JP7774183B1 - A floating barge towing the temporary enclosure that makes up the temporary cofferdam - Google Patents

Abstract

[Problem] To provide a floating barge that tows a temporary enclosure that constitutes a temporary closure body, which can be towed and installed around the weir pillars at the end of an estuary weir formed to form part of a revetment.
[Solution] A temporary enclosure 250 is constructed to the side of the weir pillar 10A at an estuary weir having a weir pillar 10A formed to form part of the revetment and a permanent gate 14 that can be raised and lowered freely, and the first temporary enclosure 20 and the second temporary enclosure 30 that form the temporary enclosure 250 have a planar shape, one of which is J-shaped and the other is inverted J-shaped.The floating barge 300 is used when towing the temporary enclosures 20, 30, and is provided with an inlet 320 to accommodate the temporary enclosures 20, 30, and is provided with a send-out winch 340 and a retraction winch 330.The send-out winch 340 and the retraction winch 330 are driven to move the temporary enclosures 20, 30 using wires 345, 335 extending from both, thereby positioning them at the installation position of the revetment 10 and the weir pillar 10A.
[Selected Figure] Figure 6

Description

The present invention relates to a floating barge that tows a temporary enclosure that constitutes a temporary cofferdam.

Near the branching points of rivers, diversion weirs are installed to systematically divert floodwaters and low water by regulating and restricting water levels. Tidal weirs are installed at the river mouths (tidal sections) to prevent saltwater from running up and maintain the normal function 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, of the various types of weirs mentioned above, a dam is one that is 15 meters or higher 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, of the various types of weirs mentioned above, a sluice gate or sluice gate is 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.

By the way, weirs (estuary weirs) installed at estuaries close off rivers and block seawater from running upstream, and are used to ensure agricultural and industrial water supplies, as well as for flood control purposes to prevent floods and high tides. These estuary weirs are equipped with multiple weir pillars erected at intervals, and permanent gates (gate doors) arranged between adjacent weir pillars so that they can be raised and lowered freely. 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 installed on the weir pillars.

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 in using the permanent gate, for example.

Generally, temporary cofferdams are constructed by driving steel sheet piles around the weir pillars or by building embankments to enclose the weir pillars, and the water inside these cofferdams is then drained, creating an open-air work environment. However, these methods of constructing temporary cofferdams require large-scale construction, and the work of constructing and subsequently removing the cofferdam requires a lot of time and money. As a result, in river construction where repair work may be limited to dry seasons, there is an issue of limited work time for repair work, etc.

Patent Document 1 proposes a work box with an opening on its side. In plan view, this work box accommodates a portion of a submerged structure through the opening. When the work box and the structure form a work space, the end of the work box, attached to the structure and extending vertically, comprises a first inclined surface that is inclined so that the inside of the work space is narrow and the outside is wide, and a wedge-shaped first watertight gasket is installed in the gap between the structure and the first inclined surface. The first watertight 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 watertight gasket, thereby sealing off the work box. This construction method is also known as the NDR (Neo-Dry Repair Method).

Patent Document 2 proposes a cofferdam caisson that is attached to a structure erected on a pedestal and seated on the submerged pedestal for cofferdamization. This cofferdam caisson consists of multiple vertically divided, buoyancy-adjustable, with one side of each divided section connected by a hinge for open/close flexibility. A buffer sealant is attached continuously to the bottom surface of the cutting edge of each divided section. Support legs protrude from the bottom surface of the cutting edge of each divided section to support the cutting edge of each divided section at a distance from the pedestal. Multiple 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 that make up the caisson 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 to achieve waterproofing. This construction method is also known as the RUP (Reinforce & Repair Underwater Pier) method.

With 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 a permanent gate extends to the side of a structure such as a weir pillar, only one side of the permanent gate on the structure can be temporarily cofferdammed. On the other hand, with the temporary cofferdam construction method using a cofferdam caisson described in Patent Document 2, because the temporary cofferdam is intended for a bridge pier or the like, 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 a permanent gate extends to the side of a weir pillar.

However, 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 lot of rain flowing upstream, there is a possibility that water will infiltrate the reclaimed land area. Therefore, when the water level upstream of the weir rises higher than 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 so that all of the permanent gates can be raised and lowered (operated).

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 weirs 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 weir can be completely closed off to allow repair work, etc. to be carried out.

For these reasons, by surrounding the weir with a temporary cofferdam that allows for complete or partial closure of the area around the weir, repair work can be carried out during both flood and dry seasons. However, Patent Documents 1 and 2 do not mention temporary cofferdams that allow for complete or partial closure of the area around the weir.

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 permanent gate that extends laterally from the pillar and can be raised and lowered. 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 exists 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 box bodies and both walls.

JP 2016-79591 A Japanese Patent Application Publication No. 9-189043 Japanese Patent Application Laid-Open No. 2021-63433

The temporary cofferdam described in Patent Document 3 has an upstream wall and a downstream wall, and by closing the upstream box and downstream box, 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 left open, forming an open-type temporary cofferdam. During flood seasons, both walls can be left open and the permanent gate on the side of the weir pillar can be freely raised and lowered, making it possible to carry out repair work on the area of the weir pillar surrounded by the upstream box and downstream box. On the other hand, during dry seasons, by closing both walls, a closed-type temporary cofferdam is formed that completely blocks the area around the weir pillar, making it possible to carry out repair work on the entire area around the weir pillar.

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 symmetrical external shapes about the axis of the weir pillar when viewed from above. The boxes are located upstream and downstream of the weir pillar, which has permanent gates on both sides. In addition to the weir pillars with permanent gates extending from both 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 into the water, and because it is necessary to surround the weir pillars that partially protrude from the revetment, the C-shaped upstream and downstream boxes described in Patent Document 3 cannot be used.

Furthermore, when installing the temporary enclosure that constitutes the temporary cofferdam around a dam pillar that partially protrudes from the revetment, adjusting the posture of the temporary enclosure becomes important. However, Patent Document 3 does not mention a floating barge that can be used when installing the temporary enclosure around a dam pillar that partially protrudes from the revetment.

The present invention aims to provide a floating barge that tows a temporary enclosure that constitutes a temporary cofferdam, which can be towed and installed around the weir pillars at the end of an estuary weir that is 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.

In order to achieve the above object, one aspect of the floating barge for towing a temporary enclosure constituting a temporary cofferdam according to the present invention is as follows:
In an estuary weir having a weir pillar formed to form part of a revetment and a permanent gate that can be raised and lowered and extends to the side of the weir pillar, a temporary cofferdam constructed to the side of the weir pillar is
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 dam pillar;
a temporary gate that is provided adjacent to the permanent gate and connected to the temporary enclosure unit;
A floating barge used when towing the temporary enclosure in constructing the temporary cofferdam, wherein 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 in plan view,
an inlet for accommodating the temporary enclosure;
When the temporary enclosure is housed in the inlet, a first end portion of the temporary enclosure facing the revetment and a second end portion facing the weir pillar protrude from the inlet,
A sending winch is provided to send the floating barge toward the estuary weir, and a pulling winch is provided to pull the floating barge back to the opposite side of the estuary weir.
The temporary enclosure is positioned at the installation position of the revetment and the dam pillar by driving the delivery winch and the retraction winch and moving it by wires extending from both the delivery winch and the retraction winch.

In this aspect, the temporary enclosure housed in the inlet of the floating barge has a first end facing the seawall and a second end facing the dam pillar that protrude from the inlet. By driving a send-out winch that sends the floating barge toward the estuary weir and a pull-back winch that pulls it back to the side opposite the estuary weir, and by moving it using wires extending from both winches and positioning the temporary enclosure at the installation position for the seawall and dam pillar, a temporary cofferdam with a J-shaped or inverted J-shaped plan view can be towed and installed around the dam pillar formed to form part of the seawall.

Here, the floating barge may be towed by a tugboat, or may be a self-propelled barge.

Another aspect of the floating barge that tows the temporary enclosure that constitutes the temporary cofferdam according to the present invention is as follows:
The floating barge is formed by arranging a plurality of boxes side by side and connecting them to each other, and in the event that there is a possibility that part of the floating barge may interfere with other structures, some of the boxes can be detached to prevent interference.

In this aspect, by arranging multiple boxes side by side and connecting them to each other, it is possible to easily form an inlet that can accommodate the first and second ends of a temporary cofferdam that has a J-shaped or inverted J-shaped plan view in an overhanging position, while also forming a floating barge with the desired planar dimensions and shape.

Furthermore, if there is a possibility that part of the floating barge may interfere with other structures, some of the multiple box bodies can be detached to prevent interference.This is advantageous because, even if there is a risk that some of the box bodies on the floating barge may interfere with other structures (such as adjacent weir pillars or other components of the estuary weir) when towing the temporary enclosure to the installation location or when the floating barge returns to the pier or other location in the work yard, some of the box bodies (one or more) can be quickly detached.After the floating barge with some of its box bodies detached moves to a position where it can avoid interference with other structures, the detached box bodies can be pulled into the floating barge and reattached, allowing it to be returned to the work yard.

Another aspect of the floating barge that tows the temporary enclosure that constitutes the temporary cofferdam according to the present invention is as follows:
a first connection jig having a first through hole is attached to a first' end of the floating barge near the first end of the temporary enclosure;
the revetment has a second connecting jig having 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 is adapted to be rotatable around the pivot point.

According to this aspect, the temporary enclosure is designed to be rotatable around a pivot point formed by inserting a pin through the first through hole of the first connecting jig attached to the first' end of the floating barge near the first end of the temporary enclosure, and the second through hole of the second connecting jig located at a position on the revetment corresponding to the first connecting jig. This eliminates the difficulty of towing the temporary enclosure and precisely installing it in a predetermined position, and allows the other second end to be precisely installed on or near the weir pillar while rotating the temporary enclosure in a stable position.

Another aspect of the floating barge that tows the temporary enclosure that constitutes the temporary cofferdam according to the present invention is as follows:
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;
One or more sets of the connection jig units are provided in the vertical direction.

According to this aspect, a first connection jig provided on the floating barge is arranged between two second connection jigs that are arranged at a predetermined first interval in the vertical direction on the seawall, forming a set of connection jig units. By providing one or more sets of connection jig units in the vertical direction, when the temporary enclosure rises due to the influence of waves, the upper second connection jig acts as a stopper, preventing the first connection jig from rising too high. Furthermore, when the temporary enclosure is lowered and allowed to settle on the top surface of the apron, the first connection jig can be moved within the first interval.

Another aspect of the floating barge that tows the temporary enclosure that constitutes the temporary cofferdam according to the present invention is as follows:
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,
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 apron of the embankment to resting on the top surface of the apron when the enclosure rotates.

In this aspect, 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 seawall. This allows the temporary enclosure to change its position from floating above the upper surface of the apron of the seawall to resting on the upper surface of the apron when the floating barge containing the temporary enclosure rotates.

The floating barge towing the temporary enclosure that constitutes the temporary cofferdam of the present invention can tow and install the temporary enclosure around the weir pillars 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.

FIG. 1 is a perspective view showing an example of an open-type temporary cofferdam, among examples of temporary cofferdams according to an embodiment. FIG. 1 is a perspective view showing an example of a closed-type temporary cofferdam, among examples of temporary cofferdams according to an embodiment, in a state before a temporary gate is attached. FIG. 2 is a perspective view showing an example of a temporary cofferdam according to an embodiment, with a temporary gate attached thereto. FIG. 2 is a plan view of an example of a temporary cutoff body according to the embodiment. A vertical cross-sectional view showing an example of the configuration of a temporary enclosure according to an embodiment. This is an enlarged view of part B of Figure 5A and also a view explaining a draft adjustment method for a temporary enclosure according to an embodiment. A plan view of an example of a floating barge related to an embodiment, showing the state in which the first temporary enclosure is housed in the inlet. FIG. 1 is a process diagram of an example of a method for constructing a temporary cofferdam according to an embodiment. 7B is a process diagram of an example of a method for constructing a temporary cofferdam according to the embodiment, following FIG. 7A. FIG. A diagram showing an example of a method for connecting the first end of the temporary enclosure to the revetment in a rotatable manner. 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. 7B , and FIG. 7C is a process diagram of an example of a method for constructing a temporary cofferdam according to the embodiment. This is a view taken along the arrows FF in Figure 7E, and shows an enlarged view of the lower box body that constitutes the temporary enclosure, the legs provided below the lower box body, and two guide rails. 7E is a process diagram of an example of a method for constructing a temporary cofferdam according to an embodiment. FIG. 7G , and is a process diagram of an example of a method for constructing a temporary cofferdam according to an embodiment. FIG. 7H is a process diagram of an example of a method for constructing a temporary cofferdam according to an embodiment. FIG. 7I is a process diagram of an example of a method for constructing a temporary cofferdam according to an embodiment. FIG. FIG. 10 is a process diagram of another example of a method for constructing a temporary cofferdam according to the embodiment. 8B is a process diagram of another example of the method for constructing a temporary cofferdam according to the embodiment, following FIG. 8A. FIG. 8B , and is a process diagram of another example of the method for constructing a temporary cofferdam according to the embodiment. FIG. FIG. 10 is a process diagram of yet another example of the method for constructing a temporary cofferdam according to the embodiment. 9B is a process chart of yet another example of the method for constructing a temporary cofferdam according to the embodiment, following FIG. 9A. FIG. 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. 9B , and is a process diagram of yet another example of the method for constructing a temporary cofferdam according to the embodiment. FIG. 9D , and is a process diagram of yet another example of the method for constructing a temporary cofferdam according to the embodiment. FIG.

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

[Temporary cutoff body according to the embodiment]
First, an example of a temporary cofferdam according to an embodiment will be described with reference to Figures 1 to 5. Here, Figure 1 is a perspective view showing an example of an open-type temporary cofferdam according to an embodiment. Also, Figure 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. Figure 3 is a perspective view showing an example of a temporary cofferdam according to an embodiment with a temporary gate attached. Also, Figure 4 is a plan view of a temporary cofferdam according to an embodiment. Furthermore, Figure 5A is a vertical cross-sectional view showing an example of a configuration of a temporary enclosure according to an embodiment, and Figure 5B is an enlarged view of part B of Figure 5A and is a diagram illustrating a method for adjusting the draft of a temporary enclosure according to an embodiment.

The weir pillar 10A, which undergoes repairs and renovations while the temporary cofferdam is constructed and placed in an aerial work environment, is one of several weir pillars spaced apart across the width of the estuary. It is located at the end of the estuary weir and forms part of the revetment 10. This repair is reinforcement work using a continuous fiber wrapping method, for example, as part of earthquake-resistance measures to prevent salt damage and the 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 the 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 can be applied to repair work on various weirs. In addition to weir repair work, the temporary cofferdam according to the embodiment can also be applied to temporarily cofferdam the surroundings of various underwater structures, such as underwater bridge abutments and piers, during repair work.

The estuary weir has multiple piers spaced apart across the width of the estuary (in Figure 4, piers 10A and 10B are shown, with other piers spaced apart to the side of pier 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 pier.

As shown in Figure 1, a reinforced concrete apron E is located on the bottom of the water, and a dam pillar 10A is erected above the apron E, reaching the water surface. A permanent gate drop groove 12 is provided on the side 11 of the dam pillar 10A, into which the end of the 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.

Although not shown here, for example, in Figure 4, a headroom-restricting obstacle such as a management road is installed across the adjacent weir columns 10A and 10B, which are spaced apart. Therefore, in the method of constructing a temporary cofferdam by installing the first temporary enclosure 20 and the second temporary enclosure 30 described below, construction must be carried out while preventing interference with obstacles above the construction area.

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.

Here, "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 weir in question, etc.

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 the openings 26, 36 at their respective ends, 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 open.

In order to block the side of the weir pillar 10A, which is formed to form part of the revetment 10 and protrudes into the water area, together with part of the revetment 10, with the temporary enclosure unit 100, since there is a step in plan view between the wall surface of the revetment 10 and the side surface 11 of the weir pillar 10A, the planar shape of the first temporary enclosure 20 is made inverted J-shape, and the planar 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.

There have been no examples in the past of using temporary enclosures 20, 30 of this shape to surround a dam pillar 10A formed to form part of a 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 designated 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 commonly 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: That is, 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. Alternatively, even if temporary enclosures 20, 30 are 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 work within these time constraints, a construction method is adopted in which the temporary enclosures 20, 30 are towed and installed in the designated location.

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

On the other hand, the second temporary enclosure 30 also has a three-tier structure, with a lower box 31 arranged on the lower tier and multiple tiers (two tiers in the illustrated example) of upper box bodies 32 and 33 mounted on top of the lower box body 31, and the lower box body 31 and the upper box bodies 32 and 33 are interconnected. Furthermore, a wave pressure resistance panel 34 is attached to the top surface of the uppermost upper box body 33. It should be noted 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 those shown in the illustrations, and may have an integrated structure rather than a laminated structure.

A number of struts 62 constituting the temporary support structure 60 are stretched between the side surface 11 of the weir post 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 stretched between the paired supports 61 and 63. Furthermore, near the side surface 11 of the weir post 10A, the supports 63 are erected with a small second gap 69 between them and the side surface 11 of the weir post 10A, and short struts 64 are stretched between the supports 63 and the inner wall surfaces.

The struts 61, 63 and struts 62 are formed from shaped steel materials 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 materials 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 acting on the first and second temporary enclosures 20 and 30, and the struts 62 and the corresponding short struts 64 secure the first and second temporary enclosures 20 and 30 to the side surfaces 11 of the weir pillars 10A.

The support pillar 63 included in the temporary support structure 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. A short strut 64 spans the second gap 69 between the support pillar 63 and the weir pillar 10A. When repairing the side surface 11 of the weir pillar 10A, part of the short strut 64 can be rearranged to create a work space in the second gap 69. Therefore, the length of the short strut 64 is set to a length that ensures the necessary work space.

With the configuration of the temporary support 60 shown in the illustration, if the struts become an obstacle when repairing the side surface 11 of the dam pillar 10A, there is no need to replace the long struts, and only the short struts 64 need to be replaced. This means that repairs to the dam pillar 10A can be carried out efficiently without requiring major changes to the temporary support 60.

The first and second temporary enclosures 20 and 30 are each fitted with a corresponding first wall 40 and second wall 50, which are rotatably attached via multiple hinge mechanisms 41 and 51.

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, so that 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.

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 when the first wall body 40 and the second wall body 50 are stored, and the first gap 10a is closed when the first wall body 40 and the second wall body 50 slide out. 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.

Furthermore, 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 (on the side of the first wall 40 in the illustrated example), 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.

More specifically, as shown in Figures 3 and 4, a plurality of temporary supports 71 are erected at intervals on the sides of the first wall 40, with second drop-in grooves 72 on the left and right. These temporary supports 71 are formed, for example, from H-shaped steel, with the second drop-in grooves 72 formed by a web and two flanges. Although not shown, below the temporary supports 71 are tubular members made of steel square pipes, circular pipes, etc., which are lowered so that they cover existing protrusions already installed in the apron E on the bottom of the water, allowing the temporary supports to be erected on the top surface of the apron E.

The temporary gate 73 is formed as a single unit by connecting multiple (three in the illustrated example) corner stoppers 74, 75 via connecting hardware 76. The two lower corner stoppers 74 are, for example, existing corner stoppers, while the upper corner stopper 75 is, for example, a new corner stopper. 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.

In addition, a third drop-in groove 47 is provided on the side 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-in groove 47.

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

On the other hand, during dry periods, the first wall body 40 and the second wall body 50 can be closed to form a temporary closed-off body 250 that completely blocks off the periphery of the side surface 11 of the weir pillar 10A, allowing repair work to be carried out on the entire area around the weir pillar 10A.

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

In addition, even in the case of an open-type temporary cofferdam 200, the temporary cofferdam 200 can be formed by closing one of the first wall 40 and the second wall 50 and attaching a temporary gate 73 to the closed wall.

Next, we will explain an example of the configuration of a temporary enclosure and an example of a method for adjusting the draft of the box body. Here, Figure 5A is a vertical 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 explaining a method for adjusting the draft of a temporary enclosure. Note that the following will focus on the first temporary enclosure 20 to explain its configuration, but the configuration of the second temporary enclosure 30 is substantially the same as the configuration of the first temporary enclosure 20.

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

The lower box body 21 and the upper box bodies 22 and 23 are each formed from 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'. If necessary, the steel skin plate 20c' attached to the inside may be omitted.

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, water supply/drainage pipe 21c, and water supply/drainage valve 21b, just like the lower box body 21. For example, Figure 7C shows a configuration in which all boxes include water storage spaces 21a, 22a, and 23a. Furthermore, instead of a multi-tiered stacked structure as shown in the illustrated example, the structure may also be an integrated structure that is J-shaped or inverted J-shaped when viewed from above.

As shown in the illustrated example, the first temporary enclosure 20 has a lower box body 21 and multiple upper box bodies 22, 23. This improves transportability, for example, when the first temporary enclosure 20 is large, during land transport from the factory to the pier, which serves as the work yard. This also reduces the need for large heavy machinery to be used when hoisting and lowering the first temporary enclosure 20 from the pier, improving hoisting and lowering performance.

Furthermore, because the first temporary enclosure 20 is formed from multiple shaped steel members that form 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 lightweight as possible, resulting in a first temporary enclosure that has excellent water pressure resistance when installed around the weir pillar 10A and is easy to transport overland.

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 other substances from entering the interior 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.

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

The water supply and drainage valve 21b and the water supply and exhaust valve 21d can be opened and closed manually by a worker aboard 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 for measuring draft is attached to the first temporary enclosure 20, and a user terminal or computer owned by a remote administrator receives draft data from the sensor and sends opening and closing commands to the water supply and drainage valves 21b, etc. based on the draft data, and the water supply and drainage valves 21b, etc. are automatically opened and closed based on the opening and closing commands.

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

[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 the draft thereof with reference to Fig. 6. Here, Fig. 6 is a plan view of the example of the floating barge according to an embodiment, showing the state in which the first temporary enclosure is housed in the inlet.

The floating barge 300 has multiple box bodies 310 (22 in the illustrated example) 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 detachably connected and freely changeable in plan view.

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

More specifically, an inlet 320 is provided with dimensions that allow 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) to protrude outward. The following examples of 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 a position that protrudes 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.

Multiple (two in the illustrated example) retraction winches 330 are provided on one end of the top surface of the floating barge 300, and multiple (two in the illustrated example) release winches 340 are provided on the other end. The floating barge 300 is designed 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 second temporary enclosure 30) moored (temporarily fixed) to the inlet 320. Here, the floating barge 300 may be a self-propelled barge.

For example, as shown in Figure 7A, the anchoring point 335a of the wire 335 extending from the retraction winch 330 is set at 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.

Meanwhile, the anchoring point 345a of the wire 345 extending from the release winch 340 is set near the permanent gate 14 (for example, on the top surface of apron E). When the release winch 340 is operated, a release force in the Y2 direction acts on the wire 345, allowing the floating barge 300 to be sent out to the estuary weir.

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, allowing the first temporary enclosure housed in the inlet 320 to be towed to the designated installation position while maintaining its horizontal position.

[Method for constructing a temporary cofferdam according to an 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.

First, an example of a method for constructing a temporary cofferdam according to an embodiment will be described with reference to Figures 7A to 7J.

First, in each of the upstream and downstream work yards, a first temporary enclosure 20 having an inverted J-shape in plan view and a second temporary enclosure 30 having a J-shape in plan view are prepared. A separate floating barge may be used to tow each temporary enclosure 20, 30 to the installation location, or a common floating barge may be used to install both in sequence (this completes the preparation process).

Next, as shown in Figure 7A, the floating barge 300 departs from a pier (not shown), which serves as 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 and 345a of each wire 335 and 345 are anchored at predetermined positions on the revetment 10 and near the permanent gate 14, respectively.

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, part of which is surrounded by the first temporary enclosure 20, protruding toward the water. 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, projecting from the inlet 320 toward the seawall 10.

In Figure 7A, the second temporary enclosure 30 on the downstream side has already been installed 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. Furthermore, the order of installation of the first temporary enclosure 20 and the second temporary enclosure 30 may be reversed, or both may be installed simultaneously.

In Figure 7A, the second temporary enclosure 30, which has a J-shaped planar shape, has its first end 30a fixed to the revetment 10 via anchor 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 anchor 30c, with water-stopping material 30d abutting against it. Here, the specific shapes of the water-stopping material 30d and anchor 30c are similar to those of the anchor 20c and water-stopping material 20d provided on the first temporary enclosure 20 shown in Figure 7I.

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

Now, with reference to Figures 7C and 7D, we will explain how to rotatably connect the first end 20a to the revetment 10.

As shown in the right diagram of Figure 7C, the draft depth of the first temporary enclosure 20 is adjusted so that there is a gap of height t1 between the underside 20h of the first temporary enclosure 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 20 and obstacles above the construction area when the first temporary enclosure 20 is rotated and installed as described below.

During the towing process up to this rotatable connection, the draft depth of the first temporary enclosure 20 is set to a relatively short depth to ensure a clearance to the bottom ground G, so that the bottom surface 20h of the first temporary enclosure 20 does not interfere with the bottom ground G, which may be of various depths.When connecting the first temporary enclosure 20 to the rotatable connection, water is supplied to the water storage space 21a, etc., to sink the first temporary enclosure 20 and increase the draft depth, adjusting the draft depth to achieve the clearance of height t1 in the illustrated example.

A plurality of first connection jigs 26 are provided at vertical intervals on the first end 20a of the first temporary enclosure 20. The first connection jigs 26 are made of flat steel and have first through holes 26a that are elongated holes, as shown in Figure 7D.

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, sandwiching each first connecting jig 26 from above and below, so that multiple sets of second connecting jigs 16 are provided in the vertical direction.

A single connection jig unit 17 is formed by one first connection jig 26 and two second connection jigs 16 that sandwich it vertically.

The second connection jig 16 is made of flat steel and has a second through hole 16a which is a round hole, as shown in Figure 7D.

The first vertical distance t2 between a pair of second connection jigs 16, which sandwich one first connection 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.

As shown in the right diagram 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.

Next, as shown in Figure 7C, a single pin 18 is inserted from above in the X2 direction through each of the first through holes 26a and each of the second through holes 16a that are aligned with each other, thereby forming a pivot point 19.

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 (inclination) 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.

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, which is pushed and pulled by wires 335 and 345, to a position where its second end 20b abuts against the weir pillar 10A.

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 before rotating it. This prevents localized damage or deformation of the first temporary enclosure 20 during rotation, and allows the entire structure to be rotated in a more firmly integrated state.

Furthermore, as shown in Figures 7E and 7F, a leg portion S with 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 rising legs S1 and S2 are moved along the guide rails R1 and R2 to allow smooth and precise rotation of the first temporary enclosure 20.

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 beams S3 and a pair of rising legs S1, S2 connected to the left and right ends of each horizontal beam S3, with a hydraulic jack S4 interposed midway between each rising leg S1, S2.

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 along the rails. Driving the hydraulic jacks S4 also makes it possible to finally land the temporary enclosure on the bottom.

Note that legs that do not have hydraulic jacks S4 as shown in the illustrated example may also be provided on the lower box body 21.

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. The sliding pads P reduce sliding friction while the legs S move along the guide rails R1, R2. To make the alignment of the first temporary enclosure 20 even easier, 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, 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. A rail structure may be applied in which the guide rail at the start of the rotation is set to be relatively wide in relation to the shape and dimensions of the legs S, and gradually narrows as the guide rail approaches the end point of the rotation, precisely guiding the first temporary enclosure 20 to the position where it should be installed.

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.

In this way, the first temporary enclosure 20 is rotated in the Y5 direction together with the floating barge 300, which is pushed and pulled by the wires 335 and 345, using the pivot fulcrum 19 as the center of rotation, and the second end 20b of the first temporary enclosure 20 is brought into contact with the dam pillar 10A, as shown in Figure 7G (this is the towing process).

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 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 revetment 10. As already explained, the first distance t2 is set longer than the separation height t1, ensuring that the first temporary enclosure 20 will land on the upper surface E1 of the apron E.

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

In this abutting position, the water-stopping material 20d provided at one end (the left end 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 extension plate 20j extends laterally from the other end (the right end 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 extension plate 20j.

Although not shown, the connection between the side of the dam pillar 10A and the second end 20b is also performed in a similar manner to that shown in Figure 7I, with the second end 20b being connected to the side of the dam pillar 10A with an anchor in a position that provides a watertight structure (this completes the connection process).

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

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.

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

The construction method shown in the illustration allows for the creation of a closed-type temporary cofferdam 250 that completely closes the periphery of the weir pillar 10A formed to form part of the revetment 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 also allows for the creation of an open-type temporary cofferdam 200 that is partially open.

Furthermore, even if there are obstacles above the construction area of the temporary enclosures 20, 30 at the estuary weir, interference between the temporary enclosures 20, 30 and the obstacles above the construction area of the temporary enclosures 20, 30 can be avoided, and the temporary enclosures 20, 30 can be efficiently and firmly fixed in their installation positions relative to the revetment 10 and the weir pillars 10A with high water-stopping properties, thereby constructing the temporary cofferdams 200, 250.

Next, with reference to Figures 8A to 8C, another example of a method for constructing a temporary cofferdam according to an embodiment will be described.

The preparation process for preparing the first temporary enclosure 20, which has an inverted J-shape in plan view, and the second temporary enclosure 30, which has a J-shape in plan view, is common to both the upstream and downstream work yards.

As shown in Figure 8A, the floating barge 300 departs from a pier (not shown), which serves as 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. The anchoring points 335a and 345a of each wire 335 and 345 are anchored at predetermined positions on the revetment 10 and near the permanent gate 14, respectively.

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, part of which is surrounded by the first temporary enclosure 20, protruding toward the water. 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, projecting from the inlet 320 toward the seawall 10.

Next, as shown in Figure 8B, while maintaining the horizontal position of the first temporary enclosure 20, the first temporary enclosure 20 is towed in the Y4 direction toward the estuary weir 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 20 abuts against a predetermined position on the wall of the revetment 10, and the second end 20b abuts against a predetermined position on the weir pillar 10A (this completes the towing process).

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

Next, in a manner similar to that 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 serves as the shaft, in the X4 direction. This causes the support plate 20e attached to the end of the bolt 20f to abut against the wall surface of the revetment 10, causing the water-stopping material 20d provided on one end of the first end 20a to abut against the wall surface of the revetment 10, forming a water-stopping structure. Meanwhile, an anchor 20c is driven into the wall surface of the revetment 10 via an extension plate 20j that extends laterally from the other end of the first end 20a, connecting the first end 20a to the revetment 10. A similar method is used to connect the side of the pier 10A to the second end 20b, connecting the second end 20b to the side of the pier 10A with an anchor in a water-stopping position (connection process).

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

At this time, when the floating barge 300 is evacuated from the state shown in Figure 8B while being retracted 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. Therefore, 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 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 evacuating the floating barge 300 upstream.

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

The construction method shown in the illustration also makes it possible to form a closed-type temporary cofferdam 250 that completely closes the periphery of the weir pillar 10A formed to form part of the revetment 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 also makes it possible to form an open-type temporary cofferdam 200 that is partially open.

Furthermore, even if there are obstacles above the construction area of the temporary enclosures 20, 30 at the estuary weir, interference between the temporary enclosures 20, 30 and the obstacles above the construction area of the temporary enclosures 20, 30 can be avoided, and the temporary enclosures 20, 30 can be efficiently and firmly fixed in their installation positions relative to the revetment 10 and the weir pillars 10A with high water-stopping properties, thereby constructing the temporary cofferdams 200, 250.

Next, with reference to Figures 9A to 9E, we will explain yet another example of a method for constructing a temporary cofferdam according to an embodiment.

The preparation process for preparing the first temporary enclosure 20, which has an inverted J-shape in plan view, and the second temporary enclosure 30, which has a J-shape in plan view, is common to both the upstream and downstream work yards.

As shown in Figure 9A, the floating barge 300 departs from a pier (not shown), which serves as 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. The anchoring points 335a and 345a of each wire 335 and 345 are anchored at predetermined positions on the revetment 10 and near the permanent gate 14, respectively.

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, part of which is surrounded by the first temporary enclosure 20, protruding toward the water. 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, projecting from the inlet 320 toward the seawall 10.

As shown in Figure 9A, sliding members N1 and N2 are attached to the first end 20a and second end 20b of the first temporary enclosure 20, respectively. 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.

In addition, a stopper V made of shaped steel such as an H-beam is erected at a position separated from the end of the sliding support material M1 on the estuary weir side of the revetment 10 by a small width of the push-in area Q.

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

Now, with reference to Figure 9C, an example of a sliding support material M and a sliding member N will be described.

The sliding support material M is a lipped channel steel with a through hole Ma extending laterally and facing sideways. The sliding member N comprises a support plate 20e housed inside the lipped channel steel M, and a shaft 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 shaft member 20f can be moved towards or away from the lipped channel steel M in the X4 direction.

The sliding support material M and sliding member N shown in the illustration allow the first temporary enclosure 20 to be moved (towed) to the installation position while guiding the sliding member N along the sliding support material M in a stable position.

It is preferable that the combination of sliding support material M and sliding member N in the illustrated example be provided in multiple sets in the height direction of the first temporary enclosure 20. 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 and 23 of the first temporary enclosure 20 (a total of six tiers of sliding member N), 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.

The sliding support material M and the sliding member N may be provided on only one of the revetment 10 side and the weir pillar 10A side. The specific configurations of the sliding support material M and the sliding member N include various configurations other than those shown in the illustrations.

As shown in Figure 9D, the first temporary enclosure 20 is moved to the installation position while sliding the corresponding sliding members N1 and N2 along each sliding support M1 and 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 revetment 10 and weir pillar 10A (towing process).

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

Next, in a manner similar to that 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 serves as the shaft, in the X4 direction. This causes the support plate 20e attached to the end of the bolt 20f to abut against the wall surface of the revetment 10, causing the water-stopping material 20d provided on one end of the first end 20a to abut against the wall surface of the revetment 10, forming a water-stopping structure. Meanwhile, an anchor 20c is driven into the wall surface of the revetment 10 via an extension plate 20j that extends laterally from the other end of the first end 20a, connecting the first end 20a to the revetment 10. A similar method is used to connect the side of the pier 10A to the second end 20b, connecting the second end 20b to the side of the pier 10A with an anchor in a water-stopping position (connection process).

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

At this time, when the floating barge 300 is retreated from the state shown in Figure 9D toward the pier 10B, there is a risk that the box body 310B at the end will cause the floating barge 300 to interfere with the pier 10B. Therefore, 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 Y10 direction toward the work yard. Here, the box body 310B can also be pre-sized so that it does not interfere with the pier 10B. In this case, there is no need to detach the box body 310B when the floating barge 300 is evacuated upstream.

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

The construction method shown in the illustration also makes it possible to form a closed-type temporary cofferdam 250 that completely closes the periphery of the weir pillar 10A formed to form part of the revetment 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 also makes it possible to form an open-type temporary cofferdam 200 that is partially open.

Furthermore, even if there are obstacles above the construction area of the temporary enclosures 20, 30 at the estuary weir, interference between the temporary enclosures 20, 30 and the obstacles above the construction area of the temporary enclosures 20, 30 can be avoided, and the temporary enclosures 20, 30 can be efficiently and firmly fixed in their installation positions relative to the revetment 10 and the weir pillars 10A with high water-stopping properties, thereby constructing the temporary cofferdams 200, 250.

Other embodiments may be possible in which other components are combined with the configurations described in the above embodiments, and the present invention is in no way limited to the configurations shown here. In this regard, changes are possible without departing from the spirit of the present invention, and can be determined appropriately depending on the application form.

10: Revetment 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 connecting jig 16a: Second through hole (round hole)
17: Connection jig unit 18: Pin 19: Rotation fulcrum 20: First temporary enclosure 20a: First end 20b: Second end 20c: Anchor 20d: Water stop material 20e: Support plate 20f: Shaft member (bolt)
20g: Nut 20h: Underside 20j: Projecting plate 20': Opening joint 21: Lower box 21a: Water storage space 21b: Water supply and drain valve 21c: Water supply and drain pipe 21d: Water supply and exhaust valve 21e: Water supply and exhaust pipe 21f: Compressed air supply section 22: Upper box (second box)
22a: Water storage space 23: Upper box body (third box body)
23a: Water storage space 24: Wave pressure resistance panel 26: First connection jig 26a: First through hole (long hole)
30: Second temporary enclosure 30a: First end 30b: Second end 30c: Anchor 30d: Water stop material 30': Opening joint 31: Lower box 32: Upper box (second box)
33: Upper box (third box)
34: Wave pressure resistance panel 36: Opening 40: First wall body 41: Hinge mechanism 42a: Contact area 47: Third drop groove 50: Second wall body 51: Hinge mechanism 60: Temporary support 61: Support 62: Strut 63: Support 64: Short strut 69: Second gap 71: Temporary support 72: Second drop groove 73: Temporary gate 74: Existing corner chamfer (corner chamfer)
75: Newly installed corner cutter (corner cutter)
75a: Lifting hook 76: Connecting 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: Inlet 330: Retraction winch 340: Delivery winch 335, 345: Wire 335a, 345a: Engagement point W: External water (seawater, river water)
G: Bottom ground E: Apron E1: Top surface T: Reinforcement member S: Leg S1, S2: Standing leg S3: Crosspiece S4: Hydraulic jack P: Sliding pad M, M1, M2: Sliding support material (channel steel with lip)
Ma: Through hole N, N1, N2: Sliding members V: Stopper Q: Pressing area

Claims (1)

In an estuary weir having a weir pillar formed to form part of a revetment and a permanent gate that can be raised and lowered and extends to the side of the weir pillar, a temporary cofferdam constructed to the side of the weir pillar is
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 dam pillar;
a temporary gate that is provided adjacent to the permanent gate and connected to the temporary enclosure unit;
A floating barge used when towing the temporary enclosure in constructing the temporary cofferdam, wherein 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 in plan view,
an inlet for accommodating the temporary enclosure;
When the temporary enclosure is housed in the inlet, a first end portion of the temporary enclosure facing the revetment and a second end portion facing the weir pillar protrude from the inlet,
A sending winch is provided to send the floating barge toward the estuary weir, and a pulling winch is provided to pull the floating barge back to the opposite side of the estuary weir.
The sending out winch and the pulling back winch are driven, and the temporary enclosure is positioned at the installation position of the revetment and the weir pillar while being moved by wires extending from both the sending out winch and the pulling back winch;
A floating barge that tows a temporary enclosure that constitutes a temporary cofferdam, characterized in that it is formed by multiple box bodies that are arranged side by side and connected to each other, and in the event that part of the floating barge may interfere with other structures, some of the multiple box bodies can be detached to prevent interference.