JPH04336105A - Method of raising breakwater or revetment - Google Patents

Abstract

PURPOSE:To increase width of a breakwater or a reventment and at the same time raise top end thereof by simple method. CONSTITUTION:A precast plate 2 of sectional form L is fixed on a level body 1 astride the top end and the offing-side wall surface thereof by such fixing means as anchor bolts 3. The precast plate 2 has resisting force against the slippage due to increase of weight, and also has large resisting force against the falling due not only to increase of weight but also to shift of the center of gravity thereof toward the side receiving wave force because of the L form so that its stability against the external force is enhanced.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention is used to restore the functions of breakwaters and seawalls that have sunk over the years, or
This concerns how to raise the height of breakwaters and seawalls when sea levels are expected to rise due to global warming.

0002

2. Description of the Related Art Generally, the height of the top of a breakwater is designed to be high enough to prevent the intrusion of seawater due to storm surges and tsunamis, and the height of the breakwater is also designed to be high enough to prevent seawater from entering due to storm surges and tsunamis. W. L. (High Water
Level) or higher. However, if the ground subsides due to consolidation or if the water level rises due to global warming, the top of the structure will become relatively low and will no longer function as designed. Therefore, attempts are being made to raise the tops of breakwaters and sea walls to restore their functionality. At that time, simply raising the top of the structure will make the structure vertically longer and narrower than its original shape, reducing its stability against external forces such as wave force, seismic force, and hydrodynamic pressure. It is also necessary to increase the width of the structure.

The most commonly used raising method is to construct a cofferdam by driving steel sheet piles along the structure on the offshore or land side of a breakwater, etc., and then dry the interior of the cofferdam. by increasing the width of the wall of the existing structure,
At the same time, the top is raised.

0004

[Problems to be Solved by the Invention] However, the above-mentioned raising method involves a lot of on-site work such as driving steel sheet piles at sea and concrete pouring work, resulting in long construction periods and high construction costs. The reality is that problems remain. The present invention is intended to solve the above-mentioned problems, and its purpose is to provide a method for widening a breakwater or seawall and simultaneously raising the top of the breakwater or seawall using a simple method.

[0005]

[Means for Solving the Problems] In order to achieve the above object, the method for raising the height of a breakwater or seawall of the present invention includes a precast board that spans the top of a breakwater or seawall and at least one wall surface. , the problem was solved by fixing it on the breakwater or seawall.

[0006]

[Function] The embankment body to which the precast boards are fixed raises the top of the breakwater or seawall, and has resistance to sliding due to the increased weight. In addition to the increased weight, the L-shaped structure straddles the top of the breakwater or revetment and the wall on the side that receives waves, so the center of gravity shifts toward the side that receives wave force, causing rotation. resistance increases. Therefore, stability against external forces such as wave force is increased.

[0007]

[Embodiments] Hereinafter, preferred embodiments of the method for raising a breakwater or seawall according to the present invention will be described. FIG. 1 is a sectional view showing a situation in which the present invention is applied to a caisson-type breakwater.
A precast board 2 is installed across the top of the embankment body 1 and the wall on the offshore side. If the precast board 2 is installed on the wall on the offshore side, it is advantageous in resisting external forces such as wave force, but if there are other special conditions, it may be installed on the opposite side (land side). good.

[0008] The precast plate 2 is preferably finished as a structure having a generally L-shaped cross section by a method such as integral molding or joining a plurality of members on land or on a ship. 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, such as a block with a U-shaped cross section, depending on the shape of the embankment body 1 and the state of the breakwater. The precast board 2 is installed on the embankment body 1 by a crane ship or the like, and is fixed to the embankment body 1 by fixing means such as anchor bolts 3, if necessary. Note that the bolt through holes provided in the precast board 2 may be drilled in advance or may be drilled after installation on site.

FIG. 2 is a perspective view of the precast board 2, which is integrally formed as an L-shaped block 4 made of precast concrete. Each dimension of the L-shaped block 4 is designed as follows. That is, the width a and height b of the L-shaped block 4 are mainly determined by the dimensions of the embankment body 1. Also, the thickness c is equal to the required raised height, and the thickness d is L
It is determined by the stability against its own weight and external force when the mold block 4 is installed on the embankment body 1. Furthermore, the length e is
It can be determined by the capacity of a device such as crane equipment that lifts the L-shaped block 4.

Naturally, the embankment body in which the L-shaped blocks 4 are fixed and integrated must be stable against external forces, and for this purpose, it is necessary for the L-shaped blocks 4 to be able to receive external forces such as wave forces. The condition is that you do not slip or fall. The L-shaped block 4 of the present invention has resistance to sliding due to the increased weight, and is also resistant to falling due to the increased weight.
Because of the shape of the mold, the center of gravity is closer to the side receiving wave force, resulting in greater resistance and greater stability against external forces. In addition,
Materials for the precast board 2 include concrete, steel,
A suitable material such as plastics is 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. 3 and an earth anchor 7.

0012

[Effects of the Invention] The method for raising the height of a breakwater or seawall according to the present invention allows the work to widen and raise the levee body at the same time by fixing precast plates to the levee body, so the construction period is short. It has the excellent effect of being low in construction costs. In addition, since the present invention is easy to construct, it can be used again for already raised breakwaters and seawalls.
Since the present invention can be implemented, it is highly practical as a solution to the difficult-to-predict problem of functional deterioration of breakwaters and seawalls.

[Brief explanation of 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 seawall.

[Explanation of symbols]

1 Embankment body 2 Precast board 3 Anchor bolt 4 L-shaped block 5 Steel sheet piles 6 Capping 7 Earth Anchor

Claims (1)

[Claims] 1. A method for raising a breakwater or seawall, which comprises fixing a precast board spanning the top of the breakwater or seawall and at least one wall surface to the breakwater or seawall.