Temporary cofferdam

Abstract

To provide a temporary cofferdam that enables complete and partial closure of the periphery of a weir pillar at the end of an estuary weir formed so as to form a part of a revetment, and enables repair work etc. to be carried out in both flood and dry seasons. [Solution] In an estuary weir having a weir pillar 10A formed to form part of the embankment and a permanent gate 14 that can be raised and lowered, the temporary closure body 250 is constructed to the side of the weir pillar 10A and has a temporary enclosure unit 100 formed by a first temporary enclosure body 20 and a second temporary enclosure body 30 and a temporary gate 73, one of the planar shapes of the first temporary enclosure body 20 and the second temporary enclosure body 30 is J-shaped and the other is inverted J-shaped, the temporary enclosure bodies 20, 30 have lower box bodies 21, 31 arranged on the lower tier and one or more upper box bodies 22, 23, 32, 33 stacked on top of them, and the lower box bodies 21, 31 etc. are provided with water storage space, water supply and drainage valves and water supply and exhaust valves so that the draft of the temporary enclosure bodies 20, 30 can be freely adjusted.

Description

[Technical Field]

[0001] The present invention relates to a temporary cofferdam. [Background technology]

[0002] Diversion weirs are installed near river bifurcations to systematically divert floodwaters and low water levels by regulating and restricting water levels. Tidal weirs are installed at river mouths (tidal reaches) to prevent saltwater from invading and maintain the normal functioning of flowing water. In addition, intake weirs are installed to regulate the river's water level and take in water for municipal use, irrigation, power generation, etc. Furthermore, among the various types of weirs mentioned above, a dam is defined as one that is 15 meters or more high from the base to the top of its fixed part, is intended to regulate flow by storing flowing water, and is not connected to a levee. Furthermore, among the various types of weirs mentioned above, a sluice gate or sluice gate is defined as one that functions as a levee and prevents or reduces the overflow of flowing water caused by floods or high tides. Therefore, in this specification, the term "weir" includes the various types of weirs mentioned above, as well as dams, sluice gates, sluice gates, etc.

[0003] Weirs (estuary weirs) installed at estuaries close off rivers and block seawater from running upstream, thereby ensuring agricultural and industrial water supplies, and are also used for flood control to prevent floods and high tides. These estuary weirs are equipped with a number of weir pillars erected at intervals, and permanent gates (gate doors) arranged between adjacent weir pillars so that they can be raised and lowered. The weir pillars are erected above the water, above a footing made of, for example, reinforced concrete at the bottom of the water, and the permanent gates are raised and lowered by a lifting mechanism attached to the weir pillars.

[0004] When carrying out repair or renovation work, including seismic reinforcement of the dam pillars, on a dam equipped with a dam pillar and a permanent gate, a temporary closure is carried out to place the area around the dam pillar in an aerial work environment while preventing seawater from flowing upstream using the permanent gate, for example.

[0005] Generally, temporary cofferdams are constructed by driving steel sheet piles around the weir pillars or by constructing embankments to enclose the weir pillars, and then the water inside the cofferdams is drained, creating an open-air work environment. However, these cofferdam construction methods require large-scale construction, and the construction and subsequent removal of the cofferdams require a lot of time and money. This poses a problem in river construction, where repair work can only be carried out during the dry season, as it places restrictions on the time available for repair work.

[0006] Patent Document 1 proposes a work box with an opening on its side. This work box accommodates a portion of a submerged structure through the opening in a plan view. When the work box and the structure form a work space, the end of the work box, attached to the structure and extending vertically, has a first inclined surface that is inclined so that the inside of the work space is narrow and the outside is wide. A wedge-shaped first waterproof gasket is provided in the gap between the structure and the first inclined surface. The first waterproof gasket is moved along the first inclined surface toward the work space, draining water from the work space and applying horizontal water pressure to the first waterproof gasket, thereby sealing off the work box. This construction method is also known as the NDR (Neo-Dry Repair) method.

[0007] Meanwhile, Patent Document 2 proposes a cofferdam caisson that is attached to a structure erected on a pedestal and seated on the submerged pedestal for cofferdam construction. This cofferdam caisson is composed of multiple vertically divided, buoyancy-adjustable, with one side of each divided section connected by a hinge for open / close freedom. A buffer sealant is attached continuously to the bottom of the cutting edge of each divided section. Support legs protrude from the bottom of the cutting edge of each divided section to support the cutting edge of each divided section at a distance from the pedestal. A plurality of guide spacers protrude laterally from the inside of each divided section, allowing engagement with the structure at a fixed distance. This cofferdam caisson is applied by opening and closing the divided sections to attach it to the structure, seating the buffer sealant on the pedestal, filling the cutting edge of the caisson with waterproof grout, and sealing the cutting edge of the caisson with the buffer sealant and waterproof grout, thereby achieving cofferdam construction. This construction method is also called the RUP (Reinforce & Repair Underwater Pier) method.

[0008] In the temporary cofferdam construction method using a work box described in Patent Document 1, when attempting to construct a temporary cofferdam in a state where the flow of seawater or river water is blocked at a weir where the permanent gate extends to the side of a structure such as a weir pillar, only one side of the permanent gate of the structure can be temporarily cofferdamped. On the other hand, in the temporary cofferdam construction method using a cofferdam caisson described in Patent Document 2, the temporary cofferdam is targeted at a bridge pier or the like, so it is not possible to construct a temporary cofferdam in a state where the flow of seawater or river water is blocked at a weir where the permanent gate extends to the side of a weir pillar.

[0009] The timing and frequency of raising and lowering the permanent gates differs between flood and dry seasons. For example, during flood seasons, if there is a large amount of rain flowing upstream, there is a possibility that water will infiltrate the reclaimed land. Therefore, when the water level upstream of the weir rises above the water level downstream (tide level), the permanent gates are opened to release the water from the upstream side downstream. For this reason, when multiple weirs are installed side by side and the permanent gates rise and fall between adjacent weirs, repair work must be carried out while all the permanent gates are able to rise and fall (operate).

[0010] On the other hand, during dry periods, it is not necessary for all permanent gates to be able to be raised and lowered, so for dams with only some of the permanent gates able to be raised and lowered, and the remaining permanent gates located to the side, the area around the dam can be completely closed off to allow repair work to be carried out.

[0011] For these reasons, by surrounding the weir with a temporary cofferdam that allows for complete and partial closure of the periphery of the weir, it becomes possible to carry out repair work that can be carried out during both flood and dry seasons. However, Patent Documents 1 and 2 do not mention a temporary cofferdam that allows for complete and partial closure of the periphery of the weir.

[0012] Patent Document 3 describes a temporary cofferdam that allows for complete and partial closure of the area around a weir. This temporary cofferdam is constructed around a weir pillar, which has a weir pillar and a liftable permanent gate extending laterally from the pillar. An upstream box body and a downstream box body are disposed on the upstream and downstream sides of the weir pillar, respectively. A first gap is formed on the side of the weir pillar between the two box bodies. The upstream box body and the downstream box body each have an upstream wall body and a downstream wall body. By closing the walls, the first gap is closed, and a closed-type temporary cofferdam is formed by both the box bodies and the wall bodies. [Prior art documents] [Patent documents]

[0013] [Patent Document 1] Japanese Patent Application Laid-Open No. 2016-79591 [Patent Document 2] Japanese Patent Application Publication No. 9-189043 [Patent Document 3] Patent Publication No. 2021-63433 Summary of the Invention [Problem to be solved by the invention]

[0014] The temporary cofferdam described in Patent Document 3 includes an upstream wall and a downstream wall, and by closing the upstream and downstream boxes, a closed-type temporary cofferdam can be formed. Therefore, when both walls are not closed, the first gap on the side of the weir pillar is open, forming an open-type temporary cofferdam. During flood seasons, both walls can be left open, leaving the permanent gate on the side of the weir pillar free to move up and down, allowing repair work, etc., to be performed on the area of ​​the weir pillar surrounded by the upstream and downstream boxes. During dry seasons, on the other hand, by closing both walls, a closed-type temporary cofferdam is formed that completely blocks the area around the weir pillar, allowing repair work, etc., to be performed on the entire area around the weir pillar.

[0015] The temporary cofferdam described in Patent Document 3 is an estuary weir with multiple weir pillars arranged at intervals. The upstream and downstream boxes are C-shaped in plan view and have an outer shape symmetrical about the axis of the weir pillar when viewed from the top, and are installed around the upstream and downstream sides of the weir pillar, which has permanent gates on both sides. In addition to the weir pillars with permanent gates extending from the left and right sides, estuary weirs also have weir pillars formed to form part of the revetment, i.e., weir pillars at the end of the estuary weir. However, these weir pillars partially protrude from the revetment toward the water body, and it is necessary to surround the weir pillars with partially protruding from the revetment. Therefore, the C-shaped upstream and downstream boxes described in Patent Document 3 cannot be used.

[0016] The present invention aims to provide a temporary closure body that enables complete or partial closure of the perimeter of a weir pillar at the end of an estuary weir formed to form part of a revetment, in an estuary weir where multiple weir pillars are arranged side by side at intervals and permanent gates are installed between each weir pillar so that they can be raised and lowered freely, and that enables repair work etc. to be carried out in both flood and dry seasons. [Means for solving the problem]

[0017] In order to achieve the above object, one aspect of the temporary cofferdam according to the present invention is as follows: A temporary cofferdam constructed on the side of a weir pillar at an estuary weir having a weir pillar formed to form part of a revetment and a permanent gate extending to the side of the weir pillar and capable of being raised and lowered, comprising: a temporary enclosure unit formed by a first temporary enclosure and a second temporary enclosure included in a temporary enclosure, which are respectively arranged on the upstream and downstream sides of the weir pillar; a temporary gate that is provided adjacent to the permanent gate and connected to the temporary enclosure unit; The first temporary enclosure and the second temporary enclosure are directly or indirectly connected to each other, thereby forming a closed posture of the temporary enclosure unit; One of the first and second temporary enclosures has a J-shape in plan view, and the other has an inverted J-shape. The temporary enclosure includes a lower box body disposed on the lower level, One or more upper box bodies are stacked on the lower box body, At least one of the lower box body and the upper box body is provided with a water storage space, a water supply and drainage valve, and a water supply and exhaust valve, so that the draft of the temporary enclosure can be freely adjusted.

[0018] According to this aspect, the first and second temporary enclosures, which are arranged on the upstream and downstream sides of the weir pillar to form a temporary enclosure unit, have one J-shaped plan view and the other an inverted J-shaped plan view.This allows the temporary enclosure unit to completely close off the periphery of the weir pillar, which is formed to form part of the revetment, and forms a closed-type temporary cofferdam.Furthermore, if the temporary enclosure unit does not completely close off the periphery of the weir pillar, and part of the periphery of the weir pillar is left open, an open-type temporary cofferdam can be formed, and the open gap can be used to freely raise and lower the permanent gate.

[0019] Of the multiple weir pillars that make up an estuary weir, the weir pillar at the end of the estuary weir, which is formed to form part of the revetment, protrudes from the revetment to one side, which is the water body side. Therefore, when the upstream and downstream sides of this weir pillar are surrounded by two temporary enclosures, one end of each of the temporary enclosures abuts the revetment and the other end abuts the weir pillar, so in a plan view they form a J or inverted J shape. However, there have been no previous examples of using temporary enclosures of this shape to surround a weir pillar formed to form part of the revetment and to carry out repair work on the weir pillar. When towing a J-shaped or inverted J-shaped temporary enclosure and setting it up in place, it is more difficult to maintain a horizontal position than a C-shaped box, which has a symmetrical shape, and the entire construction process from towing to setting up is difficult.This is one of the reasons why temporary enclosures with such flat shapes do not normally come to mind, and is why they have not existed until now.

[0020] Here, "the first and second temporary enclosures are directly or indirectly connected" includes not only a configuration in which the opposing sides of the first and second temporary enclosures are directly connected, but also a configuration in which openable and closable walls are attached to the opposing sides of the first and second temporary enclosures, and the two walls are connected to each other, thereby indirectly connecting the first and second temporary enclosures. In the former case, one of the first and second temporary enclosures has an openable and closable wall midway, and a liftable permanent gate is located in the gap created when this wall is opened. In the latter case, a liftable permanent gate is located in the gap created when both walls are opened. Then, the end of a temporary gate attached to the permanent gate is connected to either the first or second temporary enclosure.

[0021] When the first and second temporary enclosures completely block the weir pillar, a closed-type temporary enclosure is formed. On the other hand, when the first and second temporary enclosures block part of the periphery of the weir pillar, an open-type temporary enclosure is formed.

[0022] Therefore, during flood seasons, by leaving the first and second temporary enclosures unclosed to form an open-type temporary cofferdam, the permanent gate can be raised and lowered freely on the side of the weir pillar, allowing repair work, etc. to be carried out on the area of ​​the weir pillar surrounded by the upstream and downstream box bodies. On the other hand, during dry seasons, by completely closing the first and second temporary enclosures to form a closed-type temporary cofferdam, repair work, etc. can be carried out on the entire area around the weir pillar. Because the temporary cofferdam of this embodiment is equipped with a temporary gate, in a closed-type temporary cofferdam, the temporary gate can block the movement of seawater and river water between the upstream and downstream sides even when the permanent gate is open and fixed in the raised position.

[0023] In addition, the temporary enclosure comprises a lower box body arranged on the lower level and one or more upper box bodies stacked on top of the lower box body, and at least one of the lower box body and the upper box body is provided with a water storage space, a water supply and drainage valve, and an air supply and exhaust valve, allowing the draft of the temporary enclosure to be freely adjusted.This means that the attitude of the temporary enclosure when towed in a position floating above the top of the apron can be controlled as desired, and smooth landing on the top of the apron can be achieved.

[0024] Here, each of the lower box body and the upper box body may be configured to have an adjustable draft, or one of the lower box body and the upper box body may be configured to have an adjustable draft.

[0025] The box body, which is configured to be freely draft-adjustable, includes at least a water storage space, a water supply / drain valve, and a water supply / exhaust valve, as well as a compressed air supply unit that supplies compressed air to the water supply / drain pipes, the water supply / exhaust pipes, and the water supply / exhaust pipes. For example, by opening or closing either the water supply / drain valve or the water supply / exhaust valve, the amount of external water (ballast) supplied to the water storage space is adjusted, thereby adjusting the draft of the box body as desired. This draft adjustment allows the box body to float or sink as desired. Therefore, for example, if a sufficient draft cannot be secured, the draft can be adjusted by floating the box body as desired without needlessly dredging the seabed. Here, the compressed air supply unit may be provided in the box body beforehand, or may be added later when air is supplied.

[0026] In another aspect of the temporary cofferdam according to the present invention, A first wall body that can be opened and closed is attached to a downstream side of the first temporary enclosure body that faces the second temporary enclosure body, A second wall body that can be opened and closed is attached to the upstream side of the second temporary enclosure body facing the first temporary enclosure body, The temporary enclosure unit is characterized in that the ends of the first wall body and the second wall body are joined together to close the temporary enclosure unit.

[0027] According to this aspect, the first and second temporary enclosures each have a first wall and a second wall that can be opened and closed, respectively, and the ends of these walls are joined to close the temporary enclosure unit, i.e., the first and second temporary enclosures are indirectly connected to form a closed-type temporary enclosure. Therefore, if the two walls are not closed, part of the side of the weir pillar is opened, forming a gap, and an open-type temporary enclosure is formed.

[0028] Here, the first and second walls can be opened and closed by rotating or sliding, or by towing the first and second walls and using heavy machinery, divers, or the like.

[0029] In another aspect of the temporary cofferdam according to the present invention, the temporary enclosure has a first end portion facing the revetment and a second end portion facing the weir pillar, and a first connecting jig having a first through hole is attached to the first end portion; the revetment has a second connecting jig with a second through hole at a position corresponding to the first connecting jig, A pin is inserted through the first through hole and the second through hole to form a pivot point, and the temporary enclosure unit is capable of rotating freely around the pivot point.

[0030] According to this aspect, a first connecting jig having a first through hole is attached to one first end of the temporary enclosure facing the embankment, and a second connecting jig having a second through hole is attached to a position on the embankment corresponding to the first connecting jig, and a pivot point is formed by inserting a pin into the first through hole and the second through hole, and the temporary enclosure unit is able to rotate freely around this pivot point, thereby eliminating the difficulty of installation when towing the temporary enclosure and precisely installing it in a predetermined position, and the other second end can be precisely installed on or near the weir pillar while rotating the temporary enclosure in a stable position.

[0031] In another aspect of the temporary cofferdam according to the present invention, the temporary enclosure includes a plurality of the first connection jigs arranged at intervals in the vertical direction, the revetment includes a plurality of the second connection jigs arranged at intervals in the vertical direction, one first connecting jig is disposed between two second connecting jigs that are spaced apart at a predetermined first interval in the vertical direction, thereby forming one connecting jig unit; One or more sets of the connection jig units are provided in the vertical direction.

[0032] According to this aspect, a first connecting jig provided on the temporary enclosure is arranged between two second connecting jigs arranged at a predetermined first interval in the vertical direction on the embankment to form a set of connecting jig units, and by arranging one or more sets of connecting jig units vertically, when the temporary enclosure rises due to the influence of waves, the upper second connecting jig acts as a stopper to prevent the first connecting jig from rising too high, and also, when the temporary enclosure is lowered and landed on the top surface of the apron, the first connecting jig can be moved within the first interval.

[0033] In another aspect of the temporary cofferdam according to the present invention, The first interval is set to be larger than the distance between the upper surface of the apron of the revetment and the lower surface of the temporary enclosure when the temporary enclosure is rotated in a position where it is lifted off the upper surface of the apron of the revetment, The first connecting jig moves vertically within the first interval, allowing the temporary enclosure to freely change its position from floating above the top surface of the seawall apron to resting on the top surface of the apron when the enclosure rotates.

[0034] According to this aspect, the temporary enclosure is configured so that its draft can be adjusted freely, and the first distance is set to be larger than the distance between the upper surface of the apron and the lower surface of the temporary enclosure when the temporary enclosure is rotated in a position floating above the upper surface of the apron of the revetment.As a result, when the temporary enclosure is rotated, it can accommodate a change in position from floating above the upper surface of the apron of the revetment to a position settled on the bottom of the apron.

[0035] In another aspect of the temporary cofferdam according to the present invention, a sliding member is attached to at least one of a first end portion of the temporary enclosure facing the revetment and a second end portion of the temporary enclosure facing the weir pillar; The movement of the temporary enclosure unit is guided by the sliding member sliding against a sliding support attached to at least one of the revetment and the weir pillar.

[0036] According to this aspect, the sliding members attached to at least one of the first end and the second end at vertical intervals are arranged to slide freely relative to each of the multiple sliding receiving materials, allowing the temporary enclosure to be towed smoothly and stably to the installation position.

[0037] In another aspect of the temporary cofferdam according to the present invention, The first end and the second end of the temporary enclosure are each provided with a water-stopping material that abuts against the revetment and the dam pillar, and are also provided with anchors that are fixed to the revetment and the dam pillar.

[0038] According to this aspect, both ends of the temporary enclosure are equipped with water-stopping materials that abut against both the embankment and the dam pillars, and are equipped with anchors that are fixed to both, so that the temporary enclosure can be firmly fixed to both the embankment and the dam pillars while maintaining high water-stopping properties. [Effects of the Invention]

[0039] According to the temporary closure body of the present invention, in an estuary weir in which multiple weir pillars are arranged side by side at intervals and permanent gates are installed between each weir pillar so that they can be raised and lowered freely, it is possible to provide a temporary closure body that enables complete or partial closure of the area around the weir pillar at the end of the estuary weir, which is formed to form part of the embankment, and enables repair work to be carried out in both flood and dry seasons. [Brief explanation of the drawings]

[0040] [Figure 1] FIG. 1 is a perspective view showing an example of an open-type temporary cofferdam, among examples of temporary cofferdams according to an embodiment. [Figure 2] FIG. 1 is a perspective view showing an example of a closed-type temporary cofferdam, among examples of temporary cofferdams according to an embodiment, showing a state before a temporary gate is attached. [Figure 3] FIG. 2 is a perspective view showing an example of a temporary cofferdam according to an embodiment, with a temporary gate attached thereto. [Figure 4] FIG. 2 is a plan view of an example of a temporary cutoff body according to the embodiment. [Figure 5A] A vertical cross-sectional view showing an example of the configuration of a temporary enclosure according to an embodiment. [Figure 5B] 5B is an enlarged view of part B in FIG. 5A and is a diagram illustrating a method for adjusting the draft of a temporary enclosure according to an embodiment. [Figure 6] This is a plan view of an example of a floating barge according to an embodiment, showing the state in which the first temporary enclosure is housed in the inlet. [Figure 7A] FIG. 1 is a process diagram of an example of a method for constructing a temporary cofferdam according to an embodiment. [Figure 7B] 7B is a process diagram of an example of a method for constructing a temporary cofferdam according to the embodiment, following FIG. 7A. [Figure 7C] FIG. 10 is a diagram showing an example of a method for connecting the first end of the temporary enclosure to the revetment so that it can rotate freely. [Figure 7D] 10 is a plan view illustrating the state in which the first connecting jig on the temporary enclosure side rotates relative to the second connecting jig on the revetment side. FIG. [Figure 7E] 7B is a process diagram of an example of a method for constructing a temporary cofferdam according to the embodiment. FIG. [Figure 7F] 7E is a view taken along the arrow FF in FIG. 7E, showing an enlarged view of the lower box body constituting the temporary enclosure, the legs provided below the lower box body, and two guide rails. [Figure 7G] 7B is a process chart of an example of a method for constructing a temporary cofferdam according to the embodiment, following FIG. 7E. [Figure 7H] 7B is a process diagram of an example of a method for constructing a temporary cofferdam according to the embodiment, following FIG. 7G. [Figure 7I] 7H, followed by a process diagram of an example of a method for constructing a temporary cofferdam according to the embodiment. FIG. [Figure 7J] 7I, followed by a process diagram of an example of a method for constructing a temporary cofferdam according to the embodiment. [Figure 8A] FIG. 10 is a process diagram of another example of a method for constructing a temporary cofferdam according to the embodiment. [Figure 8B] 8B is a process chart of another example of the method for constructing a temporary cofferdam according to the embodiment, following FIG. 8A. [Figure 8C] 8B is a process chart of another example of the method for constructing a temporary cofferdam according to the embodiment. FIG. [Figure 9A] FIG. 10 is a process diagram of yet another example of the method for constructing a temporary cofferdam according to the embodiment. [Figure 9B] 9B is a process chart of yet another example of the method for constructing a temporary cofferdam according to the embodiment, following FIG. 9A. [Figure 9C] A vertical cross-sectional view showing an example of a sliding support material on the revetment side and a sliding member on the temporary enclosure side. [Figure 9D] FIG. 9C is a process chart of yet another example of the method for constructing a temporary cofferdam according to the embodiment, following FIG. 9B. [Figure 9E]FIG. 9C is a process chart showing yet another example of the method for constructing a temporary cofferdam according to the embodiment, following FIG. 9D. DETAILED DESCRIPTION OF THE INVENTION

[0041] The following describes a temporary cofferdam according to an embodiment, a method for constructing the temporary cofferdam, and a floating barge for towing a temporary enclosure that constitutes the temporary cofferdam according to an embodiment, with reference to the accompanying drawings. Note that in this specification and the drawings, substantially identical components are designated by the same reference numerals, and redundant explanations may be omitted.

[0042] [Temporary cofferdam according to the embodiment] First, an example of a temporary cofferdam according to an embodiment will be described with reference to FIGS. 1 to 5. FIG. 1 is a perspective view showing an example of an open-type temporary cofferdam according to an embodiment. FIG. 2 is a perspective view showing an example of a closed-type temporary cofferdam according to an embodiment, showing a state before a temporary gate is attached. FIG. 3 is a perspective view showing an example of a temporary cofferdam according to an embodiment with a temporary gate attached. FIG. 4 is a plan view of a temporary cofferdam according to an embodiment. FIG. 5A is a vertical cross-sectional view showing an example of a configuration of a temporary enclosure according to an embodiment. FIG. 5B is an enlarged view of part B of FIG. 5A and is also a view illustrating a method for adjusting the draft of a temporary enclosure according to an embodiment.

[0043] The weir pillar 10A, which is repaired or renovated while the temporary cofferdam is constructed and placed in an aerial work environment, is one of multiple weir pillars spaced apart across the width of the estuary, located at the end of the estuary weir and forming part of the revetment 10. This repair is, for example, reinforcement work using a continuous fiber winding method or the like, which is part of earthquake-resistance measures to prevent salt damage and loss of agricultural water sources due to damage to the sluice gate during a large-scale earthquake. While the illustrated example shows an estuary weir as an example of a weir, weirs also include diversion weirs, tidal barriers, and intake weirs, as well as dams, sluice gates, and sluice gates. Therefore, the temporary cofferdam according to the embodiment is applicable to repair work on various weirs. In addition to weir repair work, the temporary cofferdam according to the embodiment can also be applied to temporary cofferdams around various underwater structures, such as underwater bridge abutments and piers, during repair work.

[0044] The estuary weir has multiple weir pillars arranged at intervals across the width of the estuary (Figure 4 shows weir pillars 10A and 10B, with other weir pillars arranged at further intervals to the side of weir pillar 10B), and a permanent gate 14 (gate door, see Figure 4) that is raised and lowered by a lifting mechanism (not shown) on an adjacent weir pillar.

[0045] As shown in Figure 1, there is a reinforced concrete apron E on the bottom of the water, and a weir pillar 10A is erected above the apron E up to the water surface. A permanent gate drop groove 12 is provided on the side 11 of the weir pillar 10A, into which the end of a permanent gate 14 (see Figure 4) is loosely fitted, and a first drop groove 13 is provided at a position away from the permanent gate drop groove 12, into which a temporary gate 73 (see Figures 3 and 4) is dropped.

[0046] Although not shown here, for example, in Figure 4, an air-head limiting obstacle such as a management road is installed so as to straddle the adjacent weir columns 10A and 10B at a distance from each other.Therefore, in the method of constructing a temporary closure body by installing the first temporary enclosure body 20 and the second temporary enclosure body 30 described below, construction must be carried out while preventing interference with obstacles located above the construction area.

[0047] As shown in Figure 1, a first temporary enclosure 20 and a second temporary enclosure 30 are arranged on the upstream and downstream sides of the water area surrounding the side surface 11 of the weir pillar 10A, respectively, and there is a gap 10a on the side of the weir pillar 10A (the water area side of the weir pillar 10A) between the two temporary enclosures 20, 30. The first temporary enclosure 20 has an inverted J-shape in plan view, and the second temporary enclosure 30 has a J-shape in plan view, with a gap 10a existing between the openings 26, 36 at each end.

[0048] Here, the terms "upstream side" and "downstream side" can mean a variety of things, such as the lake side and the bay side, the river side and the ocean side, or the mountain side and the ocean side of a river, depending on the location of the dam in question, etc.

[0049] The first temporary enclosure 20 and the second temporary enclosure 30 have a first wall 40 and a second wall 50 that can rotate freely at openings 26, 36 at their respective ends, and the first temporary enclosure 20 and the second temporary enclosure 30, and the first wall 40 and the second wall 50 form a temporary enclosure unit 100. Figure 1 shows an open-type temporary enclosure 200 with the first wall 40 and the second wall 50 in an open state.

[0050] In order to block the side of the weir pillar 10A, which is formed to form part of the embankment 10 and protrudes into the water area, together with part of the embankment 10, with the temporary enclosure unit 100, since there is a step in a plan view between the wall of the embankment 10 and the side surface 11 of the weir pillar 10A, the plan view shape of the first temporary enclosure 20 is made inverted J-shape and the plan view shape of the second temporary enclosure 30 is made J-shaped, so that the area around the weir pillar 10A can be completely blocked with the temporary enclosure unit 100.

[0051] There have been no examples in the past of using temporary enclosures 20, 30 of this shape to surround the periphery of a dam pillar 10A formed to form part of the revetment 10 and perform repair work on the dam pillar 10A. When towing and installing a J-shaped or inverted J-shaped temporary enclosure 20, 30 in a predetermined location, it is more difficult to maintain a horizontal position than a C-shaped box-shaped enclosure, which has a symmetrical linear shape. This makes the entire process from towing to installation difficult, which is one reason why temporary enclosures 20, 30 with such a planar shape are not usually considered. The reasons for adopting the process of towing and installing the temporary enclosures 20, 30 despite the difficulty of the entire process from towing to installation due to the asymmetrical linear shape of the temporary enclosures 20, 30 are as follows. In other words, if the existing permanent gate 14 is operating, for example, opening and closing once a day, running water may occur during opening and closing, potentially causing the float barge to be washed away, making work unsafe. Or, even if temporary enclosures 20, 30 are to be assembled on-site, they cannot be temporarily placed while the gate is opening and closing because they are not secured in place. This can create time constraints, such as the need to transport and install the temporary enclosures 20, 30 to their installation locations within a limited time frame (e.g., about half a day). To complete the installation within this time constraint, a construction method is adopted in which the temporary enclosures 20, 30 are towed and installed in their designated locations.

[0052] The first temporary enclosure 20 has a three-tier structure, with a lower box body 21 disposed on the lower tier and multiple tiers (two tiers in the illustrated example) of upper box bodies 22 and 23 mounted on top of the lower box body 21, and the lower box body 21 and the upper box bodies 22 and 23 are interconnected. In addition, a wave pressure resistance panel 24 is attached to the top surface of the uppermost box body 23.

[0053] On the other hand, the second temporary enclosure 30 also has a three-tier structure having a lower box body 31 arranged on the lower tier and multiple tiers (two tiers in the illustrated example) of upper box bodies 32, 33 mounted on top of the lower box body 31, with the lower box body 31 and the upper box bodies 32, 33 being interconnected. In addition, a wave pressure resistance panel 34 is attached to the top surface of the uppermost upper box body 33. Note that the first temporary enclosure 20 and the second temporary enclosure 30 may have one or three or more tiers of upper box bodies other than the illustrated example, and may be an integral structure rather than a laminated structure.

[0054] A plurality of struts 62 constituting the temporary support structure 60 are spanned between the side surface 11 of the weir pillar 10A and the first and second temporary enclosures 20 and 30. More specifically, supports 61 are erected along the inner wall surfaces of the first and second temporary enclosures 20 and 30, and opposing supports 63 are paired with the supports 61, with struts 62 spanned between the paired supports 61, 63. In addition, near the side surface 11 of the weir pillar 10A, the supports 63 are erected with a small second gap 69 between them and the side surface 11 of the weir pillar 10A, and short struts 64 span between the supports 63 and the inner wall surfaces.

[0055] The struts 61, 63 and the struts 62 are formed from shaped steel such as H-shaped steel, and the struts 62 are equipped with jacks (not shown) such as giraffe jacks at their midpoints or ends. The short struts 64 are formed from short shaped steel such as H-shaped steel, steel pipes, circular pipes, etc., and may also be equipped with jacks (not shown). By operating the jacks, axial force is introduced into the struts 62, allowing the opposing struts 61, 63 to withstand external water pressure and the like acting on the first temporary enclosure body 20 and the second temporary enclosure body 30, and the first temporary enclosure body 20 and the second temporary enclosure body 30 are fixed to the side surface 11 of the weir pillar 10A by the struts 62 and the corresponding short struts 64.

[0056] The support pillar 63 included in the temporary support 60 is erected near the weir pillar 10A with a second gap 69 between it and the side surface 11 of the weir pillar 10A, and a short strut 64 is bridged between the support pillar 63 and the weir pillar 10A in the second gap 69. Therefore, when repairing the side surface 11 of the weir pillar 10A, a part of the short strut 64 can be rearranged to form a working space in the second gap 69. Therefore, the length of the short strut 64 is set to a length that can ensure the necessary working space.

[0057] According to the configuration of the temporary support 60 shown in the figure, if a strut becomes an obstacle when repairing the side surface 11 of the weir pillar 10A, there is no need to replace the long strut, and it is only necessary to replace the short strut 64, so repairs to the weir pillar 10A can be carried out efficiently without making major changes to the temporary support 60.

[0058] A first wall body 40 and a second wall body 50 are rotatably attached to the first temporary enclosure body 20 and the second temporary enclosure body 30 via a plurality of hinge mechanisms 41, 51, respectively.

[0059] Because the first wall body 40 and the second wall body 50 are rotatably attached to the first temporary enclosure body 20 and the second temporary enclosure body 30, respectively, the first wall body 40 and the second wall body 50 can be rotated to smoothly close (the state shown in Figure 2) and open (the state shown in Figure 1) both. Furthermore, because the first wall body 40 and the second wall body 50 rotate outside the first temporary enclosure body 20 and the second temporary enclosure body 30, respectively, the rotation of the first wall body 40 and the second wall body 50 does not affect repair work, etc., inside the first temporary enclosure body 20 and the second temporary enclosure body 30.

[0060] In addition to the illustrated example, the opening and closing configuration of the first wall body 40 and the second wall body 50 relative to the first temporary enclosure body 20 and the second temporary enclosure body 30 may be configured such that the first wall body 40 and the second wall body 50 are slidably stored in the first temporary enclosure body 20 and the second temporary enclosure body 30 toward the first gap 10a, and the first gap 10a is opened by storing the first wall body 40 and the second wall body 50, and the first gap 10a is closed by sliding the first wall body 40 and the second wall body 50 outward.Furthermore, there is also a manual configuration in which the first wall body 40 and the second wall body 50 are towed into the first gap 10a and attached to the first temporary enclosure body 20 and the second temporary enclosure body 30 by heavy machinery, divers, etc., to close the first gap 10a.

[0061] Also, as shown in Figure 3, in the closed-type temporary enclosure 250, a temporary gate 73 is attached to the side of either the first wall 40 or the second wall 50 (in the illustrated example, the side of the first wall 40), adjacent to the permanent gate 14 (see Figure 4) and connected to the temporary enclosure unit 100 (of its first wall 40), and together with the temporary enclosure unit 100, forms the temporary enclosure 250.

[0062] 3 and 4, a plurality of temporary supports 71 are erected at intervals on the sides of the first wall body 40, with second drop-in grooves 72 on the left and right. These temporary supports 71 are formed, for example, from H-shaped steel, and the second drop-in grooves 72 are formed by a web and two flanges. Although not shown, below the temporary supports 71 are provided tubular members made of steel square pipes, circular pipes, or the like, and the temporary supports are erected on the upper surface of the apron E by dropping the tubular members over existing protrusions that have been provided in advance on the apron E on the bottom of the water.

[0063] The temporary gate 73 is integrally formed by connecting multiple (three in the illustrated example) corner stoppers 74, 75 to each other via connecting hardware 76. The two lower corner stoppers 74 are, for example, existing corner stoppers, and the upper corner stopper 75 is, for example, a new corner stopper. Here, the number of corner stoppers is not limited to the illustrated example, and all of the corner stoppers may be new corner stoppers. A hanging hook 75a is provided on the top surface of the new corner stopper 75 to which the lower end of a hanging material hanging from a towing device (not shown) is attached.

[0064] In addition, a third drop groove 47 is provided on the side surface of the first wall 40, and the end of the temporary gate 73 at the end on the wall side is dropped into the third drop groove 47.

[0065] During flood seasons, the open-type temporary enclosure 200 shown in Figure 1 is formed, opening the first gap 10a, allowing the permanent gate 14 to be raised and lowered freely, and repair work can be carried out on the area of ​​the weir pillar 10A that is surrounded by the first temporary enclosure 20 and the second temporary enclosure 30.

[0066] On the other hand, during dry periods, by closing the first wall body 40 and the second wall body 50, a temporary blocking body 250 is formed that completely blocks the area around the side surface 11 of the weir pillar 10A, allowing repair work to be carried out around the entire area around the weir pillar 10A.

[0067] Furthermore, since a temporary gate 73 can be attached freely to the side of either the first wall body 40 or the second wall body 50 as shown in Figure 3, for example, by attaching the temporary gate 73 to the side of a closed-type temporary closure body 250, even when the permanent gate 14 is open (in the raised position), the temporary gate 73 can block the movement of seawater and river water between the upstream and downstream sides.

[0068] Furthermore, even in the case of an open-type temporary closure body 200, the temporary closure body 200 can be formed by closing one of the first wall body 40 and the second wall body 50 and attaching a temporary gate 73 to the closed wall body.

[0069] Next, an example of the configuration of a temporary enclosure and an example of a method for adjusting the draft of a box body will be described. Here, Figure 5A is a longitudinal cross-sectional view showing an example of the configuration of a temporary enclosure according to an embodiment, and Figure 5B is an enlarged view of part B in Figure 5A, and is also a diagram for explaining a method for adjusting the draft of a temporary enclosure. Note that, below, the configuration of the first temporary enclosure 20 will be described, but the configuration of the second temporary enclosure 30 is substantially the same as that of the first temporary enclosure 20.

[0070] The first temporary enclosure 20 has a three-tier structure, with a lower box body 21 disposed on the lower tier and multiple tiers (two tiers in the illustrated example) of upper box bodies 22 and 23 mounted on top of the lower box body 21, and the lower box body 21 and the upper box bodies 22 and 23 are interconnected. In addition, a wave pressure resistance panel 24 is attached to the top surface of the uppermost box body 23.

[0071] The lower box body 21 and the upper box bodies 22, 23 are each formed of a core member 20a' made up of multiple shaped steel members, a steel skin plate 20b' attached to the outside water side of the core member 20a', and a steel skin plate 20c' attached to the inside of the core member 20a'. Note that the steel skin plate 20c' attached to the inside may be omitted if necessary.

[0072] The lower box body 21 includes a water storage space 21a, a water supply / drainage pipe 21c that connects the water storage space 21a to external water W, a water supply / drainage valve 21b, a water supply / exhaust pipe 21e, a water supply / exhaust valve 21d, and a compressed air supply unit 21f that supplies compressed air to the water supply / exhaust pipe 21e. In addition to the illustrated example, the upper boxes 22 and 23 may also include the water storage space 21a, the water supply / drainage pipe 21c, the water supply / drainage valve 21b, etc., similar to the lower box body 21. For example, FIG. 7C shows a configuration in which all boxes include water storage spaces 21a, 22a, and 23a. Furthermore, instead of the multi-tiered stacked structure shown in the illustration, an integrated structure having a J-shape or an inverted J-shape in plan view may also be used.

[0073] As shown in the illustrated example, the first temporary enclosure 20 has a lower box body 21 and multiple upper box bodies 22, 23, which improves transportability when transporting overland from the factory to the pier, which is the work yard, for example, when the first temporary enclosure 20 is large.This prevents the heavy machinery used to hoist and lower the first temporary enclosure 20 at the pier from becoming too large, and also improves hoisting and lowering performance.

[0074] Furthermore, since the first temporary enclosure 20 is formed from multiple steel structural members that serve as the core member 20a' and a steel skin plate 20b' that is attached to at least the external water side of the core member 20a', it is possible to form a first temporary enclosure 20 that is highly rigid and as light as possible, resulting in a first temporary enclosure that has excellent water pressure resistance when installed around the weir column 10A and is easy to transport on land.

[0075] Furthermore, by attaching a wave pressure resistance panel 24 to the top surface of the first temporary enclosure 20, it is possible to prevent seawater and the like from entering the inside of the first temporary enclosure 20. Here, since the wave pressure resistance panel 24 only bears the wave pressure, a thin steel panel, for example, is used.

[0076] By opening and closing at least one of the water supply and drainage valve 21b and the water supply and exhaust valve 21d, the amount of external water (ballast) supplied to the water storage space 21a is adjusted, and the draft of the first temporary enclosure 20 can be adjusted as desired, and this adjustment of the draft allows the first temporary enclosure 20 to float or sink in the Z1 direction. Therefore, for example, if a sufficient draft cannot be secured, it is possible to adjust the draft by floating the first temporary enclosure 20 as desired without unnecessarily dredging the bottom ground G.

[0077] The water supply and drainage valve 21b and the water supply and exhaust valve 21d can be opened and closed manually by a worker on board the first temporary enclosure 20. Alternatively, the water supply and drainage valve 21b and the water supply and exhaust valve 21d may both be automatically controlled valves, a sensor that measures draft is attached to the first temporary enclosure 20, and a user terminal or computer carried by a remote manager receives draft data from the sensor and sends opening and closing commands to the water supply and drainage valves 21b etc. in accordance with the draft data, and the water supply and drainage valves 21b etc. are automatically controlled to open and close based on the opening and closing command.

[0078] When the first temporary enclosure 20 is lowered, at least water is supplied to the water storage space 21a by the water supply / drain valve 21b. On the other hand, when the first temporary enclosure 20 is raised, air is supplied to the water storage space 21a by the water supply / drain valve 21d, and water is drained from the water storage space 21a by the water supply / drain valve 21b.

[0079] [Floating barge according to the embodiment] Next, an example of a floating barge according to an embodiment will be described together with a method for adjusting its draft with reference to Fig. 6. Here, Fig. 6 is a plan view of an example of a floating barge according to an embodiment, showing the state in which the first temporary enclosure is housed in the inlet.

[0080] The floating barge 300 has multiple (22 in the illustrated example) box bodies 310 arranged side by side, and adjacent box bodies 310 are bolted together using grooves 312 at the corresponding ends of each box body 310, allowing each box body 310 to be connected detachably and freely, and allowing the planar shape to be freely changed.

[0081] The floating barge 300 has an inlet 320 that accommodates and moores the inverted J-shaped first temporary enclosure 20 (or the J-shaped second temporary enclosure 30).

[0082] More specifically, an inlet 320 is provided with dimensions such that the ends of the first temporary enclosure 20 and the second temporary enclosure 30 (in Figure 6, the first end 20a and second end 20b of the first temporary enclosure 20) protrude outward. The construction methods shown in Figures 7 to 9 include a construction method in which the first end 20a is rotatably connected to the revetment 10 and the first temporary enclosure 20 is rotated to connect the second end 20b to the side of the weir pillar 10A, and a construction method in which sliding members attached to both the first end 20a and the second end 20b slide along sliding supports attached to the revetment 10 and the weir pillar 10A. However, all of these construction methods require that the first end 20a and the second end 20b be positioned in positions that protrude outward from the inlet 320, and therefore an inlet 320 with such dimensions is provided. Here, depending on the size and shape of the first temporary enclosure 20 (or the second temporary enclosure 30), a spare float (not shown) may be placed inside the first temporary enclosure 20 (or the second temporary enclosure 30) in the inlet 320, in a location that does not interfere with the positioning of the first temporary enclosure 20 (or the second temporary enclosure 30), and the first temporary enclosure 20 (or the second temporary enclosure 30) may be auxiliary moored from inside it.

[0083] On one end of the top surface of the floating barge 300, multiple (two in the illustrated example) retraction winches 330 are provided, and on the other end, multiple (two in the illustrated example) release winches 340 are provided. The floating barge 300 is configured to be towed by a tugboat (not shown) to the vicinity of the installation position of the weir pillar 10A, with the first temporary enclosure 20 (or the second temporary enclosure 30) moored (temporarily fixed) to the inlet 320. Here, the floating barge 300 may be a self-propelled barge.

[0084] For example, as shown in Figure 7A, the anchoring point 335a of the wire 335 extending from the retraction winch 330 is set to a part of the revetment 10. When the retraction winch 330 is operated, the retraction force acting on the wire 335 in the Y3 direction can retract the floating barge 300 to the side opposite the estuary weir.

[0085] On the other hand, the anchoring point 345a of the wire 345 extending from the delivery winch 340 is set near the permanent gate 14 (for example, on the top surface of the apron E, etc.). When the delivery winch 340 is operated, a delivery force in the Y2 direction acting on the wire 345 enables the floating barge 300 to be delivered to the estuary weir.

[0086] Furthermore, by operating the retraction winch 330 and the delivery winch 340 simultaneously or alternately, the floating barge 300 can be pushed and pulled via the wires 335, 345 extending from both winches, and the first temporary enclosure housed in the inlet 320 can be towed to the designated installation position while maintaining its horizontal position.

[0087] [Method for constructing a temporary cofferdam according to the embodiment] Next, several examples of a method for constructing a temporary cofferdam according to an embodiment will be described with reference to Figures 7 to 9. Figures 7A to 7J are process diagrams of one example of a method for constructing a temporary cofferdam according to an embodiment. Figures 8A to 8C are process diagrams of another example of a method for constructing a temporary cofferdam according to an embodiment. Figures 9A to 9E are process diagrams of yet another example of a method for constructing a temporary cofferdam according to an embodiment.

[0088] First, an example of a method for constructing a temporary cofferdam according to the embodiment will be described with reference to FIGS. 7A to 7J.

[0089] First, in each of the work yards located upstream and downstream, a first temporary enclosure 20 having an inverted J-shaped plan view and a second temporary enclosure 30 having a J-shaped plan view are prepared. A unique floating barge may be used to tow each temporary enclosure 20, 30 to the installation position, or a common floating barge may be used to install both in sequence (this concludes the preparation process).

[0090] Next, as shown in Figure 7A, the float barge 300 departs from a pier (not shown), which is the work yard, and is towed in the Y1 direction to the vicinity of the estuary weir with the first temporary enclosure 20 housed in the inlet 320, and the anchoring points 335a, 345a of each wire 335, 345 are respectively anchored at predetermined positions on the seawall 10 and near the permanent gate 14.

[0091] At this time, the float barge 300 is aligned so that the first temporary enclosure 20 faces the seawall 10, which has a dam pillar 10A that is partially surrounded by the first temporary enclosure 20 and protrudes toward the water body. In this aligned position, the two ends of the first temporary enclosure 20, the first end 20a and the second end 20b, face the seawall 10 in a position that protrudes from the inlet 320 toward the seawall 10.

[0092] 7A, the second temporary enclosure 30 on the downstream side has already been installed so as to surround the area downstream of the weir pillar 10A, but the second temporary enclosure 30 may be installed using a method similar to that described below. Also, the order of installation of the first temporary cofferdam 20 and the second temporary enclosure 30 may be reversed, or both may be installed simultaneously.

[0093] In Fig. 7A, the second temporary enclosure 30, which has a J-shaped shape in a plan view, has its first end 30a fixed to the revetment 10 via anchors 30c with water-stopping material 30d abutting against it. Meanwhile, the second end 30b of the second temporary enclosure 30 is fixed to the side of the weir pillar 10A via anchors 30c with the water-stopping material 30d abutting against it. Here, the specific shapes of the water-stopping material 30d and anchors 30c are similar to those of the anchors 20c and water-stopping material 20d provided on the first temporary enclosure 20 shown in Fig. 7I.

[0094] Next, as shown in FIG. 7B, the floating barge 300 is pushed and pulled by the wires 335, 345 while being moved closer to the estuary barge in the Y4 direction, and the first end 20a of the first temporary enclosure 20 is rotatably connected to the revetment 10.

[0095] Here, a method for connecting the first end portion 20a to the revetment 10 so that it can rotate freely will be described with reference to FIGS. 7C and 7D.

[0096] As shown in the right diagram of Figure 7C, the draft depth of the first temporary enclosure body 20 is adjusted so that there is a gap of height t1 between the underside 20h of the first temporary enclosure body 20 and the upper surface E1 of the apron E. This gap height t1 is a height that prevents interference between the first temporary enclosure body 20 and obstacles above the construction area when the first temporary enclosure body 20 is rotated and installed as described below.

[0097] During the towing process until the first temporary enclosure body 20 is rotatably connected, the draft depth of the first temporary enclosure body 20 is set to a relatively short draft depth to ensure a distance to the bottom ground G so that the bottom ground G, which can vary in depth, does not interfere with the underside 20h of the first temporary enclosure body 20, and when the first temporary enclosure body 20 is rotatably connected, water is supplied to the water storage space 21a, etc. to sink the first temporary enclosure body 20 and increase the draft depth, and the draft depth is adjusted so that the distance is the height t1 in the illustrated example.

[0098] A plurality of first connecting jigs 26 are provided at intervals in the vertical direction at the first end 20a of the first temporary enclosure 20. The first connecting jigs 26 are made of flat steel and have first through holes 26a which are elongated holes as shown in Fig. 7D.

[0099] On the other hand, as shown in Figures 7C and 7D, hinge structural members 15 made of steel (H-shaped steel in the illustrated example) are attached to the revetment 10, and a set of two second connecting jigs 16 are attached to the hinge structural members 15 at intervals in the vertical direction, so that each first connecting jig 26 is sandwiched between them above and below, and multiple sets of second connecting jigs 16 are provided in the vertical direction.

[0100] A pair of connecting jig units 17 is formed by one first connecting jig 26 and two second connecting jigs 16 that sandwich it in the vertical direction.

[0101] The second connecting jig 16 is made of flat steel and has a second through hole 16a which is a round hole as shown in FIG. 7D.

[0102] The first vertical distance t2 between a pair of second connecting jigs 16 that sandwich one first connecting jig 26 from above and below is set to be longer than the height t1 of the gap between the underside 20h of the first temporary enclosure 20 and the upper surface E1 of the apron E. This ensures that the first temporary enclosure 20 will land on the upper surface E1 of the apron E. As an example, t1 can be set to approximately 500 mm, and t2 to approximately 600 mm.

[0103] As shown in the right image of Figure 7C, the first temporary enclosure 20 is moved closer to the revetment 10 in the X1 direction so that the corresponding first connection jig 26 is positioned between each pair of second connection jigs 16 that form each connection jig unit 17, and the first through holes 26a of all first connection jigs 26 are aligned with the second through holes 16a of the second connection jigs 16.

[0104] Next, as shown in FIG. 7C, a pin 18 is inserted from above in the X2 direction into each of the first through-holes 26a and each of the second through-holes 16a that are aligned with each other, thereby forming a rotation fulcrum 19.

[0105] Here, the first through hole 26a of the first connecting jig 26 on the first temporary enclosure body 20 side is an elongated hole, and the second through hole 16a of the second connecting jig 16 on the revetment 10 side is a round hole with a hole diameter approximately the outer diameter of the pin 18. This configuration allows the pin 18 to be installed vertically, preventing problems such as the pin being set at an angle and preventing the first temporary enclosure body 20 from rotating. Furthermore, the elongated hole 26a can absorb variations in horizontality (incidence of tilt) that may occur when adjusting the draft depth of the first temporary enclosure body 20 without applying undue external force to the first temporary enclosure body 20.

[0106] As shown in Figures 7B and 7D, while maintaining the horizontal position of the first temporary enclosure body 20, the first temporary enclosure body 20 is rotated in the Y5 direction together with the floating barge 300 pushed and pulled by wires 335, 345 to a position where its second end 20b abuts against the weir pillar 10A.

[0107] Here, when rotating the first temporary enclosure 20, as shown in Figure 7E, both ends of the inverted J-shaped first temporary enclosure 20 are connected via reinforcing members T made of structural steel or the like, forming a trust structure, and then the first temporary enclosure 20 is rotated, thereby preventing local damage or deformation of the first temporary enclosure 20 during rotation and allowing the entire body to be rotated in a more firmly integrated state.

[0108] Furthermore, as shown in Figures 7E and 7F, a leg S having two rising legs S1 and S2 is provided below the second end side of the first temporary enclosure 20, and two guide rails R1 and R2 are installed on the upper surface E1 of the apron E to guide the movement of each rising leg S1 and S2, and the first temporary enclosure 20 is intended to rotate smoothly and precisely by moving the rising legs S1 and S2 along the guide rails R1 and R2.

[0109] Here, the more specific configuration of the leg S is that it has a U-shaped outer shape that protrudes to the left and right sides of the lower box body 21, and has multiple horizontal bars S3 and a pair of rising legs S1, S2 connected to the left and right ends of each horizontal bar S3, with a hydraulic jack S4 interposed midway between each rising leg S1, S2.

[0110] By synchronously driving the hydraulic jacks S4 provided on each rising leg S1, S2, the temporary enclosure including the lower box body 21 can be raised and lowered in the X5 direction, and the draft depth of the temporary enclosure can be adjusted as it moves on the rails. In addition, by driving the hydraulic jacks S4, it is also possible to finally land the temporary enclosure on the bottom.

[0111] It should be noted that the lower box body 21 may be provided with a leg portion that does not include the hydraulic jack S4 as in the illustrated example.

[0112] Sliding pads P are attached to the lower end of each rising leg S1, S2 and to one or both of the upper surfaces of the guide rails R1, R2, and the legs S are moved along the guide rails R1, R2 while reducing sliding friction with the sliding pads P. Here, in order to make the alignment of the first temporary enclosure 20 even easier, taking into account errors in the landing position of the legs S on the apron E due to variations in the horizontality (tilt) of the first temporary enclosure 20, the guide rail at the start of the rotation may be set relatively wide in relation to the shape and dimensions of the legs S, and as the guide rail approaches the end point of the rotation, the width gradually narrows, and a rail structure may be applied that precisely guides the first temporary enclosure 20 to the position where it should be installed.

[0113] Although not shown here, instead of moving the rising legs S1 and S2 along the guide rails R1 and R2 as shown in the example, guide rollers may be attached to the lower ends of the rising legs, and the guide rollers may move along the top surface of an apron on the bottom of the water.

[0114] In this way, by using the pivot point 19 as the center of rotation and adjusting the posture of the first temporary enclosure body 20, it is rotated in the Y5 direction together with the floating barge 300, which is pushed and pulled by the wires 335, 345, so that the second end 20b of the first temporary enclosure body 20 abuts against the weir pillar 10A, as shown in Figure 7G (this is the towing process).

[0115] Next, as shown in Figure 7H, external water W is injected as ballast water into the water storage space 21a, etc., causing the first temporary enclosure body 20 to sink downward in the X6 direction, and the lower surface 20h to land on the upper surface E1 of the apron E of the seawall 10. At this time, as already explained, since the first interval t2 is set longer than the separation height t1, it is possible to ensure that the first temporary enclosure body 20 will land on the upper surface E1 of the apron E.

[0116] As shown in Figure 7I, when the first temporary enclosure 20 is in a bottom-landed position, at the first end 20a on the pivot point side, the nut 20g is rotated in the X3 direction to slide the bolt 20f, which is the axial member, in the X4 direction, and the support plate 20e attached to the end of the bolt 20f is abutted against the wall surface of the embankment 10.

[0117] In this abutting position, the water-stopping material 20d provided on one end side (the left end side in the illustrated example) of the first end 20a abuts against the wall surface of the revetment 10, forming a water-stopping structure. Meanwhile, an overhanging plate 20j overhangs laterally on the other end side (the right end side in the illustrated example) of the first end 20a, and the first end 20a is connected to the revetment 10 by driving an anchor 20c into the wall surface of the revetment 10 via the overhanging plate 20j.

[0118] Also, although not shown, the connection between the side of the dam pillar 10A and the second end 20b is also performed in a manner similar to that shown in Figure 7I, in which the second end 20b is connected to the side of the dam pillar 10A with an anchor in a position that provides a water-stopping structure (this concludes the connection process).

[0119] After connecting the first end 20a and the second end 20b of the first temporary enclosure body 20 to the upstream side of the upstream embankment 10 and the weir pillar 10A, respectively, the first temporary enclosure body 20 is undocked from the floating barge 300, as shown in Figure 7J, and the floating barge 300 is towed in the Y6 direction to evacuate to the work yard side (not shown).

[0120] At this time, when the floating barge 300 is retreated from the state shown in Figure 7G toward the pier 10B, there is a risk that the box body 310A at the end will cause the floating barge 300 to interfere with the pier 10B, so the box body 310A at the end is temporarily detached and the floating barge 300 is evacuated upstream. Next, as shown in Figure 7J, the detached box body 310A is reconnected to the floating barge 300 and towed toward the work yard. Here, the box body 310A can also be pre-sized so that it does not interfere with the pier 10B, in which case there is no need to detach the box body 310A when the floating barge 300 is evacuated upstream.

[0121] Then, the first wall body 40 and the second wall body 50 are rotatably connected to the first temporary enclosure body 20 and the second temporary enclosure body 30, respectively, to form a temporary enclosure unit 100, and a temporary gate 73 is installed on the side of it to construct temporary closure bodies 200, 250 (this is the temporary gate installation process).

[0122] According to the construction method of the illustrated example, a closed-type temporary enclosure 250 can be formed that completely blocks the area around the weir pillar 10A formed to form part of the embankment 10 with a temporary enclosure unit 100 consisting of a first temporary enclosure 20 that has an inverted J-shape in plan view and a second temporary enclosure 30 that is J-shaped, and an open-type temporary enclosure 200 that is partially open can be formed.

[0123] Furthermore, even if there is an obstacle above the construction area of ​​the temporary enclosure bodies 20, 30 at the estuary weir, the temporary enclosure bodies 20, 30 can be efficiently fixed firmly in their installation positions relative to the embankment 10 and the weir pillars 10A with high water-tightness, while avoiding interference between the temporary enclosure bodies 20, 30 and the obstacle above the construction area of ​​the temporary enclosure bodies 20, 30, and the temporary closure bodies 200, 250 can be constructed.

[0124] Next, another example of the method for constructing a temporary cofferdam according to the embodiment will be described with reference to FIGS. 8A to 8C.

[0125] The preparation process for preparing the first temporary enclosure 20, which has an inverted J-shaped planar shape, and the second temporary enclosure 30, which has a J-shaped planar shape, is common to both the upstream and downstream work yards.

[0126] As shown in Figure 8A, a float barge 300 departs from a pier (not shown), which is a work yard, and is towed in the Y1 direction to the vicinity of the estuary weir with the first temporary enclosure 20 housed in the inlet 320, and the anchoring points 335a, 345a of each wire 335, 345 are respectively anchored at predetermined positions on the seawall 10 and near the permanent gate 14.

[0127] At this time, the float barge 300 is aligned so that the first temporary enclosure 20 faces the seawall 10, which has a dam pillar 10A that is partially surrounded by the first temporary enclosure 20 and protrudes toward the water body. In this aligned position, the two ends of the first temporary enclosure 20, the first end 20a and the second end 20b, face the seawall 10 in a position that protrudes from the inlet 320 toward the seawall 10.

[0128] Next, as shown in Figure 8B, while maintaining the horizontal posture of the first temporary enclosure body 20, the first temporary enclosure body 20 is towed in the Y4 direction toward the estuary dam together with the floating barge 300, which is pushed and pulled by wires 335, 345, until the first end 20a of the first temporary enclosure body 20 abuts against a predetermined position on the wall surface of the embankment 10, and the second end 20b abuts against a predetermined position on the dam pillar 10A (this is the towing process).

[0129] Next, similar to the method described with reference to Figure 7H, external water W is injected into the water storage space 21a, etc. as ballast water to cause the first temporary enclosure body 20 to sink downward, and the lower surface 20h is allowed to land on the upper surface E1 of the apron E of the seawall 10.

[0130] Next, in the same manner as described with reference to FIG. 7I, with the first temporary enclosure 20 in a bottom-mounted position, the nut 20g at the first end 20a of the first temporary enclosure 20 is rotated in the X3 direction to slide the bolt 20f, which is an axial member, in the X4 direction, and the support plate 20e attached to the end of the bolt 20f is brought into contact with the wall surface of the revetment 10, thereby forming a water-stopping structure. Meanwhile, an anchor 20c is driven into the wall surface of the revetment 10 via an overhanging plate 20j that overhangs laterally at the other end of the first end 20a, thereby connecting the first end 20a to the revetment 10. A similar method is used to connect the side surface of the pier 10A to the second end 20b, and the second end 20b is connected to the side surface of the pier 10A with an anchor in a position that provides a water-stopping structure (connection process).

[0131] After connecting the first end 20a and the second end 20b of the first temporary enclosure body 20 to the upstream side of the upstream embankment 10 and the weir pillar 10A, respectively, the first temporary enclosure body 20 is undocked from the floating barge 300 as shown in Figure 8C, and the floating barge 300 is towed in the direction Y8 to evacuate to the work yard side (not shown).

[0132] At this time, when the floating barge 300 is evacuated while being retracted toward the pier 10B from the state shown in Figure 8B, there is a risk that the floating barge 300 will interfere with the pier 10B due to the presence of the box body 310A at the end, so as shown in Figure 8C, the box body 310A at the end is detached in the Y7 direction to form the floating barge 300', which is then evacuated upstream and towed in the Y8 direction towards the work yard. Here, the box body 310A can also be made to a size that does not interfere with the pier 10B in advance, in which case there is no need to detach the box body 310A when evacuating the floating barge 300 upstream.

[0133] Then, the first wall body 40 and the second wall body 50 are rotatably connected to the first temporary enclosure body 20 and the second temporary enclosure body 30, respectively, to form a temporary enclosure unit 100, and a temporary gate 73 is installed on the side of it to construct temporary closure bodies 200, 250 (this is the temporary gate installation process).

[0134] Even with the construction method shown in the illustration, it is possible to form a closed-type temporary enclosure 250 that completely blocks the area around the weir pillar 10A formed to form part of the embankment 10 with a temporary enclosure unit 100 consisting of a first temporary enclosure 20 that has an inverted J-shape in plan view and a second temporary enclosure 30 that is J-shaped, and it is also possible to form an open-type temporary enclosure 200 that is partially open.

[0135] Furthermore, even if there is an obstacle above the construction area of ​​the temporary enclosure bodies 20, 30 at the estuary weir, the temporary enclosure bodies 20, 30 can be efficiently fixed firmly in their installation positions relative to the embankment 10 and the weir pillars 10A with high water-tightness, while avoiding interference between the temporary enclosure bodies 20, 30 and the obstacle above the construction area of ​​the temporary enclosure bodies 20, 30, and the temporary closure bodies 200, 250 can be constructed.

[0136] Next, still another example of the method for constructing a temporary cofferdam according to the embodiment will be described with reference to FIGS. 9A to 9E.

[0137] The preparation process for preparing the first temporary enclosure 20, which has an inverted J-shaped planar shape, and the second temporary enclosure 30, which has a J-shaped planar shape, is common to both the upstream and downstream work yards.

[0138] As shown in Figure 9A, a float barge 300 departs from a pier (not shown), which is a work yard, and is towed in the Y1 direction to the vicinity of the estuary weir with the first temporary enclosure 20 housed in the inlet 320, and the anchoring points 335a, 345a of each wire 335, 345 are anchored at predetermined positions on the seawall 10 and predetermined positions near the permanent gate 14, respectively.

[0139] At this time, the float barge 300 is aligned so that the first temporary enclosure 20 faces the seawall 10, which has a dam pillar 10A that is partially surrounded by the first temporary enclosure 20 and protrudes toward the water body. In this aligned position, the two ends of the first temporary enclosure 20, the first end 20a and the second end 20b, face the seawall 10 in a position that protrudes from the inlet 320 toward the seawall 10.

[0140] 9A, sliding members N1 and N2 are attached to the first end 20a and the second end 20b of the first temporary enclosure 20. Meanwhile, sliding support members M1 and M2 corresponding to the sliding members N1 and N2 are attached to the revetment 10 and the weir pillar 10A, respectively.

[0141] Furthermore, a stopper V made of shaped steel such as an H-shaped steel is erected at a position away from the end of the sliding support material M1 on the river mouth weir side of the revetment 10, with a small width of a push-in area Q interposed between them.

[0142] As shown in Figure 9B, while maintaining the horizontal posture of the first temporary enclosure body 20, the first temporary enclosure body 20 is towed toward the estuary weir together with the floating barge 300 pushed and pulled by wires 335, 345, and the corresponding sliding members N1, N2 are slidably aligned with the sliding receiving members M1, M2, and the first temporary enclosure body 20 is towed (moved) in the Y4 direction toward the estuary weir while each sliding member N1, N2 is slid in the Y4' direction against the corresponding sliding receiving members M1, M2.

[0143] Here, an example of the sliding receiving material M and the sliding member N will be described with reference to FIG. 9C.

[0144] The sliding support material M is a lipped channel steel with a through hole Ma extending laterally facing the side, and the sliding member N comprises a support plate 20e housed inside the lipped channel steel M, and an axial member 20f consisting of a bolt whose end is fixed to one wide surface of the support plate 20e and passes through the through hole Ma; by rotating the nut 20g in the X3 direction, the axial member 20f can be moved towards or away from the lipped channel steel M in the X4 direction.

[0145] By using the sliding receiving material M and sliding member N in the illustrated example, the first temporary enclosure 20 can be moved (towed) to the installation position while guiding the sliding member N along the sliding receiving material M in a stable posture.

[0146] It is preferable that the combination of sliding support material M and sliding member N in the illustrated example is provided in multiple sets in the height direction of the first temporary enclosure 20, and for example, two tiers of sliding member N are attached to the upper and lower positions of each of the lower box body 21 and upper box bodies 22, 23 of the first temporary enclosure 20 (six tiers of sliding member N in total), and a total of six tiers of sliding support material M are attached at level positions corresponding to each sliding member N on the revetment 10 and weir pillar 10A. Here, the combination of sliding support material M and sliding member N may be provided in one set (one tier) at any position in the height direction of the first temporary enclosure 20.

[0147] The sliding support material M and the sliding member N may be provided only on one of the revetment 10 side and the weir pillar 10A side. Specific forms of the sliding support material M and the sliding member N include various forms other than the illustrated examples.

[0148] As shown in Figure 9D, the first temporary enclosure 20 is moved to the installation position while sliding the corresponding sliding members N1, N2 along each sliding support M1, M2, and the first end 20a of the first temporary enclosure 20 abuts against the stopper V and is pushed into the pushing area Q in the Y9 direction, thereby completing the towing of the first end 20a and second end 20b of the first temporary enclosure 20 to the respective installation positions of the embankment 10 and weir pillar 10A (towing process).

[0149] Next, similar to the method described with reference to Figure 7H, external water W is injected into the water storage space 21a, etc. as ballast water to cause the first temporary enclosure body 20 to sink downward, and the lower surface 20h is allowed to land on the upper surface E1 of the apron E of the seawall 10.

[0150] Next, in the same manner as described with reference to FIG. 7I, with the first temporary enclosure 20 in a bottom-mounted position, the nut 20g at the first end 20a of the first temporary enclosure 20 is rotated in the X3 direction to slide the bolt 20f, which is an axial member, in the X4 direction, and the support plate 20e attached to the end of the bolt 20f is brought into contact with the wall surface of the revetment 10, thereby forming a water-stopping structure. Meanwhile, an anchor 20c is driven into the wall surface of the revetment 10 via an overhanging plate 20j that overhangs laterally at the other end of the first end 20a, thereby connecting the first end 20a to the revetment 10. A similar method is used to connect the side surface of the pier 10A to the second end 20b, and the second end 20b is connected to the side surface of the pier 10A with an anchor in a position that provides a water-stopping structure (connection process).

[0151] After connecting the first end 20a and the second end 20b of the first temporary enclosure body 20 to the upstream side of the upstream revetment 10 and the weir pillar 10A, respectively, the first temporary enclosure body 20 is undocked from the floating barge 300, as shown in Figure 9E, and the floating barge 300 is evacuated to the work yard side (not shown).

[0152] At this time, when the floating barge 300 is retreated from the state shown in Figure 9D toward the dam pillar 10B, there is a risk that the floating barge 300 will interfere with the dam pillar 10B due to the presence of the box body 310B at the end, so as shown in Figure 9E, the box body 310B at the end is temporarily detached and the floating barge 300 is evacuated upstream, and the detached box body 310B is reconnected to form the floating barge 300", which is then towed in the direction Y10 toward the work yard. Here, the box body 310B can also be made in advance to a size that does not interfere with the dam pillar 10B, in which case there is no need to detach the box body 310B when the floating barge 300 is evacuated upstream.

[0153] Then, the first wall body 40 and the second wall body 50 are rotatably connected to the first temporary enclosure body 20 and the second temporary enclosure body 30, respectively, to form a temporary enclosure unit 100, and a temporary gate 73 is installed on the side of it to construct temporary closure bodies 200, 250 (this is the temporary gate installation process).

[0154] Even with the construction method shown in the illustration, it is possible to form a closed-type temporary enclosure 250 that completely blocks the area around the weir pillar 10A formed to form part of the embankment 10 with a temporary enclosure unit 100 consisting of a first temporary enclosure 20 that has an inverted J-shape in plan view and a second temporary enclosure 30 that is J-shaped, and it is also possible to form an open-type temporary enclosure 200 that is partially open.

[0155] Furthermore, even if there is an obstacle above the construction area of ​​the temporary enclosure bodies 20, 30 at the estuary weir, the temporary enclosure bodies 20, 30 can be efficiently fixed firmly in their installation positions relative to the embankment 10 and the weir pillars 10A with high water-tightness, while avoiding interference between the temporary enclosure bodies 20, 30 and the obstacle above the construction area of ​​the temporary enclosure bodies 20, 30, and the temporary closure bodies 200, 250 can be constructed.

[0156] The configurations of the above-described embodiments may be combined with other components, and the present invention is not limited to the configurations shown here. In this regard, the present invention may be modified within the scope of the spirit of the present invention, and may be appropriately determined depending on the application form. [Explanation of symbols]

[0157] 10: Seawall 10A,10B:Weir pillar 10a: Gap 11: Side 12: Permanent gate drop groove 13: First drop groove 14: Permanent gate 15: Hinge structural member 16: Second connection jig 16a: 2nd through hole (round hole) 17: Connection jig unit 18: Pin 19: Pivot point 20: First temporary enclosure 20a: First end 20b: Second end 20c: Anchor 20d:Waterproof material 20e: Support plate 20f: Shaft material (bolt) 20g: nuts 20h: Bottom surface 20j: Extension plate 20': Opening joint 21:Lower box body 21a: Water storage space 21b: Water supply and drainage valve 21c: Water supply and drainage pipe 21d: Intake and exhaust valve 21e: Supply and exhaust pipe 21f: Compressed air supply section 22: Upper box (second box) 22a: Water storage space 23: Upper box (third box) 23a: Water storage space 24: Wave pressure resistance panel 26: First connection jig 26a: 1st through hole (long hole) 30: Second temporary enclosure 30a: First end 30b: 2nd end 30c: Anchor 30d:Waterproof material 30': Opening joint 31:Lower box body 32: Upper box (second box) 33: Upper box (third box) 34: Wave pressure resistance panel 36:Aperture 40: 1st wall 41: Hinge mechanism 42a: Contact area 47: Third drop groove 50:Second wall 51: Hinge mechanism 60: Temporary shoring 61: Strut 62:Surface beam 63: Post 64: Short beam 69: Second gap 71: Temporary support 72: Second drop groove 73: Temporary Gate 74: Existing corner cut material (corner cut material) 75: Newly installed corner cutter (corner cutter) 75a: Hanging hook 76: Connection hardware 100: Temporary enclosure unit 200: Open type temporary cofferdam (temporary cofferdam) 250: Closed type temporary cofferdam (temporary cofferdam) 300: Floating barge 310,310A,310B: Box body 312: Groove 320: Cove 330: Retraction winch 340: Delivery winch 335,345: Wire 335a, 345a: Locking point W: External water (seawater, river water) G: Underwater ground E: Apron E1:Top surface T: Reinforcement member S: Legs S1, S2: Standing legs S3: Horizontal bar S4: Hydraulic jack P: Sliding putt M, M1, M2: Sliding support material (channel steel with lip) Ma: Through hole N, N1, N2: Sliding members V: Stopper Q: Push-in area

Claims

1. A temporary cofferdam constructed on the side of a weir pillar at an estuary weir having a weir pillar formed to form part of a revetment and a permanent gate extending to the side of the weir pillar and capable of being raised and lowered, comprising: a temporary enclosure unit formed by a first temporary enclosure and a second temporary enclosure included in a temporary enclosure, the first and second temporary enclosures being disposed on the sides of the weir pillar, respectively, upstream of the permanent gate and downstream of the permanent gate; a temporary gate that is provided adjacent to the permanent gate and connected to the temporary enclosure unit; The first temporary enclosure and the second temporary enclosure are directly or indirectly connected to each other, thereby forming a closed posture of the temporary enclosure unit; One of the first temporary enclosure and the second temporary enclosure has a J-shape in plan view, and the other has an inverted J-shape, a first end portion of each of the first and second temporary enclosure bodies being disposed on a part of the revetment, and a second end portion of each of the first and second temporary enclosure bodies being disposed on a side of the weir pillar; The temporary enclosure includes a lower box body disposed on the lower level, one or more upper box bodies stacked on the lower box body, A temporary enclosure characterized in that at least one of the lower box body and the upper box body is provided with a water storage space, a water supply and drainage valve, and an air supply and exhaust valve, allowing the draft of the temporary enclosure to be freely adjusted.

2. A first wall body that can be opened and closed is attached to a downstream side of the first temporary enclosure body that faces the second temporary enclosure body, a second wall body that can be opened and closed is attached to the upstream side of the second temporary enclosure body that faces the first temporary enclosure body, 2. The temporary enclosure according to claim 1, wherein the temporary enclosure unit is closed by joining the ends of the first wall body and the second wall body.

3. a first connecting jig having a first through hole is attached to one of the first ends of the temporary enclosure facing the revetment; the revetment has a second connecting jig having a second through hole at a position corresponding to the first connecting jig, A temporary enclosure as described in claim 1 or 2, characterized in that a pivot point is formed by inserting a pin into the first through hole and the second through hole, and the temporary enclosure unit is freely rotatable around the pivot point.

4. the temporary enclosure has a plurality of the first connecting jigs spaced apart in the vertical direction, The revetment has a plurality of the second connection jigs spaced apart in the vertical direction, one first connecting jig is disposed between two second connecting jigs that are spaced apart at a predetermined first interval in the vertical direction, thereby forming one connecting jig unit; 4. The temporary cutoff body according to claim 3, wherein one or more sets of said connecting jig units are provided in the vertical direction.

5. the first distance is set to be larger than the distance between the upper surface of the apron of the revetment and the lower surface of the temporary enclosure when the temporary enclosure is rotated in a position where it is lifted off the upper surface of the apron of the revetment, A temporary enclosure as described in claim 4, characterized in that the first connecting jig moves vertically within the first interval, thereby allowing the temporary enclosure to freely change its position from floating above the top surface of the apron of the seawall to resting on the top surface of the apron when the enclosure rotates.

6. a sliding member is attached to at least one of the first end and the second end of the temporary enclosure; A temporary enclosure as described in claim 1 or 2, characterized in that the movement of the temporary enclosure unit is guided by the sliding member sliding against a sliding support attached to at least one of the revetment and the weir pillar.

7. A temporary enclosure as described in claim 3, characterized in that the first end and the second end of the temporary enclosure are each provided with a water-stopping material that abuts against the revetment and the weir pillar, and anchors that are fixed to the revetment and the weir pillar are provided.

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