JPH1161775A - Repair and renovation of harbor and river civil structures - Google Patents

Abstract

(57) [Abstract] [Problem] To provide a method for repairing and renovating a port / river civil engineering structure capable of greatly reducing the construction cost and shortening the construction period. SOLUTION: A harbor / river civil engineering in which a sheet pile is cast on a water bottom close to a harbor / river civil engineering structure, and a mixture containing soil, solidified material and water is filled between the harbor / river civil engineering structure and the sheet pile. How to repair and renovate structures. A method for repairing / repairing a port / river civil engineering structure in which the soil is construction-generated soil. A method for repairing / repairing a port / river civil engineering structure in which the mixture contains fibers. A method for repairing or renovating a port / river civil engineering structure in which a tie rod is cast at the top of the sheet pile.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a breakwater, a mooring pier,
The present invention relates to a method for repairing or renovating a port / river civil engineering structure such as an embankment.

[0002]

2. Description of the Related Art Existing structures are to be repaired to repair port and river civil engineering structures such as breakwaters, mooring berths, embankments, etc. for aging, and to repair damaged areas caused by the earthquake or tsunami. It is common to do it. At this time, it is necessary to remove not only the existing structures but also the surrounding auxiliary facilities, and construction costs are increased and the construction period is often long.

Therefore, Japanese Patent No. 2524579 and Japanese Patent Application Laid-Open No. 8-277513 propose a method of repairing or reinforcing a port / river civil engineering structure without removing an existing structure.

[0004] The method described in Japanese Patent Application Laid-Open No. 8-277513 uses an existing landfill or foundation soil which has flowed due to an earthquake or the like and an existing overturned or inclined caisson, and a retaining wall, a steel pipe pile, and a box-type. This is a method of repairing the quay by installing a new steel guideway. However, this method has safety problems because it uses existing landfill and foundation sediment that has flowed due to an earthquake or the like and an existing caisson that has been overturned or tilted.In addition, retaining walls, steel pipe piles, steel It is difficult to say that it is a simple method because it requires high-precision positioning and welding of the steel pipe pile and the guide stand for installation of the guide stand made of steel.

On the other hand, in the method described in Japanese Patent No. 2524579, a sheet pile is erected on the bottom of the water near the existing retaining wall, and a backing material is filled between the retaining wall and the sheet pile to fill the existing retaining wall. This is a method of reinforcing a wall.
There is no safety problem as in the method of JP-A No. 3 and there is no need for high-precision positioning or welding.

[0006]

SUMMARY OF THE INVENTION However, Patent 2
The method described in Japanese Patent No. 524579 has the following problem. In other words, when the backing material such as gravel or crushed stone is filled between the retaining wall and the sheet pile, a relatively large horizontal earth pressure is applied to the sheet pile, so that the lower end of the sheet pile needs to be firmly fixed. Therefore, it is necessary to excavate a vertical hole in the underwater ground, inject a hardened material mixed with an admixture that increases the viscosity there, and then build a sheet pile, which is the original purpose of reducing construction costs and shortening the construction period. Cannot be achieved sufficiently. In addition, high quality gravel and crushed stone used as backing material are becoming increasingly difficult and expensive these days, which is a major obstacle to reducing construction costs.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and an object of the present invention is to provide a method for repairing / repairing a port / river civil engineering structure capable of greatly reducing the construction cost and shortening the construction period. Aim.

[0008]

Means for Solving the Problems The object of the present invention is to form a sheet pile on the bottom of water near a port / river civil engineering structure,
The problem is solved by a method of repairing / repairing a port / river civil engineering structure in which a mixture containing soil, solidified material and water is filled between the river civil engineering structure and the sheet pile.

[0009] As a backing material to be filled between the harbor / river civil engineering structure and the sheet pile, if a mixture containing soil, solidified material and water is filled instead of the existing backing material such as gravel or crushed stone, the mixture becomes Since the solidified material is solidified and self-supporting, a horizontal earth pressure acts on the sheet pile only when the mixture is filled, and the horizontal earth pressure is smaller than that of the conventional backing material. Therefore, it is not necessary to excavate the bottom of the water or to inject a special hardening material into the excavation hole for embedding the sheet pile. Therefore, it is possible to greatly reduce the construction cost and the construction period. The deteriorated or damaged port / river civil engineering structure is supported and reinforced by the solidified mixture, and will be repaired / renovated.

[0010] The construction cost can be further reduced by using construction-generated soil such as dredged soil that is originally disposed of as soil. In particular, if dredged soil from a port / river adjacent to the port / river civil structure targeted for construction is used, the cost of transporting the soil can be reduced.

When fibers are added to a mixture containing soil, a solidifying material, and water, the bending resistance and the shear resistance of the solidified mixture can be improved, and the resistance to earthquakes and the like can be further increased.

When a tie rod is cast on the top end of the sheet pile, the applied stress on the sheet pile can be reduced, and the sheet pile can cope with a large water depth.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows one embodiment of a method for repairing / repairing a port / river civil engineering structure according to the present invention. In the figure, (a) shows the repair method of the tilted existing port civil engineering structure, and (b) shows the state after the repair.

To repair the tilted existing port civil engineering structure 1 at the boundary between land and sea, first, the existing port civil engineering structure 1 is repaired.
The steel pipe sheet pile 2 is cast on the seabed 3 close to. Next, a dredger 6 loaded with a mixing device 5 for producing a mixture containing soil, solidified material, and water is moored near the steel pipe sheet pile 2, and the dredged soil collected from the seabed 3 on the sea side of the steel pipe sheet pile 2 is fed to the muddy water. The mixture is sent to a mixing device 5 through a pipe 7, where the dredged soil, the solidified material, the water and the fiber are mixed to produce a mixture 4. Then, the mixture 4 is filled between the existing port civil engineering structure 1 and the steel pipe sheet pile 2 via the mud pipe 8. When the solidified material contained in the filled mixture 4 solidifies, the tilted existing port civil engineering structure 1 is supported and reinforced by the solidified mixture 4, and the repair of the existing port civil engineering structure 1 is completed.

In the case of deep water, etc., the steel pipe sheet pile 2
It is preferable to drive a tie rod to the top end of the steel pipe because the stress applied to the steel sheet pile 2 can be reduced.

As the solidifying material, cement or cement-based solidifying material can be used according to the properties of the soil.

As the fiber, any of an artificial fiber and a natural fiber can be used, but polypropylene or polyester which is hardly deteriorated even in an alkaline environment when a cement-based solidifying material is used is preferable.

As sheet piles, steel sheet piles can be used in addition to steel pipe sheet piles.

[0019]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Taking the river embankment as an example, the method of the present invention and the patent 25245
In the case of repairing by the method described in JP 79,
The specifications of the sheet pile and the maximum generated stress of the sheet pile and the sheet pile length at that time were compared and studied by calculation.

FIG. 2 shows the specifications of the river embankment and the conditions of the mixture (backing material) used in the calculation. The specifications of the river embankment are
Based on the low water level of the river, the height of the dike head is + 2m,
The riverbed was -3 m, and the residual water level inside the embankment was +1 m.

The mixture in the present invention method and those obtained by mixing Portland cement 80kg and water 160kg into cohesive soil 1 m ^3, as the soil constants, wet unit weight γ of 1.45 T / m ^3, water unit weight γ ′ was 0.45 t / m ³ , and adhesive strength c was 25 tf / m ² .

The backing material in the method of Japanese Patent No. 2524579 is a sandy soil, and as a soil constant thereof, the wet unit weight γ is 1.8 t / m ³ and the underwater unit volume γ ′.
Was set to 1.0 t / m ³ and the internal friction angle φ was set to 30 °.

As the soil constant below the riverbed, the underwater unit weight γ ′ was 1.0 t / m ³ , and the internal friction angle φ was 30 °.

In the case of the method of the present invention, the mixture is set to a height of 2.5 so that a large horizontal external force is not suddenly applied to the sheet pile.
It was assumed that the filling was performed in two stages by m.

Table 1 shows the calculation results. In the case of the method of the present invention, the maximum generated stress of the sheet pile can be significantly reduced as compared with the case of the method disclosed in Japanese Patent No. 2524579. Therefore,
The standard of the sheet pile can be reduced by one rank and the length of the sheet pile can be shortened by 2 m, so that the cost of the sheet pile can be reduced.

[0026]

[Table 1]

[0027]

Since the present invention is configured as described above, it is possible to provide a method for repairing / repairing a port / river civil engineering structure capable of greatly reducing the construction cost and shortening the construction period.

In the present invention, since construction waste soil such as dredged soil that has been disposed of so far can be used, it is very useful for environmental protection.

[Brief description of the drawings]

FIG. 1 is a view showing one embodiment of a repair / repair method for a port / river civil engineering structure according to the present invention.

FIG. 2 is a diagram showing specifications of a river embankment and conditions of a mixture (backing material) used for calculation.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Existing port civil engineering structure 2 Steel sheet pile 3 Sea bottom 4 Mixture of dredged soil, solidified material, water and fiber 5 Mixing device 6 Dredger 7 Mud pipe 8 Mud pipe

Claims (4)

[Claims] 1. A harbor / river in which a sheet pile is driven into the water bottom adjacent to a harbor / river civil engineering structure, and a mixture containing soil, solidified material and water is filled between the harbor / river civil engineering structure and the sheet pile. Repair and renovation of civil engineering structures. 2. The method according to claim 1, wherein said soil is soil generated from construction. 3. The method for repairing or repairing a port / river civil engineering structure according to claim 1, wherein the mixture contains fibers. 4. The method for repairing or renovating a port / river civil engineering structure according to claim 1, wherein a tie rod is cast on a top end of the sheet pile.