 9/20

Claims (7)

(57) [Claims] 1. A global positioning system in which a sheet roll formed by winding a sandproof sheet on a shaft member in a roll shape is rotatably supported by a hanging tool, and the hanging tool is lowered into water by a work machine on a work boat. (GPS) and an ultrasonic surveying system, while checking the position of the hanging tool on the work boat, moving the hanging tool along the sheet laying surface,
A sandproof sheet is provided from the sheet roll on a hanger.
A sheet laying method, wherein the sheet roll is fed while controlling the rotation speed of the sheet roll by means . 2. The sheet laying method according to claim 1, wherein the position data of the hanger is corrected based on data received by a GPS fixed station installed at a known point on land. 3. The method according to claim 1, wherein the position of the hanger is confirmed on a monitor on the work boat, and the movement of the work machine and the work boat is controlled by remote control to move the hanger along the sheet laying surface. The sheet laying method according to claim 1. 4. The sheet laying method according to claim 1, wherein a sheet having a high elongation property is used as the sandproof sheet. 5. The sheet laying method according to claim 4, wherein a weight member for increasing the sheet weight is added to the sandproof sheet. 6. A suspending tool having a rotating shaft at both ends for supporting a shaft member on which a sandproof sheet is wound in a roll form, a work boat on which a crane for suspending and supporting the suspending tool is mounted, a GPS and an ultrasonic wave. Positioning means for obtaining the position of the hanger by a surveying system, a display for displaying position data of the hanger obtained by the positioning means, and a braking means for controlling a rotation speed of a rotation axis of the hanger. A rotation amount detector that detects a rotation amount of a rotation shaft of the hanging device, and a control unit that controls an operation of the braking unit based on a detection result by the rotation amount detector. Sheet laying equipment. 7. A hanging tool, wherein a rotating shaft is provided at both ends of a long main body frame having hooks on which a hanging wire of a crane is hooked so that a distance between them is variable, and a sandproof sheet is wound around the rotating shaft. The sheet laying apparatus according to claim 6, wherein both ends of the shaft member are detachably connected.