JPH09150886A - Supporting structure for spherical tank - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the earthquake resistance of a supporting structure of a spherical tank by a method wherein tensile strength and shearing farces acting on the supporting structure of the spherical tank due to an earthquake are transmitted not only to the supporting legs but also to wires so as to be dispersed so that tensile forces and shearing forces acting on individual supporting leg are reduced so that buckling, separation, shearing, and collapse of the supporting legs can be avoided. SOLUTION: On the installation surface G of a spherical tank 1, a plurality of supporting legs 2 are erected in a spaced apart relationship along an imaginary circle on the surface G, and the tank 1 is supported by these legs 2 inside the legs 2. In this case, a plurality of wire pulling means 20 comprising a wire fixing part 21 provided on the side surface of the tank 1, a first block 22 provided above the top of the tank 1, and a second block 23 provided on the side of the tank 1 opposite to the part 21, and a wire 24 whose one end is fixed to the part 21 and which is put around the block 22 and further around the block 23 and whose other end is fixed to the surface G are radially disposed about the top of the tank 1 in a top plan view.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a support structure for a spherical tank.

[0002]

As is well known, primary energy resources such as petroleum, LNG, and LPG are stored in storage tanks in order to secure a long-term stable supply. Storage tanks used in this type of field include aboveground tanks and underground tanks.

One of the forms of the aboveground tank is a spherical tank. The spherical tank 1 shown in FIG. 6 is generally a medium-capacity storage facility, and is supported by a plurality of support legs 2 standing upright along a virtual circle O on the installation surface G. A brace 4 is arranged between adjacent support legs 2 to enhance the integrity of the support legs 2 as a whole.

[0004]

By the way, in the support structure of the spherical tank shown in FIG. 6, a certain degree of seismic strength is provided by the integration of the support legs 2 by the braces 4. However, if a large earthquake that exceeds the current seismic resistance standard occurs, for example, vertical seismic force acts on the support leg 2 to cause buckling, and lateral vibration causes lateral seismic force to act on the support leg. 2 may be deformed.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a support structure for a spherical tank which improves the seismic resistance of the spherical tank.

[0006]

A support structure for a spherical tank according to claim 1 is a wire fixing portion provided on a side surface of the spherical tank, and a first fixing portion provided above a top portion of the spherical tank.
Pulley, a second pulley provided on the side of the spherical tank on the opposite side of the wire fixing portion, and one end fixed to the wire fixing portion and hung on the first pulley, and further hung on the second pulley. In addition, a plurality of pulling means composed of a wire stretched at the other end fixed to the installation surface are radially arranged in a plan view centering on the crown of the spherical tank.

In the support structure for a spherical tank according to claim 1, when vertical vibration due to an earthquake is transmitted from the support structure for the spherical tank to the spherical tank, the spherical tank vibrates in the vertical direction, so that the support structure for the spherical tank is pulled. Power works. Here, since the wire is stretched in the direction of pulling the spherical tank to the installation surface, the tensile force that acts on the support structure of the spherical tank is distributed not only to the support legs but also to the wire,
The tensile force acting on each support leg is reduced.

When the rolling due to the vibration of the ground is transmitted from the supporting structure of the spherical tank to the spherical tank, the spherical tank vibrates in the lateral direction, so that a shearing force acts on the supporting structure of the spherical tank in a direction parallel to the installation surface. Here, since the wire is stretched not only to pull the spherical tank toward the installation surface side but also to pull it toward the outside in the radial direction of the spherical tank, the shearing force acting on the supporting structure of the spherical tank is In addition to being distributed to the wires, the shear forces acting on the individual support legs are reduced.

Moreover, since the pulling means including the wires are arranged radially around the crown of the spherical tank, the pulling means exhibits its seismic resistance against shaking transmitted from all directions around the spherical tank.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of a support structure for a spherical tank according to the present invention will be described in detail with reference to FIGS. As shown in FIG. 1, the spherical tank 1 is supported by a plurality of support legs 2 standing upright on the installation surface G at equal intervals,
Braces 4 are provided so as to intersect between adjacent support legs 2. A support frame 10 is fixed to the upper portion of the spherical tank 1, and a plurality of traction means 20 are provided on the support frame 10.

As shown in FIG. 2, the grounding portion 2a of the support leg 2 is mounted on a base 5 embedded in the installation surface G and bolts 6 are mounted thereon.
It is fixed by. Further, one end 4a of the brace 4 is fixed to a plate 7 provided near the grounding portion 2a.

The supporting portion 2b of the supporting leg 2 is fixed to the outer shell of the spherical tank 1, as shown in FIG. Further, the other end 4b of the brace 4 is fixed to a plate 7 provided below the supporting portion 2b.

As shown in FIG. 4, the support frame 10 is a band plate 11 which is wound around the spherical tank 1 above the support portion 2b of the support leg 2 and welded to the spherical tank 1, and the band 11. It comprises a pulley block 13 positioned on the top of the spherical tank 1 supported by a support member 12 extending from the plate 11 toward the top of the spherical tank 1.

The pulling means 20 includes a wire fixing portion 21 provided on the strip 11 on the side surface of the spherical tank 1 and the spherical tank 1.
A first pulley 22 provided on the pulley base 13 at the top of the
The second pulley 23 provided on the strip plate 11 on the side surface of the spherical tank 1 facing the wire fixing portion 21 with the center of the spherical tank 1 sandwiched between the second pulley 23 and one end fixed to the wire fixing portion 21. It is constituted by a wire 24 which is hung on one pulley 22 and further hung on a second pulley 23 and whose other end is fixed to the installation surface G and stretched.

The wire fixing portion 21 is, as shown in FIGS. 1 and 4, a strip plate 1 located above the supporting portion 2b of the supporting leg 2.
It is fixed on 1. The first pulley 22 is the pulley base 13
Is rotatably fixed along the radial direction of the spherical tank 1. The second pulley 23 is a first pulley 2 on the strip 11.
It is fixed rotatably in the same direction as 2. The wire 24 has one end fixed to the wire fixing portion 21, is hung on the first pulley 22, and is further hung on the second pulley 23, and then is fixed to the base 5 embedded in the installation surface G. It is fixed with tension.

Each traction means 20 provided on the support frame 10
Are arranged at equal intervals in a plan view radially centering on the crown of the spherical tank 1 so that the respective traction means 20 do not interfere with each other.

In the support structure for a spherical tank constructed as described above, when vertical vibration due to an earthquake is transmitted from the support structure for the spherical tank to the spherical tank 1, the spherical tank 1 vibrates in the vertical direction, so that the support structure for the spherical tank is provided. Has a tensile force. Here, the wire 24 mounts the spherical tank 1 on the installation surface G
Since it is stretched in the direction in which it is pulled toward the base, the tensile force that acts on the support structure of the spherical tank is not limited to the support legs 2 but also the wire 2.
4 is distributed and dispersed, and the tensile force acting on each support leg 2 is reduced. Therefore, it is possible to prevent the support leg 2 from being divided or collapsed.

When the rolling due to an earthquake is transmitted from the support structure of the spherical tank to the spherical tank 1, the spherical tank 1 vibrates in the lateral direction, so that a shearing force acts on the support structure of the spherical tank in a direction parallel to the installation surface G. . Here, since the wire 24 is stretched not only to attract the spherical tank 1 to the installation surface G side but also in a direction to attract the spherical tank 1 toward the outer side in the radial direction of the spherical tank 1, a shear acting on the support structure of the spherical tank is exerted. The force is distributed not only to the support legs 2 but also to the wires 24 located on both sides in the vibration direction, and the shearing force acting on each support leg 2 is reduced. Therefore, it is possible to prevent shearing, bending, and collapse of the support leg 2. Moreover, since the towing means 20 is radially arranged around the spherical tank 1, its quake resistance is exerted even against shaking transmitted from all directions around the spherical tank 1.

By arranging the supporting frame 10, the pulling means 20 are arranged radially without the individual pulling means 20 interfering with each other and the wires 24 contacting the surface of the spherical tank 1 and damaging the spherical tank. can do.

The support structure for the spherical tank described in the present embodiment is relatively simple in structure and does not require relocation or removal of each equipment of the spherical tank. Therefore, it can be applied to an existing spherical tank. It is possible.

FIG. 5 shows another embodiment of the support in the support structure for the spherical tank of the present invention. In the support structure of the spherical tank in the figure, the fixed end of the wire 24 on the installation surface G side is fixed not to the base 5 of the support leg 2 but to the newly provided wire base 50. This is effective when it is difficult to modify the base 5 such as when constructing an existing spherical tank.

The dimensions of the support frame 10 and the tension applied to the wires 24 are preferably designed in consideration of the reduction in strength of the spherical tank 1 and the support legs 2 due to the weight of the support frame 10 itself.

[0023]

According to the support structure for a spherical tank of the present invention, a plurality of traction means are radially arranged in the spherical tank, and the wire pulls the spherical tank toward the installation surface and directs the spherical tank radially outward. The tensile force and shear force that acts on the support structure of the spherical tank due to the earthquake is distributed not only to the support legs but also to the wires and is distributed to the individual support legs. The power becomes smaller. Therefore, it is possible to prevent the supporting legs from buckling, dividing, shearing or collapsing, and improve the earthquake resistance of the supporting structure of the spherical tank. Moreover, since the traction means are radially arranged toward the periphery of the spherical tank, it is possible to exert its earthquake resistance against vibrations transmitted from all directions around the spherical tank.

[Brief description of the drawings]

FIG. 1 is a side view showing an embodiment of a support structure for a spherical tank of the present invention.

FIG. 2 is a side view showing a grounding portion of a support leg.

FIG. 3 is a side view showing a joint portion of support legs.

FIG. 4 is a plan view showing a support frame.

FIG. 5 is a side view showing another embodiment of the support structure for the spherical tank of the present invention.

FIG. 6 is a perspective view showing an example of a conventional spherical tank.

[Explanation of symbols]

 1 spherical tank 2 support leg 10 support frame 20 traction means 21 wire fixing part 22 first pulley 23 second pulley 24 wire G installation surface O virtual circle

Claims (1)

[Claims] 1. A plurality of support legs are erected on an installation surface of the spherical tank along a virtual circle on the installation surface at intervals from each other, and the spherical tank is provided inside the support legs by the support legs. In a supporting structure for a spherical tank, which is supported, a wire fixing portion provided on a side surface of the spherical tank, a first pulley provided above the top of the spherical tank, and a spherical tank on the opposite side of the wire fixing portion. A second pulley provided on the side surface and one end fixed to a wire fixing portion and hung on the first pulley, further hung on the second pulley and then the other end is fixed to the installation surface and stretched. A support structure for a spherical tank, characterized in that a plurality of pulling means composed of the formed wires are arranged radially in a plan view centering on the crown of the spherical tank.