JPH04349090A - Structure of concrete form for pontoon and manufacture of pontoon - Google Patents

Abstract

PURPOSE:To construct a pontoon from a buoy having a small specific gravity and a concrete shell of specified thickness enclosing the buoy, wherein the pontoon is equipped with good stability and durability, deep draft to cause lesser rocking, and with no problem about water stopping at the shell body. CONSTITUTION:An outer form 16 is assembled, and bottom concrete 13 is placed. A buoy 11 is installed in place on this bottom concrete 13, and a buoyant preventing means 22 is provided which detains the installed buoy and fixes. The side concrete 14 is placed between the outer form 16 and buoy 11, and the mentioned buoyant preventing means 22 is removed, followed by placing of the oversurface concrete, and the outer form 16 is removed after curing for a specific period of time.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention relates to a method of manufacturing a pontoon used as a pier, etc. on the water surface, and a formwork structure for the pontoon, and particularly relates to a floating body with a light specific gravity that floats on the water surface, and a predetermined thickness to cover the periphery of the floating body. The present invention relates to a method for manufacturing a pontoon comprising a concrete outer shell, and a formwork structure for a pontoon used in the manufacturing method.

0002

[Prior Art] A floating structure that floats on the water surface, that is, a pontoon, rises and falls as the water surface rises and falls, and the difference between its top and the water surface, that is, the freeboard, is constant. It is convenient for mooring ships and ferryboats, and is therefore used as a mooring quay and as a floating pier connecting this with the shore. Conventionally, many of these pontoons have been manufactured from reinforced concrete with hollow holes to provide buoyancy. Here, pontoons made of reinforced concrete have a strong and durable structure, and are less susceptible to shaking because of their deep water, but they require a rich mix of concrete to make them watertight, and they also tend to crack or crack due to impact. However, it has the disadvantage that its water-stopping properties tend to be impaired.

On the other hand, various types of pontoons have been developed that use floating bodies with light specific gravity that float on the water surface, such as styrofoam, and do not have water-stopping properties.
In order to prevent shells, seaweed, etc. from attaching to the periphery of the Styrofoam and causing the Styrofoam to thin or become damaged, the outer periphery of the Styrofoam is covered with shotcrete, reinforced plastic, etc.

0004

[Problem to be solved by the invention] However, in the conventional pontoon using a floating body as described above, the outer shell of the pontoon, such as shotcrete or reinforced plastic, is used only to protect the floating body, and the pontoon is It does not demonstrate its strength as a member. Therefore, in order to maintain the strength as a floating structure, it is necessary to strengthen the structure of the upper part of the pontoon, which causes the problem that the weight of the upper part increases and the pontoon becomes unstable.

[0005] In addition, in order to obtain the same advantages as conventional reinforced concrete pontoons, which are highly durable and have little oscillation due to deep water, it is necessary to increase the thickness of the concrete shell surrounding the floating body to some extent. However, if necessary, it is necessary to include reinforcing bars to strengthen the structure.
Conventional concrete outer shells covering floating bodies were formed by spraying concrete, so there were limits to the thickness and quality of the concrete, making it impossible to obtain a strong structure.

[0006] Therefore, the present invention was made to solve the above-mentioned problems, and its purpose is to strengthen the structure of the concrete shell that covers a floating body with a light specific gravity floating on the water surface, and to simplify the structure of the upper part. To provide a method for manufacturing a pontoon that can obtain a pontoon with good stability, and also a pontoon that is highly durable and has deep water and less oscillation, and a formwork structure for a pontoon used in the manufacturing method. be.

[0007]

[Means for Solving the Problems] The present invention has been made in view of the above object, and its gist is to provide a floating body with a light specific gravity that floats on the water surface, a concrete outer shell of a predetermined thickness that covers the periphery of the floating body, and A method for manufacturing a pontoon, comprising: assembling an outer formwork for the concrete outer shell; pouring concrete on the bottom of the outer shell; and placing the floating body on the bottom concrete as a hollow formwork, , a step of installing at a predetermined position using a positioning means such as a ruler, and installing a floating prevention means for restraining and fixing the upper end surface of the floating body to prevent it from rising due to buoyancy during side concrete pouring; A step of placing side concrete between the outer formwork and the floating body, a step of removing the floating prevention means after curing the side surface concrete for a predetermined period of time, a step of placing top surface concrete, and a step of placing the top surface concrete, and a step of placing the side surface concrete for a predetermined period of time. The method of manufacturing a pontoon comprises the step of demolding the outer formwork after curing.

[0008] Furthermore, if reinforcing bars are placed on each surface of the concrete shell before concrete is placed on each surface,
The concrete outer shell can be made stronger as reinforced concrete.

[0009] Here, it is not necessary to assemble all the frames for the outer formwork prior to other processes, but only the necessary frames can be assembled as appropriate in view of the workability of installing the floating body and assembling reinforcing bars. You can assemble it.

[0010]The floating body to be installed on the bottom concrete is positioned at an accurate position and firmly fixed so as not to shift during pouring of the side concrete. If the positioning is not accurate or if a positional shift occurs during pouring of the side concrete, both are undesirable because the balance of the completed pontoon will deteriorate due to the difference in wall thickness of the side concrete.

[0011] As the floating body with a light specific gravity that floats on the water surface covered by the concrete shell, for example, in addition to foamed polystyrene processed into a predetermined shape, a rubber air bag, a resin air bag, etc. can also be used.

Another gist of the present invention is a formwork structure for installing and fixing the floating body in a predetermined position as a hollow formwork and pouring concrete around the floating body, the bottom formwork and A side formwork connected to the floating body and erected around it at a predetermined distance from the floating body as the abandoned formwork, and a beam member fixed to the upper end of the side formwork across one opposing side formwork;
A holding member is interposed between the beam member and the floating body, makes surface contact with a predetermined area of the upper end face of the floating body, and has an upper end fixed to the beam member, and restrains the upper end face of the floating body over a wide range. The structure of the pontoon formwork is characterized by preventing the floating body from rising during side concrete pouring.

[0013] Here, the holding member itself has, for example, a flange portion and comes into direct contact with the upper end surface of the floating body, as well as a plate-shaped member such as plywood laid on the upper surface of the floating body, and the plate-shaped member and the beam. It may also be used in combination with a width stopping member interposed between the member and the member.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, one embodiment of the present invention will be described in detail with reference to the accompanying drawings.

According to this embodiment, as shown in FIG. 1, the pontoon 10 has a width of 200 cm and a height of 100 cm, for example, and is made up of a styrofoam 11 and a reinforced concrete 12 that covers the outer periphery of the pontoon to form an outer shell. , length 300
Manufactured as a cm hexahedron. The thickness of the reinforced concrete 12 is calculated based on various design conditions, but it is preferably 50 mm to 100 mm. In order to sufficiently spread the concrete to every corner of the formwork, and to use well-balanced pontoons. The pontoon 10 is manufactured according to the following steps in order to encapsulate the foamed polystyrene 11 in the exact position to be manufactured.

1) Assembling the formwork Prior to pouring concrete, a box-shaped steel frame 16 as an outer formwork is assembled using bolts or the like. As shown in FIG. 2, the box-shaped steel frame 16 is first assembled into a bottom formwork 1 in order to facilitate the assembling of reinforcing bars, which will be described later.
7 and one opposing side formwork 18 necessary for positioning the reinforcing bars are assembled, and later the other opposing side formwork 19 is assembled.

2) Assembling the bottom and side reinforcements and pouring the bottom concrete (see FIG. 3) Using the bottom formwork 17 and one opposing side formwork 18 as guides, the bottom reinforcement 20 is assembled using spacers, binding wires, etc. And the necessary side reinforcing bars 21 are arranged at predetermined positions. When the reinforcement is completed, the other opposing side formwork 19 is attached, and bottom concrete 13 is poured using a concrete bucket or the like. When the poured bottom concrete 13 has hardened to a certain extent, distribution bars etc. are attached to the side reinforcement 21, and the reinforced concrete 12
Attach the sheath tube, insert, etc. that should be buried in the

3) Installation and fixation of the foamed polystyrene and installation of a lifting prevention device consisting of a beam member and a holding member (see FIG. 4) A foamed polystyrene 11 of a predetermined shape is installed in a box-shaped steel frame 16 at an accurate position. Note that the styrofoam 11 is processed into a plurality of predetermined shaped members using a wood saw, a hacksaw, or the like. And Styrofoam 11
For this purpose, cut out boxes, cut out grooves, etc. will be made as appropriate at predetermined locations, increase the thickness of the reinforced concrete at those locations, and reinforce the locations where sheath pipes, inserts, etc. will be installed. In addition, during installation, the plurality of polystyrene foam members are integrated using double-sided tape, gummed tape, etc., and are accurately positioned using, for example, a guide 35 attached to a steel beam 23, which will be described later. It is fixed with a ruler material 36 provided at. Note that the styrofoam 11 may be formed by manually positioning the divided individual styrofoam 11 by a worker and integrating them in a mold.

[0019] Above the styrofoam 11,
Styrofoam 11 during side concrete pouring described later
An anti-surfacing device 22 is installed to prevent the float from rising due to buoyancy. The floating prevention device 22 has a bulk specific gravity of approximately 0.016.
It is necessary to have a strong structure to resist the large buoyant force that the styrofoam 11 is subjected to in the concrete that has not yet solidified. A protruding plate 2 as a width stopper that protrudes downward and comes into contact with a plywood board 24 laid on the top surface of the Styrofoam 11 to prevent damage to the Styrofoam 11 and receive buoyancy across the surface.
5. A plurality of steel beams 23 and protruding plates 25 are arranged in parallel at predetermined intervals, and restrict the upper end surface of the foamed polystyrene 11 over a wide range via the plywood board 24. Note that the protruding plate 25 constitutes a holding member together with the plywood board 24.

4) Placing side concrete (see Figure 5)
The plywood board 24 laid on the top surface of the Styrofoam 11
is used as a work scaffold, and after conveying concrete to the plywood board 24 using a concrete bucket or the like, it is poured onto the side using a shovel or the like. After pouring concrete evenly around the entire circumference, compaction is performed to form side concrete 14.

5) Curing of the side concrete and removal of the floating prevention device The side concrete 14 begins to harden, and the floating prevention device 2 is removed.
The foamed polystyrene 11 is allowed to stand still and cure indoors for a predetermined period of time until it no longer rises even if the styrofoam 11 is removed. When you can no longer press the top surface of the concrete with your fingers, loosen the bolts 26 and remove the anti-lifting tool 22 and the plywood board 24.

6) Assembling the top reinforcing bars and placing the top concrete (see Figure 6) Attach the top reinforcing bars 26 and, if necessary, use long bolts or the like to connect the box fittings 27 between the pontoons (see Figure 1). etc., and pour concrete 15 on the top surface using a concrete bucket or the like.

7) Curing and demolding After pouring the top concrete 15, it is preferably kept for about 1.5 hours until breathing is completed and a thin hardened layer is formed on the surface.
Let stand indoors for 0 hours. Next, the top surface of the top concrete 15 is finished smooth using a wooden trowel, a metal trowel, or the like. moreover,
Curing is performed for a specified period of time. Here, the curing time can be shortened by covering the entire box-shaped steel frame 16 with a sheet or the like and providing steam piping inside for steam curing. After curing is completed, the mold is removed and the completed pontoon 10
Transport and store indoors or in a work yard.

[0024] In this embodiment, in the step 3), a device is used to prevent the styrofoam 11 from rising by pressing the styrofoam 11 from above through the steel beam 23 attached to the upper end of the side formwork 19. However, as shown in FIG.
Styrofoam 11 may be prevented from rising by the tensile force of a plurality of anchor reinforcing bars 33 that have one end fixed to Styrofoam 11 and the other end fixed to the top of Styrofoam 11 via fixing plate 32. .

[0025]

Effects of the Invention As described above, the method for manufacturing a pontoon of the present invention involves pouring a concrete outer shell that covers the periphery of a floating body with a light specific gravity that floats on the water surface, dividing it into the bottom, side, and top surfaces, and By precisely positioning and fixing the floating body and preventing it from rising due to the buoyancy of the floating body during side concrete pouring using anti-floating means, it is possible to easily and accurately form a concrete shell with a thickness that cannot be obtained with shotcrete. can. Therefore, according to the present invention, by strengthening the structure of the concrete outer shell that covers the floating body, the structure of the upper part of the pontoon can be simplified, resulting in a pontoon that is excellent in stability and durability, and has deep water and less oscillation. can be easily manufactured.

Furthermore, according to the pontoon formwork structure of the present invention, the holding member contacts the upper end surface of the floating body over a wide area, restrains the upper end surface over a wide range, and prevents the extremely large buoyancy during side concrete pouring. By stably preventing the floating body from rising and preventing damage to the floating body, it is possible to manufacture a pontoon with high precision.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram showing the configuration of a pontoon manufactured according to an embodiment of the present invention.

FIG. 2 is an explanatory diagram showing the process of assembling the frame.

FIG. 3 is an explanatory diagram showing the process of pouring concrete on the bottom of the concrete shell.

FIG. 4 is an explanatory view showing a step of attaching a discarded formwork and floating prevention means.

FIG. 5 is an explanatory diagram showing the process of pouring concrete on the side surface of the concrete shell.

FIG. 6 is an explanatory diagram showing the process of pouring concrete on the upper surface of the concrete shell.

FIG. 7 is an explanatory diagram showing another example of floating prevention means.

[Explanation of symbols]

10 Pontoon 11 Styrofoam (floating body) 12 Reinforced concrete (outer shell) 13 Bottom concrete 14 Side concrete 15 Top concrete 16 Box-shaped steel frame 17 Bottom formwork 19 Side formwork 22 Anti-surfacing device 23 Steel beam 24 Plywood board (holding member) 25 Protruding plate (holding member) 35 Guide 36 Ruler material

Claims (2)

[Claims] 1. A method for manufacturing a pontoon comprising a floating body with a light specific gravity floating on the water surface and a concrete shell having a predetermined thickness surrounding the floating body, comprising the steps of: assembling an outer formwork for the concrete shell; A step of pouring concrete on the bottom of the outer shell, and setting the floating body on the bottom concrete as a hollow formwork in a predetermined position using positioning means such as guides and rulers, and restraining the upper end surface of the floating body. , a step of fixing and installing a floating prevention means to prevent the floating body from rising due to buoyancy during side concrete pouring; and a step of pouring side concrete between the outer formwork and the floating body;
A method for manufacturing a pontoon, which comprises the steps of removing the floating prevention means after curing the side concrete for a predetermined period of time, placing concrete on the top surface, and demolding the outer formwork after curing for a predetermined period of time. 2. In order to manufacture a pontoon consisting of a floating body with a light specific gravity that floats on the water surface and a concrete shell of a predetermined thickness that covers the periphery of the floating body, the floating body is installed and fixed at a predetermined position as a hollow formwork, A formwork structure for pouring concrete around a floating body, the side formwork being connected to the bottom formwork and erected around the floating body at a predetermined distance from the floating body as the abandoned formwork. , a beam member fixed to the upper end of one of the opposing side formworks, interposed between the beam member and the floating body, the beam member is in surface contact with a predetermined area of the upper end surface of the floating body, and the upper end is A formwork structure for a pontoon, comprising a holding member fixed to a beam member, and restraining the upper end surface of the floating body over a wide range to prevent the floating body from rising during side concrete pouring.