Method for installing a hoist gate and a hoist gate

Abstract

To provide an erecting gate installation method allowing transportation of the erecting gate to an installation area to be easily carried out.SOLUTION: A derricking gate installation method is provided with the processes of: producing a derricking gate 1 in a dock; floating the erected gate 1 on a water surface through buoyant force of a box body 2 by injecting water in the dock; towing to an installation area the derricking gate 1 floated on the water surface in a state a door body 3 is accommodated in a pit 21; settling the derricking gate 1 in a water bottom by sinking it; mooring in the pit 21 the door body 3 on which erecting moment is generated through retention of air by supplying air inside of the door 3 in a lodging state. This allows transportation of the derricking gate 1 to be easily carried out.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a bottom-mounted undulating gate and a method for installing the same. [Background technology]

[0002] In recent years, in order to prevent tsunamis, high tides, etc. from flowing into ports and harbors, etc., undulating gates have been installed on the bottom of the water at the entrances and exits of ports and harbors. For example, the bottom-mounted undulating gate described in Patent Document 1 comprises a box body installed on the bottom of the water and a door body attached to the box body. The door body is stored in a lying-down state in a recess provided on the top surface of the box body. Air is stored inside the door body in its lying-down state, and the door body is moored in the recess so that it does not stand up. When the door body is released from its mooring, its buoyancy causes it to rotate around a rotation axis provided on the box body and stand up.

[0003] When installing such a blast gate, a factory-manufactured blast gate is typically lifted by a floating crane or similar device and placed on a barge at sea. The barge is then towed by a tugboat or similar device, and the blast gate is transported by sea to the sea area where it is to be installed. When the barge arrives at the sea area, the blast gate is lifted by a floating crane or similar device and lowered to the sea surface, where water is poured into the box, causing it to sink to the seabed. Once the blast gate reaches the seabed, concrete is poured into the box, and the blast gate is installed on the seabed. However, because this type of blast gate is a relatively new technology, there is not much knowledge about installing blast gates.

[0004] Meanwhile, Patent Document 2 proposes a method for installing a large sluice gate that closes a waterway. The large sluice gate comprises a foundation that is installed on the seabed, and a gate that stands on the foundation and slides sideways to close the waterway. When installing the large sluice gate, the foundation is first floated on the sea surface by itself, towed to the installation area, and sunk into the seabed. Next, the gate is constructed until it floats above the sea surface, towed to the installation area, and sunk onto the foundation. The remaining part of the gate is then constructed in the installation area. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 2019-044351 [Patent Document 2] Japanese Patent Application Laid-Open No. 2004-3211 Summary of the Invention [Problem to be solved by the invention]

[0006] The installation method for a large sluice gate described in Patent Document 2 requires the foundation and gate sections to be towed separately to the installation area. Furthermore, this installation method requires the gate section to be erected on the foundation section at the installation area, and then the remaining section of the gate section to be constructed. Furthermore, the foundation and gate sections of the large sluice gate are each relatively simple, such as a roughly rectangular parallelepiped, making towing them over the sea relatively easy. However, a sluice gate like the one described in Patent Document 1 has a complex shape, including not only the box and gate body described above, but also a pair of side structures erected on the box body on both sides of the gate body in the width direction. Therefore, it is difficult to simply apply the transportation method and sinking method for the large sluice gate described above to the installation of this sluice gate.

[0007] The present invention has been made in consideration of the above problems, and aims to make it easier to transport a hoisting gate to the water area where it will be installed. [Means for solving the problem]

[0008] The invention described in claim 1 is a method for installing a bottom-mounted type of elevation gate, the elevation gate comprising: a box body having a pit, which is a recess, on the top surface; a door body connected to the box body at the rear end, which stands up and lies down by rotating around a rotation axis extending in the width direction, and which is accommodated in the pit in the laid-down state; and a pair of closing side walls which are erected on the box body on both sides in the width direction of the pit and which close the space on both sides in the width direction of the door body in the erected state. The method for installing a sag gate includes the steps of: a) manufacturing the sag gate in a dock; b) filling the dock with water to float the sag gate on the water surface by the buoyancy of the box; c) towing the sag gate, which is floating on the water surface with the door body housed in the pit, to an installation area; d) sinking the sag gate to install it on the bottom of the water; and e) supplying and storing air inside the door body in a collapsed state, and mooring the door body, which has an upright moment, in the pit. and, prior to the step c), further comprising a step of detachably attaching a pair of temporary wall portions extending in the width direction at the front and rear sides of the pit and watertightly connected to the pair of closing side wall portions to the upper surface of the box body. .

[0010] Claim 2 The invention described in claim 1 In the method for installing a hoisting gate described in the above, in the step c), the pair of closed side wall portions are aligned along the towing direction of the hoisting gate.

[0011] Claim 3 The invention described in claim 1 or 2 In the method for installing a relief gate described above, in the step c), a temporary drainage pump is installed in the pit.

[0012] Claim 4 The invention described in claim 1 Or 3 The method for installing a raised gate described in any one of the above items further comprises, between step a) and step b), a step of conducting a trial run to confirm that an upright moment is generated in the door body in a collapsed state with air stored inside by pouring water into the pit and into the space above the pit surrounded by the pair of closed side wall portions and the pair of temporary wall portions.

[0013] Claim 5 The invention described in claim 4 In the method for installing a rise-and-fall gate described above, during the trial operation, water is poured into the dock and the water level in the dock is set to a position between the bottom and top surfaces of the box body, where the rise-and-fall gate is maintained in a bottomed state.

[0014] Claim 6 The invention described in Install a bottom-mounted relief gate A method for installing a relief gate, comprising: The elevation gate comprises a box body having a recessed pit on the top surface, a door body connected to the box body at the rear end, which stands up and falls by rotating around a rotation axis extending in the width direction and is stored in the pit in the fallen state, and a pair of closing side walls which are erected on the box body on both sides of the width direction of the pit and close the space on both sides of the width direction of the door body in the upright state, and the elevation gate installation method comprises: a) a step of manufacturing the elevation gate in a dock; b) a step of pouring water into the dock to float the elevation gate on the water surface by the buoyancy of the box body; c) a step of towing the elevation gate floating on the water surface with the door body stored in the pit to an installation water area; d) a step of sinking the elevation gate and installing it on the bottom of the water; and e) a step of supplying air to the inside of the door body in the fallen state and storing it, and mooring the door body in the pit when an elevation moment is generated. In the step c), the pressure in the cavity defined by the watertight bulkhead inside the housing is maintained at a predetermined pressure higher than atmospheric pressure.

[0015] Claim 7 The invention described in claim 6 In the method for installing a wavy gate described above, the wavy gate further comprises an air supply unit that supplies air to the inside of the door body in step e), and air is supplied to the cavity from the air supply unit.

[0016] Claim 8 The invention described in claim 7 The method for installing a raised gate described in the above item (1) is characterized in that the air supply unit includes an air tank that stores air at a higher pressure than the air in the cavity, a pipe that connects the air tank to the cavity, and a pressure reducing valve and an exhaust valve that are provided on the pipe.

[0017] Claim 9 The invention described in claim 6 Or 8 In the step c), the pressure in the cavity is remotely monitored at a location away from the relief gate.

[0018] Claim 10 The invention described in claims 1 to 9 A method for installing a drapery gate according to any one of the above, wherein draft marks or sensors for measuring draft are provided at multiple locations around the box body.

[0019] Claim 11 The invention described in claims 1 to 10 A method for installing a support gate described in any one of the above, wherein, prior to step c), a towing appendage is attached to the box body in front of the towing direction in step c) so as to cover the side of the box body and reduce the drag coefficient of the box body.

[0020] Claim 12 The invention described in is a bottom-mounted type elevation gate, comprising a box body with a pit that is a recess on its upper surface, a door body that is connected to the box body at its rear end and that stands up and falls down by rotating around a rotation axis that extends in the width direction and is stored in the pit in the fallen state, a pair of closing side wall portions that are erected on the box body on both sides of the width direction of the pit and that close the spaces on both sides of the width direction of the door body in the upright state, and a pair of temporary wall portions that extend in the width direction at the front and rear of the pit and are watertightly connected to the pair of closing side wall portions and are detachably attached to the top surface of the box body. [Effects of the Invention]

[0021] The present invention makes it easy to transport the elevation gate to the water area where it is to be installed. [Brief explanation of the drawings]

[0022] [Figure 1] 1 is a perspective view of an elevation gate according to one embodiment; [Figure 2] FIG. 1 is a side view of a waving gate. [Figure 3] FIG. 1 is a plan view of a waving gate. [Figure 4] FIG. 1 is a side view of a waving gate. [Figure 5A] 10 is a flowchart showing the procedure for installing a hoisting gate. [Figure 5B] 10 is a flowchart showing the procedure for installing a hoisting gate. [Figure 6] FIG. 1 is a perspective view of a waving gate. [Figure 7]FIG. 1 is a perspective view of a waving gate. [Figure 8] FIG. 1 is a side view of a waving gate. [Figure 9] FIG. 1 is a plan view of a waving gate. [Figure 10] FIG. 1 is a side view of a waving gate. [Figure 11] FIG. 1 is a side view of a waving gate. [Figure 12] FIG. 2 is a schematic diagram showing an air supply section and a void space. [Figure 13] FIG. 1 is a plan view of the tugboat and hoisting gate. [Figure 14] FIG. 1 is a plan view of the tugboat and hoisting gate. [Figure 15] FIG. 1 is a side view of a waving gate. [Figure 16] FIG. 4 is a schematic diagram showing an air supply unit and a door body. DETAILED DESCRIPTION OF THE INVENTION

[0023] FIG. 1 is a perspective view showing a relief gate 1 according to one embodiment of the present invention. FIG. 2 is a side view showing the relief gate 1. In FIG. 2, a portion of the box body 2 and a pair of closing side wall portions 41, 42, which will be described later, are omitted from the illustration, and the pit 21 is shown in cross section (the same applies to FIGS. 8, 10, and 11, which will be described later). FIG. 3 is a plan view showing the relief gate 1. The relief gate 1 is a bottom-mounted relief gate that is installed on the bottom of the water at the entrance to a port, waterway, etc. to prevent tsunamis, high tides, etc. from flowing into the port, waterway, etc. In this embodiment, the relief gate 1 is installed on the seabed at the entrance to the port, and is used to prevent flooding from the entrance to the port.

[0024] In Figures 1 to 3, the lower left side in Figure 1, the left side in Figure 2, and the left side in Figure 3 are the offshore side (i.e., the side into which seawater flows during floods). In the following explanation, the offshore side will also be referred to as the "front side," and the harbor side, which is opposite the offshore side, will also be referred to as the "rear side." In other words, the left and right sides in Figure 2 are the "front side" and "rear side," respectively, and the left-right direction in Figure 2 is the "front-to-back direction." In the following explanation, the up-to-down direction in Figure 2 will also be simply referred to as the "up-to-down direction," and the direction perpendicular to the plane of the paper in Figure 2 will also be referred to as the "width direction." The front-to-back direction, width direction, and up-to-down direction are perpendicular to each other. The up-to-down direction is approximately parallel to the direction of gravity.

[0025] The elevation gate 1 comprises a box body 2, a door body 3, a pair of closed side walls 41, 42, and an air supply unit 44. The box body 2 is a substantially rectangular parallelepiped structure formed, for example, by welding steel plates or the like, and is placed on a foundation (hereinafter simply referred to as the "bottom") provided on the bottom of the water. Specifically, concrete is poured into the internal space of the box body 2 as a filler, and the position of the box body 2 on the bottom of the water is fixed by the weight of the elevation gate 1. Note that the filler is not limited to concrete, and other materials such as sand or crushed stone may also be used as the filler.

[0026] The shape of the case 2 in a plan view is, for example, a substantially rectangular shape. A pit 21, which is a recess that opens upward, is provided on the top surface of the case 2. The shape of the pit 21 in a plan view is, for example, a substantially rectangular shape. In the example shown in FIG. 3, the pit 21 is positioned rearward of the center of the case 2 in a plan view.

[0027] The size of the box body 2 in the front-to-back direction and the width direction in a plan view is, for example, several tens of meters. The size of the pit 21 in the front-to-back direction in a plan view is, for example, several tens of meters, and the size in the width direction is, for example, several tens of meters. The pit 21 is not a through-hole that passes through the box body 2, and the depth of the pit 21 (i.e., the vertical distance from the top surface 22 of the box body 2 to the bottom surface of the pit 21) is, for example, about two-thirds of the vertical height of the box body 2 (hereinafter simply referred to as "height"). The height of the box body 2 is, for example, several meters.

[0028] The door body 3 is a substantially rectangular parallelepiped member formed, for example, by welding steel plates or the like. Figures 1 to 3 depict the door body 3 in a state lying flat on the bottom of the water. The door body 3 in its lying flat state is housed in the pit 21 of the box body 2. The top surface of the door body 3 in its lying flat state is located at substantially the same vertical position as the top surface 22 of the box body 2. The rear end of the door body 3 (i.e., the end on the right side in Figure 2) is connected to the box body 2. Specifically, a rotation shaft 33 is provided at the rear end of the door body 3, and the rotation shaft 33 is rotatably connected to the box body 2 within the pit 21 of the box body 2. The rotation shaft 33 extends in the width direction within the pit 21. The door body 3 stands up and lies down by rotating around the rotation shaft 33. In Figure 2, the door body 3 in its standing state is depicted by a two-dot chain line.

[0029] The front end of the door body 3 is a free end when the door body 3 rotates, and the rear end of the door body 3 is a fixed end (i.e., a supported end) when the door body 3 rotates. In the following description, the direction perpendicular to the width direction and connecting the rear end and front end of the door body 3 along the door body 3 is also referred to as the "longitudinal direction" of the door body 3. When the door body 3 is in a laid-down state, the longitudinal direction approximately coincides with the front-to-rear direction. The rotation shaft 33 may be provided as a part of the box body 2. In this case, the door body 3 is rotatably connected to the rotation shaft 33.

[0030] The pair of closing side walls 41, 42 are, for example, substantially rectangular parallelepiped structures formed by welding steel plates or the like. The pair of closing side walls 41, 42 are erected on the upper surface 22 of the box 2 on both sides in the width direction of the pit 21. The widthwise inner end of the upper closing side wall 41 in FIG. 3 (i.e., the lower end in FIG. 3) is located at substantially the same position in the width direction as the widthwise edge of the pit 21. The widthwise inner end of the lower closing side wall 42 in FIG. 3 (i.e., the upper end in FIG. 3) is located at substantially the same position in the width direction as the widthwise edge of the pit 21. Note that the widthwise inner ends of the pair of closing side walls 41, 42 may be spaced apart in the width direction from the widthwise edge of the pit 21.

[0031] Each of the pair of closing side walls 41, 42 is longer in the front-to-rear direction than the pit 21. In the example shown in Fig. 3, on the upper surface 22 of the case 2, the rear ends of each of the pair of closing side walls 41, 42 are located rearward of the rear edge of the pit 21 and are located at approximately the same position in the front-to-rear direction as the rear end of the case 2. Furthermore, on the upper surface 22 of the case 2, the front ends of each of the pair of closing side walls 41, 42 are located at approximately the same position in the front-to-rear direction as the front edge of the pit 21 and are located rearward of the front end of the case 2.

[0032] In the example shown in FIG. 3 , the pair of closing side walls 41, 42 are asymmetrical with respect to a centerline extending in the front-to-rear direction through the center of the width of the undulating gate 1 in a plan view. Specifically, the width of one closing side wall 41 (hereinafter simply referred to as "width") is greater than the width of the other closing side wall 42. Furthermore, the height of the closing side wall 41 from the top surface 22 of the box body 2 is greater than the height of the closing side wall 42 from the top surface 22 of the box body 2. The length of the closing side wall 41 in the front-to-rear direction is approximately the same as the length of the closing side wall 42 in the front-to-rear direction. The positions of the front and rear ends of the closing side wall 41 in the front-to-rear direction are approximately the same as the positions of the front and rear ends of the closing side wall 42 in the front-to-rear direction. Note that the widths of the closing side wall 41 and the closing side wall 42 may be the same. Furthermore, the heights of the closing side wall 41 and the closing side wall 42 may be the same. The lengths and positions of the closed side wall portions 41 and 42 in the front-rear direction may be changed as appropriate.

[0033] The upper portions of the pair of closing side walls 41, 42 each protrude above the water surface. In the example shown in Fig. 1, the internal space above the closing side wall 41 is a control room 43 in which various devices related to raising and lowering the door body 3 are arranged. The control room 43 is provided with, for example, an air supply unit 44. The control room 43 is also provided with, for example, a control unit (not shown) that controls the mooring unit 24, which will be described later, etc.

[0034] A door body 3 is provided inside with a door body buoyancy chamber (not shown), which is a space capable of storing air supplied from the air supply unit 44. When the door body 3 is in the lying down state, air is stored in the door body buoyancy chamber, so that the force acting in the direction of floating the door body 3, such as the buoyancy of the door body 3, is greater than the force acting in the direction of sinking the door body 3, such as the weight of the door body 3. In the following description, the "buoyancy force" refers to the force acting in the direction of floating the door body 3 minus the force acting in the direction of sinking the door body 3. When the door body 3 is in the lying down state, the buoyancy force is positive, so a moment acting in the direction of raising the door body 3 (hereinafter also referred to as "raising moment") is generated. The number of door body buoyancy chambers provided in the door body 3 may be one or two or more.

[0035] As shown in FIG. 2, the door body 3 in the laid-down state is moored in the pit 21 (i.e., to the bottom of the water) by mooring parts 24 provided in the pit 21 of the box body 2. This prevents the door body 3 from standing up unintentionally. The mooring parts 24 are provided, for example, on the front wall of the pit 21, and fasten the front end of the door body 3 with a hook member or the like. In the example shown in FIG. 3, four mooring parts 24 are provided lined up in the width direction. The number and arrangement of the mooring parts 24 may be changed as appropriate.

[0036] When the gate body 3 is raised in response to a tsunami or the like, the mooring unit 24 is driven by the control unit, and the gate body 3 is released from its mooring state. As a result, the gate body 3 rotates clockwise about the rotation axis 33 to a certain extent in FIG. 2, and the front end of the gate body 3 protrudes above the water surface. When seawater flows into the gate body 3 from the offshore side (i.e., the front side), the raising moment acting on the gate body 3 increases, and the gate body 3 enters the raised state as shown in FIG. 4. This prevents seawater from flowing from the offshore side of the gate body 3 into the port, thereby preventing the water level in the port from rising. The front end of the gate body 3 in the raised state (i.e., the upper end in FIG. 4) protrudes above the water surface 91 on the offshore side of the gate body 3. The gate body 3 in the raised state is supported by the tension rod 34. The angle between the gate body 3 in the raised state and the horizontal plane may be set appropriately within a range greater than 0 degrees and less than or equal to 90 degrees.

[0037] In FIG. 4 , the closing side wall 41 located at the rear of the door body 3 is indicated by a thin line. The door body 3 in the upright state is located between the pair of closing side walls 41, 42. Both widthwise end faces of the door body 3 in the upright state contact, for example, the inner side walls of the pair of closing side walls 41, 42 in the widthwise direction. Note that a slight gap may exist between both widthwise end faces of the door body 3 in the upright state and the inner side walls of the pair of closing side walls 41, 42 in the widthwise direction. In other words, the door body 3 in the upright state is sandwiched between the pair of closing side walls 41, 42 from both sides in the widthwise direction, and the spaces on both sides of the door body 3 in the widthwise direction are closed by the pair of closing side walls 41, 42. The contact portions between the door body 3 and the pair of closing side walls 41, 42 are preferably sealed watertight. The upper end of the door body 3 in the upright state is located below the upper ends of the closing side walls 41 and 42.

[0038] When the water level 91 on the offshore side of the gate body 3 begins to drop, the gate body 3 gradually collapses as the water level 91 drops. In other words, the gate body 3 rotates counterclockwise in FIG. 4 around the rotation axis 33. When the water level difference between the offshore side and the port side of the gate body 3 disappears (i.e., when the water level difference between the front and rear of the gate body 3 disappears), the gate body 3 stops in a position between the upright state and the collapsed state, with its front end protruding above the water surface 91. After that, the exhaust unit (not shown) provided in the gate body 3 is opened by the above-mentioned control unit, and water flows into the above-mentioned gate body buoyancy chamber through an opening (not shown) located below the water level 91. The air in the gate body buoyancy chamber is exhausted through the exhaust unit. As the air in the gate body buoyancy chamber is replaced with water, the gate body 3 further collapses, and as shown in FIG. 2, it is stored in the pit 21 in a collapsed state. At this time, the tension rod 34 is folded and stored below the gate body 3. When the door body 3 is in a collapsed state, air is supplied from the air supply section 44 to the door body buoyancy chamber and stored therein, and the door body 3 is moored by the mooring section 24 with an upright moment acting on it.

[0039] 1 to 3, the door body 3 is depicted as a single member, but the door body 3 may be divided into multiple members arranged in the width direction. In this case, if each of the multiple members is considered to be a door body, multiple door bodies are arranged in the width direction between the pair of closing side walls 41, 42.

[0040] Next, a method for installing the undulating gate 1 will be described with reference to Figures 5A, 5B, and 6 to 15. Figures 5A and 5B are flowcharts showing the procedure for installing the undulating gate 1. Figures 6 to 15 are diagrams showing how the undulating gate 1 is installed.

[0041] First, the elevation gate 1 is manufactured in a dock (i.e., a dry dock) used for building ships, marine structures, and the like (step S11). The dock is in a state where the gate is closed and drained (i.e., a dry state, hereinafter also referred to as a "drained state"). In step S11, the box body 2 and the pair of closed side walls 41, 42 are manufactured as a continuous structure. The box body 2 and the pair of closed side walls 41, 42 are manufactured, for example, on a frame (e.g., a wooden block) not shown. Specifically, multiple frames contact the bottom surface of the box body 2 and support the box body 2 and the pair of closed side walls 41, 42 from below. The space inside the box body 2 and the pair of closed side walls 41, 42 is divided into multiple watertight compartments 52 by watertight bulkheads 51 arranged in a lattice pattern, as illustrated by dashed lines in FIG. 6. Each watertight bulkhead 51 is arranged approximately vertically in the fore-and-aft direction, width direction, or up-and-down direction. The number, arrangement, shape, etc. of the watertight compartments 52 may be variously changed.

[0042] Concrete is poured into some of the multiple watertight compartments 52 in the dock. The position of the watertight compartments 52 into which concrete is poured is preferably close to the bottom of the box body 2 from the viewpoint of lowering the center of gravity of the elevation gate 1 during towing, etc., as described below. Furthermore, the position of the watertight compartments 52 into which concrete is poured is determined so that the center of gravity of the elevation gate 1 is at a desired position, taking into consideration imbalance due to differences in size between the closed side wall portions 41 and 42, and shifts in the center of gravity due to the installation of the door body 3. The multiple watertight compartments 52 into which concrete is not poured become water ballast compartments into which seawater is poured, or void spaces into which seawater is not poured, when the elevation gate 1 is submerged, as described below.

[0043] In step S11, the door body 3 is manufactured in the dock in parallel with, or before or after, the manufacturing of the box body 2 and the pair of closed side wall portions 41, 42. Then, the door body 3 is mounted on the box body 2 and connected to the box body 2. The door body 3 is stored in a lying down state in the pit 21 of the box body 2.

[0044] Next, as shown in FIGS. 7 to 9, a pair of temporary wall portions 23 are detachably attached to the upper surface 22 of the box body 2 (step S12). The pair of temporary wall portions 23 are substantially rectangular parallelepiped members and extend substantially linearly and substantially parallel to the width direction at the front and rear sides of the pit 21. The pair of temporary wall portions 23 are disposed adjacent to the pit 21 along the front and rear edges of the pit 21. Each of the pair of temporary wall portions 23 is provided across the entire width of the pit 21. In FIG. 8, the pair of temporary wall portions 23 is shown in cross section (the same applies to FIGS. 10 and 11 described below). In addition, in FIG. 9, the pair of temporary wall portions 23 are indicated by parallel diagonal lines to facilitate understanding of the drawing (the same applies to FIGS. 13 and 14 described below).

[0045] The connection between the pair of temporary wall sections 23 and the box body 2 is watertight. The temporary wall sections 23 and the box body 2 are connected, for example, by bolting with watertight rubber sandwiched between them. The height of each temporary wall section 23 is lower than the pair of closed side wall sections 41, 42, for example, about 1 m. The height of each temporary wall section 23 may be changed as appropriate. Each temporary wall section 23 is divided, for example, into multiple blocks arranged along the width direction. It is preferable that the blocks are large enough that workers can attach and detach them manually, for example.

[0046] Of the pair of temporary wall portions 23, the temporary wall portion 23 on the front side of the pit 21 is watertight connected at both widthwise ends to the front side walls of the pair of closing side walls 41, 42. In addition, the temporary wall portion 23 on the rear side of the pit 21 is watertight connected to the inner side walls of the pair of closing side walls 41, 42 in the widthwise direction. As a result, a substantially rectangular parallelepiped space (hereinafter also referred to as "temporary space 25") surrounded by the pair of closing side walls 41, 42 and the pair of temporary wall portions 23 is formed above the pit 21. The temporary space 25 is a space that is continuous with the pit 21 in the vertical direction. The temporary wall portion 23 and the closing side walls 41, 42 are connected, for example, by bolting with watertight rubber sandwiched between them.

[0047] When the front ends of the pair of closing side walls 41, 42 are located forward of the front edge of the pit 21, the temporary wall 23 located on the front side of the pit 21 may be watertight connected to the inner side walls in the width direction of the pair of closing side walls 41, 42. On the other hand, when the rear ends of the pair of closing side walls 41, 42 are located forward of the rear end of the box 2, the temporary wall 23 located on the rear side of the pit 21 may be watertight connected to the rear side walls of the pair of closing side walls 41, 42. Furthermore, the attachment of the pair of temporary wall parts 23 in step S12 may be performed before the door body 3 is mounted on the box 2 in step S11.

[0048] After the installation of the pair of temporary wall sections 23 is completed, a trial run of the elevation gate 1 is performed (step S13). In step S13, water is first poured into the dock. As shown in FIG. 10, the water level in the dock after the water pouring (i.e., the vertical position of the water surface 92) is located between the bottom surface 26 and the top surface 22 of the elevation gate 1 arranged on the multiple mounts 81. In the state shown in FIG. 10, the elevation gate 1 does not float on the water surface 92, and the bottom surface 26 of the box body 2 remains in contact with the multiple mounts 81. In other words, the elevation gate 1 remains attached to the bottom even after water is poured into the dock. When pouring water into the dock, ballast water may be poured into one or more watertight compartments 52 (see FIG. 6) where concrete is not poured in order to eliminate load imbalances in the fore-aft and lateral directions caused by the buoyancy of the box body 2. Ballast water is injected, for example, through an openable and closable water injection valve provided on the upper end surface of the watertight compartment 52.

[0049] In step S13, water is poured into the pit 21 and the temporary space 25 in parallel with the pouring of water into the dock. The pouring of water begins after the exhaust unit of the door body 3 is closed by the above-mentioned control unit, and continues until the water level 93 in the pit 21 and the temporary space 25 reaches a predetermined position higher than the upper surface 22 of the box body 2. The position of the water level 93 is below the upper ends of the temporary wall portions 23. When the door body 3 is in the collapsed state, air is stored in the door body buoyancy chamber, so that an upright moment is generated by pouring water into the pit 21 and the temporary space 25. Then, when the above-mentioned control unit releases the mooring unit 24 from the door body 3, the door body 3 rotates slightly clockwise around the rotation axis 33 from the collapsed state shown in FIG. 10 and assumes a slightly upright state as shown in FIG. 11. In this way, the trial operation of the elevation gate 1 is completed by closing the exhaust section, releasing the mooring section 24, and confirming that a normal erection moment is generated in the door body 3, causing the door body 3 to erect.

[0050] In step S13, as described above, water is poured into the dock in parallel with the pouring of water into the pit 21 and the temporary space 25, causing buoyancy in the box body 2, and therefore, the pouring of water into the pit 21 and the temporary space 25 prevents an excessive load from being applied to the multiple racks 81. In step S13, the water poured into the pit 21 may flow into the watertight compartment 52 that communicates with the pit 21, among the multiple watertight compartments 52 (see FIG. 6 ) in the pair of closing side wall portions 41, 42. For example, water may flow from the pit 21 into one watertight compartment 52 on the front side of the closing side wall portion 41 and two or three watertight compartments 52 on the rear side. Note that in step S13, the pouring of water into the pit 21 and the temporary space 25 may be performed after the pouring of water into the dock has been completed or before the pouring of water into the dock.

[0051] Once the trial run of the elevation gate 1 is complete, the dock is drained. In parallel with this drainage of the dock, the water in the pit 21 and the temporary space 25 is drained, and the door body 3 is collapsed and stored in the pit 21. The exhaust section of the door body 3 is opened. This prevents the door body 3 from unintentionally rising up, even if water seeps into the pit 21 during the transportation of the door body 3, as described below. Once the drainage of the dock is complete, the elevation gate 1 is rigged, and inspections before leaving the dock are carried out.

[0052] Next, water is poured into the dock. As a result, the elevation gate 1 is separated from the multiple platforms 81 and floats on the water surface (step S14). The draft of the elevation gate 1 is located between the bottom surface 26 and the top surface 22 of the box body 2, and the elevation gate 1 floats due to the buoyancy of the box body 2. When the elevation gate 1 is raised, ballast water may be poured into one or more watertight compartments 52 (see FIG. 6) in which concrete has not been poured in order to adjust the draft and attitude of the elevation gate 1. For example, the ballast water may be poured into the same watertight compartment 52 as the watertight compartment 52 into which ballast water was loaded in step S13, or into a watertight compartment 52 different from the watertight compartment 52. In the following description, the watertight compartment 52 into which ballast water is to be loaded before the elevation gate 1 has completely sunk to the bottom of the water will also be referred to as the "water ballast compartment."

[0053] When the hoisting gate 1 floats, the draft of the hoisting gate 1 is measured to confirm that the draft and attitude of the box body 2 are at predetermined values. The draft measurement is performed, for example, using draft marks (draft indicators) pre-installed at multiple locations on the outer surface of the box body 2 (e.g., the four corners of the box body 2 in a plan view). Specifically, the draft is measured by having an operator on a boat or other vessel move around the box body 2 and visually check the draft marks and draft. Alternatively, draft measurement sensors (e.g., water level indicators) may be installed at multiple locations around the box body 2, and the draft measurement may be performed remotely using these sensors. In this embodiment, the draft and freeboard at the four corners are set to be approximately the same so that the top surface 22 of the box body 2 is approximately horizontal. If the draft of the hoisting gate 1 deviates from the predetermined value, the draft is adjusted by injecting or discharging ballast water into or from the watertight compartment 52.

[0054] Next, air at a pressure higher than atmospheric pressure is supplied from the air supply unit 44 shown in FIG. 1 to a section of the watertight compartment 52 where concrete has not been poured and where no ballast water is loaded (hereinafter also referred to as a "void space"). This void space is an airtight compartment. As a result, the pressure in the void space is maintained at a predetermined pressure higher than atmospheric pressure (hereinafter also referred to as a "towing pressure") (step S15). This void space may be a section facing the outer wall of the box body 2, etc., or may be a section not facing the outer wall. The number of such void spaces may be one or more. In the following description, it is assumed that air is supplied to multiple void spaces.

[0055] 12 is a schematic diagram showing an example of a connection between the air supply unit 44 and the cavity 52a. The air supply unit 44 includes an air tank 441, pipes 442 and 449, a pressure reducing valve 443, a branching unit 444, an exhaust valve 447, and a shutoff valve 448. The air tank 441 is disposed in the control room 43 (see FIG. 1). The air tank 441 is connected to an air supply source 440 (e.g., a compressor) disposed in the control room 43, and stores compressed air (i.e., air with a higher pressure than atmospheric pressure) supplied from the air supply source 440. The air supply source 440 may be disposed in an onshore facility or the like separated from the elevation gate 1. The number of air tanks 441 may be one or more.

[0056] The pressure of the air stored in the air tank 441 is maintained at a predetermined pressure that is higher than the towing pressure described above and the sinking pressure described below. When the pressure in the air tank 441 drops below the predetermined pressure, compressed air is automatically supplied to the air tank 441 by the air supply source 440. The air tank 441 is connected to each of the plurality of spaces 52a via a pipe 442 and a plurality of pipes 449. The pipes 442 and 449 are installed in advance, for example, in step S11. Alternatively, the pipes 442 and 449 may be installed during outfitting after the trial run in step S13.

[0057] A branching portion 444, a shutoff valve 448, a pressure reducing valve 443, and an exhaust valve 447 are provided on the pipes 442, 449 connecting the plurality of spaces 52a and the air tank 441. Specifically, the branching portion 444 is provided at the end of the pipe 442 extending from the air tank 441. The branching portion 444 is, for example, a branching pipe or a branch valve that connects the plurality of pipes 449 to one pipe 442. The branching portion 444 and the plurality of spaces 52a are connected to each other by the plurality of pipes 449. The shutoff valve 448, the pressure reducing valve 443, and the exhaust valve 447 are arranged on each pipe 449 in this order from the branching portion 444 side. The arrangement order of the shutoff valve 448, the pressure reducing valve 443, and the exhaust valve 447 may be changed as appropriate. The pressure reducing valve 443 maintains the pressure on the secondary side (i.e., the cavity 52a side) at a predetermined pressure lower than the pressure on the primary side (i.e., the air tank 441 side). Compressed air in the air tank 441 is supplied to each cavity 52a via the pressure reducing valve 443. This allows the pressure in each cavity 52a to be maintained approximately constant at the above-mentioned towing pressure, which is lower than the air pressure in the air tank 441 and higher than atmospheric pressure. The shutoff valve 448 is open when the cavity 52a and the air tank 441 are connected, and is closed to disconnect the cavity 52a from the air tank 441. The exhaust valve 447 is normally closed when the cavity 52a and the air tank 441 are connected. When a large amount of air is to be discharged from the cavity 52a, the shutoff valve 448 is closed and the exhaust valve 447 is opened, so that the air in the cavity 52a is discharged to the outside through the exhaust valve 447.

[0058] 12 includes a plurality of pressure sensors 445 capable of measuring the pressure in each of the plurality of spaces 52a. The pressure sensors 445 are provided, for example, on the pipe 449, between the spaces 52a and the branching section 444. The pressure in the spaces 52a measured by the pressure sensors 445 is transmitted to a monitoring device provided outside the elevation gate 1. This allows the pressure in each space 52a to be remotely monitored from a location away from the elevation gate 1.

[0059] Step S15 may be performed in parallel with step S14. Alternatively, step S15 may be performed before step S14 (for example, before water is poured into the dock during trial operation in step S13). In addition, in step S15, all of the watertight compartments 52 in which concrete has not been poured and in which ballast water has not been loaded may be made into void spaces 52a to which air is supplied from the air supply unit 44, or only some of the watertight compartments 52 may be made into void spaces 52a to which air is supplied from the air supply unit 44.

[0060] After steps S14 and S15 are completed, the boom-raising gate 1, floating on the water surface, is towed out of the dock by a tugboat or the like and towed to the water area where the boom-raising gate 1 is to be installed (hereinafter also referred to as the "installation water area") (step S16). In step S16, as shown in FIG. 13, the boom-raising gate 1 is connected to the tugboats 82, 82a and towed so that one side of the width direction of the boom-raising gate 1 faces forward in the towing direction (i.e., downward in FIG. 13). In other words, the pair of closing side walls 41, 42 are aligned along the towing direction of the boom-raising gate 1. In the example shown in FIG. 13, the closing side wall 42 of the boom-raising gate 1 is located forward in the towing direction (i.e., the up-down direction in FIG. 13), and the closing side wall 41 is located rearward in the towing direction. The pair of temporary wall sections 23 extend approximately parallel to the towing direction on both the left and right sides of the towing direction of the boom-raising gate 1. The tugboat 82 is the main tugboat located in front of the boom-raising gate 1 in the towing direction. The tugboat 82a is the auxiliary tugboat located behind the boom-raising gate 1 in the towing direction.

[0061] During towing, the pair of closed side walls 41, 42 and the pair of temporary walls 23 surround the entire periphery of the pit 21 on the upper surface 22 of the box body 2. This prevents seawater from entering the pit 21 even when waves crash onto the upper surface 22 of the box body 2. This prevents an increase in the draft of the boom gate 1 (i.e., a decrease in freeboard), improving the safety of the towing operation of the boom gate 1. Furthermore, a decrease in the initial stability of the boom gate 1 due to the effect of free water in the pit 21 is also prevented, further improving the safety of the towing operation of the boom gate 1.

[0062] In step S16, a temporary drainage pump 84 may be installed in the pit 21. The temporary drainage pump 84 is, for example, a submersible pump, and is disposed below the gate body 3. The temporary drainage pump 84 is activated when seawater enters the pit 21, and sucks up the seawater in the pit 21 and releases it outside the boom gate 1. This further improves the safety of the towing operation of the boom gate 1. The number of temporary drainage pumps 84 may be one or more. The temporary drainage pump 84 is preferably remotely operated from a location away from the boom gate 1 (for example, a tugboat 82, 82a). This eliminates the need for workers to board the boom gate 1 during towing to operate the temporary drainage pump 84, further improving the safety of the towing operation of the boom gate 1.

[0063] During towing in step S16, the pressure in each of the empty spaces 52a (see FIG. 12) of the boom-raising gate 1 is maintained at a towing pressure higher than atmospheric pressure. This prevents water from flooding the empty spaces 52a when the boom-raising gate 1 is towed. As a result, the safety of the towing operation of the boom-raising gate 1 is improved. In step S16, the pressure in each empty space 52a is remotely monitored from a location (e.g., tugboats 82, 82a) away from the boom-raising gate 1 using the pressure sensor 445 described above. For example, if a pressure drop occurs in one of the empty spaces 52a, the operator who discovers the pressure drop through remote monitoring remotely operates the air supply unit 44 to quickly increase the pressure in that empty space 52a and restore the pressure to the towing pressure. Specifically, for example, the shutoff valves 448 corresponding to the other spaces 52a other than the space 52a whose pressure has been reduced are closed, the other spaces 52a are disconnected from the air tank 441, and air is supplied from the air tank 441 only to the space 52a whose pressure has been reduced to increase the pressure. Note that monitoring the pressure of each space 52a and supplying air to the space 52a whose pressure has been reduced do not necessarily have to be performed by an operator; for example, a pressure control system using a computer or the like may automatically detect the pressure drop in the space 52a and increase the pressure in the space 52a. The above-mentioned pressure drop in the space 52a may be caused by, for example, a temporary air leak from the space 52a or a drop in the temperature of the air in the space 52a.

[0064] As described above, during towing of the boom-raising gate 1, the pressure of the air stored in the air tank 441 is higher than the pressure in each cavity 52a (i.e., the towing pressure), and each cavity 52a is connected to the air tank 441 via a pressure reducing valve 443. Therefore, even if a drop in pressure occurs in the cavity 52a while the air supply unit 44 cannot be operated due to a power outage or the like, air is supplied from the air tank 441 to the depressurized cavity 52a as long as the pressure in the air tank 441 remains equal to or higher than the towing pressure, and the pressure in the cavity 52a is restored to the towing pressure. This further improves the safety of the towing operation of the boom-raising gate 1. Furthermore, by remotely monitoring the pressure in the cavity 52a and remotely operating the air supply unit 44, it is not necessary for an operator to board the boom-raising gate 1 during towing, further improving the safety of the towing operation of the boom-raising gate 1.

[0065] In step S16, as shown in FIG. 14, a towing appendage 83 may be attached to the front end of the boom gate 1 in the towing direction. The towing appendage 83 covers the side of the box body 2 in front of the boom gate 1 in the towing direction, reducing the drag coefficient of the box body 2 when the boom gate 1 is towed by tugboats 82, 82a. This reduces water resistance when the boom gate 1 is towed. In the example shown in FIG. 14, the towing appendage 83 is a hollow member in the shape of a substantially triangular prism that extends vertically through the water surface and covers the side of the box body 2 in front of the towing direction over substantially the entire length in the left-right direction when towing. When towing of the boom gate 1 is completed, the towing appendage 83 is detached from the boom gate 1. The shape and size of the towing appendage 83 may be modified in various ways.

[0066] When the boom-raising gate 1 is towed to the installation waters, it is handed over to a floating crane (not shown) waiting in the installation waters, and the boom-raising gate 1 comes alongside the floating crane.

[0067] In the elevation gate 1, by operating the pressure reducing valve 443 of the air supply unit 44 shown in FIG. 12, air is supplied from the air tank 441 to the plurality of spaces 52a, and the pressure in the plurality of spaces 52a is maintained at a predetermined pressure higher than atmospheric pressure (hereinafter also referred to as the "sinking pressure") (step S17). This reduces the force acting on the box body 2 and other components due to water pressure when the elevation gate 1 is sunk, as described below. The sinking pressure is set appropriately based on the water depth at the location where the elevation gate 1 is sunk, etc. The sinking pressure is, for example, higher than the towing pressure. The sinking pressure may be the same as the towing pressure, or may be lower than the towing pressure.

[0068] The plurality of voids 52a whose pressure is set to the pressure at the time of sinking in step S17 may all be the same as the plurality of voids 52a whose pressure is set to the pressure at the time of towing in step S13, for example, or may be partially or entirely different from the plurality of voids 52a whose pressure is set to the pressure at the time of towing in step S13. The plurality of voids 52a whose pressure is set to the pressure at the time of sinking may be sections facing the outer wall of the box body 2, etc., or may be sections not facing the outer wall. The number of voids 52a whose pressure is set to the pressure at the time of sinking may be one.

[0069] If the above-mentioned pressure at the time of sinking is the same as the pressure at the time of towing, and the multiple voids 52a whose pressure at the time of sinking is the same as the multiple voids 52a whose pressure at the time of towing in step S13 are all the same, step S17 may be omitted since the pressure in the multiple voids 52a has been increased in step S13.

[0070] Next, as shown in FIG. 15 , multiple wires 87 extending from the crane 85 of the floating crane are connected to the boom gate 1. Specifically, the multiple wires 87 are connected to hanging fittings 88 provided on the upper surface 22 of the box body 2 and the upper surfaces of the pair of closed side wall portions 41, 42 via a hanging frame 86 having a substantially rectangular shape in a plan view. The boom gate 1 is supported by the crane 85 while floating on the water surface 94 (step S18). In other words, part of the weight of the boom gate 1 is supported by the crane 85, and the remaining weight of the boom gate 1 is balanced by the buoyancy of the boom gate 1. In step S18, the draft of the boom gate 1 is located between the bottom surface 26 and the upper surface 22 of the box body 2.

[0071] In a floating crane, the center position of the load applied to the crane 85 is required to be located within a predetermined suspension range. The suspension range is, for example, a rectangular area of ​​several meters by several meters centered on the hook of the crane 85 in a plan view. In step S18, ballast water may be poured into one or more watertight compartments 52 (i.e., water ballast compartments) where concrete has not been poured so that the center position of the load applied to the crane 85 (i.e., the weight of a portion of the boom gate 1 supported by the crane 85) is located within the suspension range.

[0072] Once the elevation gate 1 is auxiliarily supported by the crane 85, the pair of temporary wall sections 23 (see Figures 7 to 9) are detached from the box body 2 and the pair of closed side wall sections 41, 42 and removed to the outside of the elevation gate 1. Next, the draft of the elevation gate 1 is measured. This draft measurement is performed using the above-mentioned draft marks or a draft measurement sensor. Note that the temporary wall sections 23 may be removed before the elevation gate 1 is auxiliarily supported by the crane 85. Furthermore, the draft measurement of the elevation gate 1 may also be performed as many times as necessary in step S19, which will be described later.

[0073] Next, water is poured into the pit 21 while the draft of the elevation gate 1 is maintained unchanged by the crane 85. Water is poured into the pit 21 while the center position of the load applied to the crane 85 is always located within the suspension range. When pouring water into the pit 21, for example, ballast water may be poured into the water ballast section so that the center position of the load applied to the crane 85 does not move due to the weight of the water in the pit 21 and fall outside the suspension range.

[0074] In this way, by pouring water into the pit 21 before the lowering of the elevation gate 1, it is possible to prevent seawater from suddenly flowing into the pit 21 when the elevation gate 1 is lowered, which would cause a sudden increase in the load on the crane 85 or a sudden shift in the center position of that load. When pouring water into the pit 21, the exhaust section of the door body 3 is open and water also flows into the door body buoyancy chamber, so no upright moment is generated in the door body 3. Note that if the draft of the elevation gate 1 is located below the upper surface 22 of the box body 2, the elevation gate 1 may be lowered while water is being poured into the pit 21.

[0075] Once water injection into the pit 21 is complete, water is injected into the multiple water ballast compartments that have not yet been filled with water (i.e., watertight compartments 52 that have not been filled with concrete and are not void spaces 52a) in order to ensure the weight required for the sinking of the elevation gate 1 (step S19). In step S19, the order of water injection into the multiple water ballast compartments is determined in advance so that the center position of the load applied to the crane 85 is always located within the above-mentioned suspension range.

[0076] In step S19, for example, water is poured into the water ballast compartment while the draft of the boom lift gate 1 is maintained unchanged by the crane 85. Alternatively, in step S19, the boom lift gate 1 may be lowered to increase the draft while water is being poured into the water ballast compartment. In this case, it is preferable that the draft of the boom lift gate 1 be positioned below the upper surface 22 of the box body 2 until water pouring into the water ballast compartment is complete. This improves the safety of the water pouring operation into the water ballast compartment.

[0077] In this embodiment, as shown in FIG. 5B , the injection of water into the multiple water ballast compartments in step S19 is performed in two stages after the injection of water into the pit 21 (step S191). First, water is injected into some of the multiple water ballast compartments while the draft of the hoisting gate 1 is maintained unchanged by the crane 85. Then, the crane 85 lowers the hoisting gate 1 a predetermined distance, increasing the draft of the hoisting gate 1 (step S192). This reduces the load on the crane 85 and improves the safety of the installation work of the hoisting gate 1. After completion of step S192, the draft of the hoisting gate 1 is located below the upper surface 22 of the box body 2. Note that, as long as the draft of the hoisting gate 1 is located below the upper surface 22 of the box body 2, the hoisting gate 1 may be lowered while water is being injected into some of the water ballast compartments.

[0078] After step S192 is completed, water is poured into the remaining of the plurality of water ballast compartments (step S193), while the draft of the hoisting gate 1 is maintained unchanged by the crane 85. This facilitates the water pouring operation into the remaining water ballast compartments (for example, the opening of water pouring valves by divers), improving the safety of the work of setting down the hoisting gate 1. It is preferable that the draft of the hoisting gate 1 after step S193 is completed is also located below the upper surface 22 of the box body 2.

[0079] When step S19 is completed, the wire 87 is let out by the crane 85, and the elevation gate 1 is lowered toward the bottom of the water and installed there (step S20). The elevation gate 1 is lowered while the center of the load applied to the crane 85 is always located within the suspension range. When the elevation gate 1 is lowered, for example, the position of the center of buoyancy of the elevation gate 1 may change significantly before and after the upper surface 22 of the box body 2 is submerged. In this case, the position of the water ballast compartment in which ballast water is loaded, etc., is determined in step S19 so that the center of the load applied to the crane 85 does not fall outside the suspension range.

[0080] During the sinking in step S20, the pressure in each cavity 52a (see FIG. 12) of the undulating gate 1 is maintained substantially constant at a sinking pressure higher than atmospheric pressure. As a result, the force (hereinafter also referred to as "external force") applied from the outside by water pressure to the structural materials (e.g., the shell, watertight bulkheads 51, aggregates, etc.) that make up each cavity 52a is reduced by the air at the sinking pressure inside each cavity 52a. The reduction in the external force is performed in the cavity 52a facing the shell of the box body 2, etc., and in the cavity 52a that does not face the shell but through which ballast water is injected into the adjacent watertight compartment 52. As a result, the strength of the box body 2, etc., is prevented from being increased in order to withstand the water pressure during sinking.

[0081] In step S20, the pressure in each of the cavities 52a is monitored using the pressure sensor 445. For example, if a pressure drop occurs in one of the cavities 52a, an operator who discovers the pressure drop in the control room 43 (see FIG. 1 ) or the like operates the air supply unit 44 to quickly increase the pressure in the cavities 52a and restore the pressure at the time of installation. Specifically, for example, the shutoff valves 448 corresponding to the cavities 52a other than the cavities 52a whose pressure has dropped are closed, the other cavities 52a are disconnected from the air tank 441, and air is supplied from the air tank 441 only to the cavities 52a whose pressure has dropped to increase the pressure. Note that the monitoring of the pressure in each of the cavities 52a and the supply of air to the cavities 52a whose pressure has dropped do not necessarily have to be performed by an operator. For example, a pressure control system using a computer or the like may automatically detect the pressure drop in the cavities 52a and increase the pressure in the cavities 52a. The pressure drop in the cavity 52a may occur due to, for example, temporary air leakage from the cavity 52a or a drop in the temperature of the air in the cavity 52a.

[0082] As described above, in the lowering operation of the elevation gate 1, the pressure of the air stored in the air tank 441 is higher than the pressure in each of the spaces 52a (i.e., the pressure at the time of lowering), and each space 52a is connected to the air tank 441 via a pressure reducing valve 443. Therefore, even if a drop in pressure occurs in the space 52a while the air supply unit 44 cannot be operated due to a power outage or the like, air is supplied from the air tank 441 to the lowered pressure space 52a as long as the pressure in the air tank 441 is equal to or higher than the pressure at the time of lowering, and the pressure in the space 52a is restored to the pressure at the time of lowering. This improves the safety of the lowering operation of the elevation gate 1.

[0083] In step S20, the pressures at the time of sinking in the plurality of spaces 52a are substantially the same. Specifically, the pressure in each space 52a is a predetermined pressure set by the pressure reducing valve 443. This simplifies the pressure control in the plurality of spaces 52a. Note that in the elevation gate 1, the pressures in the plurality of spaces 52a may be set to be different by, for example, operating the shutoff valve 448 or the pressure reducing valve 443 corresponding to each space 52a.

[0084] The above-mentioned pressure during sinking is set, for example, based on the void 52a, which requires the greatest increase in strength to withstand water pressure when the undulating gate 1 is seated on the bottom of the water. In other words, if the internal pressure were atmospheric pressure, the pressure during sinking is set based on the void 52a, where the weight of the structural material required to support the water pressure at the bottom of the water would be the greatest. For example, the pressure during sinking is set to approximately half the water pressure applied to the void 52a from the outside at the bottom of the water. This prevents the strength of the box body 2 and other components from being increased solely to withstand water pressure during sinking.

[0085] When the elevation gate 1 hits the bottom, the connection between the air tank 441 and the plurality of voids 52a is blocked by the shutoff valve 448. Then, after the water inlet valve of each void 52a is opened, the exhaust valve 447 corresponding to each void 52a is opened, thereby injecting water into each void 52a. Note that the water inlet valves may be opened in advance before the elevation gate 1 hits the bottom (for example, while the elevation gate 1 is sinking or before it starts to sink). In this case, too, water injection into the voids 52a does not start until the exhaust valve 447 is opened. Thereafter, concrete is poured into the plurality of watertight compartments 52 filled with seawater (i.e., the plurality of water ballast compartments and the plurality of voids 52a after water injection).

[0086] When the installation of the elevation gate 1 is complete, the exhaust unit is closed in the door body 3 in the collapsed state, and air is supplied to and stored in the door body buoyancy chamber inside the door body 3 by the air supply unit 44. As shown in FIG. 16, the door body 3 is connected to an air tank 441 via a pipe 446. The pipe 446 is installed in advance in the elevation gate 1 so that compressed air stored in the air tank 441 can be supplied to the door body buoyancy chamber of the door body 3. The installation of the pipe 446 is performed, for example, in step S11. In the elevation gate 1, an elevation moment is generated in the door body 3 as air is stored in the door body buoyancy chamber. With the elevation moment acting on the door body 3, the door body 3 is moored in the pit 21 by the mooring unit 24, and is ready to begin elevation immediately (step S21).

[0087] As described above, the bottom-mounted elevation gate 1 comprises a box body 2, a door body 3, and a pair of closing side walls 41, 42. A recessed portion, the pit 21, is provided on the top surface 22 of the box body 2. The door body 3 is connected to the box body 2 at its rear end. The door body 3 stands up and lies down by rotating around a rotation axis 33 extending in the width direction. The door body 3 is housed in the pit 21 in the laid-down state. The pair of closing side walls 41, 42 are erected on the box body 2 on both sides of the pit 21 in the width direction. The pair of closing side walls 41, 42 close off the spaces on both sides of the width direction of the door body 3 when it is in the upright state.

[0088] The method for installing the elevation gate 1 includes the steps of manufacturing the elevation gate 1 in a dock (step S11), filling the dock with water to cause the elevation gate 1 to float on the water surface using the buoyancy of the box body 2 (step S14), towing the elevation gate 1 floating on the water surface with the door body 3 housed in the pit 21 to the installation water area (step S16), sinking the elevation gate 1 and installing it on the bottom of the water (steps S18 to S20), and supplying air to the inside of the door body 3 in a collapsed state to store it, and mooring the door body 3 with an upright moment generated in it in the pit 21 (step S21).

[0089] In this way, by manufacturing the elevation gate 1 at a dock, a floating crane or other equipment required for beach unloading, which would be required if the elevation gate 1 were manufactured in a building on land, is not required, thereby reducing the cost of transporting the elevation gate 1. Furthermore, by floating the elevation gate 1 on the water and towing it to the installation area, the floating crane or barge used to load the elevation gate 1 is not required, compared to when the elevation gate 1 is loaded onto a barge or other equipment for transport, thereby further reducing the cost of transporting the elevation gate 1. Furthermore, in step S16, the elevation gate 1 is towed with the gate body 3 housed in the pit 21, thereby lowering the center of gravity of the elevation gate 1 and facilitating its transport to the installation area. Furthermore, according to the above-described elevation gate installation method, even if the elevation gate 1 is large, the elevation gate 1 can be easily transported to the installation area without being limited by the performance of the floating crane.

[0090] As described above, the method for installing a roofing gate preferably further includes, before step S16, a step (step S12) of removably attaching a pair of temporary wall sections 23 to the upper surface 22 of the box body 2. The pair of temporary wall sections 23 extend widthwise at the front and rear sides of the pit 21 and are watertightly connected to the pair of closed side walls 41, 42. This allows the pair of temporary wall sections 23 to function as wavebreaks and prevent water from flowing into the pit 21 when the roofing gate 1 is towed in step S16. As a result, an increase in the draft of the roofing gate 1 (i.e., a decrease in freeboard) can be prevented, thereby improving the safety of the towing operation of the roofing gate 1. Furthermore, a decrease in the initial stability of the roofing gate 1 due to the influence of free water in the pit 21 can be prevented, further improving the safety of the towing operation of the roofing gate 1.

[0091] As described above, in step S16, it is preferable that the pair of closing side walls 41, 42 be aligned along the towing direction of the boom-raising gate 1. In this way, by positioning one of the closing side walls 41, 42, which is taller in the vertical direction than the temporary wall 23, on the front side in the towing direction of the boom-raising gate 1, it is possible to suitably prevent waves from crashing onto the upper surface 22 of the box body 2 from the front side in the towing direction of the boom-raising gate 1. As a result, it is possible to further prevent water from flowing into the pit 21, thereby further improving the safety of the towing operation of the boom-raising gate 1.

[0092] As described above, in step S16, it is also preferable to install a temporary drainage pump 84 in the pit 21. This allows the water to be discharged to the outside of the pit 21 even if it flows into the pit 21. As a result, the safety of the towing operation of the hoisting gate 1 can be further improved.

[0093] As described above, the method for installing a elevation gate preferably further includes, between steps S11 and S14, a test run (step S13) for confirming that an upright moment is generated in the door body 3 in a collapsed state with air trapped inside by pouring water into the pit 21 and the space above the pit 21 surrounded by the pair of closed side walls 41, 42 and the pair of temporary walls 23 (i.e., the temporary space 25). This shortens the time required for the test run compared to pouring water into the dock up to the water level required for the test run of the elevation gate 1 (hereinafter also referred to as the "test run water level"). Furthermore, even if the time required to maintain the water level in the dock at the test run water level is short or impossible due to geographical factors of the dock, the test run of the elevation gate 1 can be suitably performed without considering the geographical factors. Furthermore, the temporary space 25 is formed using a pair of temporary walls 23 that act as a wavebreak when towing the hoisting gate 1, simplifying the temporary structure that is used only during the trial run of the hoisting gate 1. As a result, the cost required for the trial run of the hoisting gate 1 can be reduced.

[0094] As described above, during trial operation, it is preferable that water is poured into the dock and the water level in the dock be set to a position between the bottom surface 26 and the top surface 22 of the box body 2, where the bottom-mounted state of the elevation gate 1 is maintained. This allows the buoyancy generated in the box body 2 to reduce the load applied to the platform 81 supporting the elevation gate 1, etc., caused by pouring water into the pit 21 and temporary space 25. As a result, the safety of the trial operation of the elevation gate 1 can be improved.

[0095] As described above, in the method for installing a hoist gate, it is preferable that the pressure in the void space 52a partitioned by the watertight bulkhead 51 inside the box body 2 is maintained at a predetermined pressure (i.e., towing pressure) higher than atmospheric pressure in step S16 (i.e., when the hoist gate 1 is towed). This makes it possible to suppress water from entering the void space 52a when the hoist gate 1 is towed. As a result, the safety of the towing operation of the hoist gate 1 can be improved.

[0096] As described above, it is preferable that the elevation gate 1 further includes an air supply unit 44 that supplies air to the inside of the door body 3 in step S21. It is also preferable that air be supplied to the cavity 52a from the air supply unit 44. In this way, by using the air supply unit 44 that is used to raise the door body 3 in the elevation gate 1 after installation to also maintain the pressure in the cavity 52a at the pressure during towing, it is possible to simplify the temporary configuration that is used only when towing the elevation gate 1. As a result, it is possible to reduce the cost required for towing the elevation gate 1.

[0097] As described above, the air supply unit 44 preferably includes the air tank 441, pipes 442 and 449, a pressure reducing valve 443, and an exhaust valve 447. The air tank 441 stores air at a higher pressure than the air in the cavity 52a. The pipes 442 and 449 connect the air tank 441 to the cavity 52a. The pressure reducing valve 443 and the exhaust valve 447 are provided on the pipes 442 and 449. By providing the pressure reducing valve 443, the pressure in the cavity 52a can be maintained at the towing pressure with a simple structure when the hoisting gate 1 is towed. Furthermore, the pressure in the cavity 52a can be maintained at the sinking pressure with a simple structure when the hoisting gate 1 is lowered. Furthermore, even if a drop in pressure occurs in the void 52a while the air supply unit 44 cannot be operated due to a power outage or the like, air is automatically supplied from the air tank 441 to the depressurized void 52a, thereby restoring the pressure in the void 52a. As a result, the safety of the towing and installation operations of the hoisting gate 1 can be further improved. When water is to be injected into the void 52a, water injection into the void 52a can be easily started by opening the exhaust valve 447. Furthermore, when water is to be injected into multiple voids 52a, it is preferable to arrange multiple exhaust valves 447 corresponding to the multiple voids 52a together in one location (i.e., near each other). This improves the work efficiency of the worker operating the multiple exhaust valves 447.

[0098] As described above, in step S16, it is preferable that the pressure in the void space 52a be remotely monitored at a location away from the boom gate 1. This allows the pressure in the void space 52a to be quickly restored to the towing pressure if it drops below the towing pressure. As a result, the safety of the towing operation of the boom gate 1 can be improved. Furthermore, by remotely monitoring the pressure in the void space 52a, it is no longer necessary for workers to board the boom gate 1 during towing, further improving the safety of the towing operation of the boom gate 1.

[0099] As described above, the pressure in the void 52a may be increased to the towing pressure in step S15 before the lifting of the boom gate 1 in step S14. This makes it possible to prevent water from entering the void 52a in step S14. Also, step S15 may be performed before water is poured into the dock during the test run of the boom gate 1 in step S13. This makes it possible to prevent water from entering the void 52a in step S13.

[0100] As described above, it is preferable that the elevation gate 1 has draft marks or sensors for measuring draft at multiple locations around the box body 2. This makes it possible to easily and accurately check the posture of the elevation gate 1 when towing and when sinking. Furthermore, if sensors for measuring draft are provided, the draft of the elevation gate 1 can be measured remotely, thereby reducing the effort and time required for draft measurement.

[0101] As described above, in the method for installing the elevation gate, it is also preferable that, prior to step S16, a towing appendage 83 is attached to the box 2 on the front side in the towing direction in step S16, which covers the side surface of the box 2 and reduces the drag coefficient of the box 2. This reduces the resistance of the elevation gate 1 during towing.

[0102] The above-described bottom-mounted elevation gate 1 includes a box body 2, a door body 3, a pair of closing side walls 41, 42, and a pair of temporary walls 23. A recessed pit 21 is provided on the top surface 22 of the box body 2. The door body 3 is connected to the box body 2 at its rear end. The door body 3 stands upright and lies down by rotating around a rotation axis 33 extending in the width direction. When the door body 3 is in the lies down position, it is housed within the pit 21. The pair of closing side walls 41, 42 are erected on the box body 2 on both sides of the pit 21 in the width direction. The pair of closing side walls 41, 42 close the spaces on both sides of the door body 3 in the upright position. The pair of temporary walls 23 extend in the width direction at the front and rear of the pit 21 and are watertightly connected to the pair of closing side walls 41, 42. The pair of temporary walls 23 are detachably attached to the top surface 22 of the box body 2.

[0103] As described above, this improves the safety of the towing operation of the hoisting gate 1. It also reduces the time required for the trial run of the hoisting gate 1 and the cost required for the trial run. Furthermore, the trial run of the hoisting gate 1 can be carried out suitably without considering the geographical factors of the dock, etc.

[0104] The above-described relief gate 1 and relief gate installation method can be modified in various ways.

[0105] For example, in the undulating gate 1, the configuration of the air supply unit 44 is not limited to the above and may be modified in various ways. For example, the pressure in the cavity 52a may be adjusted by a structure other than the pressure reducing valve 443 and the exhaust valve 447.

[0106] In the undulating gate 1, the above-mentioned draft marks and sensors for measuring draft do not necessarily have to be provided.

[0107] It is not necessary to pour water into the dock during the trial run (step S13) of the elevation gate 1. Alternatively, in step S13, water may be poured into the dock so that the water level in the dock is positioned at a position where the elevation gate 1 can be trial run (i.e., a position above the upper surface 22 of the box body 2). In this case, it is not necessary to provide a temporary wall portion 23 for trial run of the elevation gate 1.

[0108] When the elevation gate 1 is towed (step S16), the pressure in the void space 52a does not necessarily have to be monitored remotely. For example, pressure monitoring of the void space 52a may be performed on the elevation gate 1, or such pressure monitoring may be omitted. Furthermore, when the elevation gate 1 is towed, air does not necessarily have to be supplied to the void space 52a by the air supply unit 44 used to raise the gate body 3, but may be supplied by another air supply unit. Furthermore, the pressure in the void space 52a when the elevation gate 1 is towed does not necessarily have to be maintained at a pressure higher than atmospheric pressure.

[0109] In step S16, the temporary drainage pump 84 does not necessarily have to be installed in the pit 21. In addition, the pair of temporary wall portions 23 does not necessarily have to be provided.

[0110] In step S16, the towing direction of the hoisting gate 1 is not limited to the above example and may be changed in various ways. For example, the hoisting gate 1 may be towed so that the pair of temporary wall portions 23 are aligned along the towing direction.

[0111] In the method for installing a hoisting gate, the water injection operation into the water ballast compartment in step S19 does not necessarily have to be carried out in two or more stages, but may be carried out continuously while maintaining the draft of the hoisting gate 1 or while gradually lowering the hoisting gate 1.

[0112] The operation of pouring water into the pit 21 in step S19 does not necessarily have to be completed when the water surface 94 is located below the upper surface 22 of the box body 2.

[0113] When the elevation gate 1 is lowered (step S20), the pressure in the void 52a does not necessarily need to be monitored. Furthermore, when the elevation gate 1 is lowered, the supply of air to the void 52a does not necessarily need to be by the air supply unit 44 used to raise the door body 3, but may be by another air supply unit. Furthermore, the pressure in the void 52a when the elevation gate 1 is lowered does not necessarily need to be maintained higher than atmospheric pressure.

[0114] The configurations in the above-described embodiment and each modification may be combined as appropriate as long as they are not mutually contradictory. [Explanation of symbols]

[0115] 1. Rising gate 2 box 3 Door body 21 Pit 22 (Top of the box) 23 Temporary wall 25 Temporary Space 26 (Box) bottom 33 Rotation axis 41, 42 Closed side wall 44 Air supply section 51 Watertight bulkhead 52 Watertight Compartment 52a Blank space 83 Towing appendages 84 Temporary drainage pump 85 Crane 91,92,94 water surface 441 Air Tank 442,449 Piping 443 Pressure reducing valve 445 Pressure Sensor S11~S21, S191~S193 steps

Claims

1. A method for installing a bottom-mounted undulating gate, comprising: The undulating gate is a box having a pit formed on the top surface thereof; a door body connected to the box body at a rear end thereof, which is capable of standing up and lying down by rotating about a rotation axis extending in the width direction, and which is accommodated in the pit in a laid-down state; A pair of closing side walls that are erected on the box body on both sides in the width direction of the pit and close the spaces on both sides in the width direction of the door body in the upright state; Equipped with The method for installing the elevation gate comprises: a) manufacturing the relief gate in a dock; b) filling the dock with water to allow the buoyancy of the box to float the undulating gate on the water surface; c) Towing the hoisting gate floating on the water surface with the door body housed in the pit to an installation water area; d) lowering the undulating gate to the bottom of the water; e) A step of supplying and storing air inside the door body in a collapsed state, and mooring the door body in which an upright moment has been generated in the pit; Equipped with A method for installing a rise-and-fall gate, characterized in that it further comprises, prior to step c), a step of removably attaching a pair of temporary wall sections extending widthwise at the front and rear of the pit and watertightly connected to the pair of closing side wall sections to the upper surface of the box body.

2. 2. The method for installing a relief gate according to claim 1, A method for installing a roof gate, characterized in that in step c), the pair of closed side wall portions are aligned along the towing direction of the roof gate.

3. The method for installing a wavy gate according to claim 1 or 2, A method for installing a relief gate, characterized in that in step c), a temporary drainage pump is installed in the pit.

4. 4. The method for installing a wavy gate according to claim 1, A method for installing a rise-and-fall gate, characterized in that it further comprises, between steps a) and b), a test run step of pouring water into the pit and into the space above the pit surrounded by the pair of closing side wall sections and the pair of temporary wall sections, to confirm that an upright moment is generated in the door body in a collapsed state with air stored inside.

5. 5. The method for installing a relief gate according to claim 4, A method for installing a rise-and-fall gate, characterized in that during the trial operation, water is poured into the dock and the water level in the dock is set to a position between the bottom and top surfaces of the box body, where the rise-and-fall gate is maintained in a bottomed state.

6. A method for installing a bottom-mounted undulating gate, comprising: The undulating gate is a box having a pit formed on the top surface thereof; a door body connected to the box body at a rear end thereof, which is capable of standing up and lying down by rotating about a rotation axis extending in the width direction, and which is accommodated in the pit in a laid-down state; A pair of closing side walls that are erected on the box body on both sides in the width direction of the pit and close the spaces on both sides in the width direction of the door body in the upright state; Equipped with The method for installing the elevation gate comprises: a) manufacturing the relief gate in a dock; b) filling the dock with water to allow the buoyancy of the box to float the undulating gate on the water surface; c) Towing the hoisting gate floating on the water surface with the door body housed in the pit to an installation water area; d) lowering the undulating gate to the bottom of the water; e) A step of supplying and storing air inside the door body in a collapsed state, and mooring the door body in which an upright moment has been generated in the pit; Equipped with A method for installing a wale gate, characterized in that the pressure in the void space defined by the watertight bulkhead inside the box is maintained at a predetermined pressure higher than atmospheric pressure in step c).

7. 7. The method for installing a relief gate according to claim 6, The undulating gate further includes an air supply unit that supplies air to the inside of the door body in the e) step, A method for installing a wavy gate, characterized in that air is supplied to the void from the air supply unit.

8. 8. The method for installing a relief gate according to claim 7, The air supply unit is an air tank in which air having a higher pressure than the air in the cavity is stored; A pipe connecting the air tank and the cavity; a pressure reducing valve and an exhaust valve provided on the piping; A method for installing a wavy gate, comprising:

9. 9. The method for installing a relief gate according to any one of claims 6 to 8, A method for installing a relief gate, characterized in that in step c), the pressure in the cavity is remotely monitored at a location away from the relief gate.

10. 10. The method for installing a relief gate according to any one of claims 1 to 9, A method for installing a ditch gate, characterized in that draft marks or sensors for measuring draft are provided at multiple locations around the periphery of the box.

11. 11. The method for installing a support gate according to any one of claims 1 to 10, A method for installing a hoist gate, characterized in that, prior to step c), a towing appendage is attached to the box body, covering the side of the box body in front of the towing direction in step c) and reducing the drag coefficient of the box body.

12. A bottom-mounted undulating gate, a box having a pit formed on the top surface thereof; a door body connected to the box body at a rear end thereof, which is capable of standing up and lying down by rotating about a rotation axis extending in the width direction, and which is accommodated in the pit in a laid-down state; A pair of closing side walls that are erected on the box body on both sides in the width direction of the pit and close the spaces on both sides in the width direction of the door body in the upright state; A pair of temporary wall portions extending in the width direction at the front and rear sides of the pit, watertightly connected to the pair of closing side wall portions, and detachably attached to the top surface of the box body; A waving gate characterized by comprising:

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