JP6097595B2 - Pier structure and reconstruction method - Google Patents

Description

The present invention relates to a structure of a jetty and a reconstruction method.
In particular, the object of the present invention is a case where a sheet pile wall in which a steel pipe or the like is placed along a quay has already been constructed, and a method for reconstructing a pier constructed by obtaining support force on the sheet pile wall, or a pier Is related to the structure of

Since more than 30 years have passed since the construction of existing piers at ports nationwide, concrete deterioration due to salt damage etc. is remarkable, and immediate replacement is desired especially in the recent high possibility of earthquake disaster.
However, the replacement of the existing jetty requires the use of existing piles that have already been placed on the sea floor, and there are many restrictions such as restrictions on the construction period and response to changes in the tide level.
Therefore, a new technology that meets these requirements is required.

JP 2000-248526 A

The conventional pier repair method as described above has the following problems.
<1> When constructing a new jetty, it is common to construct it with seawater cut off. However, in the case of the rebuilding method of the existing jetty, the seawater cannot be closed because it is a partial construction while maintaining the service of the jetty.
<2> Because of this, it is a highly constrained construction that is carried out in response to changes in the full tide level, so it is impossible to perform operations such as placement of rebar, formwork, concrete placement, etc. Have difficulty.
<3> The existing piles that have already been placed will be used as they are, and only the superstructure will be constructed. However, there is generally a large error in the placement position of the existing piles, and superstructures must be constructed based on this assumption. I must.
<4> Since the construction work will be rebuilt while the existing pier is in service, the construction period is limited and construction is required as quickly as possible.

  The method for reconstructing a jetty according to the present invention that solves the above-described problems is that a bracket is attached to the head of an existing sheet pile wall, a precast formwork is installed through this bracket, and concrete is cast into the formwork. A sheet pile head block is formed by integrating the head of the sheet pile wall, while an independent precast formwork is installed via a bracket on the head of the existing support pile located opposite the sheet pile wall. Then, concrete is cast in the formwork to form a pile head block at the head of the pile, a precast beam is installed between the sheet pile head block and the pile head block, and the sheet pile head block, pile head block, and precast It is characterized in that the PC steel wire placed between the beams is tensioned and integrated, and then a precast floor slab is installed on the sheet pile head block and the pile head block.

Since the structure and reconstruction method of the pier of the present invention are as described above, at least one of the following effects can be obtained.
<1> Existing piles are not always placed at accurate positions, and there may be large positional errors. On the premise of such a situation, even if there is an error in the position of the pile head, it is possible to reconstruct the pier using these sheet pile walls.
<2> Since the cast-in-place concrete and precast concrete are used in combination, a quick construction can be performed and the pier in service can be fully opened early.

Explanatory drawing of the pier reconstruction process of this invention. Explanatory drawing of the pier reconstruction process of this invention. Explanatory drawing of the pier reconstruction process of this invention. Explanatory drawing of the pier reconstruction process of this invention. Explanatory drawing of the pier reconstruction process of this invention. Explanatory drawing of the pier reconstruction process of this invention. Explanatory drawing of the completed state of the pier reconstruction of this invention. Explanatory drawing of the completed state of the pier reconstruction of this invention.

  Hereinafter, preferred embodiments of the pier reconstruction process of the present invention will be described in detail with reference to the drawings.

<1> Prerequisites The object of the present invention is a method of reconstructing a jetty constructed by obtaining a supporting force on the sheet pile wall 1 in which a sheet pile wall 1 in which a steel pipe or the like is placed along the quay wall, Or the structure of the pier in that case.
Therefore, the rebuilding method of the pier of the present invention uses the existing sheet pile wall 1 and the support pile 3 as they are, such as the pile of the sheet pile wall 1 and the support pile 3 driven in a position independent of the sheet pile wall 1. It is a construction method.
In this case, as described above, the position of the pile head is not necessarily accurate according to the design drawing, and it is assumed that there is a high possibility that an error has occurred.

<2> Attaching the bracket (Fig. 1)
The bracket 2 is attached to the head of the existing sheet pile wall 1.
This sheet pile wall 1 is a wall body constructed by placing steel pipe piles and concrete piles side by side.
The bracket 2 attached to the head of the sheet pile wall 1 is a steel member for supporting a formwork described later.
If the existing pile is a steel pipe pile, it is welded to the side.
When the existing pile is a concrete pile, the bracket 2 is attached by drilling holes on the side surface and inserting bolts.
The bracket 2 is attached to a height common to the plurality of sheet pile walls 1.
An independent support pile 3 is placed at a position facing the sheet pile wall 1.
The bracket 2 is also attached to the head of the support pile 3 as described above.
Similarly, the bracket 2 is attached to the retaining pile 4 located on the sea side of the sheet pile wall 1.

<3> Installation of bottom plate (Fig. 2)
A bottom plate 5 common to the sheet pile wall 1 is installed through the bracket 2.
The bottom plate 5 is also installed on the bracket 2 of the support pile 3 independent of the sheet pile wall 1.
Since this bottom plate 5 is a thin plate for supporting a precast formwork described later, its processing is easy.
Therefore, even if the position of the pile head in plan view is uneven, by processing the shape of the bottom plate 5, it is possible to install the bottom plate 5 maintaining a horizontal plane in a state common to a plurality of pile groups.

<4> Installation of precast formwork (Figure 3)
On the bottom plate 5 attached to the pile head of the sheet pile wall 1, the precast formwork 6 produced in the factory is installed.
The precast form 6 is a concrete plate produced in the factory, and does not need to be demolished after placing the concrete like a steel form, and is integrated as a surface of the concrete structure.
The precast mold 6 can be configured not only as a single plate body but also as a container-shaped mold having a rectangular shape in plan view.
Similarly, the precast formwork 6 is also installed on the bottom plate 5 attached to the pile head of the support pile 3.
Since the bottom plate 5 group is installed in a state where the horizontal plane is maintained as described above, the precast form 6 can be installed easily.
The formwork 6 surrounds the pile head and is installed on both sides of the pile head. However, even if the pile head positions are uneven, if the gap between the formwork 6 is kept wide, the position of the pile head will be an obstacle to the installation of the formwork 6. Never become.
Reinforcing bars are assembled in the space surrounded by the precast form 6.

<5> Formation of sheet pile head block (FIG. 4)
Filled concrete 7 is placed and placed in a precast form 6 installed in a state common to the pile heads of the sheet pile wall 1.
The interstitial concrete 7 is hardened to form a sheet pile head block 8 in which the heads of the sheet pile walls 1 are integrated.
In addition to the reinforcing bars, a sheath, a PC steel wire, and a steel bar are arranged in the sheet pile head block 8 before placing the concrete 7.
By tensioning the steel wire and the steel rod after the concrete 7 is hardened, the sheet pile head block 8 in which a large number of pile groups are integrated can be firmly integrated.

<6> Pile head block formation (Figure 4)
A support pile 3 is placed at a position facing the sheet pile wall 1.
Also on the head of the support pile 3, an independent precast formwork 6 is installed through the bracket 2 in the same process as described above, a reinforcing bar is assembled in this formwork, and the concrete concrete 7 is placed.
This padded concrete 7 is hardened and a pile head block 9 of the head of the support pile 3 is formed.

<7> Distance between Blocks As described above, the distance between the pile head of the existing sheet pile wall 1 and the pile head of the support pile 3 is not constant due to construction errors during placement.
However, it is possible to adjust the distance between the sheet pile head block 8 and the pile head block 9 after placing the concrete 7 by finely adjusting the position of the precast form 6 to be attached to the bracket 2 slightly before and after. it can.
Therefore, when the precast beam 10 is installed between the sheet pile head block 8 and the pile head block 9 as will be described later, the length of the precast beam 10 which is a factory product and the distance between the two blocks should be exactly matched. Can do.

<8> Installation of precast beams (Fig. 5)
The sheet pile head block 8 and the pile head block 9 are installed at opposing positions, and the distance between the opposing block surfaces is accurate as described above.
Therefore, a precast beam 10 produced in a factory is installed between the two.
Inside the precast beam 10, a sheath, a PC steel wire, and a steel bar are disposed in the longitudinal direction separately from the reinforcing bars.
After that, the PC steel wire P arranged through the sheet pile head block 8, the pile head block 9, and the precast beam 10 is tensioned and integrated.
The precast beam 10 is also attached to both sides of the pile head block 9 in a direction parallel to the sheet pile wall 1.
Also in that case, it can be firmly integrated by tensioning the PC steel wire P through which the pile head block 9 and the precast beam 10 are penetrated.

<9> Precast floor slab installation (Figs. 6, 7, 8)
A saddle mortar is placed on the sheet pile head block 8, the pile head block 9, and the precast beam 10, a rubber bearing is installed, and an anchor bar is installed.
On top of that, a precast floor slab 11 which is a factory product is mounted and installed.
In this way, even if the position of the existing pile head is not on the exact design line, those errors can be absorbed and the reconstruction of the pier can be completed in a short time.

1: Sheet pile wall 1
2: Bracket 3: Support pile 6: Precast formwork 8: Sheet pile head block 9: Pile head block 10: Precast beam 11: Precast floor slab

Claims (1)

Install a precast formwork on the head of the existing sheet pile wall,
Concrete is placed in the formwork to form a sheet pile head block that integrates the head of the sheet pile wall,
On the other hand, an independent precast formwork is also installed on the head of the existing support pile at the position facing the sheet pile wall,
Concrete is placed in the formwork to form a pile head block on the pile head,
Install a precast beam between the sheet pile head block and the pile head block,
Tension and unify the PC steel wire placed between the sheet pile head block, pile head block, and precast beam,
After that, it is characterized by installing a precast floor slab on the sheet pile head block and pile head block,
How to rebuild the pier.

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