JPS61155573A - Anchoring of compression ring or knuckle in underground tank - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a method for installing a compression ring or knuckle ring in an underground tank.

(Prior art) and (Problem to be solved by the invention)
Conventionally, when constructing an underground tank, a continuous underground wall (1) was constructed underground around the tank's outer periphery, the earth and sand inside the continuous underground wall (1) was excavated, and the side wall concrete (2) of the tank body was constructed.
Then, the bottom slab concrete (3) is poured to complete the series of civil engineering works.

Next, mechanical work begins, first installing compression (4) or knuckle rings (4) on the top of the side wall concrete (2).
4α), and then attach the roof (5) and hanging deck (6) assembled on the concrete bottom slab (3) to the side wall concrete.
) (2) Lift it up and secure it using the center hole jack installed for temporary installation at the top. With the completion of the roof (5) construction, the roof will be completely protected from rain), followed by insulation work and membrane installation, completing a series of tank construction works.

Next is the side wall concrete, which is also the point of contact between civil engineering and mechanical construction, which is a problem with the tank construction mentioned above! J-) The conventional construction method from installation of the top compression ring (4) or knuckle ring (4α) in (2) to concrete pouring will be explained.

In the conventional underground tank construction method, the side walls are made of concrete [2]
When pouring concrete at the top, an anchor plate (4b) fixed in advance by welding is buried in the anchor reinforcing bar (7), and then concrete is placed at the top of the side wall concrete (2). (See Figure 6) Same side wall conch I
J-) After curing in (2), the civil engineering contractor hands it over to the machinery contractor, who then installs the compression ring (4).
) or knuckle ring (4α) to the anchor plate (
4b), and fix the lower end of the compression ring (4) or knuckle ring (4) to the upper surface of the anchor plate (4b) by fillet welding or the like (see Figure 7). There was no mixed work at the intersection of civil engineering and mechanical work, and the construction progressed smoothly.

However, due to specification upgrades, etc., side wall damage may occur.
-G (2) Improving the pressure resistance and airtightness of the top is required;
The anchor plate (4b) was to be buried in the top of the side wall concrete (2).

This ml not only causes the material of the compression ring (4) or the knuckle ring (4α) to extend downward, but also complicates the interface between the aforementioned civil engineering work and mechanical work, resulting in more mixed work.

Next, a typical construction method of this type will be explained.

Figure 8 shows an overview of the jack-down construction method, in which anchor reinforcing bars (7) are planted at the top of the side wall concrete (2) in advance when pouring the side wall concrete (2). Concrete is poured, but the extra width of the anchor plate (4b) of the compression ring (4) or knuckle ring (4α) is taken and a box is cut out in a band shape in the circumferential direction to form the top side wall concrete IJ-).
(2C) is poured.

At this point, the work was transferred from civil engineering to mechanical work. Temporary support material (9) was placed in an appropriate position on top of the boxed-out side wall concrete top (2C), and the compression ring (4) was brought in. Alternatively, the knuckle ring (4) is loaded onto the temporary support material (9) and temporarily fixed. Then, after welding between each block and various inspections are completed, the compression ring (
4) Or pick up the knuckle ring (4α) with a jack,
Alternatively, after lifting it with a lifting device and pulling out the temporary support material (9), slowly lower it onto the support object (8) of the anchor plate (4b) at the top of the side wall concrete (the two boxed-out points) and position it. Fix it.

At this point, the work is transferred from mechanical engineering to civil engineering again, and medium-grade concrete is poured into the boxed-out area at the top of the side wall concrete (2C).

The disadvantage of this method is that the compression ring (4) or knuckle ring (4) is connected in a circular shape and then lowered as described above, so each point on the circumference is lowered at the same time, and a large number of machines It also requires a watchman, which requires a large amount of cost.Furthermore, since the entire ring is suspended in the air, installation standards become difficult, and many problems are expected from the standpoint of installation accuracy and safety, making it far from practical.

Figures 8 and 9 show a conventionally commonly used expansion method. Similar to the method described above, anchor reinforcing bars (7α) are attached to the side wall concrete (2) in advance when pouring the side wall concrete (2). j −t(
2) Plant it at the top. After the concrete hardens, the measurement is performed and the metal support (8) is welded and fixed to the protruding end of the anchor reinforcing bar (7α). The compression ring (4) or knuckle ring (4α) brought to the site is temporarily placed on the metal holder (8), positioned, and fixed. When the compression ring (4) or knuckle ring (4) is connected in a circular shape, the work is transferred from mechanical work to civil engineering work.

For civil engineering work, prepare for pouring concrete for the top of the side wall concrete (F), set formwork (10) on the outer and inner surfaces of the side wall concrete (2) and the top of the side wall concrete (21L), and place thick timbers ( 10α) etc., and then concrete for the top of the rear side wall concrete (2d) is poured.

The disadvantage of the above construction method is that the formwork (10) on the inner side for pouring concrete at the top of the side wall concrete (C%) is in the way, making it difficult for workers to enter. The biggest drawback is that when removing the formwork (10) and thick timber (10α) after pouring concrete at the top of the side wall concrete (2ft), the compression ring (4) or knuckle ring (4) must be placed inside the tank. It is impossible to work with heavy equipment in such a narrow place because it requires a large extension and a large lateral movement distance in relation to the height of the hoist.
) and thick timber (10α) cannot be removed.

(Means for Solving the Problems) The present invention was proposed in order to solve these problems, and consists of constructing parapet concrete on the inside of tank side wall concrete with anchor reinforcing bars planted on the top surface. After fixing the bracket to the protruding end of the anchor reinforcing bar, the compression ring or knuckle ring with the folding scaffold attached is carried in, the anchor plate at the lower end of the ring is fixed to the bracket, and then the folding The present invention relates to a method for installing a compression ring or a knuckle ring in an underground tank, which comprises deploying a tatami scaffold and supporting it at the top of the concrete parapet, and then placing embedded concrete on the concrete side wall.

(Function) As described above, in the present invention, #wall concrete is continuously installed inside the tank side wall concrete with anchor reinforcing bars planted on the top surface, and a receiving object is fixed to the protruding end of the anchor reinforcing bars, The compression ring or top knuckle ring with the folding scaffold attached is carried in, and the anchor plate at the lower end of the ring is fixed to the receiver, and then the ring is tightly attached to the ring in a folded state so as not to hinder the carrying. The folded scaffold is unfolded, the scaffold is supported by the concrete parapet, and embedded concrete is poured onto the side wall concrete from above the folded scaffold, using the concrete parapet as an inner formwork.

(Effects of the Invention) According to the present invention, as described above, the parapet concrete is provided in succession inside the side wall concrete, and the parapet concrete is used as a support for the folding scaffold attached to the compression ring or knuckle ring. By using the inner formwork for pouring the embedded concrete on the side wall concrete, it is easy and accurate.
It can be constructed at low cost.

(Example) The present invention will be described below with reference to the illustrated embodiments.

Side wall conch! j −) (11) At the time of casting, anchor reinforcing bars (12) are planted in advance at predetermined positions on the top surface of the side wall concrete (11) so as to protrude by approximately 150+m.

(See Figures 2 and 3) Side wall concrete IJ -) (1
1) Parapet concrete ')-) (11α) is installed continuously on the inside of 1), but even if the parapet concrete (11α) is poured at the same time as the side wall concrete (11), it is not possible to construct it with post-cast concrete. may be done.

At this time, at the site joints of the compression ring or knuckle ring, the parapet concrete (11 cL) will be applied as thinly as possible to take up sufficient work space.

At this point, the work is handed over to mechanical engineering.

After the poured concrete has hardened, leveling and centering measurements are carried out, and the anchor reinforcing bars (12) and K brackets (13) are fixed in predetermined positions by welding.

Next, the folding scaffold (14) carries in the compression ring (16) or knuckle ring (167L) that is pivotally supported on the eye plate (15), and places the anchor plate (17) at the lower end of the ring on the holder (13). Place it on a shelf and fix it. Then pre-compression phosphorus/(16)
Alternatively, the folding scaffold (14) in a folded state can be deployed on the inner surface of the knuckle ring (16α) and the parapet concrete (11
α), attach an approach staircase, etc. over the compression ring (16) or knuckle ring (16), and insert it into the folding scaffold (12).

Now the work will move on to civil engineering work again. (See Figure 1) Then the side wall concrete) (11) Embedded concrete at the top
J-(11) is poured.At this time, the inner parapet concrete! It becomes the inner formwork. (See Figure 4) Also, the compression ring (16) or knuckle ring (16α)
) For work in narrow spaces inside, a special folding scaffold (14
) is extremely safe and easy to perform. After concrete is poured, if the folding scaffold (14) is not needed, it shall be removed, leaving the eye plate (15).

In the above-mentioned conventional expansion method, the inner formwork and thick timbers are in contact with each other, and when removing the mold, it is impossible to remove it to the center of the tank, and the only way is to lift it vertically.For this reason, the compression ring (16 ) or knuckle ring (1
The overhang of the 6-ring is large and heavy machinery cannot be used.
It becomes impossible to remove.

In addition, when pouring concrete at the top of the side wall, the formwork can be a hindrance, such as compression ring (16) or knuckle ring (
16α) It is difficult to erect the inner scaffolding, and it is also difficult for workers to enter and exit.It is also unfavorable from a safety standpoint.

Furthermore, the conventional jack-down construction method is an expansion method, that is, the so-called box-cutting method used when the concrete around the roots of the structure to be installed cannot be cast at the same time.After the concrete has hardened, the structure is installed in the predetermined position of the box-cutting. In particular, there was a problem in that it was difficult to simultaneously lower a ring-like joint such as a compression ring (16) or a knuckle ring (16α).

However, according to the method of the above-mentioned embodiment, the work space and assembly order are set in a certain order as described above, and furthermore, the parapet concrete has a formwork function and a scaffold support function, which is safer, easier, and more accurate. It can be constructed at low cost.

Although the present invention has been described above with reference to embodiments, the present invention is, of course, not limited to such embodiments, and can be modified in various ways without departing from the spirit of the present invention. .

[Brief explanation of drawings]

FIG. 1 is a vertical cross-sectional view showing the implementation status of an embodiment of the method for installing a compression ring or knuckle ring in an underground tank according to the present invention, and FIGS. 2 and 3 are vertical cross-sectional views showing the preceding steps, respectively. A plan view, FIG. 4 is a longitudinal sectional view showing the state at the time of completion of construction, FIG. 5 is a longitudinal sectional view of the underground tank, and FIGS. 8 and 9 are longitudinal sectional views showing steps of other examples of the conventional construction method, respectively. (11)... Side wall concrete, (11α)... Parapet wall concrete, (11b)... Embedded concrete, (12)... Anchor reinforcement, (13)... Bracket, (14)...・Folding scaffold, (16)...Compression Lin, /, (16α)...Knuckle Lin,
/, (17)...Anchor Plate Sub-Agent Patent Attorney Kaihon Important Literature 3 Persons No. 40

Claims (1)

[Claims] A compression ring or knuckle ring with a folding scaffold attached after parapet wall concrete is connected to the inside of tank side wall concrete with anchor reinforcing bars planted on the top surface and a receiver is fixed to the protruding end of the anchor reinforcing bars. is carried in and the anchor plate at the lower end of the ring is fixed to the receiver, the folding scaffold is then unfolded and supported on the top of the parapet concrete, and embedded concrete is then placed on the side wall concrete. Installation method for compression rings or knuckle rings in underground tanks.