JP2842955B2 - How to raise a breakwater or seawall - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention is intended to restore the function of breakwaters and seawalls that have sunk over time, or
It relates to a method of elevating breakwaters and seawalls when the sea level is expected to rise due to global warming.

[0002]

2. Description of the Related Art In general, the height of a breakwater is designed to be high enough to prevent intrusion of seawater due to storm surges and tsunamis, and the height of seawalls is set to HWL (High Water Level) or higher. I have. However, if the ground subsides or the water level rises due to global warming,
The top of the structure becomes relatively low, and the function as designed cannot be achieved. Therefore, the top of the breakwater or seawall is raised to restore its function. At that time, simply raising the top will make the structure longer and thinner than the original shape, and the stability against external forces such as wave force, seismic force, and hydrodynamic pressure will decrease.
It is necessary to increase the width of the structure at the same time as raising.

[0003] The most commonly used lifting method is to construct a cut-off wall by driving steel sheet pile or the like along the structure offshore or on the land side, such as a breakwater, and dry the inside of the cut-off wall. Up and widen the walls of existing structures,
At the same time, the top is raised.

[0004]

However, the above-mentioned raising method includes many on-site operations such as a sea sheet pile driving operation and a concrete driving operation at sea, which requires a long construction time and a high construction cost. It is the fact that the problem remains. An object of the present invention is to solve the above-mentioned problem, and an object of the present invention is to provide a method of widening a breakwater or a seawall by a simple method and simultaneously raising a top end thereof.

[0005]

In order to achieve the above object, a method for raising a breakwater or a seawall according to the present invention is to provide a method for raising an existing seawall or seawall with a ceiling and an underwater wall surface. A precast plate integrally formed over the bridge, the length of the precast plate located on the underwater side has a length from the top end of the breakwater or seawall to the vicinity of the bottom surface, the breakwater or The problem was solved by establishing on the revetment.

[0006]

The embankment on which the precast plate is anchored raises the top of the breakwater and seawall, and has resistance to sliding due to the increase in weight. In addition to the weight increase against falling, the L-shaped shape straddles the top of the breakwater or seawall and the wall surface receiving the wave, so the center of gravity is closer to the side receiving the wave force, so it rotates. Increases resistance. Therefore, stability against external force such as wave force is increased.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the method for raising a breakwater or seawall according to the present invention will be described below. FIG. 1 is a sectional view showing a situation in which the present invention is applied to a caisson breakwater,
A precast plate 2 is provided so as to straddle the top of the embankment 1 and the wall surface on the offshore side. If the precast plate 2 is provided on the offshore wall surface, it is advantageous to counter external forces such as wave force, but if there are other special conditions, the opposite side (land side)
May be provided.

The precast plate 2 is preferably finished as a structure having a substantially L-shaped cross section on land or on a ship by a method such as integral molding or joining a plurality of members. However, depending on the cross-sectional shape of the embankment body 1, it is not limited to the L-shape, and in some cases, various variations are possible depending on the shape of the embankment body 1 and the state of the breakwater, such as a block having a U-shaped cross section. Precast plate 2
Is mounted on the bank 1 by a crane ship or the like, and is fixed to the bank 1 by anchoring means such as anchor bolts 3 if necessary. The through holes for bolts provided in the precast plate 2 may be drilled in advance, or may be drilled after installation on site.

FIG. 2 is a perspective view of the precast plate 2, which is made of precast concrete and integrally molded as an L-shaped block 4. The dimensions of the L-shaped block 4 are designed as follows. That is, the width “a” and the height “b” of the L-shaped block 4 are mainly determined by the dimensions of the bank 1. Also,
The thickness c is equal to the required raising height, and the thickness d is
It is determined by the stability against its own weight and external force when the L-shaped block 4 is installed on the bank 1. Furthermore, the length e
Can be determined by the capacity of a device for lifting the L-shaped block 4 such as a crane facility.

The embankment body to which the L-shaped block 4 is fixed and integrated must naturally be stable against external force. For this purpose, the L-shaped block 4 receives external force such as wave force. Not to slide or fall. The L-shaped block 4 according to the present invention has a resistance against sliding due to an increase in weight.
Since the center of gravity is shifted to the side receiving the wave force due to the L-shaped shape, the resistance is large, and the stability against external force is increased. The material of the precast plate 2 is concrete,
Appropriate materials such as steel and plastics are selected.

FIG. 3 is a sectional view showing a situation in which the L-shaped block 4 is applied to a sheet pile type seawall. The L-shaped block 4 extends over a steel sheet pile 5 and a capping 6 at the top end. 3 and a ground anchor 7.

[0012]

According to the method for raising a breakwater or seawall according to the present invention, the work for widening and raising the levee body is performed simultaneously by fixing the precast plate to the levee body. It has an excellent effect that the construction cost is low. In addition, since the present invention is easy to construct, the present invention can be applied again to a breakwater or seawall that has already been raised, so that it is difficult to predict the problem of the functional deterioration of the seawall or seawall. Practical as a solution.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a situation in which an L-shaped block is applied to a breakwater.

FIG. 2 is a perspective view of an L-shaped block.

FIG. 3 is a sectional view showing a situation in which an L-shaped block is applied to a revetment.

[Explanation of symbols]

 Reference Signs List 1 embankment body 2 precast plate 3 anchor bolt 4 L-shaped block 5 steel sheet pile 6 capping 7 earth anchor

Claims (1)

(57) [Claims] 1. A precast plate integrally formed on an existing breakwater or seawall over a top end of the breakwater or seawall and a wall surface on the underwater side , wherein the precast plate is located on the underwater side.
The length of the precast plate to be cut is the top of the breakwater or seawall
A method of raising a breakwater or seawall, comprising fixing a precast plate having a length from the bottom to the vicinity of the bottom surface on the seawall or seawall.