JP6104138B2 - Rehabilitation of river structures - Google Patents

Description

  The present invention relates to a method for repairing a structure in a river installed in a river.

  Japanese Patent Application Laid-Open No. 2006-124929 describes a method of performing repair work one by one on a gate provided with four movable weirs constituting a dam. In the method described in this publication, a temporary pier that is used as a work space for performing various work related to gate repair is installed on the downstream side of the dam, and a temporary closing gate is installed on the upstream side of the gate to be repaired. Repair work is performed. In this way, water is stopped by installing a temporary gate, and river water is divided in repair work.

JP 2006-124929 A

  By the way, in a relatively close place from the coast of the river, a river structure with a movable weir or a gate such as a sluice prevents the sea water from going up in the river water and releases the water downstream during floods. Provided. In other words, in river structures located near the coast, the gate is normally closed, so that the river water upstream of the river structures and the downstream salt from the river structures are mixed. The water is separated. When a flood occurs, the gate is opened, and the water upstream of the river structure is opened downstream. Here, when the seawater mixed with downstream salinity goes up from the river structure, the river water containing a large amount of salt will move upstream from the river structure, so it is acquired from the river. May affect drinking water and industrial water. Therefore, in river structures located near the coast, the river structure is repaired while the upstream river water and the downstream river water are separated to maintain the functions of the river structure. Is required to do.

  The present invention provides a method for repairing a river structure that can prevent downstream river water from moving upstream from the river structure even during the repair of the river structure. With the goal.

  The present invention relates to an in-river structure that is performed on a structure in a river including at least two weir pillars installed in a river and an existing gate installed so as to bridge between the two weir pillars. In the renovation method, the first water stop structure that prevents the inflow of river water from the upstream side to the downstream side is installed on each of the weir pillars upstream from the existing gate, and from the downstream side to the upstream side. Water stop structure installation step of installing a second water stop structure for preventing inflow of river water in each of the weir pillars downstream from the existing gate, and the first water stop structure and the second water stop structure Between the two weir pillars, the river water removal process to remove the river water located between the water structure, the existing gate removal process to remove the existing gate from the space obtained by removing the river water, and New gate installation that installs a new gate on each of the weir pillars Characterized in that it comprises a degree, the.

  In this river structure renovation method, the first water stop structure and the second water stop structure are installed on each of the weir pillars, so that the inflow of river water from the upstream side to the downstream side Since inflow of river water from the downstream side to the upstream side is prevented, the upstream side of the river structure can be separated from the downstream side of the river structure. Therefore, even when rehabilitating river structures, river water on the downstream side containing a large amount of salt is prevented from moving upstream from the river structures, so that the functions as river structures are maintained. However, it is possible to repair river structures. In addition, after the first water stop structure is installed upstream of the existing gate and the second water stop structure is installed downstream of the existing gate, the first water stop structure and the first water stop structure By removing the river water between the two water stop structures, a work space that does not have river water is formed between the first water stop structure and the second water stop structure. Since the existing gate is located in this work space, the above-described work space can be effectively used as a work space for removing the existing gate and installing a new gate.

  Moreover, you may provide the dam pillar reinforcement | strengthening process which inserts a reinforcing bar in a dam pillar and reinforces a dam pillar after a river water removal process. When the reinforcing reinforcing bars are inserted into the weir pillars in this way, the reinforcing reinforcing bars can increase resistance to the force by which the weir pillars are pulled, and it is possible to perform seismic reinforcement for the weir pillars.

  Moreover, before the water stop structure installation step, a dam pillar shape changing step is provided to change the shape of the dam pillar so that the first water stop structure and the second water stop structure are in close contact with the dam pillar. May be. By providing the weir column shape changing step in this manner, the first water stop structure and the second water stop structure are brought into close contact with the weir column, and the above-described leakage of river water into the work space is more reliably prevented. It becomes possible to do. That is, by removing the river water located between the first water stop structure and the second water stop structure, the outer side with respect to the first water stop structure and the second water stop structure. The river water pressure is applied to the first water stop structure and the second water stop structure in close contact with the weir pillar. Therefore, the water stop by the first water stop structure and the second water stop structure can be easily performed by the pressure of the river water.

  Moreover, before a water stop structure installation process, the 1st water stop structure and the 2nd water stop structure may be towed by the ship in the state made hollow. As described above, the first water stop structure and the second water stop structure are towed by a ship as a hollow floating structure, so that the first water stop structure and the second water stop structure are installed on the site. The work to transport to can be done easily. For example, the first water stop structure and the second water stop structure are manufactured in advance at a place different from the site, and the construction of the river structure starts and the first water stop structure and the second water stop structure are started. When the water stop structure is required, it is possible to transport the first water stop structure and the second water stop structure by towing the ship.

  Further, the first water stop structure and the second water stop structure are partitioned so that the work space has the first space and the second space, and the first water stop structure and the second water stop structure are provided. The water-stopping structure is tilted by being poured into the first space after being towed by the ship, and sunk into the river by being poured into the second space after being pressed against the weir pillar by the ship. It may be. As described above, the first water stop structure and the second water stop structure are tilted by water injection into the first space, pressed against the weir pillar by the ship, and then injected into the second space. Sunk into the river. Accordingly, it is possible to easily perform the installation work on the weir pillars of the first water stop structure and the second water stop structure, and to install the first water stop structure and the second water stop structure into the river. By sinking, it is possible to reliably prevent the first water stop structure and the second water stop structure from moving.

  Also, in the weir pillar reinforcement process, the surface of the weir pillar is swept with water flow to expose the core rebar embedded in the weir pillar in advance, and a hole is made at a position avoiding the core rebar, and the reinforcement reinforcing bar is placed in the hole. It may be inserted and filled with grout between the hole and the reinforcing bar. Thus, the situation where the reinforcing reinforcing bar interferes with the central reinforcing bar can be avoided by exposing the central reinforcing bar in advance and opening the hole at a position avoiding the central reinforcing bar and inserting the reinforcing reinforcing bar. Moreover, the rust prevention effect of the reinforcing reinforcing bar can be exhibited by filling the grout between the hole and the reinforcing reinforcing bar.

  ADVANTAGE OF THE INVENTION According to this invention, even if it is in the middle of repair work of a river structure, it can prevent that downstream river water moves to an upstream rather than a river structure.

It is a perspective view which shows the movable weir which is the application object of the repair method which concerns on this invention. It is a perspective view which shows the reinforcement object part in the movable dam of FIG. It is a perspective view which shows the state which installed the liner plate in the movable dam of FIG. It is a perspective view which shows the state which installed the water stop structure in the dam pillar of the movable weir of FIG. It is a perspective view which shows the state which remove | eliminated the river water from between the water stop structures of FIG. It is a perspective view which shows the reinforcement object part in the movable dam shown in FIG. It is a figure explaining the operation | work which inclines a water stop structure. It is a figure explaining the operation | work which presses a water stop structure on a weir pillar with a ship. It is a figure explaining the operation | work which makes a water stop structure closely_contact | adhere to a dam pillar. It is a figure explaining the operation | work which sinks a still water structure by water injection. It is a side view of a dam pillar for demonstrating the operation | work which reinforces a dam pillar. It is a perspective view which shows the dam pillar improvement body formed in the edge part of a dam pillar.

  Hereinafter, a method for repairing a river structure according to the present invention will be described in detail with reference to the drawings.

  As shown in FIG. 1, the movable weir 1 that is a river structure partitions river water upstream of the movable weir 1 in the river R from river water downstream of the movable weir 1. The movable weir 1 is arranged so as to span the river R, and is provided at a location relatively close to the coast in the river R. The movable weir 1 is used to adjust the flow rate and water level in the river R. Moreover, this movable weir 1 is provided in order to prevent the river water containing much salt from moving upstream.

  The movable weir 1 is normally in a state in which the existing gate 2 is closed, and when the existing gate 2 closes the river R, the flow that attempts to exceed the movable weir 1 of the river R is blocked. In addition, when an abnormality such as a flood occurs, the movable weir 1 raises the existing gate 2 with respect to the weir pillar 3 and opens it, thereby causing the upstream river water to flow downstream. In addition, the height of the existing gate 2 at the time of opening is about 5 m, for example. Thus, in the movable weir 1, the flow of river water in the river R can be controlled. A plurality of flat floor boards B are arranged below the movable weir 1 (see FIGS. 8 to 10).

  The existing gate 2 is hollow and is arranged in a straight line so as to block the flow of the river R. Two dam posts 3 which are concrete structures standing on the river R are provided at both ends in the longitudinal direction of the existing gate 2, and the existing gate 2 bridges the two dam posts 3. As shown in FIG. A rail part 3a for raising and lowering the existing gate 2 with respect to the dam pillar 3 is arranged on the side surface of each dam pillar 3 where the existing gate 2 is installed, and the existing gate 2 slides on the rail part 3a. Supported as possible.

  In FIG. 1, two dam posts 3 and one existing gate 2 that bridges the two dam posts 3 are illustrated, but actually, the four dam posts 3 Three existing gates 2 that bridge the weir pillar 3 are provided. Moreover, the number of the dam pillar 3 and the existing gate 2 is not specifically limited.

  Further, both ends of the existing gate 2 are supported by a plurality of chains (not shown), and when pulled up by the chain, it is lifted along the rail portion 3a while rotating in one direction, and the chain is lowered. As a result, it is lowered along the rail portion 3a while rotating in the other direction. Thus, the existing gate 2 is a so-called rolling gate that moves up and down along the rail portion 3a of the weir column 3 while rotating. In the river R, the weir pillar 3 has an elongated shape extending in the flow direction of the river R. Moreover, since the rail part 3a of the weir column 3 is slightly inclined with respect to the vertical direction, the load required for raising and lowering the existing gate 2 is reduced.

  As shown in FIG. 11, in the inside of the dam pillar 3, a guard rebar 5 for preventing the dam pillar 3 from cracking is embedded in a lattice shape. The guard rebar 5 is embedded in a grid of about 20 cm square when viewed from the width direction of the river R. In addition, a filling station C and a bridge D where an operator waits are provided on the upper part of the weir pillar 3. Here, since the bridge D is bridged on the plurality of dam pillars 3, automobiles and the like pass over the river R through the bridge D regardless of whether or not the movable dam 1 is being repaired. It is possible to cross.

  In the repair work of the movable weir 1 configured as described above, the work for replacing the existing gate 2 with a new gate and the work for seismic reinforcement of the weir pillar 3 are performed. A side surface 3b of the weir column 3 shown in FIG. 2 is a portion to be reinforced. The new gate is, for example, a so-called shell structure roller gate that moves up and down without rotating along the rail portion 3a of the weir column 3 and has a hollow shell structure. Further, in the seismic reinforcement of the dam pillar 3, the two dam pillars 3 located on both sides of the existing gate 2 to be repaired are reinforced.

  Below, the repair method of the movable weir 1 is demonstrated, referring drawings. Since the repair of the movable weir 1 is performed on two existing gates 2 of the three existing gates 2, while the two existing gates 2 are being repaired, the remaining one existing gate 2 Can be used as usual.

  The reinforcement work of the dam pillar 3, the removal work of the existing gate 2, and the installation work of the new gate are all performed in the work space S (see FIG. 5) formed between the two dam pillars 3. The work space S includes two dam pillars 3, a prismatic first water stop structure 7 installed on the upstream side of the dam pillar 3, and a prismatic first part installed on the downstream side of the dam pillar 3. This is a space formed by two water-stop structures 8. In the work space S, the inflow of river water from both the upstream side of the dam pillar 3 and the downstream side of the dam pillar 3 is prevented by the first and second water stop structures 7 and 8. The length of the width direction in the river R of the 1st and 2nd water stop structures 7 and 8 is 35 m, for example. The working space S has, for example, a length in the flow direction of the river R of about 30 m, a length in the width direction of the river R of about 30 m, and a height of about 5 m.

  First, the preliminary work before forming the work space S will be described. As prior work before forming the work space S, as shown in FIG. 3, the end of the dam pillar 3 is repaired so that the second water stop structure 8 is in close contact with the dam pillar 3. First, a substantially cylindrical liner plate 9 is installed on the end 3d of the weir column 3 so as to surround the end 3d on the downstream side of the weir column 3 to close the end 3d. Then, the river water inside the liner plate 9 is removed by a pump, and the end 3d of the weir column 3 is exposed to the atmosphere, so that a work space A for the end 3d of the weir column 3 is obtained.

  Here, rubber (not shown) is interposed at the contact portion between the end portion 3d of the weir column 3 and the liner plate 9, and the liner plate 9 is in close contact with the weir column 3 through this rubber. 9 Inflow of river water into the interior is prevented. Further, since the liner plate 9 has a cylindrical shape, the water pressure of the river water applied to the liner plate 9 from the outside is applied to the liner plate 9 from almost all directions. Therefore, it is difficult for the liner plate 9 to move in the river R due to water pressure.

  After obtaining the work space A, as shown in FIG. 12, concrete is placed on the end 3d of the dam pillar 3 to form a substantially rectangular parallelepiped dam pillar improvement body 3e (dam pillar shape changing step). . The dam pillar improvement body 3e is provided to bring the second water stop structure 8 into close contact with the dam pillar 3. That is, since the plane of the second water stop structure 8 can be brought into close contact with the side surface 3f on the downstream side of the weir post improvement body 3e, the second water stop structure 8 is attached to the side face 3f of the weir post improvement body 3e. It is possible to prevent the inflow of river water into the work space S simply by pressing. Similarly to the above, the end of the dam pillar 3 is repaired so that the first water stop structure 7 is in close contact with the dam pillar 3 also on the upstream side of the dam pillar 3.

  After the end of the dam pillar 3 is repaired as described above, the first and second water-stop structures 7 and 8 are installed on the dam pillar 3 as shown in FIG. Structure installation process). Before the installation on the weir column 3, the first and second water-stop structures 7 and 8 are substantially rectangular parallelepiped hollow boxes. Moreover, the 1st and 2nd water stop structures 7 and 8 are towed by the ship F (refer FIG. 8) in the state made hollow, and are pushed in and closely contacted to the dam pillar improvement body 3e of the dam pillar 3. FIG. Then, water is poured into the internal space of the water stop structures 7 and 8 and the water stop structures 7 and 8 are submerged in close contact with the weir pillar 3. As described above, since the water-stopping structures 7 and 8 sink into the river R when the water is injected into the water-stopping structures 7 and 8, a situation where the water-stopping structures 7 and 8 float is avoided. Is done.

  Next, as shown in FIG. 5, the work space S is removed by removing the river water in the area surrounded by the weir pillar 3, the first water stop structure 7, and the second water stop structure 8. Form (river water removal process). Thus, by removing the river water located between the weir column 3, the first water stop structure 7 and the second water stop structure 8 to form the work space S, You can work as you would on land. This operation of removing river water is performed, for example, by pumping river water with a plurality of pumps.

  After the work space S is formed, the existing gate 2 is removed (existing gate removal step). The existing gate 2 is taken out of the work space S and removed in a state of being disassembled by ring cutting. The existing gate 2 is disassembled by, for example, applying the tip of the lancer cutting rod to the existing gate 2 and melting it. The disassembled existing gate 2 is removed from the work space S by being lifted by a crane of a crane carrier.

  Then, as shown in FIGS. 6 and 11, reinforcement work is performed on the side surface 3b of the dam pillar 3 (dam pillar reinforcement process). In addition, the location and size of the core rebar 5 embedded in the weir column 3 can be grasped in advance by rebar exploration, and after grasping the layout state of the core rebar 5, The guard rebar 5 is exposed over the surface. As a method of rolling the surface of the weir column 3, a water jet can be used, and the surface of the weir column 3 can be easily rolled by the high-pressure water flow of the water jet. In the above-described reinforcing bar exploration, the amount by which the weir pillar 3 is swung is also grasped in advance.

  After exposing the core reinforcing bar 5 over the surface of the weir column 3, the bar-shaped reinforcing reinforcing bar 6 is inserted into the side surface 3 b of the weir column 3 so as to avoid the lattice-shaped core reinforcing bar 5. Thus, by inserting the reinforcing reinforcing bars 6 so as not to interfere with the central reinforcing bar 5, problems such as cutting of the central reinforcing bar 5 due to the insertion of the reinforcing reinforcing bars 6 can be avoided. The reinforcing reinforcing bars 6 are shear reinforcing bars for preventing breakage due to shearing, for example, the concrete is displaced and cut by an earthquake. As an operation for inserting the reinforcing reinforcing bars 6, first, a through hole for inserting the reinforcing reinforcing bars 6 is opened on the side surface 3 b of the weir column 3 by horizontal boring performed by the core boring method.

  The reinforcing reinforcing bars 6 are inserted into the through holes, and a rust preventing grout is filled between the through holes and the reinforcing reinforcing bars 6. Then, both ends of the reinforcing reinforcing bar 6 are exposed from the weir column 3 and passed through a washer. In this state, both ends of the reinforcing reinforcing bar 6 are fixed to the side surface 3 b of the weir column 3. By inserting the reinforcing reinforcing bars 6 into the dam pillar 3 and fixing them in this way, it is possible to reinforce the dam pillar 3 and increase the resistance to the pulling force of the dam pillar 3 that is a concrete structure. Can do. Further, in the reinforcement work of the dam pillar 3, the strength of the dam pillar 3 can be further increased by fixing the bearing plates 21 at both ends of the reinforcing reinforcing bars 6 or increasing the thickness of the dam pillar 3.

  After the reinforcement work of the dam pillar 3 is completed in this way, the new gate is installed by performing work such as repairing the rail portion 3a of the dam pillar 3 (new gate installation process). After the installation of the new gate is completed, water is injected into the work space S, and the first and second water stop structures 7 and 8 are removed from the weir pillar 3. The removed water-stop structures 7 and 8 are carried out by being towed by the ship F, and then a series of operations is completed. The water-stop structures 7 and 8 carried out in this way can be used at another site and can be reused as appropriate.

  Next, a method for installing the first and second water-stop structures 7 and 8 on the dam pillar 3 will be described in detail with reference to FIGS. As FIG. 7 shows, the inside of the 1st and 2nd water stop structures 7 and 8 is divided so that it may have the 1st-3rd space P1-P3 in three places. In addition, since the structure of the 1st water stop structure 7 and the 2nd water stop structure 8 is the same, below, it demonstrates focusing on the method of installing the 1st water stop structure 7 in the weir pillar 3 To do.

  As shown in FIG. 7A to FIG. 7C, the cross section when the water stop structure 7 is cut along a plane orthogonal to the longitudinal direction of the water stop structure 7 is a rectangular shape. A third space P3 is formed on one side of the first central wall K1 connecting the midpoints of the long sides in the cross section. Further, on the other side of the first central wall K1, a first space P1 and a second space P2 are partitioned by a second central wall K2 extending in a direction orthogonal to the first central wall K1. Is formed.

  In addition, water can be injected from the outside into the first to third spaces P1 to P3, and air can be vented from the first to third spaces P1 to P3. . Note that the volumes of the first space P1 and the second space P2 are substantially the same, and the sum of the volumes of the first space P1 and the second space P2 is substantially the same as the volume of the third space P3.

  As shown in FIG. 7A, the water stop structure 7 is towed by the ship F (see FIG. 8) in a hollow state before being installed on the weir pillar 3. At this time, the water stop structure 7 has fallen sideways, and the second space P2 is located immediately above the first space P1. Next, as shown in FIG. 7B, the water injection pipe M1 is inserted from the outside of the third space P3 to the first space P1 to start water injection into the first space P1 and the exhaust valve H1. Then, the air in the first space P1 is removed. As water injection into the first space P1 and air bleeding from the first space P1 progress, the first space P1 side in the water stop structure 7 starts to be inclined downward due to gravity.

  After the water injection into the first space P1 is completed, as shown in FIG. 7C, the water injection hose M2 starts the water injection into the second space P2, and from the outside of the third space P3. The air in the second space P2 is vented by the air vent pipe H2 inserted up to the second space P2. As water pouring into the second space P2 and air bleeding from the second space P2 proceed, the second space P2 side of the water stop structure 7 starts to tilt downward, and the water stop structure 7 rises.

  As shown in FIG. 8, after starting the water stop structure 7, the water stop structure 7 and the weir column 3 are connected by the chain block N, and the water supply valve M <b> 3 is connected to the third space P <b> 3. Air bleeding from the third space P3 by the water injection and the exhaust valve H3 is started. Note that a total of two chain blocks N are provided, for example, one above and below. Then, when the water injection into the third space P3 and the air bleeding from the third space P3 proceed, for example, when the draft Q of the water stop structure 7 becomes 3.22 m, the water stop structure at the ship F Move 7 to the weir pillar 3.

  While continuing the water injection to the third space P3 and the air bleeding from the third space P3 while bringing the water stop structure 7 to the weir pillar 3 by the ship F, as shown in FIG. The water stop structure 7 sinks and contacts the floor board B. At this time, when the diver T pulls the water stop structure 7 with the chain block N, the water stop structure 7 comes into close contact with the side surface 3f of the weir pillar improvement body 3e.

  Then, as shown in FIG. 10, the water stop structure 7 is further filled with water by further pouring water into the third space P3 by the water injection hose M4 and the submersible pump M5. However, it stabilizes in the state which contact | adhered to the side surface 3f of the dam pillar improvement body 3e of the dam pillar 3. FIG. The second water stop structure 8 is also installed on the weir pillar 3 in the same manner as the water stop structure 7.

  As described above, according to the repair method of the movable weir 1 according to the present embodiment, the first water stop structure 7 and the second water stop structure 8 are installed in each of the two weir pillars 3. Since the inflow of river water from the upstream side to the downstream side and the inflow of river water from the downstream side to the upstream side are prevented, the upstream side and the downstream side of the movable weir 1 can be divided. Therefore, even when the movable weir 1 is repaired, the river water on the downstream side containing a large amount of salt is prevented from moving upstream from the movable weir 1. The repair work of the weir 1 can be performed.

  In addition, after the first water stop structure 7 is installed on the upstream side of the existing gate 2 and the second water stop structure 8 is installed on the downstream side of the existing gate 2, the first water stop structure 7 is installed. By removing the river water between the structure 7 and the second water stop structure 8, there is river water between the first water stop structure 7 and the second water stop structure 8. A non-working space S is formed. Since the existing gate 2 is located in the work space S, the work space S can be effectively used as a work space for removing the existing gate 2 and installing a new gate.

  Further, since the reinforcing bar 6 is inserted into the weir column 3 to reinforce the weir column 3, the reinforcing bar 6 can increase the resistance to the force by which the weir column 3 is pulled. 3 can be seismically strengthened.

  Further, the first water stop structure 7 and the second water stop structure 8 are connected to the weir pillar by changing the shape of the weir pillar 3 by forming the weir pillar improvement body 3e at the end 3d of the weir pillar 3. It is possible to prevent the river water from leaking into the work space S. That is, by removing river water located between the first water stop structure 7 and the second water stop structure 8, the first water stop structure 7 and the second water stop structure 8. On the other hand, the pressure of the river water is applied from the outside, and the first water stop structure 7 and the second water stop structure 8 are pressed against the weir column 3 by the pressure of the river water. Therefore, the water stop by the first water stop structure 7 and the second water stop structure 8 can be easily performed.

  Moreover, the 1st water stop structure 7 and the 2nd water stop structure 8 are towed by the ship F as a hollow floating body structure, and the 1st water stop structure 7 and the 2nd water stop structure The work of transporting 8 to the site can be performed easily. For example, the first water stop structure 7 and the second water stop structure 8 are manufactured in advance at a place different from the site, and the construction of the movable weir 1 starts and the first water stop structure 7 and When the second water stop structure 8 is required, the first water stop structure 7 and the second water stop structure 8 can be transported by the towing of the ship F.

  Moreover, after the 1st water stop structure 7 and the 2nd water stop structure 8 are inclined by the water injection to 1st and 2nd space P1, P2, and are pressed against the dam pillar 3 by the ship F, It is submerged in the river R by water injection into the third space P3. Accordingly, the first water stop structure 7 and the second water stop structure 8 can be easily installed with respect to the dam pillar 3 and the first water stop structure 7 and the second water stop structure can be performed. By sinking the object 8 in the river R, it is possible to reliably prevent the first water stop structure 7 and the second water stop structure 8 from moving.

  In reinforcing the weir column 3, the reinforcing bar 6 interferes with the central reinforcing bar 5 by exposing the central reinforcing bar 5 in advance and opening a hole at a position avoiding the central reinforcing bar 5 and inserting the reinforcing reinforcing bar 6. The situation can be avoided. Furthermore, the rust prevention effect of the reinforcing reinforcing bars 6 can be exhibited by filling the grout between the through holes for inserting the reinforcing reinforcing bars 6 and the reinforcing reinforcing bars 6.

  The present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the gist of the present invention.

  For example, in the above embodiment, the river structure is the movable weir 1. However, the in-river structure is not limited to the movable weir 1 and may be, for example, a head dam having a fixed weir, a sluice gate, or a gate. Here, the sluice is a gate or a structure that can be opened and closed as necessary in the river R for water volume adjustment, water intake, drainage, ship operation, or the like. The head work is a structure that draws agricultural water from the river R into the irrigation channel, for example.

  Moreover, in the said embodiment, although the water stop structures 7 and 8 had the 1st-3rd space P1-P3 inside, the internal structure of a water stop structure is not limited to the said embodiment. For example, the first space P1 and the second space P2 may be integrated.

  Moreover, in the said embodiment, although the water stop structures 7 and 8 were conveyed to the spot by the towing of the ship F, you may carry the water stop structures 7 and 8 by methods other than the towing of the ship F.

  Moreover, in the said embodiment, in order to make the water stop structures 7 and 8 contact | adhere to the dam pillar 3, the edge part improvement of the dam pillar 3 was performed and the dam pillar improvement body 3e was formed, However, Water stop structure by another structure. The objects 7 and 8 may be brought into close contact with the weir pillar 3.

  Moreover, in the said embodiment, although the reinforcing bar 6 was inserted in the side surface 3b of the dam pillar 3 and the dam pillar 3 was reinforced, the reinforcement method of the dam pillar 3 can also be changed suitably, depending on the case. It is also possible to omit reinforcement of the weir column 3.

DESCRIPTION OF SYMBOLS 1 ... Movable weir (structure in river), 2 ... Existing gate, 3 ... Weir pillar, 3a ... Rail part, 3b ... Side face, 3d ... End part, 3e ... Weir pillar improvement body, 3f ... Side face, 5 ... Heart reinforcement , 6 ... reinforcing bars, 7 ... first water stop structure, 8 ... second water stop structure, 9 ... liner plate, F ... ship, P1 ... first space, P2 ... second space, P3 ... Third space, R ... River.

Claims (6)

Rehabilitation of river structures for river structures including at least two weir pillars installed in the river and an existing gate installed so as to bridge between the two weir pillars In the method
A first water stop structure for preventing inflow of river water from the upstream side to the downstream side is installed on each of the weir pillars upstream of the existing gate, and the river water from the downstream side to the upstream side is installed. A water stop structure installation step of installing a second water stop structure for preventing inflow on each of the weir pillars downstream of the existing gate; and
A river water removal step of removing river water located between the first water stop structure and the second water stop structure;
An existing gate removal step of removing the existing gate from the space obtained by removing the river water;
A new gate installation step in which a new gate is installed on each of the dam columns so as to bridge between the two dam columns;
A method of repairing a river structure characterized by comprising:   The method for repairing an in-river structure according to claim 1, further comprising a dam pillar reinforcing step for reinforcing the dam pillar by inserting a reinforcing bar into the dam pillar after the river water removing step.   Prior to the water stop structure installation step, the weir column shape changing step for changing the shape of the weir column so that the first water stop structure and the second water stop structure are in close contact with the weir column. The method for refurbishing a river structure according to claim 1 or 2, characterized by comprising:   The said 1st water stop structure and the said 2nd water stop structure are towed by the ship in the state made into the hollow before the said water stop structure installation process, The Claim 1 characterized by the above-mentioned. 3. A method for repairing a river structure according to any one of 3 above. The first water stop structure and the second water stop structure are partitioned so that an internal space has a first space and a second space,
The first water stop structure and the second water stop structure are tilted by being poured into the first space after being towed by the ship and pressed against the weir pillar by the ship. The method for repairing a river structure according to claim 4, wherein the river is submerged by being poured into the second space later.   In the dam pillar reinforcing step, the core rebar embedded in the dam pillar is exposed by rolling the surface of the dam pillar with a water flow, and a hole is formed at a position avoiding the core rebar to the hole. The method for repairing an in-river structure according to claim 2, wherein a reinforcing bar is inserted and a grout is filled between the hole and the reinforcing bar.