JPH047886B2 - - Google Patents

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention relates to a method for manufacturing a prefabricated concrete pile, particularly a short composite type steel pipe concrete pile whose surroundings are integrally covered with a steel pipe. The present invention relates to a method for manufacturing multiple short piles that makes it possible to manufacture a large number of steel pipe concrete piles with different dimensions in a single process.

<Prior art> Conventionally, for example, as shown in Japanese Utility Model Publication No. 52-44296, two opposing joint end plates are connected using a joint jig and loaded into a single formwork. In order to fix the end plate of the joint to the formwork, there is a method of fixing the final joint end plate to the formwork with bolts, and when using this method, as the number of piles manufactured within the formwork increases, However, the number of steps for fixing and releasing the joint jig increases and becomes complicated, resulting in poor efficiency, poor workability, and high costs.

Therefore, it has been extremely difficult in practice to efficiently manufacture short-sized piles by implementing the method described above.

<Problems to be Solved by the Invention> The present invention is a completely new technology developed in view of the above-mentioned drawbacks of the conventional technology.
The purpose of the present invention is to provide a specific method that can inexpensively mass-produce short steel pipe concrete piles, for example, 4 m or less, preferably about 0.4 to 3 m, by a simple and reliable process, several at a time.

<Means for Solving the Problems> The present invention provides several short steel pipes, end plates, donut-shaped partition plates, and/or donut-shaped joint end plates, respectively, in a predetermined order inside a centrifugal forming mold. They were assembled and stored in the formwork, and while they were fixed by applying pressure with a predetermined means, concrete was poured into the formwork and centrifugally formed, and after the concrete was cured, it was covered with a steel pipe. This is a method for producing multiple short piles, which is characterized by taking out several short piles from the formwork.

<Function> As described above, the method according to the present invention involves arranging a plurality of steel pipes, end plates, partition plates, etc. in an appropriate order in a centrifugal molding frame, and fixing them under pressure to each other. Since they can be closely fixed, there is no need to connect them to each other via special joint jigs, etc., and therefore there is no need to install or dismantle multiple joint jigs. ,
It is possible to reduce the number of parts and significantly improve work efficiency.

<Example> A specific example of the method according to the present invention will be explained with reference to the drawings.One example of the present invention is as shown in FIG.
A plurality of short steel pipes 2, doughnut-shaped partition plates 5, and end plates 3, 4 are combined and housed in a predetermined order inside the centrifugal forming form 1, and these are assembled into rods 10, etc. The concrete is poured into the formwork 1 and centrifugally formed. After curing the concrete molded product, the steel pipe 2 is taken out from the formwork 1 and the steel pipe is coated. This is a method for manufacturing a large number of short piles in one process.

An apparatus for carrying out this manufacturing method and a manufacturing method using the apparatus will be specifically explained with reference to the drawings.
In Figs. 1 to 9, reference numeral 1 denotes a conventional bifurcated cylindrical centrifugal molding form that can be opened and closed vertically, and as shown in the figure, several short steel pipes 2 are used. , end plates 3, 4, donut-shaped partition plate 5, etc., are configured so that they can be combined and stored in an appropriate order. Further, a fixing plate 6 and a pressurizing fixing plate 7 are removably attached and fixed to the ends of the formwork 1 via bolts, respectively. This fixing plate 6 is attached to one end of the formwork 1 to hold down the aforementioned steel pipes, end plates, etc. inserted and connected into the formwork 1, and is made of steel or the like having a substantially rectangular shape, and has bolt holes. 8 are bored and fixed to the lower formwork of the formwork 1 via bolts 9. The pressure fixing plate 7 is attached to the other end of the lower formwork of the formwork 1, into which a pressure rod 10 (described later) can be inserted and attached, and has an approximately trapezoidal shape and is made of steel or the like. configured,
Furthermore, bolt holes 11 used for fixing to the formwork 1 and rod holes 12 for inserting pressure rods 10 are provided on both sides thereof, respectively. Further, it is attached and fixed to one end of the formwork 1 via bolts 13.

Next, as mentioned above, the pressure rod 10 is inserted through the pressure/fixation plate 7 and presses the end plate 3 etc. in the formwork 1, and a nut 14 is attached to at least one end thereof. A threaded portion 15 is provided that allows the screw to be rotated. As shown in FIGS. 6 to 8, this rod 10 can have various structures, including one with a threaded portion 15 on the other end, and one with a coupler 16 having a threaded portion on the inner periphery. Several rods 1
0 connected together, and a structure in which the coupler 16 does not come off even if the rod 10 is rotated by tightening a screw pin drilled in the coupler 16, and a tip with rotational play at the tip. A structure to which the structure 17 is attached can be used. The diameter of this pressure rod 10 is generally 20
A length of about mm is sufficient, and the length can be selected appropriately, but generally a length of about 50 to 100 cm is sufficient.

This rod 10 is connected to the rod hole 12 of the pressure fixing plate 7.
and threaded portion 15 at one end of the rod 10.
The rod 10 is fixed by screwing together the nut 14 and tightening the nut 14 to the pressure fixing plate 7. At this time, as shown in FIG. 9, an auxiliary nut 18 is attached to the back side of the pressure fixing plate 7.
It is also possible to configure the rod 10 so that it does not loosen completely.

Using a device having the above-mentioned configuration, the steel pipe 2, end plates 3, 4, partition plate 5, etc. housed in the formwork 1 are connected in a predetermined order and pressed into the formwork 1. The state in which it is fixed is shown in FIG.

As shown in FIG. 1 above, a steel pipe 2, end plates 3 and 4, and a doughnut-shaped partition plate 5 are housed in a formwork 1.
The steel pipes 2 and 2 may remain individually independent, or as shown in Fig. 10, the steel pipes 2
The end plates 3 and 4 or the donut-shaped joint end plate 19 having a hollow part in the center are respectively welded to the ends of the joint, or the independent donut-shaped partition plate 5 is interposed between them. The present invention can be implemented by combining the following.

In addition, if end plates or joint end plates are not welded, or if there are parts of the steel pipe that do not have end plates or joint end plates, it is possible to attach end plates or joint end plates to the steel pipe in a later process if necessary. I can do it.

Generally, it is easier to fix using steel pipes 2. In addition, when using this steel pipe 2, a steel pipe having the same diameter and wall pressure as the steel pipe used for conventional long steel pipe concrete piles is generally used. Also, the end plates 3, 4, partition plate 5, and joint end plate 19 have the same diameter and thickness as those used as conventional steel pipe concrete pile end plates and joint end plates, and Except for a part of the end plate 3, it is formed in a donut shape with a hollow part in the center, and is configured so that concrete can be poured into the hollow part.

Next, a specific example of the method of making a short steel pipe concrete pile according to the present invention will be explained. The plate 19 is housed in the lower formwork of the usual two-split cylindrical formwork 1, which is configured to open and close up and down in an appropriate order, and the formwork 1
Fixing plate 6 or pressure fixing plate 7 to fix both ends of the lower formwork.
Then, the pressure rod 10 is inserted into the rod hole 12 of the pressure fixing plate 7, and the lower part of the end plate 3 is strongly pressed with the rod 10 through the nut 14.
As a result, the various steel pipes 2, end plates 3, 4, partition plates 5, and joint end plates 19 are connected in close contact with each other, and then the upper formwork above the formwork 1 is connected to these steel pipes. 2. Cover the upper parts of the end plates 3, 4, the partition plate 5, and the joint end plate 19, fix the upper formwork and the lower formwork to each other using screws, etc., and in this state, formwork 1 is heated at high speed. By injecting concrete into the formwork 1 and solidifying it while rotating, it is possible to form a hollow concrete 20 integrally formed within the steel pipe 2 as shown in FIG. 11.

The concrete 20 is allowed to cure in this state, and then the pressurizing rod 10 is loosened, the pressurizing fixing plate 7 or the fixing plate 6 is removed from the formwork 1, the formwork 1 is opened, and the steel pipes 2 are inserted into the formwork 1. A short steel pipe concrete pile 21 can be manufactured by taking out the hollow concrete 20 integrally formed with the hollow concrete 20 as shown in FIG. 12, for example.

For curing of the concrete 20 in the above embodiment, the steel pipe concrete pile 21 may be removed from the formwork 1 after curing is completely completed, but generally, the concrete 20 is cured in a step called pre-curing, for example, by raising the temperature to 60°C. Heat to 60°C for at least 40°C for 1 hour until 13
After being cured in a curing pot for more than an hour, the short steel pipe concrete piles 21 may be removed from the formwork 1, and after being taken out, the separated short steel pipe concrete piles 21 may be stored in a pallet or the like and cured in an autoclave.

A more detailed illustration of the state in which the pressure fixing plate 7 is attached to the formwork 1 via the bolt 13 in the above embodiment (the state in which the fixing plate 16 is attached is omitted) is as shown in FIGS. 13A and B. It is. The fixing plate 7 may be attached directly to the flange of the formwork 1, or it may be attached to the formwork 1 via a rib with a tap or the like.
It is also possible to attach it to

As mentioned above, when storing the steel pipe 2 etc. in the forming frame 1, a spacer 22 made of a rubber plate or the like is placed between the form 1 and the steel pipe 2 etc. as shown in FIG. By intervening, the steel pipe 2 and the like can be stabilized within the formwork 1.

Furthermore, it is effective to arrange the spacers 22 at about four locations at the joints of the steel pipes 2, as shown in FIGS. 15 and 16. 23 is a connecting line that connects the spacers to each other.

<Effects of the Invention> Since the method according to the present invention has the above-described structure and operation, it is possible to easily and reliably arrange a plurality of short steel pipes, end plates, partition plates, etc. in a desired order without adhering them to each other. The concrete can be connected in close contact with the steel pipes, and the concrete can be centrifugally formed in that state.Therefore, there is no need to install and dismantle multiple joint jigs as in the past, and it is possible to form multiple short steel pipes using concrete. The piles can be easily manufactured in a single process, and this type of pile can be mass-produced at low cost.

[Brief explanation of drawings]

1 to 10 are views showing embodiments of an apparatus for carrying out the method of the present application, in which FIG. 1 is a horizontal sectional view, and FIGS. 2 and 3 are side views seen from the respective ends. , FIG. 4 to FIG. 9 are explanatory diagrams showing the respective parts, FIG. 11 and FIG.
16 through 16 are explanatory diagrams of other examples. 1 is a formwork, 2 is a steel pipe, 3 and 4 are end plates, 5 is a partition plate, 6 and 7 are fixed plates, 10 is a rod, 14, 18
15 is a nut, 15 is a screw, 19 is a joint end plate, 20 is concrete, 21 is a short steel pipe concrete pile, and 22 is a spacer.

Claims (1)

[Claims] 1 Several short steel pipes, end plates, donut-shaped partition plates, and/or donut-shaped joint end plates are combined and stored in a predetermined order inside a centrifugal forming form, and these are assembled using a predetermined means. It is characterized by pouring concrete into the formwork while fixing it by pressurizing it and performing centrifugal forming, and after further curing the concrete, several short piles covered with steel pipes are taken out from the formwork. A method for manufacturing multiple short piles.