JPS61130512A - Construction work of cell revetment - Google Patents

Abstract

PURPOSE:To easily construct a cell revetment by a method in which plural steel cells are uprightly erected at a given interval on the upside of a base steel casing, and connected with each other by paired arcs facing each other, and soil is packed into the steel cells. CONSTITUTION:Plural steel cells 5 are installed and welded at a given interval on the upside of the steel casing 11 of a base 3 with an air chamber formed of a high-strength film 13. Paired arcs 7 are each set between the cells 5 in a mutually facing manner, the cells 5 are welded on the upside of the cell 11, and connecting pieces 9 are welded to the cells 5 on both ends to construct a structure 1. The structure 1 is towed to a construction site and settled on a mound 21 while adjusting ballast in the base 3, and a filling material 23 is placed into the base 3. New structure 1 is then settled and connected through connecting pieces 9, a filling material is placed, and the structures 1 are connected in order.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a construction method for revetment of reclaimed land, etc. using steel cells.

(Conventional technology) This is a rapid construction method for revetments on reclaimed land, etc.

Generally, the cell method or caisson method is known. In this cell construction method, cylindrical steel cells are erected sequentially on the seabed and connected by arcs, and each steel cell and arc is filled with earth and sand to form a cell revetment. Here, as the steel cell, a steel plate cell formed into a cylindrical shape using one steel plate, or a steel sheet pile cell formed by connecting a large number of straight steel sheet piles together and assembled into a cylinder, etc. have been mainly used.

Conventionally, when erecting this type of steel cell at a construction site, the steel cell was first constructed on land, then placed on a barge or hoisted by a large floating crane, transported to the construction site, and then poured. It was common to
-86206, JP-A-58-8620.7, etc.).

(Problems to be solved by the invention) However, since this type of construction method uses floating cranes, etc., the costs involved are high;
In addition, in order to reduce this cost, a method of floating the Wei cell on the sea and towing it (for example, Japanese Patent Application Laid-Open No. 58-110724, etc.) has been proposed, but in any case, since it is a cell type, There was a limit to the possible depth. In other words, in order to cope with deep-water seawalls such as offshore artificial islands, it is necessary to increase the radius of the steel cells in order to obtain stability, but if the radius is 1
A large steel cell with a length exceeding 0 m has an unstable shape and is difficult to handle alone.Furthermore, the force acting on the cell shell increases in proportion to the radius and water depth, making construction workability and economical difficult. There were limits from both gender perspectives.

The present invention has been made with attention to these points, and it is an object of the present invention to provide a construction method for a cell revetment that is easy to construct, can be applied to deep-water revetments, and is economically advantageous.

(Means for Solving the Problems) Therefore, in the present invention, a steel shell is produced by bending a steel plate into a gutter shape and having a cross-sectional shape of a half oval shape with a flat top surface and an open bottom surface. The parts where steel plates are not used, such as the bottom and both end faces, are covered and sealed with a high-strength membrane reinforced with a tensile material, and an air chamber is formed within this steel shell, which is used as a base. A structure is constructed by erecting and fixing a plurality of steel cells at predetermined intervals on the upper surface of the shell, and connecting each steel cell with a pair of arcs placed opposite each other. At the revetment construction site, ballast adjustment is performed by injecting water into the base of the structure, and the ballast is then deposited. After that, the steel cells and arcs are filled with filling material to form a unit block of cell revetment.

(Function) In such a construction method of a cell revetment of the present invention, a plurality of steel cells are erected and fixed at predetermined intervals on the upper surface of a steel shell of a base body in which an air chamber is formed by a high-strength membrane, and each steel cell is Since the structure is constructed by connecting the two arcs with a pair of arcs placed opposite each other, each of them reinforces each other, making it easy to handle steel cells, etc., which are relatively unstable when used alone. In addition, since the air chamber of the base, which is sealed with a high-strength membrane, acts as a float, it can be easily towed to the seawall construction site without using a large floating crane, etc. At this point, the ballast inside the base is adjusted by water injection, etc., the structure is sunk, the filling material is placed inside the base, and then the steel cells and arcs are filled with filler earth and sand. The purpose of this project is to construct a stable cell revetment that is easy to deal with, and has excellent construction and economical efficiency.

(Example) Next, an example of implementation of the present invention will be described with reference to the drawings. FIG. 1 is a perspective view showing an example of a structure used in the cell revetment construction method according to the present invention. In the same figure,
3 is a base body, 5 is a steel cell, 7 is an arc, and 9 is a connecting piece, and the structure 1 is constituted by these. This base body 3 is made by bending a steel plate, and has a height of, for example, 8 m and a width of 30 m.
m, a steel shell 11 made of a steel plate with a cross section of about 80 m in length and formed in the shape of a half-split oval inverted gutter, with an open bottom and a flat top, and a steel plate of this steel shell 11. A high-strength membrane body 13 that covers and seals the bottom opening and both end faces that are not used and forms an air chamber within the steel shell 11,
In order to reinforce this high-strength membrane body 13, tensile members 15 are stretched in the bottom opening of the steel shell 11 at predetermined intervals in the direction normal to the seawall where the seawall is constructed and in the direction perpendicular thereto. Further, a large number of stiffeners 17 are provided on the inner surface of the steel shell 11 to further strengthen the steel shell 11.

The steel cell 5 is made by winding one steel plate and welding the joint,
For example, they are formed into a cylindrical shape with a radius of about 10 m and a height of about 22 m, and three of them are set upright at predetermined intervals on the flat upper surface of the steel shell 11 of the base body 3 and fixed by welding. Further, the arcs 7 are arranged in pairs between the steel cells 5 so that each side is in contact with each steel cell 5, and each pair of the arcs 7 is welded to the steel cell 5. At the same time, the lower side is also welded to the upper surface of the steel shell 11 of the base body 3. moreover,
The connecting piece 9 is made of, for example, a straight steel sheet pile cut in half in the vertical direction, and the half-split surfaces are welded to the steel cells 5 at both ends in the same manner as the arc 7. Construction of these structures 1 is performed, for example, on a dry dock.

The structure 1 built on a dry dock has a base body 3 sealed with a high-strength membrane 13 to form an air chamber, is floated on the sea using this base body 3 as a float, and is towed by a tugboat to a seawall construction site. . The second @ is a cross-sectional view of the structure 1 showing the state at that time, where the high-strength membrane body 13 is curved inward by water pressure. The structure 1 that has arrived at the seawall construction site is gradually sunk by adjusting the ballast inside the base 3. This palast adjustment involves gradually injecting water into the base 3 using, for example, a pump, and this water injection is carried out carefully while controlling and adjusting the attitude 1 position of the sinking structure 1. , the structure 1 is accurately sunk on a mound 21 built in advance at a seawall construction site.

Next, the filling material 23 is injected into the inside of the base body 3. This filling material 23 is made of cement for earth and sand.

The combination of hardening agents such as lime, slag, and special cement provides early strength and salt resistance.

It is a mixture of additives with fluidity. here,
Since the bottom surface of the base body 3 is made of a flexible high-strength membrane 13, the high-strength membrane 13 bends according to the unevenness of the mound 21 when the filling material 23 is placed, thereby increasing the resistance against sliding of the constructed cell revetment. It will increase. Next, the inside of the steel cell 5 and the space surrounded by the opposing arcs 7 are filled with earth and sand 25 to form a unit block of a cell revetment. Third
The figure is a sectional view of the structure 1 showing the state at that time.

Thereafter, in a process similar to this, a second unit block is placed adjacent to the first unit block, and a connecting piece 9 is formed between the two units.
are connected using straight steel sheet piles or the like, and the resulting space is filled with earth and sand 25. Thereafter, the cell revetment is constructed by sequentially submerging and connecting the unit blocks through the above steps.

Although the present invention has been described in detail according to the illustrated embodiments, the present invention is not limited thereto. For example, the size of the structure 1 is changed as appropriate depending on the depth of the sea area where the cell revetment is constructed and other environmental conditions, and the number of steel cells 5 erected and fixed on the base 3 is also changed according to the conditions. All you have to do is decide. In addition, if it is a relatively small-scale device, it is possible to omit the stiffener 17 for reinforcing the steel shell 11, and the opening of the steel shell 11 can also be closed at both ends with steel plates and only the bottom surface is closed. Furthermore, depending on the geology of the ocean floor, the cell revetment may be constructed directly on the ocean floor without constructing the mound 21. In addition, as the filling material 23 to be filled into the base body 3, if particularly strong strength is required, concrete with reinforcing bars may be used, and if so strong strength is not required, hardening agent, It is also possible to omit the mixing of additives and the like and use only earth and sand.

(Effects of the Invention) According to the construction method of the cell revetment of the present invention, a plurality of steel cells are erected and fixed at predetermined intervals on the upper surface of the steel shell of the base, and the steel cells are arranged oppositely to each other. Since the structure is constructed by connecting with a pair of arcs, each of them reinforces each other, making steel cells, etc., which are relatively unstable when used alone, become solid, and their shape becomes unstable when used alone. Even large steel cells with a radius of over 10 m, which would be difficult to handle, can be easily sunk, making it easier to construct deep-water seawalls. Furthermore, in the present invention, a steel shell is produced by bending a steel plate into a gutter shape and has a cross-sectional shape of a half oval shape with a flat top surface and an open bottom surface, and the bottom surface of this steel shell is
The parts where steel plates are not used, such as both end faces, are covered and sealed with a high-strength membrane, and an air chamber is formed within this steel shell, which serves as the base.This base can be used as a float, and can be used for large-sized floats. It can be easily towed to the revetment construction site without using a floating crane, etc. Therefore, the construction method of cell revetment is easy to construct, can be applied to deep water revetment, and is economically advantageous. Not only is this possible, but because the filling material is filled into the base when constructing the cell revetment, it can easily support the weight of large steel cells, arcs, etc. that have become extremely heavy due to filling with earth and sand. Effects such as being able to do this can be obtained.

[Brief explanation of the drawing]

Fig. 1 is a perspective view showing an example of a structure used in the cell revetment construction method according to the present invention, Fig. 2 is a sectional view showing the state of the structure when being towed, and Fig. 3 is a unit block. It is a sectional view showing the state of the submerged structure. 1...Structure, 3...Base, 5...
...Steel cell. 7...Arc, 9...Connection piece, 11.
...Steel shell. 13... High strength membrane body, 15... Tensile material. Patent applicant Pentayo Construction Co., Ltd. Nippon Kokan Co., Ltd. Nishimatsu Construction Co., Ltd. Figure 1 13 Island strength membrane body

Claims (1)

[Claims] A steel shell is formed by bending the steel plate into a gutter shape and has a half-oval cross-sectional shape with a flat top and an open bottom. A plurality of steel shells are arranged on the upper surface of the steel shell of the base body, which is made up of a high-strength membrane forming a chamber, and a tensile material stretched at a predetermined interval from the bottom opening of the steel shell to reinforce the high-strength membrane. A structure is constructed by erecting and fixing steel cells at predetermined intervals and connecting each steel cell with a pair of arcs placed opposite each other, and using the buoyancy of the base body to construct a structure as a seawall. The structure is towed to the construction site, the ballast inside the base is adjusted, and the structure is sunk at the seawall construction site. Filling material is then poured into the base, and then the inside of the steel cell and the arc and steel cell are placed. A cell revetment construction method characterized by filling the space surrounded by sand with filler soil.