JP7157682B2 - Wave-breaking steel material and caisson repair method - Google Patents

Description

TECHNICAL FIELD The present invention relates to a wave-breaking steel material used for repairing a damaged caisson, and a caisson repairing method using the wave-breaking steel material.

In breakwaters constructed using caissons, the side wall of the caisson facing the open sea is pierced and damaged by the movement and shaking of the wave-dissipating blocks due to the large waves of stormy weather such as typhoon attacks, and the sand inside the caisson is damaged. may flow out and disappear, causing the caisson to lose its function as an embankment.

As methods for repairing such damaged caissons, the bagged concrete construction method and the steel outer formwork construction method are known (see Non-Patent Document 1).
The bagged concrete construction method is a construction method in which a concrete bag is inserted into the caisson compartment and the inside is filled with concrete to close the damaged part and fill concrete inside the compartment.
The steel outer formwork method is a construction method in which a steel formwork is fixed to the damaged sea-side wall with anchor bolts or the like, and filling concrete is poured into the compartment.

Further, Patent Document 1 proposes a caisson repair method.
The method of repairing the caisson is to fix a breakwater plate on the outside of the side wall with an anchor or the like in advance so as to cover the damaged portion of the caisson, and then drill a through hole from the upper surface of the caisson into the compartment. Then, a plurality of civil engineering sheets are brought into the compartment through the through hole, stretched on the wall surface, and the ends are connected to block the damaged portion, and then filling concrete is placed.

"Repair Manual for Breakwater Caisson Damage (January 2007) 11.4MB" <http://www.pa.thr.mlit.go.jp/sendaigicho/technology/technology01.html>

JP 2006-219851 A

However, as in Non-Patent Document 1, the conventional bagged concrete construction method has problems such as the inability to maintain the shape of the concrete bag, the possibility that anchors will come off, and the possibility that the anchors will come off when the flow velocity inside the compartment is high. There were issues such as the safety of divers because it was an underwater operation.

Next, as in Non-Patent Document 1, the conventional steel outer formwork construction method requires sufficient strength against the side pressure and wave pressure of the filling concrete, and a water stoppage that prevents the filling concrete from leaking. Anchor bolts fixed to the side walls of the caisson are also required to have sufficient anchoring performance.
In addition, since the steel formwork is firmly fixed on the side wall facing the open sea, it takes time to work underwater, and there was also a problem in ensuring the safety of divers.

Next, the caisson repair method of Patent Document 1 requires work to firmly fix the wave breaker, which is easily moved by waves underwater on the outer side of the side wall facing the ocean, with an anchor or the like. However, there are still issues to be addressed in terms of ensuring safety and the risk of the breakwater falling.

An object of the present invention is to block the damaged caissons on the inner and outer sides of the harbor, thereby making it possible to bear the lateral pressure and wave pressure of the filling concrete, and to reduce underwater work by divers as much as possible to ensure safety. In addition, it is possible to repair the caisson in a short period of time.

In order to solve the above problems, the invention according to claim 1,
A wave-breaking steel material used for repairing a damaged portion of a caisson,
a main body made of H-shaped steel and configured in a substantially U-shape when viewed from the side, and hung on the side wall having the damaged portion of the caisson;
two steel plates joined to face each other on the inner side of the substantially U-shaped portion of the main body in a side view, and closing the damaged portions on the port inner side and the port outer side along the side wall, respectively;
characterized by comprising

The invention according to claim 2,
The wave-breaking steel material according to claim 1,
The main body is formed in the substantially U-shape in side view by connecting the upper ends of a pair of ladder-shaped members formed of the H-section steel when viewed from the front, with the H-section steel.

The invention according to claim 3,
A method of repairing a caisson using the wave breaking steel material according to claim 1 or 2 for repairing a damaged portion of the caisson,
By lifting the wave breaking steel material with a crane and then hanging it at the position of the side wall having the damaged part of the caisson,
while hanging the body on the side wall having the damaged portion;
It is characterized in that the damaged portion along the side wall is closed by the two steel plates facing each other on the inner side of the port and the outer side of the port.

The invention according to claim 4,
A method for repairing a caisson according to claim 3, comprising:
It is characterized in that the two steel plates closing the damaged portion on the inner side of the port and the outer side of the port are fixed with through bolts.

The invention according to claim 5,
A caisson repair method according to claim 3 or 4,
In the step after the crane has installed the wave-breaking steel material on the side wall having the damaged portion of the caisson,
After placing a special large bag in the caisson with the damaged part,
It is characterized in that filling concrete is placed in the special large bag.

According to the present invention, the wave-breaking steel material of the main body, which is configured in a substantially U-shaped side view of H-shaped steel, is hung on the damaged caisson side wall, and faces the inner side of the substantially U-shaped part in the side view of the main body. Damaged parts of the caisson side walls can be sealed on the inner side and the outer side of the port by two steel plates joined to each other.
Therefore, the side pressure and wave pressure of the filling concrete can be borne by each steel plate, and furthermore, there is no risk of the steel plate falling, and underwater work by divers is reduced as much as possible, and the caisson can be repaired safely in a short period of time. can be done.

FIG. 1 is a vertical cross-sectional view showing the configuration of one embodiment of a wave-breaking steel material to which the present invention is applied, in a state where the wave-breaking steel material is hung on a damaged caisson side wall. It is the front view which looked at the wave-breaking steel material of FIG. 1 from the port inner side. FIG. 2 is a perspective view of the wave-breaking steel material of FIG. 1 as seen from the outside of the harbor. FIG. 4 is a schematic perspective view showing a state in which a wave-breaking steel material is applied to a damaged caisson side wall. FIG. 5 is a view showing the installation of a special large bag inside the damaged caisson of FIG. 4; It is the figure which showed the completion state of filling concrete pouring in the special large sized bag of FIG.

(Overview)
Two pieces of wave-breaking steel made of H-shaped steel, which is constructed in a substantially U-shaped side view, are hung on the damaged caisson side wall and joined to face each other inside the substantially U-shaped part in a side view of the main body. Steel plates seal the damaged caisson sidewalls on the inner and outer sides of the port, respectively.
As a result, the side pressure and wave pressure of the filling concrete can be borne by each steel plate, and there is no risk of the steel plate falling, minimizing underwater work by divers, and safely repairing the caisson in a short period of time. .

DETAILED DESCRIPTION OF THE INVENTION Embodiments for carrying out the present invention will be described in detail below with reference to the drawings.
(embodiment)
1 to 3 show a state in which a caisson 100 constituting part of a breakwater is hung on a damaged side wall 101 as an embodiment of a wave breaking steel material 1 to which the present invention is applied, 103 is another side wall, 105 is a partition wall, and 107 is a cover concrete.

As shown in the figure, the wave breaking steel material 1 is joined to a main body 2 formed of H-shaped steel and having a substantially U-shape when viewed from the side facing the inner side of the substantially U-shaped portion of the main body 2 when viewed from the side. It consists of two steel plates 6 and 7 with the same shape.
That is, the wave-breaking steel material 1 is configured such that the main body 2 configured in a substantially U-shaped side view is hung on the side wall 101 having the damaged part 102 of the caisson 100, and the inner side of the substantially U-shaped part in the side view of the main body 2 is hung. The two steel plates 6 and 7 respectively joined facing each other block the damaged part 102 due to the through hole whose outline is indicated by the thick dotted line and the area is indicated by the dotted oblique line on the inner side and the outer side of the port along the side wall 101. .

In the main body 2, the upper ends of the ladder-shaped members 3 and 4 in a front view, which have approximately the same shape on the inner side and the outer side of the port and are welded with H-section steel, are connected with bolts and nuts by upper end connection members 5 in which the H-section steel is connected with bolts and nuts. It is what I did.

The ladder-shaped member 3 on the inner side of the port is a pair of left and right vertical frames 31 made of H-shaped steel welded with five smaller horizontal frames 32 made of H-shaped steel. Upper and lower three reinforcing members 33 made of angle steel are welded to the outer surfaces of the vertical frames 31,31.
In the illustrated example, the upper two horizontal frames 32, 32 and the lower three horizontal frames 32 are spaced relatively far apart, and one frame is provided between the upper two horizontal frames 32, 32. , and two upper and lower reinforcing members 33 are arranged between the upper two horizontal frames 32 and the lower three horizontal frames 32 .

The ladder-shaped member 4 on the outside of the harbor is a pair of left and right vertical frames 41 made of H-shaped steel welded with six upper and lower horizontal frames 42 made of smaller H-shaped steel. Upper and lower three reinforcing members 43 made of angle steel are welded to the outer surfaces of the vertical frames 41.41.
In the illustrated example, the upper two horizontal frames 42, 42 and the lower four horizontal frames 42 are spaced relatively far apart, and one frame is provided between the upper two horizontal frames 42, 42. are arranged, and two upper and lower reinforcing members 43 are arranged between the two horizontal frames 42 on the upper side and the four horizontal frames 42 on the lower side.
Note that the ladder-shaped member 4 in front view on the port outside has the same length as the vertical frame 31 of the ladder-shaped member 3 in front view on the port inside, and is lower than the interval between the upper two horizontal frames 42 . The intervals between the four horizontal frames 42 on the side are small.

The upper end connecting member 5 is configured by connecting an upper connecting frame 53 to the center of the upper surface of a pair of left and right connecting frames 51 made of H-shaped steel with bolts and nuts.
First, a pair of left and right connecting frames 51, 51 made of H-shaped steel are composed of an end plate 35 welded to the upper end portion of the vertical frame 31 of the ladder-shaped member 3 in front view on the harbor side, and the ladder-shaped member 4 in front view on the harbor side. They are bolted and nut-connected to end plates 45 welded to the upper end of the vertical frame 41 .

Here, as shown in FIG. 1, the connecting frame 51 made of H-shaped steel is long on the port side, and has spare bolt holes on the lower surface of the flange. This spare bolt hole makes it possible to change the attachment position of the front view ladder-like member 3 on the harbor side according to the thickness of the damaged side wall 101 .

In addition, the upper end side surfaces of the left and right vertical frames 41 of the ladder-shaped member 4 on the port outside and the end plates 55 welded to the ends of the left and right connecting frames 51, 51 thereabove are joined by joint plates 46. They are connected with bolts and nuts.
Further, a pair of right and left hangers 57 are connected to the ends of the upper connecting frame 53 by bolts and nuts.

Steel plates 6 are provided on the inner surfaces of the left and right vertical frames 31, 31 and the lower two horizontal frames 32, 32 of the ladder-shaped member 3 in a front view on the harbor side, on the side of the ladder-shaped member 4 in a front view on the port side. Welded.
A lower end of the steel plate 6 protrudes downward from the vertical frames 31,31.

Further, on the ladder-shaped member 4 in front view on the port outside, steel plates 7 are provided on the inner surfaces of the left and right vertical frames 41 and four horizontal frames 42 . is welded.
A lower end of the steel plate 7 protrudes downward from the vertical frames 41,41.

Furthermore, as shown in FIG. 3, the ladder-shaped member 4 on the front view outside the port has two upper horizontal frames 32 and 32 and the first Lateral anchor plates 47 projecting laterally corresponding to the positions of the reinforcing members 43 below are respectively welded.
Vertical anchor plates 48 projecting laterally are welded to four locations on the left, right, top and bottom of the steel plate 7, respectively.

As shown in FIGS. 1 and 2, anchor plates 59, 59 projecting sideways are welded to the upper outer center of the connecting frames 51, 51 of the upper end coupling member 5, respectively.

"Construction procedure"
The procedure for repairing the caisson 100 using the wave-breaking steel material 1 having the above configuration is as follows.

Procedure 1. Removal of wave-dissipating blocks (not shown) Wave-dissipating blocks around the caisson 100 including the damaged portion 102 are lifted by a crane and removed sequentially.

Procedure 2. Removal of the cover concrete 107 above the damaged portion 102 of the caisson 100 The cover concrete 107 above the damaged portion 102 of the caisson 100 is drilled using a core drill to cut and cut the edge, and the cut concrete mass is lifted by a crane. to remove.

Step 3. Installation of wave-breaking steel material 1 (see Fig. 4)

Step 4. Installation of a special large-sized bag 121 (see FIG. 5), followed by placing filling concrete 122 (see FIG. 6)

Step 5. Removal of steel materials above the caisson 100 When removing steel materials above the caisson 100, the connecting frame 51 and the upper connecting frame 53 of the upper end connecting member 5, which hinder the construction of the upper concrete, are removed by releasing the bolt and nut connections.
The ladder-like member 4 in the front view below it is also used to reinforce the missing portion of the side wall of the damaged portion 102 .

Step 6. Restoration (reinstallation) of cover concrete 107 above repaired portion of caisson 100
Concrete is newly placed above the repaired portion of the caisson 100 to construct the superstructure.

Step 7. Restoration of wave-dissipating blocks (reinstallation)
The temporarily placed wave-dissipating blocks are sequentially re-installed around the caisson 100 including the repaired portion by crane.

FIG. 4 shows a state in which the wave-breaking steel material 1 is hung on the side wall of the damaged caisson 100. After the wave-breaking steel material 1 is lifted by hanging the lifting wire 111 of the crane (not shown) to the lifting hardware 57, 57, as shown in the figure, Suspended at side wall 101 with damaged portion 102 of caisson 100 .
As a result, as shown in FIGS. 1 to 3, the main body 2 having a substantially U-shaped side surface is hung on the top end of the side wall 101, and at the same time, the damaged portion (through hole) 102 is formed along the side wall 101 on the port side. and are blocked by two steel plates 6 and 7 facing each other on the outside of the port.

Then, the front view ladder-like member 4 on the harbor outside is fixed to the side wall 101 by underwater chemical anchors at the anchor plates 47 and 48, respectively.
Also, the upper end coupling member 5 is fixed to the top end of the side wall 101 by chemical anchors at the anchor plates 59, 59, respectively.
In addition, each of the anchor plates 47 and 48 has four holes, one of which is used to install an all-anchor for temporary fixing, and one of the remaining three holes is used to hold an underwater anchor with a diameter of φ22 mm. Install a chemical anchor.

Then, as shown in FIGS. 1 to 3, the two steel plates 6 and 7 that close the damaged portion (through hole) 102 on the inner side and the outer side of the port are attached to the through bolt 8 and Fix with nut 9.

FIG. 5 shows the installation state of the special large bag 121 in the damaged caisson 100 of FIG. .
Filling concrete 122 is placed in this special large bag 121 .

FIG. 6 shows a state in which filling concrete 122 has been poured into the special large bag 121 of FIG. Next, pour new concrete and construct the superstructure.

"Principle/Features"
Next, the principles and features of the present invention are as follows.

1) Since the damaged portion (through hole) 102 is closed with the two steel plates 6 and 7 on the inner side and the outer side of the port, the side pressure and wave pressure of the filling concrete 122 can be borne by the respective steel plates 6 and 7. .

2) By hanging the wave-breaking steel material 1 on the caisson side wall 101 in a substantially U-shape when viewed from the side, there is no danger of it falling off, and it can be easily installed with a simple fixation.
In the actual work, the outer peripheral portion of the harborside steel material (ladder-shaped member 4 when viewed from the front) is fixed using an underwater chemical anchor with a diameter of φ22 mm.

3) The inner and outer two steel plates 6 and 7 are fixed at the damaged portion 102 with a through bolt 8 and a nut 9 having a diameter of φ22 mm so that the tip of the substantially U-shaped end when viewed from the side does not open.

4) The connecting frame 51 and the upper connecting frame 53 of the upper end connecting member 5 are removed because they interfere with the construction of the upper concrete.
The port-side steel material (ladder-shaped member 4 when viewed from the front) also serves as reinforcement for the missing portion of the side wall of the damaged portion 102 and remains as a reinforcement against wave pressure.
The compartment-side steel material (ladder-shaped member 3 when viewed from the front) remains.

5) By using the steel plates 6 and 7 as thick plates of 22 mm, the strength and weight of the steel plates 6 and 7 push aside obstacles such as reinforcing bars with a diameter of 16 mm in the damaged portion 102 and set them aside.

6) No waterproofing measures (such as waterproofing rubber) are applied to the wave-breaking steel material 1.
Therefore, underwater work such as cleaning the caisson side wall 101 outside the harbor is unnecessary.

7) Filling concrete 122 is poured into special large-sized bag 121 as a countermeasure against leakage of filling concrete 122 .

8) Underwater work after installing the wave-breaking steel material 1 consists of underwater chemical anchor fixing (see anchor plates 47 and 48) on the outer periphery of the harbor-side steel material (ladder-shaped member 4 when viewed from the front), and inside the compartment and outside the harbor. Only the three-point fixing by the through bolt 8 and the nut 9 is provided.

As described above, according to the repair of the caisson 100 using the wave-breaking steel material 1 of the embodiment, the wave-breaking steel material body 2 formed of H-shaped steel in a substantially U-shape when viewed from the side is hung on the damaged caisson side wall 101, and the Damaged portions (through holes) 102 of the caisson side wall 101 are blocked on the port inner side and the port outer side by two steel plates 6 and 7 respectively joined facing the inner side of the substantially U-shaped portion of the main body 2 when viewed from the side. be able to.
Therefore, the side pressure and wave pressure of the filling concrete 122 can be borne by the respective steel plates 6 and 7, and there is no danger that the steel plates 6 and 7 will fall. The caisson 100 can be repaired in between.

(Modification)
In addition to the above embodiments, the shape of the damaged portion, the shape of the wave-breaking steel material, the shape of the steel plate, the specific details of the structure, etc., can of course be changed as appropriate.

1 Wave breaking steel 2 Main body 3 Ladder-like member in front view inside the harbor 31 Vertical frame 32 Horizontal frame 33 Reinforcement member 35 End plate 4 Ladder-like member in front view outside the port 41 Vertical frame 42 Horizontal frame 43 Reinforcing member 45 End plate 46 Joint plate 47 anchor plate 48 anchor plate 5 upper end connecting member 51 connecting frame 53 connecting frame 55 end plate 57 hanging hardware 59 anchor plate 6 steel plate 7 steel plate 8 through bolt 9 nut 100 caisson 101 damaged side wall 102 damaged portion 103 other side wall 105 bulkhead 107 lid concrete 111 lifting wire 121 special large bag 122 filling concrete

Claims (5)

A wave-breaking steel material used for repairing a damaged portion of a caisson,
a main body made of H-shaped steel and configured in a substantially U-shape when viewed from the side, and hung on the side wall having the damaged portion of the caisson;
two steel plates joined to face each other on the inner side of the substantially U-shaped portion of the main body in a side view, and closing the damaged portions on the port inner side and the port outer side along the side wall, respectively;
A wave-breaking steel material characterized by comprising: The main body is formed in the substantially U-shape in side view by connecting the upper ends of a pair of ladder-shaped members formed of the H-section steel when viewed from the front with the H-section steel. Item 1. The wave-breaking steel material according to Item 1. A method of repairing a caisson using the wave breaking steel material according to claim 1 or 2 for repairing a damaged portion of the caisson,
By lifting the wave breaking steel material with a crane and then hanging it at the position of the side wall having the damaged part of the caisson,
while hanging the body on the side wall having the damaged portion;
A method of repairing a caisson, wherein the damaged portion along the side wall is closed by the two steel plates facing each other on the inner side of the port and the outer side of the port. 4. The method of repairing a caisson according to claim 3, wherein the two steel plates closing the damaged portion on the inner side of the port and the outer side of the port are fixed with through bolts. In the step after the crane has installed the wave-breaking steel material on the side wall having the damaged portion of the caisson,
After placing a special large bag in the caisson with the damaged part,
5. A method for repairing a caisson according to claim 3 or 4, wherein filling concrete is poured into said special large bag.

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