JPH07119125A - Construction method of breakwater - Google Patents

Abstract

PURPOSE:To make it possible to strengthen a seabed foundation ground and construct a steel plate cell no matter how the ground is strong or weak by integrating the bottom of a steel plate cell main body into the seabed foundation ground with concrete, thereby stabilizing the steel plate cell main body. CONSTITUTION:A surface layer of a seabed foundation ground is dredged up to a support layer. Underwater concrete is being placed, thereby constructing foot protection concrete which serves as bottom concrete 5 while a steel plate cell 1 is lowered underwater. The steel plate cell 1 is integrated with a seabed foundation ground by foot protection concrete which serves as bottom concrete 5. Filler sand 11 is filled up in the steel plate cell 1 and inner lining concrete 6 is constructed and then capped with a precast concrete-made cover 4. An arc unit 2 which connects both sides of the steel plate cell 1 installed is lowered underwater in a similar method of the steel plate cell 1. This construction makes it possible to utilize the special features of the steel plate cell construction method and, what is more, to prevent the suction of the filler sand 11 or submerged weir.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of constructing a breakwater, and an object thereof is to rapidly construct a breakwater in a sea area where weather conditions are severe by using steel plate cells.

[0002]

2. Description of the Related Art Most of the methods for constructing a breakwater in a sea area where the weather conditions are severe, such as the open sea, are the ones in which concrete caisson is sunk, and there are few examples of using steel plate cells. Steel plate cells are often used in the construction of relatively quiet coastal quay walls and revetments, and as a construction method, a rooting method is used in which the lower part of the cell is driven into the seabed foundation ground.

[0003]

Since the root-insertion type steel plate cell method is a method of driving a steel plate cell to a predetermined position by vibration using several vibro hammers, it is sufficient when the seabed foundation ground is strong. There is a case that you can't use it and you cannot use it even if you want to use it.

[0004]

The present invention is a construction method which can be constructed regardless of the strength or softness of the seabed foundation ground, and which makes full use of the rapid construction property which is a characteristic of the steel plate cell construction method.

That is, according to the present invention, while pouring underwater concrete on the seabed foundation ground whose surface layer has been dredged to the support layer,
A method of constructing a breakwater that consists of staking a steel plate cell with bottom plate concrete reinforcing steel material on the bottom and slip-preventing steel material on the outer peripheral surface of the bottom, filling the steel plate cell with filling material, and then using a precast concrete lid. Is.

The point of the present invention is that the bottom of the steel plate cell is integrated with the seabed foundation ground by concrete to stabilize the steel plate cell body. For this reason, a bottom plate concrete reinforcing steel material is welded to the bottom surface of the steel plate cell, and a slip prevention steel material is welded to the bottom peripheral surface. For the seabed foundation ground, the surface layer is dredged to the support layer. When submerged concrete is poured into this foundation ground and the steel plate cell is sunk while the concrete does not harden, a root-consolidated concrete / bottom plate concrete is constructed at the bottom of the steel plate cell, and this root-consolidated concrete / bottom plate concrete is attached to the steel plate cell side. The bottom plate concrete is reinforced with steel for reinforcement, and the steel for slip prevention is used for slip prevention. After constructing the root-consolidating concrete and the bottom slab concrete, the filling material is filled inside the steel plate cell, which further increases the weight, and the weight also resists waves and the like, which further stabilizes the steel plate cell body. To be

The steel plate cell used in the present invention is made by welding a steel plate into a cylindrical shape like a normal steel plate cell, and is reinforced by welding vertical ribs and horizontal ribs on the inner surface. In the present invention, the steel plate cell is further welded with a bottom plate concrete reinforcing steel material and a slip preventing steel material. In the case of constructing a steel sheet cell in an ice sea area according to the present invention, in order to prevent damage to the steel sheet cell at the time of collision with drift ice, the inner surface of the steel sheet cell is provided with a formwork for slipping concrete construction and a steel material for slip prevention in advance. It is preferable to weld the steel sheet, and then install inner-rolled concrete after installing the steel plate cell. As in the conventional method, the arc-shaped arc portion is sunk in order to connect the steel plate cells to each other. Similar to the steel plate cell, this arc portion is also sunk while welding concrete reinforcing steel and slip-preventing steel to the bottom and pouring concrete and bottom slab concrete.

The root-consolidating concrete / bottom slab concrete according to the present invention is usually 1 to several meters depending on the size of the steel plate cell.
It is cast to the thickness of. By constructing this concrete and bottom slab concrete, the steel plate cell and the foundation ground are integrated, and in addition, suction and scour of the filling material are prevented.

As the filling material, sand or crushed stone is usually used. However, in the cold sea area, water remaining in the filling material may freeze and damage the steel plate cell. It is preferable to take measures such as construction and mixing antifreeze liquid in the filling material.

The upper part of the steel plate cell constructed according to the invention is usually provided with an upper concrete made of cast-in-place concrete.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The construction method of the present invention will be described below with reference to the drawings.

FIG. 1 shows a breakwater constructed according to the present invention,
(A) is a plan view, (b) is a sectional view taken along the line AA of (a),
(C) is a detailed view of a B section in (b), and (d) is a detailed view of a C section in (b).

FIG. 2 is a plan view of the bottom surface of the steel plate cell.

Steel plate cells 1 are welded on the bottom surface thereof with a bottom slab concrete reinforcing steel material 10 as shown in FIG. 2 in a radial or grid pattern, and on the outer peripheral surface of the bottom portion, as shown in FIG. A slip prevention steel material 9 is welded, and a steel form frame 7 for construction of the inner-rolled concrete 6 and a slip prevention steel material 8 are welded to the upper inner peripheral surface as shown in FIG. 1 (c). Although not shown, vertical ribs and horizontal ribs are welded and reinforced on the inner surface of the steel plate cell 1.

The surface layer of the submarine foundation ground is dredged to the support layer, and underwater concrete is poured to solidify the concrete and the bottom slab concrete 5 while the steel plate cell 1 is submerged.
Steel plate cell 1 is root consolidation concrete and bottom slab concrete 5
Is integrated with the seabed foundation ground. The steel plate cell 1 is filled with the filling sand 11, the inner wound concrete 6 is applied, and then the lid 4 is made of the precast concrete. The arc part 2 connecting both sides of the installed steel plate cell 1 is installed by sinking it in the same manner as the steel plate cell 1. The work is completed by placing the upper concrete 3 made of cast-in-place concrete on the lid 4 made of precast concrete.

[0016]

[Effects of the Invention] Since the bottom of the steel plate cell is integrated with the seabed foundation ground by concrete to stabilize the steel plate cell body, it can be constructed regardless of the strength or softness of the seabed foundation ground, and the rapid construction that is a characteristic of the steel plate cell construction method It is possible to make full use of the property, and further, it is possible to prevent the filling and scouring of the filling material.

[Brief description of drawings]

FIG. 1 shows a breakwater constructed according to the present invention, where (a) is a plan view, (b) is a sectional view taken along the line AA of (a), (c) is a detailed view of part B of (b), (d). Is a detailed view of part C in (b).

FIG. 2 is a plan view of the bottom surface of a steel plate cell.

[Explanation of symbols]

1 ・ ・ Steel plate cell, 2 ・ ・ Arc part, 3 ・ ・ Top concrete, 4 ・ ・ Lid, 5 ・ ・ Rooted concrete and bottom plate concrete, 6 ・ ・ Inner wrapping concrete, 7 ・ ・ Steel formwork, 8 ・.Steel material for slip prevention, 9 ... Steel material for slip prevention, 1
0 ... Steel material for bottom slab concrete reinforcement, 11 ...

Front page continued (72) Inventor Nobuyasu Suzuki 1-2-7 Moto-Akasaka, Minato-ku, Tokyo Kashima Construction Co., Ltd.

Claims (1)

[Claims] 1. A submarine foundation ground dredging the surface layer to a support layer, while immersing underwater concrete, a steel plate cell having a bottom slab concrete reinforcing steel material and a bottom outer peripheral surface slip-preventing steel material is sunk, A method of constructing a breakwater, which comprises filling a steel plate cell with a filling material and then applying a lid made of precast concrete.