JP2913335B2 - Asphalt mat construction method - Google Patents

Description

Description: FIELD OF THE INVENTION The present invention relates to a caisson in which a steel plate main body is formed by covering the surface of concrete with concrete and a bottom portion is integrally provided with an asphalt mat. The present invention relates to a method for connecting asphalt mats at a connection portion of each caisson when a caisson is connected to form a large caisson structure.

(Conventional technology) In general, when constructing a breakwater, a pier, or the like, a construction method is used in which a foundation is constructed with rubble or the like on the seabed ground, and a concrete caisson is placed thereon. Since the concrete caisson is very heavy, for example, the concrete caisson is manufactured as a block having a length of about 10 m or the like which can be handled, and a predetermined number of blocks are arranged by arranging the blocks. Build a long breakwater, etc.

However, when a breakwater is constructed with a concrete caisson as described above, an extremely large number of caisson blocks must be manufactured and transported over the sea to be installed at the construction site. The period is longer,
There is a problem that the process management becomes troublesome.

In order to solve the problem of the caisson made of concrete, it has been proposed to use a caisson made of a steel plate. As shown in FIG. 4, the caisson made of the steel plate is manufactured by combining steel plates at a shipyard or the like to produce caisson 2 as a box-shaped block.
A large caisson main body is manufactured by connecting many via the connecting portion 3 and the surface of the main body is covered with concrete, thereby constituting the caisson 1 as a structure that can withstand seawater.

By installing the caisson on a foundation constructed on the sea floor in the same manner as in the case of a concrete caisson, a pier or breakwater can be easily constructed. The caisson has, for example, a length L
Can be configured as a very large object of about 50 m, so that the number of operations such as sea transportation of the caisson is reduced, and advantages such as easy management of construction process can be exhibited.

However, the above-mentioned caisson is lighter than concrete ones.Because the bottom plate is an iron plate, there is a problem that it is slippery on rubble, etc. There is a problem that it is easily corroded by seawater. Therefore, in order to solve the problem of slippage and corrosion of the bottom plate, it has been proposed to provide an asphalt mat 10 integrally on the lower surface of the bottom plate of the caisson 1.

The caisson is manufactured through the steps shown in FIGS. 5 (a) to (e). In the example shown in FIG. 5, first, as shown in FIG. 5A, the caisson 2 is placed in a state where the bottom plate 5 is placed on the lower main body 6 and the caisson 2 is inverted. A substructure is formed. Then, as shown in FIG. 2B, an asphalt mat 10 is applied on the bottom plate 5 to a predetermined thickness.

As described above, the lower structure in which the asphalt mat is integrally attached to the bottom plate 5 is created, and then, as shown in FIG. The mat 10 is in a state of being located below. After that, as shown in FIG. 3D, the main body extension portion 7 is connected to form a caisson main body made of a steel plate, and a predetermined surface is formed on the surface of the main body as shown in FIG. A concrete caisson having a predetermined size can be constructed by integrally constructing concrete 8 having a thickness of.

In the process shown in FIG. 5, when connecting the caisson, as shown in FIG. 5C, the caisson is turned over, and then the operation of connecting a plurality of caissons is performed. Work to connect the extension and cover concrete. By connecting a plurality of caissons, a very large caisson structure can be manufactured.

(Problems to be Solved by the Invention) However, in the case of manufacturing the above-described caisson, when connecting the bottom plate of each caisson, if the steel plate is covered with an asphalt mat, means such as welding is applied. The problem that it is difficult occurs. Therefore,
Conventionally, the end of the bottom plate is exposed, a portion of the exposed steel plate is connected by welding or the like, and a material similar to an asphalt mat is later embedded in the connection portion. Is used.

In order to apply asphalt to the connection part, for example, a method as shown in FIG. 6 has been considered. In the conventional example shown in FIG. 6, a portion where two ends of the bottom plates 5 and 5 of two caissons abut each other is connected via a welded portion 27, and an asphalt mat provided integrally with the bottom plates.
The space between 10, 10 is filled with a connecting iron plate member.

However, between the asphalt mats on both sides,
For example, the bottom plate 5, the lower backing plate 28, and the sides of the asphalt mat on both sides have a rectangular cross section of about 10 cm, and are very long corresponding to the width D of the caisson (FIG. 4). A space 29 is formed, and a reinforcing member such as a reinforcing bar is inserted into the space. Therefore, the space
Filling the asphalt into 29 has a problem that even if the asphalt is heated at a high temperature to improve the fluidity, bubbles may enter inside. In addition, there is a problem in the connectivity between the asphalt mat provided integrally with the bottom plate and the asphalt filled in the space, and there is a problem that the protection of the iron plate of the bottom plate of the caisson is hindered.

(Object of the Invention) The present invention solves the above-mentioned drawbacks of the conventional method. In a state in which the caisson is reversed, an asphalt mat is integrally formed on the entire bottom plate thereof, and the caisson is normally mounted. After reversing to the position, arrange the two caisson bottom plates with a slight gap, fill the asphalt of the same specification while interconnecting the reinforcing members of the asphalt mat on both sides, and then It is an object of the present invention to provide a method of connecting an iron plate via a connecting iron plate member to integrally form each member.

(Means and Actions for Solving the Problems) The present invention comprises a steel caisson main body coated with concrete, and an asphalt mat provided integrally with a lower part of a bottom plate of the main body. It is related to those that are erected and constitute harbors, etc.

In the present invention, in a state in which the caisson is inverted, a step of integrally constructing an asphalt mat in which reinforcing steel for reinforcement and other reinforcing members are disposed on the upper surface of the bottom plate, and inverting the caisson to a use state In a state where the other caissons to be connected are arranged at predetermined intervals, the reinforcing members of the asphalt mat of the caisson members on both sides are connected to each other in the space formed between the two caissons, and the asphalt A step of filling asphalt of the same material as the mat, and a step of connecting the bottom plates on both sides using a connecting iron plate member in order, so as to form a caisson by integrally connecting a plurality of caissons. I have.

Further, in the present invention, the asphalt mat provided in the caisson and the surface of the connecting portion of the connecting iron plate member are coated with an asphalt adhesive and then filled with asphalt, so that the asphalt filled later can be used as another member. Means for making a connection in good condition can be used.

By configuring the caisson as described above, asphalt can be easily applied to the connection portion of the caisson, and the caisson can be easily manufactured. By using the method of the present invention, the asphalt mat covering the iron plate of the bottom plate can be integrated with the asphalt to be filled later, so that the caisson can be fixed to the seabed in a favorable state.

In addition, by providing the asphalt mat without any gap on the surface of the iron plate, the iron plate of the bottom plate of the caisson can be shielded from seawater, and the durability of the caisson can be improved.

(Example) A method for manufacturing a caisson of the present invention and a method for asphalt construction will be described with reference to the illustrated hybrid caisson example.

The caisson simple substance 2 of the present invention shown in FIG. 1 shows a state where an asphalt mat is applied to the surface of the bottom plate 5 in a state where the caisson simple substance is inverted as shown in FIG. 5 (b). ing. Further, in FIG. 2, as shown in FIG. 5 (c), the operation of connecting the bottom plates of the two caisson units with the caisson unit rotated by 180 ° and the operation of asphalt mats 10 and 10 on both sides are performed. In the figure, asphalt is filled, and asphalt mats on both sides are integrally formed.

In the example shown in FIG. 1, when asphalt mat is applied to the surface of the bottom plate 5 of the caisson unit 2, a large number of stud streaks 11 are attached to the iron plate of the bottom plate at predetermined intervals by welding or the like. . And formwork 19 at the end of the bottom plate
Is fixed to the bottom plate 5 via a spot welding portion 19a, and a release tape 18 is arranged on the surface of the formwork 19,
An asphalt primer 17 is applied to the surface of the bottom plate, and a lower asphalt layer 15 is applied with a predetermined thickness. In this state, the head of the stud streaks 11 is exposed from the surface of the lower asphalt 15.

Next, on the asphalt layer 15, vertical and horizontal reinforcing bars
Combine 12, 13 and fasten by means such as binding to the end of stud streak 11, and wire mesh 14 or
A reinforcing member such as a glass cloth is laid, and those members are also integrally attached to the reinforcing bar.

Thereafter, asphalt primer is applied to the surface of the reinforcing member, then asphalt 16 of the surface layer is applied, and the upper and lower asphalts 15 and 16 are sandwiched with the reinforcing member between one asphalt mat 10 As an integral part of the bottom plate. When the asphalt mat 10 is constructed, the end of the member 14 such as a wire mesh and the end 13a of the horizontal reinforcing bar 13 are made to rise along the vertical surface of the formwork 19.

After the asphalt mat 10 is integrally formed on the surface of the bottom plate 5 in the above-described state to form a caisson unit, as shown in FIG. The device is turned upside down using the device described above, and the work is returned to a normal position where the work is performed on site.

Then, the two caissons alone are arranged at a predetermined interval, and as shown in FIGS. 2 (a) to 2 (c),
Work of connecting the bottom plate between both members and connecting the asphalt mat is performed.

In the example shown in FIG. 2 (a), the asphalt mats 10, 10 on both sides of the connection portion are in a state where the surface of the asphalt layer 16 is in contact with the ground or the like, and between the asphalt mats on both sides. A predetermined gap is formed as the connection portion 20 in the connector. First, in order to fill the gap between the asphalt mats 10 and 10 of the caisson alone on both sides, first, the end 13a of the reinforcing reinforcing bar and the end of the wire mesh 14 are bent upward so as not to be in the way. After the asphalt primer 17 is applied to the side surfaces of the asphalt mats 16 on both sides, the thickness of the asphalt layer 16 is made the same as the thickness of the asphalt layer 16 as shown in FIG.
To construct.

Next, as shown in FIG. 3B, the end of the reinforcing member such as the metal rope 14 and the end 13a of the reinforcing bar are connected to the asphalt layer 2 by
Polymerization is performed on 4a, and connection is made using a fastening member 21 such as a wire. Then, as shown in FIG. 2A, the asphalt primer 17 is applied to the surface of the reinforcing member and the ends of the asphalt mats on both sides, and the asphalt 24b of the upper layer is applied, and A layer similar to the asphalt mat 15 is formed on the connection portion.

As mentioned above, caisson asphalt mat alone
When asphalt members 24 of the same quality are installed between 10 and 10, and they are integrally formed, and the bottom plates 5 on both sides are connected using the iron plate member 22 for connection, as shown in FIG. It is formed.

In the example shown in FIG. 3, an asphalt adhesive 23 is applied to the surface of the asphalt layer 24b from the state of FIG. A state is shown in which the member 22 is placed, and the bottom plates 5, 5 and the connecting iron plate member 22 are connected by the welded portion 27.

In the method of the present invention described above, the bottom plates 5 and 5 of the caisson units to be connected to each other and the asphalt mats 10 and 10 integrally provided on the bottom plates can be connected integrally. . And the asphalt filled in the connection part and the asphalt mat on both sides,
Since there is no gap, even when the caisson is installed in seawater, seawater is prevented from entering the iron plate portion, and the iron plate is not corroded by salt.

In addition, by applying the method of the present invention to the connection portion of each caisson unit, even if a large number of caisson units are connected to form a large hybrid caisson, the seal at each connection unit is good. And the iron member of the caisson can be prevented from coming into direct contact with seawater.

In the method for manufacturing a hybrid caisson of the present invention, the asphalt mat provided on the lower surface of the bottom plate can be configured in the same manner as a conventional asphalt mat, and the thickness of the asphalt mat, the arrangement interval of the reinforcing member, and the like. Can be set as appropriate according to the ground where the caisson is constructed and the sea conditions.

As described in FIG. 4, the hybrid caisson manufactured as described above connects a plurality of caisson pieces 2... The hybrid caisson 1 having the height H can be manufactured. In the case of manufacturing a single caisson, each caisson is manufactured through the steps shown in FIG.
By applying the connecting means as shown in FIG. 3, a hybrid caisson which is not affected by seawater can be manufactured. By providing the asphalt mat covering on the lower surface of the hybrid caisson, it is possible to construct a hybrid caisson that is installed in a stable state without slipping on the base member and has good durability. .

(Effect of the Invention) In the method for manufacturing a caisson according to the present invention, asphalt can be easily applied to the connection portion of the caisson by configuring the caisson as described above, and the caisson can be easily mounted. It becomes possible to manufacture.

By using the method of the present invention, the asphalt mat covering the iron plate of the bottom plate can be integrated with the asphalt to be filled later, so that the caisson can be fixed to the seabed in a favorable state.

In addition, by providing the asphalt mat without any gap on the surface of the iron plate, the iron plate of the bottom plate of the caisson can be shielded from seawater, and the durability of the caisson can be improved.

[Brief description of the drawings]

FIG. 1 is an explanatory view showing the structure of the end portion of the caisson simple substance of the present invention. FIG. 3 is an explanatory view showing the structure of a connecting portion of a single caisson, FIG. 4 is a perspective view of a hybrid caisson to which the manufacturing method of the present invention can be applied, and FIGS.
FIG. 6 is an explanatory view showing a manufacturing process of each caisson in order, and FIG. 6 is an explanatory view showing a configuration of a connecting portion of a conventional caisson alone. Reference symbol 1 in the figure: a hybrid caisson, 2 ... a single caisson, 5
...... Bottom plate, 8 ... Concrete, 10 ... Asphalt mat, 11 ... Stud bar, 12/13 ... Reinforcing bar, 14 ...
… Wire mesh, 15/16 …… asphalt layer, 20 …… connection, 22
... Iron plate member for connection.

Claims (2)

(57) [Claims] 1. A steel caisson main body having a surface coated with concrete, an asphalt mat being integrally provided below a bottom plate of the main body, and the caisson being erected under the sea to constitute a port wharf or the like. In the caisson to perform, in a state in which the caisson is reversed, on the upper surface of the caisson bottom plate, a step of integrally constructing an asphalt mat in which reinforcing steel for reinforcement and other reinforcing members are arranged, and inverting the caisson up and down Return to the use state, with the other caisson to be connected arranged at a predetermined interval,
In the space formed between both caissons, connect the asphalt mat reinforcing members of the caisson members on both sides to each other,
A step of filling asphalt of the same material as the asphalt mat, and a step of connecting the bottom plates on both sides using a connecting iron plate member are sequentially performed, and a plurality of caissons are integrally connected to form a caisson. Asphalt mat construction method characterized by that. 2. An asphalt adhesive is applied to each connection portion to perform asphalt construction in order to bond an asphalt mat provided in a caisson and a connecting iron plate member to asphalt filling a space portion. The asphalt mat construction method according to claim 1, wherein: