JPH09250147A - Connection structure and tool of side wall and bottom slab of underground tank - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the relative displacement between the side wall and the bottom slab of an underground tank in an earthquake, by arranging an elliptic steel pipe having the longitudinal direction thereof in the radial direction of the underground tank, at the lower face of the side wall and arranging metal fitting as a connecting tool fitted to an elliptically cylindrical hole at the upper face of the bottom slab. SOLUTION: An underground tank 1 is installed in the ground 3 and materials 9 in the tank are arranged within the tank 1. And an elliptical steel pipe 33 having the longitudinal direction thereof in the radial direction of the tank 1 is arranged at the lower face of the side wall 5 of the tank. In this case, a metal fitting 31 fitted to the elliptical steel pipe 33 is arranged at the upper face of the bottom slab 7 to form a connection tool 41. The diameter of the metal fitting 31 is made a little smaller than the tangential inner width of the tank, of the pipe 33 and the pipe 33 is stretched to the same direction with the radial direction of the tank. Accordingly, the side wall 5 and the bottom slab 7 can be transferred in the radial direction of the tank 1 but the relative movement in the other directions than the radial direction is restricted. In this way, the stresses of the side wall 5 and the bottom slab 7 can be made small in the radial relative displacement of the tank at the usual operation time and the relative displacement between the side wall 5 and the bottom slab 7 can be restricted in an earthquake.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a side wall / bottom plate joint structure and a joint tool for a low temperature liquefied gas underground tank.

[0002]

2. Description of the Related Art Generally, low temperature liquefied gas (LPG, LN
G) etc. are stored in underground tanks. FIG. 6 is a sectional view showing the overall structure of a conventional underground tank 101. The underground tank 101 includes a cylindrical side wall 103, a bottom slab 105, a roof 107, and the like. The underground tank 101 is a water-covered type in which the water level in the surrounding ground after the completion is the natural water level 109. Therefore, the bottom plate 105 is thick so as to resist the groundwater pressure acting on the bottom plate 105.

When the underground tank 101 is constructed, the work is performed at the outside temperature. However, since the low temperature liquefied gas (LNG) 111 stored inside the underground tank 101 during operation is extremely low temperature, it can be used both during construction and during operation. Then, the side wall 103 and the bottom plate 105
The temperature change is remarkable. Also, the side wall 103 and the bottom plate 105
Then, there are differences in how these temperature changes work. Also, the temperature change varies depending on the part.

The side wall 103 and the bottom plate 10 are subject to temperature changes and the like.
In order to reduce the stress generated between the side wall 103 and
The bottom plate 105 and the bottom plate 105 are joined together at the joint 113 by the hinge 115.
It is common to join with. FIG. 7 is a vertical cross-sectional view showing the joint portion 113 of the conventional underground tank 101. The hinge 115 is free from rotational deformation, free from horizontal displacement, and restrained from vertical displacement.

The joining method using the hinge 115 is the side wall 1
03, since the excessive stress is not generated in the bottom slab 105, there is a merit that the amount of the reinforcing bars forming the side wall 103 and the bottom slab 105 can be reduced. FIG. 8 is an enlarged vertical cross-sectional view showing the support plate 121, which is an example of the hinge 115.

As the inner tank material (membrane) 117 covering the entire inner surface of the underground tank 101, a member / structure excellent in airtightness, liquidtightness and displacement absorption is used, and the side wall 103 caused by temperature change and The relative displacement with the bottom plate 105 in the radial direction can be dealt with. Inner tank material 11
For No. 7, generally, a stainless steel sheet having a thickness of 1 to 2 mm and having a fold is used.

[0007]

However, the use of the conventional bearing plate 121 has the following problems. FIG. 9 is a diagram for explaining the relative displacement due to the seismic force E. The conventional bearing plate 121 and the inner tank member 117 can sufficiently cope with the relative displacement G in the radial direction. However, due to the seismic force E or the like, a force in a biased direction that is not axially symmetrical acts on the underground tank 101, and the side wall 103 and the bottom plate 105
When the tangential relative displacement F shown in FIG. 9 occurs in the and, the inner tank material 117 may be sheared and damaged.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a joining structure and joining tool for a side wall / bottom slab of an underground tank, which can cope with relative displacement in the tangential direction due to an earthquake or the like. To provide.

[0009]

In order to achieve the above-mentioned object, the first invention is a long cylindrical hole in which the radial direction of the underground tank is the longitudinal direction at the joint between the side wall of the underground tank and the bottom plate. Is provided on one of the side wall and the bottom plate,
The sidewall / bottom plate joint structure of an underground tank is characterized in that a rod-shaped member that fits into the hole is provided on the other of the side wall or the bottom plate.

A second aspect of the present invention is used in the joint structure of a side wall and a bottom slab of an underground tank according to claim 1, and comprises an oblong cylindrical steel pipe and a rod-shaped member fitted to the steel pipe. It is a joint between the side wall and bottom slab of an underground tank.

[0011]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a vertical cross-sectional view showing a joint portion of an underground tank 1. Underground tank 1
It is provided in the ground 3, and includes a side wall 5, a bottom slab 7, a roof (not shown), etc., and an inner tank material 9 is provided inside.
There is a gap 11 between the side wall 5 and the bottom plate 7.

At the joint between the side wall 5 of the underground tank 1 and the bottom slab 7, an oblong steel pipe 33 whose longitudinal direction is the radial direction of the underground tank 1 is provided on the lower surface of the side wall 5, and an upper surface of the bottom slab 7 is provided. , A metal fitting 31 that is a rod-shaped member that fits into the oval steel pipe 33
Is provided to form a joint tool 41. In addition, 13 is the ground surface, 15
Is the water table, and 17 is L stored in the underground tank 1.
It is NG.

FIG. 2 is a perspective view of the oval steel pipe 33. The elliptical steel pipe 33 is a long cylindrical pipe having both ends or one end opened.

FIG. 3 is an enlarged vertical sectional view showing the joint portion of the underground tank 1, and FIG. 4 is a transverse sectional view taken along the line BB of FIG. C indicates the tank radial direction of the underground tank 1.
The fitting 31 has a diameter slightly smaller than the inner width of the oval steel pipe 33 in the tank tangential direction. The oval steel pipe 33 has a shape extending in the same direction as the tank radial direction C. For this reason, the side wall 5 and the bottom slab 7 can move in the radial direction of the underground tank 1, but the relative movement in a direction other than the radial direction is restricted.

FIG. 5 is a cross-sectional view taken along the line AA of FIG. When the seismic force E shown in Fig. 9 acts on the underground tank 1,
A force that causes relative displacement F in the tangential direction acts on the connector 41. Therefore, by calculating a force obtained by multiplying the assumed maximum seismic force E by a predetermined safety factor, the size and the number of the connectors 41a, 41b, ... Are determined so as to cope with the earthquake. 43 is the bottom plate center.

As described in detail above, according to the present embodiment, the tangential relative displacement between the side wall 5 of the underground tank 1 and the bottom slab 7 is restrained against a unidirectional load such as an earthquake. Therefore, shear deformation does not occur in the inner tank material 9, and there is no possibility of damage.

Since the side wall 5 and the bottom slab 7 are free from relative displacement in the radial direction, they are not restrained against temperature changes that cause only relative displacement in the radial direction, and the generated stress is small like the hinge joining.

In the present embodiment, the joining tool 4
Although the elliptical steel pipe 33 and the metal fitting 31 are used as 1, the elliptic steel pipe 33 may be replaced with a similar shape to the elliptical steel pipe 33 or a material other than steel. Alternatively, depending on the skeleton material of the side wall 5, the oval steel pipe 33 may not be used and only the hole may be provided in the side wall 5. Also, metal fittings 3
A rod-shaped member having a shape similar to that of No. 1 and other than metal may be used.

Further, in the present embodiment, the connector 4
Although the oval steel pipe 33 is provided on the side wall 5 and the metal fitting 31 is provided on the bottom plate 7 as 1, the oval steel pipe 33 is provided on the bottom plate 7 and the metal fitting 3 is provided.
1 may be provided on the side wall 5. Further, the connector 41 for providing the elliptical steel pipe 33 on the side wall 5 and the connector for providing the elliptical steel pipe 33 on the bottom plate 7 may be mixed.

[0020]

As described above in detail, according to the present invention, it is possible to reduce the stress on the side wall and the bottom slab against the radial relative displacement of the underground tank during normal operation. Side wall of underground tank that can be restrained so that relative displacement in the tangential direction between the side wall and bottom slab does not occur.
A bottom plate joint structure and a joint tool can be provided.

[Brief description of drawings]

FIG. 1 is a vertical sectional view showing a joint portion of an underground tank 1.

FIG. 2 is a perspective view of an oval steel pipe 33.

FIG. 3 is an enlarged vertical sectional view showing a connector 41 of the underground tank 1.

4 is a cross-sectional view taken along the line BB of FIG.

5 is a cross-sectional view taken along the line AA of FIG.

FIG. 6 is a sectional view showing the overall structure of a conventional underground tank 101.

FIG. 7 is a vertical sectional view showing a joint portion 113 of a conventional underground tank 101.

FIG. 8 is an enlarged vertical sectional view showing the support plate 121.

FIG. 9 is a diagram for explaining relative displacement due to seismic force E.

[Explanation of symbols]

 1 ... Underground tank 3 ... Ground 5 ... Side wall 7 ... Bottom plate 9 ... Inner tank material 11 ... Void 13 ... Ground surface 15 ... Groundwater surface 17 ... LNG 31 ………… Metal fittings 33 ………… Oval steel pipe 41 ………… Connectors C ………… Tank radial direction E ………… Seismic force F ……… Tangential relative displacement G ……… Radial relative displacement

Claims (4)

[Claims] 1. An elongated cylindrical hole whose longitudinal direction is the radial direction of the underground tank, at the joint between the side wall of the underground tank and the bottom plate,
A joint structure of a side wall / bottom plate of an underground tank, characterized in that the side wall / bottom plate is provided on either one of the side wall and the bottom plate, and a rod-shaped member fitted in the hole is provided on the other of the side wall or the bottom plate. 2. The joint structure for a side wall / bottom plate of an underground tank according to claim 1, wherein a plurality of the holes and the rod-shaped members are provided in a circumferential direction of the underground tank. 3. The side wall / bottom plate joint structure for an underground tank according to claim 1, wherein the hole is formed by embedding a long cylindrical steel pipe in the concrete of the side wall or the bottom plate. . 4. The side wall of an underground tank, which is used for a joint structure of a side wall and a bottom slab of an underground tank according to claim 1, and is composed of a long cylindrical steel pipe and a rod-shaped member fitted to the steel pipe. -Bottom plate joint.