JP7489350B2 - Improvement structure and method of existing wharf - Google Patents

Description

The present invention relates to an improvement structure and an improvement method for existing wharfs, such as a pier-type wharf, a jacket-type wharf or a grid-strut-type wharf, in which the superstructure is supported by support piles driven into the waterbed.
Factors that require improvements here include improving earthquake resistance (review of technical standards and change of use (for example, designation as an earthquake-resistant quay), increase in the load on the apron (including larger cranes), deepening of quayside water depth due to larger ships, response to deterioration of existing structures over time, extension of service period, etc.

Existing quays which are the subject of improvement by the present invention include, for example, a pier-type quay 21 shown in Figs. 7 and 8, a jacket-type quay 23 shown in Fig. 9, or a grid-strut type pier (not shown).
In the pier-type wharf 21 shown in Fig. 7, the superstructure 5 is supported by support piles 3 driven into the waterbed 2, and a retaining wall made of L-shaped blocks 25 is placed on the land side of the superstructure 5. In addition, rubble 27 is laid on the waterbed below the superstructure 5.

The pier-type wharf 21 shown in Figure 8 is constructed by using a pile-type sheet pile wall 29 with piles 30 on the land side instead of the L-shaped blocks 25 shown in Figure 7. In addition, concrete caissons, concrete blocks, etc. may be used instead of the L-shaped blocks.

The jacket-type wharf 23 shown in Figure 9 has a jacket section 31 below the superstructure 5 for integration with the support piles 3, and the pile heads are inserted into the cylindrical body of the jacket section 31 for integration.

Existing quays in this type support superstructure 5 with support piles 3 driven into the waterbed 2. Factors that require improvement of existing quays include, as mentioned above, improving earthquake resistance (review of technical standards and change of use (e.g. designation as earthquake-strengthened quay), increase in the load on the apron (including larger cranes), deepening of the quay water depth due to larger ships, response to deterioration of the existing structure over time, extension of service period, etc.

As a method for improving existing pier-type quays, for example, Patent Document 1 proposes a method of reducing the bending moment acting on the support piles by installing reinforcing beams between the support piles.

Patent No. 5136589

The improvement method disclosed in Patent Document 1 can be used to improve earthquake resistance, that is, when the bending moment of the pier pile head (the joint between the superstructure and the steel pipe pile) is severe, that is, when the superstructure shakes too much during an earthquake, but it cannot be used when reinforcement of the retaining wall is required.
Furthermore, in Patent Document 1, there is also the problem that much of the work required to attach the reinforcing members relies on underwater human labor, such as scraping and welding work inside the steel pipe pile.

Furthermore, to increase the depth of the water as ships get larger, additional structures are required that do not affect the pier or retaining wall. In this regard, it may be possible to design excavation and install steel sheet piles or steel pipe sheet pile walls to increase the depth of the water bottom (depending on the degree of depth), but some kind of countermeasure construction may be necessary on the water side of the sheet pile wall. In such cases, ground improvement work such as cement solidification may be carried out, but this may not be possible due to environmental and other constraints.

The present invention has been made to solve one or more of these problems.

(1) The improved structure of an existing wharf according to the present invention is an improvement of an existing wharf in which a superstructure is supported by bearing piles driven into the bottom ground,
A sheet pile wall is newly installed under the water surface at a predetermined distance toward the water surface from directly below the water surface end of the superstructure in the direction normal to the quay so as to protrude above the water bottom surface;
A raising material for raising the water bottom surface installed on the land side of the sheet pile wall;
A pile is driven into the bottom surface of the water area side of the sheet pile wall;
The pile head connection structure is characterized in that it connects and integrates the pile heads of the piles, is arranged so as to contact the water side of the sheet pile wall, transmits only horizontal forces from the sheet pile wall to the piles, and is installed so that its top surface is at the same level as or lower than the water bottom surface where ships come alongside.

(2) In addition, in the above (1), the pile head connection structure is characterized in that its upper surface is installed below the water bottom surface before improvement, which is set for ships to dock.

(3) Also, an improved structure of an existing wharf in which the superstructure is supported by support piles driven into the bottom ground,
A sheet pile wall newly installed below the water surface at a predetermined distance toward the water area from directly below the water area end of the superstructure;
The present invention is characterized by comprising a pile head connection structure which connects and integrates the pile heads of the piles driven into the waterbed surface on the water area side of the sheet pile wall, is arranged so as to contact the water area side of the sheet pile wall, transmits only horizontal forces from the sheet pile wall to the piles, and is installed so that its upper surface is lower than the waterbed surface before improvement where ships can dock.

(4) The method for improving an existing quay wall according to the present invention is a method for improving an existing quay wall in which a superstructure is supported by bearing piles driven into the bottom ground,
a sheet pile wall installation process for installing a sheet pile wall under the water surface at a predetermined distance toward the water surface from directly below the water surface end of the superstructure in a direction normal to the quay so as to protrude from the water surface;
A step of constructing a raising material to raise the water bottom surface on the land side of the sheet pile wall;
A pile driving process of driving piles into a bottom surface of the water area side of the sheet pile wall;
and a pile head connection structure installation process for connecting and integrating the pile heads of the piles and installing the pile head connection structure so that it is in contact with the water side of the sheet pile wall and transmits only horizontal forces from the sheet pile wall to the piles, and so that its upper surface is at the same level as or lower than the water bottom surface where ships come alongside.

(5) In addition, in the above-mentioned (4), the pile head connection structure installation process is characterized in that the bottom surface of the water where the ship will be docked is excavated and the pile head connection structure is installed so that the upper surface of the pile head connection structure is lower than the pre-improvement bottom surface set for the ship to be docked.

(6) A method for improving an existing quay wall in which a superstructure is supported by support piles driven into the bottom of the water, comprising the steps of:
A sheet pile wall installation process of installing a sheet pile wall below the water surface at a predetermined distance toward the water area from directly below the water area side end of the superstructure;
and a pile head connection structure installation process for connecting and integrating the pile heads of the piles driven into the waterbed surface on the water area side of the sheet pile wall, and installing a pile head connection structure so that it is in contact with the water area side of the sheet pile wall and transmits only horizontal forces from the sheet pile wall to the piles, and so that its upper surface is lower than the waterbed surface before improvement where ships can dock.

The improved structure of the existing wharf according to the present invention can achieve the following effects.
In cases where there are concerns about insufficient earthquake resistance but construction cannot be carried out on the ground behind, in other words where construction such as ground improvement work on the retaining wall (ground behind) is required due to a review of the design target earthquake, but construction cannot be carried out due to issues with the use of the area behind, this method can still be applied because construction can be carried out only on the water side and no construction is carried out on land.

By constructing the padding materials, the riprap layer becomes thicker and the protruding length of the support piles becomes shorter, reducing the stress generated in the support piles during an earthquake and improving earthquake resistance. In addition, by constructing the padding materials, the riprap layer becomes thicker, reducing the flow force caused by deformation of the retaining wall during an earthquake, improving earthquake resistance in this sense as well. Furthermore, the passive resistance of the L-shaped blocks increases, improving the safety factor against movement and collapse, and increasing the bearing capacity of the existing foundation riprap.

In addition, it is only necessary to be able to transmit horizontal forces between the sheet pile wall and the pile head connection structure; the sheet pile wall and the pile head connection structure do not need to be integrated, making underwater stud welding, etc. unnecessary.

FIG. 2 is a vertical cross-sectional view of an improved structure of an existing wharf according to the first embodiment of the present invention. 2 is a view taken along line AA in FIG. 1. FIG. 11 is an explanatory diagram of another aspect of the pile head connection structure. A vertical cross-sectional view of another aspect of the improved structure of an existing quay wall related to embodiment 1 of the present invention. FIG. 5 is a vertical cross-sectional view of an improved structure of an existing wharf according to embodiment 2 of the present invention. 6 is a view taken along the line BB in FIG. 5. This is an explanatory diagram of a pier-type quay as an existing quay that supports a superstructure (part 1). This is an explanatory diagram of a pier-type quay as an existing quay that supports a superstructure (part 2). This is an explanatory diagram of a jacket-type quay as an existing quay that supports a superstructure.

[First embodiment]
In this embodiment, a case will be described in which the existing wharf to be improved is a pier-type wharf.
The improved structure 1 of an existing wharf according to this embodiment, as shown in Figures 1 and 2, is an improvement of an existing wharf in a type in which a superstructure 5 is supported by support piles 3 driven into the waterbed 2, and comprises a sheet pile wall 7 newly installed under the water surface at a predetermined distance toward the water from directly below the water area side end of the superstructure 5 in the direction normal to the wharf so as to protrude above the waterbed surface, raising materials 9 installed on the land side of the sheet pile wall 7 to raise the waterbed surface, piles 11 driven into the waterbed 2 on the water area side of the sheet pile wall 7, and a pile head connecting structure 13 which connects and integrates the pile heads of the piles 11 and is provided so as to contact the water area side of the sheet pile wall 7 so as to transmit only horizontal force from the sheet pile wall 7 to the piles 11, and which is installed so that its top surface is at the same level as or lower than the waterbed surface where ships come alongside.
In Figs. 1 and 2, the same parts as those in Fig. 7 showing the existing pier-type wharf are denoted by the same reference numerals.
The details of each component and the relationship between each component will be described below.

<Existing wharf>
The existing pier-type quay, which is the target of improvement, consists of support piles 3 driven into the waterbed 2, a superstructure 5 supported by the support piles 3, an L-shaped block 25 serving as a retaining structure installed on the land side of the superstructure 5, and foundation rubble 27 in the area below the superstructure 5 from the L-shaped block 25 toward the water side, which slopes from the land side toward the water side.
The existing wharf to be improved may be a pile-type sheet pile wall 29 shown in FIG. 8, a jacket-type wharf 23 shown in FIG. 9, or a grid-strut type pier (not shown), etc.

＜Sheet Pile Wall＞
The sheet pile wall 7 was newly installed below the water surface a predetermined distance toward the water surface from directly below the water surface end of the superstructure 5 in the direction normal to the quay (the direction of arrows X-X in Figure 2) so as to protrude above the water bottom surface.
In this embodiment, an example has been shown in which a steel sheet pile is used as the sheet pile wall 7, but the sheet pile wall 7 is not limited to a steel sheet pile, and a steel pipe sheet pile may also be used.
The steel sheet piles include U-type steel sheet piles, hat-type steel sheet piles, Z-type steel sheet piles, H-type steel sheet piles, straight steel sheet piles, and the like.
Furthermore, the sheet pile wall 7 may be made of steel pipe sheet piles or steel sheet piles, either alone or in combination, or may include straight steel sheet piles with H-shaped steel beams or CT steel beams attached, and in short, it is sufficient that the wall is continuous in the direction normal to the quay.

<Additional materials>
The raising material 9 is for raising the water bottom surface from just below the pier to the retaining portion on the land side of the sheet pile wall 7, and is, for example, rubble. However, the raising material 9 is not limited to rubble and may be, for example, artificial stone, concrete blocks, etc.
The land side of the raising material 9 is constructed so as to cover part of the front surface (the surface facing the water area) of the L-shaped block 25, and the water area side of the raising material 9 is constructed up to the upper end of the sheet pile wall 7.

By installing such a bulkhead 9, the following effects are achieved.
- By installing the raising material 9, the rubble layer taken into account in the design (foundation rubble 27 + raising material 9) becomes thicker, shortening the protruding length of the support pile 3, thereby reducing the stress generated in the support pile 3 during an earthquake and improving earthquake resistance.
- By installing the raising material 9, the rubble layer (foundation rubble 27 + raising material 9) becomes thicker, reducing the flow force caused by deformation of the retaining wall during an earthquake and improving earthquake resistance.
The passive resistance of the L-shaped block 25 is increased, improving the safety factor against slipping and falling.
- The supporting capacity of the rubble 27 at the bottom of the L-shaped block 25 is increased.

<Pile>
The piles 11 are, for example, steel pipe piles, and are driven into the water bottom surface on the water area side of the newly constructed sheet pile wall 7. A plurality of piles 11 are driven into the ground, and the arrangement of the piles may be in a lattice pattern as shown in Fig. 2 or in a staggered pattern, and is not particularly limited.
In addition, in the example shown in Figs. 1 and 2, the piles are straight piles, but all or some of the piles 11 may be inclined piles.

<Pile head connection structure>
The pile head connection structure 13 connects and integrates the pile heads of the piles 11 and is arranged so as to contact the water side of the sheet pile wall 7 and transmits only horizontal force from the sheet pile wall 7 to the piles 11, and is positioned so that its upper surface is at the same level as or lower than the water bottom surface where ships come alongside.
The pile head connection structure 13 is intended to prevent the newly constructed sheet pile wall 7 from collapsing into the water area.
The pile head connection structure 13 will be described in more detail below.

The pile head connection structure 13 is provided to connect and integrate the heads of multiple piles 11 and to be in contact with the water side of the sheet pile wall 7. In this embodiment, as shown in Figure 2, an example is shown in which the pile head connection structure 13 is composed of a framework structure 15 and a horizontal member 17.

<<Framework structure>>
As shown in Fig. 2, the framework structure 15 has openings at intersections 15b of lattice-shaped beams 15a, into which piles 11 are inserted. The pile heads and the openings are integrated, and the integration method may be the same as that used in the conventional jacket-type wharf 23 and strut-type wharf, specifically, by injecting grout material.

The framework structure 15 may be formed of steel members such as shaped steel, or may be a precast concrete structure or a composite steel-concrete structure.
In addition, the pile head connection structure 13 may be composed of each girder 15a and the intersection 15b, but it may also be a deck-like structure in which each girder 15a and the entire intersection 15b are covered with concrete or the like.

Horizontal Members
The horizontal member 17 is a member interposed between the sheet pile wall 7 and the frame structure 15, and serves to transmit the horizontal force received from the sheet pile wall 7 to the frame structure 15. The horizontal member 17 can be made of a steel material such as an H-shaped steel, for example, arranged between the frame structure 15 and the sheet pile wall 7 so as to abut against each other in a state in which the load can be transmitted between them.

The horizontal member 17 may be attached to the framework structure 15 in advance to form a unit.
Furthermore, like the frame structure 15, the horizontal member 17 may be formed of steel members such as shaped steel, or may be a precast concrete structure or a composite steel-concrete structure.

The horizontal member 17 only needs to be able to transmit the horizontal force from the sheet pile wall 7 to the framework structure 15, and therefore the horizontal member 17 does not need to be integrated with the sheet pile wall 7 and the framework structure 15, making underwater stud welding, etc. unnecessary.

The horizontal members 17 can also be constructed from steel materials such as H-shaped steel and underwater concrete or underwater mortar. Specifically, steel materials such as H-shaped steel are arranged continuously in the width direction of the sheet pile wall 7 so as to abut against the framework structure 15, and underwater concrete or underwater mortar is placed in the gap between the steel materials and the sheet pile wall 7.

In addition, the pile head connection structure 13 in this embodiment has a planar shape as shown in Figure 1, but the pile head connection structure 13 of the present invention is not limited to this and may also have a three-dimensional structure.
In addition, the pile head connection structure 13 in this embodiment is based on a framework structure 15, but it may not be based on such a framework structure 15 and may be constructed of reinforced concrete structure 18 as shown in Figure 3.
In the structure shown in FIG. 3, the reinforced concrete structure 18 can also serve as the horizontal member 17.

<Arrangement of pile head connection structure>
As shown in FIG. 1, the pile head connection structure 13 is arranged so that its upper surface is at the same level as or lower than the water bottom level before improvement, which is set so that ships can come alongside.

Next, a construction method for improving the above-mentioned pier-type wharf structure, i.e., a method for improving an existing pier-type wharf, will be described.
The pile head connection structure 13 is fabricated in advance in a factory or the like and then transported to a construction site where an existing pier-type wharf to be improved is located.

At the construction site, a sheet pile wall 7 is installed below the water surface a specified distance into the water from directly below the water-side end of the superstructure 5 of the existing pier-type wharf, in the direction normal to the wharf so that it protrudes above the water bottom (sheet pile wall installation process).

Next, a plurality of piles 11 are driven into the bottom of the water on the water area side of the sheet pile wall 7 at predetermined positions to a predetermined height (pile driving process).
Next, the pile head connection structure 13 is installed so that the pile heads are connected and in contact with the water side of the sheet pile wall 7 (pile head connection structure installation process).
At this time, the pile head connection structure 13 needs to be installed so that its upper surface is at the same level as or lower than the water bottom surface where the ship will be docked, so the pile head connection structure 13 is first installed after excavating the water bottom surface an amount equivalent to the height of the pile head connection structure 13.
In addition, when the pile head connection structure 13 is the framework structure 15 shown in Figures 1 and 2 and has been prefabricated in a factory, the intersection portion 15b of the framework structure 15 of the pile head connection structure 13 can be installed so as to cover the pile head of the pile 11, and the pile head connection structure 13 can be connected to the pile 11.
In addition, the pile head connection structure 13 may be installed first, and then the piles may be driven.

Next, on the water side of the L-shaped block 25 installed on the land side, pile stones or other raising materials 9 are installed to raise the water bottom surface in the area up to the newly constructed sheet pile wall 7 (raising material installation process).

In addition, when it is necessary to increase the water depth of the quay wall due to the increase in size of ships, a water bottom excavation process can be carried out after the sheet pile wall 7 is installed, in which the water bottom on the water area side is excavated to deepen the water depth, as shown in Figure 4.
By doing this, the pile head connection structure 13 is installed so that the water bottom surface where ships come alongside is deeper than the state before improvement.

According to the improvement structure 1 for an existing quay wall of this embodiment, the following effects can be achieved.
In cases where there are concerns about insufficient earthquake resistance but construction cannot be carried out on the ground behind, i.e., in cases where construction such as ground improvement of the retaining wall (ground behind) is desired due to a review of the design target earthquake, but construction cannot be carried out due to issues with the use of the area behind, this embodiment is applicable because construction can be carried out only on the water side, with no construction on land.

By constructing the padding material 9, the rubble layer (foundation rubble 27 + padding material 9) becomes thicker and the protruding length of the support pile 3 becomes shorter, reducing the stress generated in the support pile 3 during an earthquake and improving earthquake resistance. In addition, by constructing the padding material 9, the rubble layer becomes thicker, reducing the flow force caused by deformation of the retaining wall during an earthquake, improving earthquake resistance in this sense as well. Furthermore, the passive resistance of the L-shaped block 25 increases, improving the safety factor against movement and tipping, and increasing the bearing capacity of the foundation rubble 27 at the bottom of the L-shaped block 25.

In addition, it is sufficient to be able to transmit horizontal forces between the sheet pile wall 7 and the pile head connection structure 13; the sheet pile wall 7 and the pile head connection structure 13 do not need to be integrated, making underwater stud welding and the like unnecessary. In the case of stud welding, if the steel sheet pile or steel pipe sheet pile does not have a composition suitable for welding, there is a concern that it may become embrittled due to welding, but this embodiment does not have such concerns.

Furthermore, since the sheet pile wall 7 is cast, even if deepening is required due to the larger size of the ship, the bottom surface excavation process of excavating the bottom surface on the water area side to deepen the water depth can be carried out without any problems.
In addition, there is no need to carry out ground improvement work to prevent the sheet pile wall 7 from collapsing, and there are no environmental restrictions.

In this embodiment, the sheet pile wall 7 is cast below the water surface at a predetermined distance toward the water area from directly below the water area-side end of the superstructure 5, so that the position of the sheet pile wall 7 protrudes toward the water area. In this case, in order not to impede the docking of ships, an amplifying superstructure 5a may be installed to widen the existing superstructure 5 toward the water area, as shown in Figure 1. However, the amplifying superstructure 5a does not need to be the entire length of the quay, and it may be possible to deal with this by changing the docking fender without installing the amplifying superstructure 5a.
This does not prevent the removal of part or all of the superstructure 5 in order to renew the existing superstructure 5 due to deterioration, before introducing riprap or other raising materials, and the construction of a new superstructure that does not interfere with the docking of ships.

When using a horizontal member 17 to transmit horizontal forces, the horizontal member 17 may be attached in advance to, for example, the framework structure 15 constituting the pile head connection structure 13, or after the framework structure 15 is placed on the bottom of the water, the horizontal member 17 may be disposed on the bottom of the water so that horizontal forces can be transmitted to the framework structure 15.

In addition, as described above, when a steel sheet pile is used as the sheet pile wall 7, contact with the pile head connection structure 13 (horizontal member 17) is surface contact, so there is no need to place underwater concrete or underwater mortar between the sheet pile wall 7 and the pile head connection structure 13.

[Embodiment 2]
In the first embodiment, riprap or other bulkhead material 9 is installed on top of the existing riprap 27 in order to improve earthquake resistance, etc., but the present embodiment relates to an improvement structure 1 for an existing quay wall, the purpose of which is not to improve earthquake resistance, but to increase the depth of the quay wall in order to accommodate larger ships.
As shown in Figures 5 and 6, the improved structure 19 of an existing wharf in this embodiment comprises a sheet pile wall 7 newly installed below the water surface a predetermined distance toward the water surface from directly below the water surface side end of the superstructure 5, and a pile head connecting structure 13 which connects and integrates the pile heads of the piles 11 driven into the water surface on the water surface side of the sheet pile wall 7 and is arranged so as to contact the water surface side of the sheet pile wall 7 so as to transmit only horizontal force from the sheet pile wall 7 to the piles 11 and has its top surface lower than the water surface before improvement where ships come docked.

5 and 6, the same parts as those in FIGS. 1 and 2 are denoted by the same reference numerals.
The differences between this embodiment and embodiment 1 are that when the sheet pile wall 7 is installed, its upper end does not protrude above the water bottom surface (although it is not essential that it does not protrude), that no padding material 9 is installed, and that the water bottom surface is deepened.

According to this embodiment, when it becomes necessary to deepen the water bottom due to the increase in size of the ship, etc., the sheet pile wall 7 can be installed to easily deepen the water bottom while maintaining the shape of the existing foundation rubble 27.

In the above first and second embodiments, a pier consisting of vertically driven support piles 3 and superstructure 5 is described as the subject, but the present invention can be applied to any type of quay where the superstructure 5 is supported by support piles 3 driven into the waterbed 2, and can also be applied to, for example, piers with inclined piles, piers that also serve as retaining walls, jacket-type piers 23, and grid-point strut-type piers.

1. Improved structure of existing wharf (Embodiment 1)
Reference Signs List 2: Water bottom ground 3: Support pile 5: Superstructure 5a: Amplification superstructure 7: Sheet pile wall 9: Raising material 11: Pile 13: Pile head connection structure 15: Frame structure 15a: Beam 15b: Intersection 17: Horizontal member 18: Reinforced concrete structure 19: Improved structure of existing quay (Embodiment 2)
21 Pier type wharf 23 Jacket type wharf 25 L-shaped block 27 Rubble stone 29 Pile-type sheet pile wall 30 Pile 31 Jacket section

Claims (6)

This is an improvement structure of an existing wharf in which the upper structure is supported by support piles driven into the waterbed.
A sheet pile wall is newly installed under the water surface at a predetermined distance toward the water surface from directly below the water surface end of the superstructure in the direction normal to the quay so as to protrude above the water bottom surface;
A raising material made of rubble, artificial stone, or concrete block that raises the water bottom surface installed on the land side of the sheet pile wall;
A pile is driven into the bottom surface of the water area side of the sheet pile wall;
and a pile head connection structure which connects and integrates the pile heads of the piles and is installed so as to contact the water side of the sheet pile wall, transmits only horizontal forces from the sheet pile wall to the piles, and has its top surface at the same level as or lower than the water bottom surface where ships come alongside. An improvement structure for an existing quay as described in claim 1, characterized in that the pile head connection structure is installed so that its upper surface is lower than the water bottom level before improvement, which was set for ships to dock. This is an improvement structure of an existing wharf in which the upper structure is supported by support piles driven into the waterbed.
A sheet pile wall newly installed below the water surface at a predetermined distance toward the water area from directly below the water area end of the superstructure;
a pile head connection structure that connects and integrates the pile heads of the piles driven into the bottom surface on the water area side of the sheet pile wall, is provided so as to be in contact with the water area side of the sheet pile wall, transmits only horizontal forces from the sheet pile wall to the piles, and is installed so that its upper surface is lower than the water bottom surface before improvement where ships come alongside;
An improved structure for an existing wharf, characterized in that no raising materials are installed on the land side of the sheet pile wall to raise the water bottom surface . A method for improving an existing quay wall in which a superstructure is supported by support piles driven into the waterbed, comprising the steps of:
a sheet pile wall installation process for installing a sheet pile wall under the water surface at a predetermined distance toward the water surface from directly below the water surface end of the superstructure in a direction normal to the quay so as to protrude from the water surface;
a step of constructing a raising material made of rubble, artificial stone, or concrete blocks to raise the water bottom surface on the land side of the sheet pile wall;
A pile driving process of driving piles into a bottom surface of the water area side of the sheet pile wall;
and a pile head connection structure installation step for connecting and integrating the pile heads of the piles and installing the pile head connection structure so that it is in contact with the water side of the sheet pile wall and transmits only horizontal forces from the sheet pile wall to the piles, and so that its upper surface is at the same level as or lower than the water bottom surface where ships come alongside. The method for improving an existing quay wall described in claim 4, characterized in that the pile head connection structure installation process involves excavating the bottom surface of the water where the ship will come ashore, and installing the pile head connection structure so that the top surface of the pile head connection structure is lower than the pre-improvement bottom surface set for the ship to come ashore. A method for improving an existing quay wall in which a superstructure is supported by support piles driven into the waterbed, comprising the steps of:
A sheet pile wall installation process of installing a sheet pile wall below the water surface at a predetermined distance toward the water area from directly below the water area side end of the superstructure;
and a pile head connection structure installation process for connecting and integrating the pile heads of the piles driven into the bottom surface on the water area side of the sheet pile wall, and installing a pile head connection structure so that the pile head connection structure is in contact with the water area side of the sheet pile wall and transmits only horizontal forces from the sheet pile wall to the piles, and the top surface of the pile head connection structure is lower than the water bottom surface before improvement where ships come alongside.
A method for improving an existing wharf, characterized in that no raising materials are installed on the land side of the sheet pile wall to raise the water bottom surface .

Images