JP2022108444A - Reinforcement method for existing bank - Google Patents

Abstract

To provide a reinforcement method of an existing bank hardly affected by a weather or the like and capable of shortening a construction period and reducing costs.SOLUTION: Steel pipe sheet piles 3 are installed in a ground 2 at a land side of an existing bank 1 to reinforce the existing bank 1 facing a water area such as a river 6. Then, space-filling concrete 8 is filled with fluid solidification material between the existing bank 1 and the steel pipe sheet piles 3 after constructing coping concrete 7 on upper parts of the steel pipe sheet piles 3. The space-filling concrete 8 prevents corrosion of the steel pipe sheet piles 3. After the space-filling concrete 8 is placed, fall prevention fences are installed on the coping concrete 7, and excavated sections are refilled with refill material 24 to complete a reinforcement structure 9.SELECTED DRAWING: Figure 13

Description

TECHNICAL FIELD The present invention relates to a method for reinforcing an existing seawall.

Seawalls, which are used to protect land from waves and river flooding, are prone to deterioration because they are used under severe conditions at the water's edge. In addition, revetments that have been built for many years may need to be made earthquake-resistant to meet current earthquake resistance standards.

As a method to reinforce and earthquake-proof the existing revetment, a method to improve the ground behind the quay while supporting the front side of the quay wall from the water (see, for example, Patent Document 1), and a method to improve the ground on the back side of the existing steel sheet pile A method of removing existing steel sheet piles and the like and installing new members after constructing a soil improvement body (see, for example, Patent Document 2) has been proposed.

JP-A-11-323872 Patent Publication No. 6322560

However, the method described in Patent Document 1 is susceptible to weather and water currents because it requires work in or on water. The method described in Patent Document 2 requires time and effort to remove existing steel sheet piles and the like. Therefore, the construction cost increases and the construction period becomes long.

SUMMARY OF THE INVENTION The present invention has been made in view of the aforementioned problems, and its object is to provide a method of reinforcing an existing seawall that is less susceptible to the effects of weather and the like, and that can shorten the construction period and reduce the cost. be.

In order to achieve the above-mentioned object, the present invention provides a method for reinforcing an existing seawall facing a water area, comprising a step a of erecting a steel pipe sheet pile on the land side of the existing seawall; A method for reinforcing existing revetments, comprising a step b of constructing and a step c of filling a space between the existing revetments and the steel pipe sheet piles with a fluid solidifying material.

In the present invention, since all the processes are carried out on the land side of the existing seawall, it is less likely to be affected by weather and water currents during work, and large-scale removal work of the existing seawall is unnecessary, so that the construction period can be shortened and the cost can be reduced.

In the step a, on the land side of the steel pipe sheet pile, a stay pile having a smaller diameter than the steel pipe sheet pile is erected at a predetermined interval, and after the step a, the steel pipe sheet pile and the stay pile are connected as a connecting member. It is desirable to concatenate with
Thereby, the earth pressure from the back surface of the steel pipe sheet pile can be supported.

In this case, for example, the connecting member is a tie rod, and the site where the connecting member is to be installed is dug down in advance between the steel pipe sheet pile and the stay pile, and then backfilled after the connecting member is installed. Thereby, a connection member can be constructed easily.
In addition, the connecting member is connected to a part of the steel pipes constituting the steel pipe sheet pile, and the steel pipes to which the connecting member is not connected are not filled with the fluid solidifying material, and the steel pipes to which the connecting member is connected are not filled. At least the upper portion of the steel pipe may be filled with a fluid solidifying material. Thereby, the connecting member and the steel pipe can be firmly connected.
In addition, before the step b, ground improvement may be performed in a range including the stay piles. Thereby, a construction machine such as a pile driver can be installed on the ground on the land side of the steel pipe sheet pile.

The steel pipe sheet piles are preferably installed by hammering or press-fitting after drilling with an all-round rotary excavator.
As a result, steel pipe sheet piles can be constructed using general-purpose machines, making it possible to reduce costs.

The shed concrete is desirably constructed using precast members. If precast members are used, shed concrete can be easily constructed.
It is desirable that the precast member is placed on a dump concrete placed around the steel pipe sheet pile. Placing the precast members on the dump concrete eliminates the need for shoring for the precast members.
The precast member has a plurality of concave shapes corresponding to the outer shape of the steel pipe sheet pile, a cushioning material is arranged at a contact portion with the steel pipe sheet pile, and the precast member is arranged to straddle a plurality of adjacent steel pipe sheet piles. should be placed in This simplifies the positioning of the precast member with respect to the steel pipe sheet pile, thereby preventing misalignment. By arranging the cushioning material, the gap between the steel pipe sheet pile and the precast member can be reliably closed.

When the shed concrete is a precast member, an opening is formed in the upper portion of the precast member, and in the step b, the space between the precast member and the steel pipe sheet pile is filled with a fluid solidifying material from the opening. good too. Forming an opening in the upper portion of the precast member facilitates filling the fluid solidifying material even when the precast member has an upper surface member.
In addition, the precast member does not have an upper surface member, and in the step b, the precast member arranged on the existing bank protection side of the steel pipe sheet pile and the formwork arranged on the land side of the steel pipe sheet pile. It may be filled with a hardening material. A wall-shaped or L-shaped precast member that does not have an upper surface member can be stored or transported in layers, and is light and easy to lift. In addition, since the fluid solidifying material can be filled from the entire surface of the top of the shed concrete, construction can be performed in a lower cost and in a shorter process than when filling from the opening, and it is also advantageous in terms of strength.

The existing revetment is, for example, a retaining wall attached to a river hydraulic structure. Retaining walls attached to hydraulic structures are particularly susceptible to deterioration due to changes in river flow velocity, and the method of the present invention is also suitable for reinforcing such retaining walls.
It is desirable that the steel pipe sheet piles be spaced apart from the retaining wall so as not to interfere with the foundation of the retaining wall. This makes it possible to reinforce the retaining wall without removing the foundation.
The existing revetment has a continuous part arranged along the river and a part arranged toward the land side from the river, and the steel pipe sheet piles are arranged on the back side of the existing revetment in each direction. good too. As a result, it is possible to reinforce the existing L-shaped revetment in plan view.

ADVANTAGE OF THE INVENTION According to this invention, the reinforcement method of the existing revetment which can shorten a construction period and can reduce cost can be provided.

Diagram showing each process when reinforcing the existing revetment 1 The figure which shows the state where step 101 was implemented. The figure which shows the state where step 101 was implemented. A diagram showing a state in which step 102 has been carried out. A diagram showing a state in which step 102 has been carried out. The figure which shows the state where step 103 was implemented. The figure which shows the state where step 103 was implemented. A diagram showing a state in which step 104 has been carried out. A diagram showing a state in which step 104 has been carried out. Figure showing precast member 71 The figure which shows the state which arranged the precast member 71. A diagram showing a state in which step 105 has been carried out. The figure which shows the state where step 105 was implemented. The figure which shows the reinforcement structure 9a Perspective view of precast member 71a The figure which shows the state which has arrange|positioned the precast member 71a. Perspective view of precast member 71b

Preferred embodiments of the present invention will be described in detail below with reference to the drawings. FIG. 1 is a diagram showing each process when reinforcing an existing revetment 1. As shown in FIG. 2 and 3 are diagrams showing a state in which step 101 shown in FIG. 1 has been carried out, FIG. 2 being a plan view, and FIG. 3 being a sectional view taken along the line AA shown in FIG.

As shown in FIGS. 2 and 3, the existing revetment 1 has a portion arranged along the flow of the river 6 (horizontal direction in FIG. 2) and a portion extending from the river 6 toward the land side (downward in FIG. 2). It is continuous with the part where it is arranged, and has an L-shaped shape in a plan view. The existing revetment 1 is a retaining wall attached to a hydraulic structure (for example, a movable weir) of the river 6 . For example, in the vicinity of the movable weir, when the weir is opened, a large turbulent flow occurs in the vicinity, and a retaining wall is required to protect the ground against this.

The existing revetment 1 is composed of a wall portion 11, a bottom plate portion 12, a reinforcing member 13, a foundation 14, and the like. The reinforcing members 13 are provided so as to be orthogonal to the wall portion 11 and the bottom plate portion 12 at intervals in the extending direction of the wall portion 11 . The foundation 14 is, for example, a pile arranged below the bottom plate portion 12 . A considerable amount of time has passed since the construction of the existing revetment 1, and it may not have sufficient seismic strength.

In step 101, ground improvement is carried out as shown in FIGS. Soil improvement is carried out by cement mixing, for example, using a construction machine in which a backhoe boom is modified into an agitating blade. The improved ground 21 is formed on the ground 2 on the back side of the existing revetment 1 . The depth of the improved ground 21 from the ground surface 22 is set so as to obtain sufficient strength to support the construction machine.

4 and 5 are diagrams showing a state in which step 102 shown in FIG. 1 has been carried out, FIG. 4 being a plan view, and FIG. 5 being a sectional view taken along line BB shown in FIG.

In step 102, the steel pipe sheet piles 3 and the stay piles 4 are erected as shown in FIGS. The steel pipe sheet pile 3 is spaced from the existing revetment 1 toward the land side and installed so as not to interfere with the bottom slab part 12 and the foundation 14.例文帳に追加The steel pipe sheet piles 3 are installed on the rear side of each of the part of the existing revetment 1 that is arranged along the river 6 and the part that is arranged facing the land side from the river 6 . The steel pipe sheet pile 3 is formed by connecting a plurality of steel pipes 31 with joint portions 32 . The steel pipe sheet pile 3 is constructed by drilling the construction site with a full-circumference rotary excavator and removing construction obstacles. Constructed by injecting non-shrinking mortar, etc.

The stay piles 4 are installed further on the land side of the steel pipe sheet piles 3 with a predetermined spacing, and within the range of the improved ground 21 in a plan view. The stay pile 4 is a steel pipe pile or the like having a diameter smaller than that of the steel pipe sheet pile 3, and is installed by press fitting or the like.

6 and 7 are diagrams showing a state in which step 103 shown in FIG. 1 has been carried out, FIG. 6 being a plan view, and FIG. 7 being a cross-sectional view taken along line CC shown in FIG.

In step 103, tie rods 5 are installed. As shown in FIGS. 6 and 7 , the tie rod 5 is a connecting member that connects some steel pipes 31 a of the plurality of steel pipes 31 forming the steel pipe sheet pile 3 and the stay pile 4 . The tie rods 5 connected to the steel pipes 31a of the portion of the steel pipe sheet pile 3 arranged along the river 6 and the tie rods 5 connected to the steel pipes 31a of the portion arranged toward the land side from the river 6 are shown in plan view. intersect at The tie rod 5 is not connected to the steel pipe 31b.

When installing the tie rod 5 , a dug-down portion 23 is provided in advance at a portion where the tie rod 5 is to be installed between the steel pipe 31 a and the stay pile 4 , and the tie rod 5 is arranged in the dig-down portion 23 . The tie rod 5 is, for example, a four-strand high-strength steel, and has two hinges (vertical direction and horizontal direction) and one long nut so that the direction and length can be adjusted.

8 and 9 are diagrams showing a state in which step 104 shown in FIG. 1 has been carried out, FIG. 8 being a plan view, and FIG. 9 being a cross-sectional view taken along line DD shown in FIG. FIG. 10 is a diagram showing a precast member 71. FIG. 11A and 11B are views showing a state in which the precast member 71 is arranged, FIG. 11A is an enlarged view of a portion corresponding to the range E in FIG. Fig. 3F is a sectional view through F;

At step 104, the shed concrete 7 is constructed. The shed concrete 7 is constructed using precast members 71 shown in FIG. The precast member 71 consists of an upper surface member 71-1, a lower surface member 71-2, and a front surface member 71-3 connecting the upper and lower surfaces. The top member 71-1 has an opening 74. As shown in FIG. The openings 74 are formed at two locations, for example, at the same intervals as the adjacent steel pipes 31 of the steel pipe sheet pile 3 . The lower surface member 71-2 has two recesses 75 corresponding to the outer shape of the steel pipe sheet pile 3, and a cushioning material 76 is arranged along the surfaces forming the recesses 75. As shown in FIG. The cushioning material 76 is, for example, a hard rubber material.

In order to construct the shed concrete 7, as shown in FIG. 11, a precast member 71 is placed on top of the steel pipe sheet pile 3 so as to straddle two adjacent steel pipes 31. As shown in FIG. In the precast member 71, the opening 74 of the upper surface member 71-1 is positioned above the steel pipe 31, the steel pipe 31 is fitted into the recess 75 of the lower surface member 71-2, and the front surface member 71-3 is the wall portion of the existing revetment 1. 11 are arranged to face each other. The precast member 71 may be arranged on a mount (not shown) installed on the top of the steel pipe sheet pile 3, or may be arranged on discarded concrete as in the second embodiment described later.

After arranging the precast member 71 , reinforcing bars 77 are arranged on the back side of the precast member 71 , and a formwork 78 is installed on the back side of the reinforcing bars 77 . A contact portion between the recessed portion 75 of the precast member 71 and the steel pipe sheet pile 3 is waterproofed by a buffer material 76 . A mold 34 is installed below the tie rod 5 inside the steel pipe 31a of the steel pipes 31 constituting the steel pipe sheet pile 3, and the steel pipe 31b is closed with a lid 33 at the top.

After the precast members 71 and the like are arranged as shown in FIG. 11, filling concrete 72 and backside concrete 73, which are fluid solidifying materials, are placed as shown in FIGS. The filling concrete 72 is filled between the precast member 71 and the steel pipe sheet pile 3 from the opening 74 . The filling concrete 72 is also filled in the upper portion of the steel pipe 31a, thereby firmly connecting the tie rod 5 and the steel pipe 31a. The back side concrete 73 is filled between the precast member 71 and the formwork 78 at the same time as the filling concrete 72 .

Here, since the lid 33 described above is installed inside the steel pipe 31b, the filling concrete 72 is not filled. The steel pipe 31a also does not necessarily need to be filled with the filling concrete 72, and if it is not filled, a lid 33 is placed on the top of the steel pipe 31a as indicated by the dotted line in FIG. 11(b).

12 and 13 are diagrams showing a state in which step 105 shown in FIG. 1 has been carried out, FIG. 12 being a plan view, and FIG. 13 being a sectional view taken along line GG shown in FIG.

At step 105, the interstitial concrete 8 is filled. As shown in FIGS. 12 and 13 , the interstitial concrete 8 is a fluid solidification material, and is filled between the existing revetment 1 and the steel pipe sheet piles 3 and shading concrete 7 . The filling concrete 8 prevents corrosion of the steel pipe sheet pile 3 . After placing the interstitial concrete 8 , a fall prevention fence (not shown) is installed on the shade concrete 7 . In addition, the dug-down portion 23 is backfilled with a backfilling material 24 to complete the reinforcing structure 9 .

As described above, according to the first embodiment, all the steps shown in FIG. 1 are performed on the land side of the existing revetment 1, so that the work is less likely to be affected by weather and water currents. Moreover, since reinforcement is carried out so as not to interfere with the existing revetment 1, large-scale removal work is not required. In addition, since the existing revetment 1 is used as it is, the desired seismic strength can be obtained with minimal reinforcement. Therefore, the construction period can be shortened and the cost can be reduced compared to the conventional construction method.

In the first embodiment, by using the stay piles 4 and the tie rods 5, a member for supporting the earth pressure from the back surface of the steel pipe sheet pile 3 can be easily constructed. Moreover, by using the precast members 71, the shade concrete 7 can be easily constructed. Furthermore, by providing the precast member 71 with the recessed portion 75 and arranging it across two or more adjacent steel pipes 31, the positioning of the precast member 71 with respect to the steel pipe sheet pile 3 becomes easy, and by providing the opening 74, the filling concrete 72 becomes easier to fill.

Note that the existing revetment 1 is not limited to a retaining wall attached to the hydraulic structure of the river 6, and may face a water area other than the river 6. The planar shape of the existing revetment 1 is not limited to the L shape. In addition, the formation of the improved ground 21 is not essential, and if the construction machine used for installing the steel pipe sheet pile 3 and the stay pile 4 can be installed on the ground on the land side of the steel pipe sheet pile 3, ground improvement can be omitted. good.

The connecting member that connects the steel pipe sheet pile 3 and the stay pile 4 may not be the tie rod 5, and if sufficient strength can be obtained without the stay pile 4 and the tie rod 5, they may be omitted. The precast member 71 is not limited to being arranged across two adjacent steel pipes 31 , and the recesses 75 are formed according to the number of corresponding steel pipes 31 .

Next, a second embodiment will be described. 2nd Embodiment demonstrates a different point from 1st Embodiment, A description is abbreviate|omitted by attaching|subjecting the same code|symbol in a figure etc. about the same structure. Moreover, the configurations described in each embodiment can be combined as necessary.

FIG. 14 shows a reinforcing structure 9a according to a second embodiment of the invention. The reinforcement structure 9a mainly differs from the reinforcement structure 9 of the first embodiment in that instead of the shed concrete 7, the shed concrete 7a is constructed.

FIG. 15 is a perspective view of the precast member 71a, and FIG. 16 is a diagram showing a state in which the precast member 71a is arranged. FIG. 16 is an enlarged view of a portion corresponding to range H in FIG.

The shade concrete 7a shown in FIG. 14 is constructed using precast members 71a shown in FIG. The precast member 71a is an L-shaped member composed of a lower surface member 71a-2 and a front surface member 71-3, and does not have an upper surface member.

Crushed stone and dump concrete 79 are placed around the steel pipe sheet pile 3 to construct the shading concrete 7a. The crushed stone and dump concrete 79 consist of a crushed stone layer 79-2 laid on the ground 2 and a dump concrete 79-1 placed on the crushed stone layer 79-2, as shown in FIG.

Next, the precast member 71a is placed on the discarded concrete 79-1 of the steel pipe sheet pile 3 on the existing bank protection 1 side. The length of the lower surface member 71a-2 in the left-right direction in FIG. 16 is set so that the precast member 71a does not interfere with the steel pipe sheet pile 3 when placed on the dump concrete 79-1 and can stand on its own stably. A water stop plate or a joint material is attached to the joint between the precast members 71a. The precast member 71 a is provided with an insert hardware 82 for receiving a bolt on the surface facing the existing revetment 1 . A horizontal end thick member 86a and a vertical end thick member 86b are fixed to the precast member 71a using an insert hardware 82 and a binding tool 80. As shown in FIG.

Also, a formwork 78 is placed on the waste concrete 79-1 on the land side (back side) of the steel pipe sheet pile 3. Horizontal end thick members 86a and vertical end thick members 86b are fixed to the formwork 78a using wooden concrete 81 and binding tools 80. As shown in FIG.

A temporary separator 85 is installed between the vertical end thick member 86b fixed to the precast member 71a and the vertical end thick member 86b fixed to the formwork 78. As shown in FIG. The separator 85 is installed, for example, above the top end height 84 of the shading concrete 7a. Since the separator 85 cannot be installed at a height that interferes with the steel pipe sheet pile 3, a jack 83 is installed between the lower part of the precast member 71a and the existing revetment 1 or between the formwork 78 and the back ground 2 as an alternative. be. The top of steel pipe 31 is closed with lid 33 .

After placing the precast member 71a and the like as shown in FIG. The concrete 72a is placed up to a top height 84, and the side pressure applied to the precast member 71a and the formwork 78 during placement is supported by the jacks 83, separators 85 and the like. After the concrete 72a hardens to some extent, the binding tool 80 and the jack 83 are removed, and the separator 85, the horizontal end thick member 86a, the vertical end thick member 86b, and the formwork 78 are removed.

In the second embodiment, since the precast member 71a is placed on the discarded concrete 79-1, the precast member 71a does not require support. Since the precast member 71a does not have an upper surface member, the concrete 72a can be filled from the entire top end of the shading concrete 7a. In addition, the precast members 71a can be stored or transported in a stacked state, and are lightweight and easy to lift.

In the second embodiment, only the portion of the shed concrete 7a on the side of the existing revetment 1, which is to be constructed in a narrow space, is constructed with precast members 71a, and the remaining portion is constructed with cast-in-place concrete 72a. A dry area formed by leaving the existing revetment 1 in place can be utilized to the maximum. Therefore, compared with the first embodiment, it can be constructed in a short process at a low cost, and is also advantageous in terms of strength.

Although the precast member 71a is an L-shaped member in the second embodiment, the shape of the precast member is not limited to this, as long as it does not have an upper surface member. For example, the lower surface member 71-2 may be omitted and only the front surface member 71-3 may be used as a wall member, or a precast member 71b shown in FIG. It can be a thing.

Although the preferred embodiments of the present invention have been described above with reference to the accompanying drawings, the present invention is not limited to such examples. It is obvious that a person skilled in the art can conceive of various modifications or modifications within the scope of the technical ideas disclosed in the present application, and these also belong to the technical scope of the present invention. Understood.

1……Existing revetment 2……Ground 3……Steel pipe sheet pile 4……Standing pile 5……Tie rod 6……River 7, 7a……Shedding concrete 8……Infill concrete 9, 9a Reinforcement structure 11 Wall portion 12 Bottom plate portion 13 Reinforcing member 14 Foundation 21 Improved ground 22 Ground surface 23 Excavation portion 24 Backfilling material 31, 31a, 31b Steel pipe 32 Joint 33 Lid 34, 78 Mold 71, 71a, 71b Precast member 71-1 Upper surface member 71-2, 71a-2 --- Lower member 71-3 --- Front member 72 --- Filling concrete 72a --- Concrete 73 --- Back side concrete 74 --- Opening 75 --- Recess 76 ………… Cushioning material 77 …… Reinforcing bars 79 …… Crushed stone and waste concrete 79-1 …… Waste concrete 79-2 …… Crushed stone layer 80 …… Binder 81 …… Wood concrete 82 …… …Insert hardware 83 … Jack 84 … Top height 85 … Separator 86a … Thick material at horizontal end 86b … Thick material at vertical end

Claims (14)

A method for reinforcing an existing seawall facing a water area, comprising:
A step a of placing a steel pipe sheet pile on the land side of the existing revetment;
a step b of constructing shed concrete on top of the steel pipe sheet pile;
A step c of filling a space between the existing revetment and the steel pipe sheet pile with a fluid solidifying material;
A method for reinforcing existing revetments, comprising: In the step a, anchor piles having a smaller diameter than the steel pipe sheet pile are erected on the land side of the steel pipe sheet pile at predetermined intervals,
2. The method of reinforcing an existing revetment according to claim 1, wherein said steel pipe sheet pile and said stay pile are connected with a connecting member after said step a. 2. The connection member is a tie rod, and the portion between the steel pipe sheet pile and the stay pile, where the connection member is to be installed, is dug down in advance, and is backfilled after the connection member is installed. Reinforcement method of the existing revetment described. The connecting member is connected to a part of the steel pipes constituting the steel pipe sheet pile, the steel pipes to which the connecting member is not connected are not filled with a fluid solidifying material, and the steel pipes to which the connecting member is connected are not filled. 4. The method of reinforcing an existing revetment according to claim 2 or 3, wherein at least the upper portion is filled with a fluid solidifying material. 5. The method of reinforcing an existing revetment according to any one of claims 2 to 4, wherein ground improvement is performed in a range including the stay piles before the step b. 6. The method of reinforcing an existing revetment according to any one of claims 1 to 5, wherein the steel pipe sheet pile is installed by hammering or press-fitting after drilling with an all-round rotary excavator. 7. The method of reinforcing an existing bank protection according to any one of claims 1 to 6, wherein the shading concrete is constructed using precast members. 8. The method of reinforcing an existing revetment according to claim 7, wherein the precast member is placed on a surplus concrete placed around the steel pipe sheet pile. The precast member has a plurality of concave shapes corresponding to the outer shape of the steel pipe sheet pile, and a cushioning material is arranged at a contact portion with the steel pipe sheet pile,
9. The method of reinforcing an existing revetment according to claim 7, wherein the precast members are arranged so as to straddle a plurality of adjacent steel pipe sheet piles. An opening is formed in the upper part of the precast member, and in step b, a fluid solidifying material is filled between the precast member and the steel pipe sheet pile through the opening. Item 9. A method for reinforcing an existing seawall according to any one of items 9. The precast member does not have an upper surface member, and in the step b, fluidity is solidified between the precast member arranged on the existing bank protection side of the steel pipe sheet pile and the formwork arranged on the land side of the steel pipe sheet pile. 10. The method for reinforcing existing revetment according to any one of claims 7 to 9, wherein the revetment is filled with material. 12. The method for reinforcing an existing bank protection according to any one of claims 1 to 11, wherein the existing bank protection is a retaining wall attached to a hydraulic structure of a river. 13. The method of reinforcing an existing revetment according to claim 12, wherein the steel pipe sheet pile is arranged away from the retaining wall so as not to interfere with the foundation of the retaining wall. The existing revetment has a continuous part arranged along the river and a part arranged toward the land side from the river, and the steel pipe sheet pile is arranged on the back side of the existing revetment in each direction. 14. The method for reinforcing an existing seawall according to claim 12 or 13, characterized in that:

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