Rectangular steel tank

Abstract

To provide a rectangular steel tank that can prevent damage involving water leakage from the tank body, even during a massive earthquake. [Solution] The rectangular steel tank uses flat bars as bracing members 44, with one bracing member 44 connecting the other end to one vertical flange plate 11 being designated as the first bracing member 44, and the other bracing member 44 connecting the other end to the other vertical flange plate 11 being designated as the other bracing member 44. The first bracing member 44 and the other bracing member 44 are arranged such that, during an earthquake, when a compressive force is applied to the first bracing member 44, a tensile force is applied to the other bracing member 44, and when a compressive force is applied to the other bracing member 44, a tensile force is applied to the first bracing member 44.

Description

Technical Field

[0001] The present invention relates to a rectangular steel tank.

Background Art

[0002] Municipalities construct and manage water storage tanks that temporarily store water produced at water purification plants. Conventionally, concrete tanks with a cylindrical or rectangular shape have been commonly used as the tanks for this water storage facility equipment. However, rectangular stainless steel tanks are increasing in number in terms of durability, sanitation of tap water, and effective utilization of the site. The types of stainless steel tanks include panel tanks that are rectangular with a side wall plate thickness of 3 mm or less and are composed of combinations of panels such as 1 m square panel sizes, thick plate tanks that are rectangular with a side wall plate thickness of 10 mm or less and a unit size of 1×2 m, and circular cylindrical tanks. In the past market, panel tanks with high cost performance were the mainstream. However, many leakage accidents occurred in panel tanks during the Great East Japan Earthquake and the Kumamoto Earthquake. In rectangular tanks such as panel tanks and thick plate tanks, it has been found that a bulging phenomenon occurs where the water inside the tank and the body resonate due to vibration and the vibration is amplified. This bulging phenomenon is considered to be one of the causes of leakage accidents. The natural frequency of a rectangular tank is about 5 Hz. It has been found that when a panel tank resonates (bulging phenomenon), the hydrodynamic pressure increases, and as a result, damage due to an earthquake occurs, but it has not been fully elucidated. Since water supply infrastructure is very important infrastructure, the guidelines for seismic design were revised in June 2022, and higher seismic performance is required than before. Therefore, it is required to develop a technology that can meet this new seismic design guideline and also exhibit cost advantages. For example, Patent Document 1 proposes an internal reinforcement structure for a tank that can surely prevent the side wall of the tank body from deforming even when an earthquake occurs.

Prior Art Documents

[0003] [Patent Document 1] Japanese Patent Publication No. 2002-362682 [Overview of the project] [Problems that the invention aims to solve]

[0004] However, as proposed in Patent Document 1, in structural designs that prevent deformation of the side walls of the tank body, it is not only difficult to anticipate seismic forces caused by massive earthquakes, but it is also necessary to deal with the effects of hydrodynamic pressure due to the bulging phenomenon. Therefore, the present invention is based on the concept of a structure that ensures the supply of tap water by pre-designating points that will break, thereby eliminating damage that causes water leakage even during a massive earthquake. Specifically, for seismic motion below a predetermined level, the bracing material undergoes elastic buckling (stable buckling) under compressive force and elastic deformation under tensile force, thereby preventing damage to the tank body. For seismic motion above a predetermined level, the bracing material undergoes elastic buckling under compressive force and plastic deformation under tensile force. Damage to the plastically deformed bracing material changes its eigenvalues, preventing resonance and thus preventing damage to the tank body accompanied by water leakage.

[0005] Thus, the present invention aims to provide a rectangular steel tank that can prevent damage involving water leakage from the tank body, even during a massive earthquake. [Means for solving the problem]

[0006] The rectangular steel tank of the present invention as described in claim 1 is a rectangular steel tank in which the tank body is formed of side plates 10, a top plate 20, a bottom plate 30, and internal reinforcing members 40, wherein the side plates 10 are provided with a plurality of vertical flange plates 11 that are continuous from the bottom plate 30 to the top plate 20 at a predetermined pitch, and the internal reinforcing members 40 are composed of a long-side horizontal member 41 arranged in the long-side direction of the tank body, a short-side horizontal member 42 arranged in the short-side direction of the tank body, a vertical member 43 arranged vertically between the bottom plate 30 and the top plate 20, and a brace member 44 with one end connected to the intersection of the long-side horizontal member 41, the short-side horizontal member 42, and the vertical member 43, wherein a flat bar is used as the brace member 44, and the pair of side plates 10 arranged opposite each other are one side plate 10 and the other side plate 10, and the vertical flange plate 11 on the one side plate 10 If we define one vertical flange plate 11 and the vertical flange plate 11 on the other side plate 10 as the other vertical flange plate 11, and the brace member 44 connecting the other end to the one vertical flange plate 11 as the one brace member 44, and the brace member 44 connecting the other end to the other vertical flange plate 11 as the other brace member 44, then the one brace member 44 and the other brace member 44 are placed in all the steps that are partitioned from the bottom plate 30 to the ceiling plate 20 by the long-side horizontal member 41 and the short-side horizontal member 42, all the one brace members 44 in the step direction are inclined in the first direction, and all the other brace members 44 in the step direction are inclined in the second direction, and in the event of an earthquake, when a compressive force is applied to the one brace member 44, a tensile force is applied to the other brace member 44, and when a compressive force is applied to the other brace member 44, a tensile force is applied to the one brace member 44. Therefore, in the event of seismic motion below a predetermined level, the brace material 44 will elastically buckle (stable buckling) against the compressive force and elastically deform against the tensile force, thereby preventing damage to the tank body. In the event of seismic motion above a predetermined level, the brace material 44 will elastically buckle against the compressive force and plastically deform against the tensile force. It is characterized by the following: The present invention as described in claim 2 is characterized in that, in the rectangular steel tank described in claim 1, one end of the one brace member 44 is positioned higher than the other end of the one brace member 44, and one end of the other brace member 44 is positioned higher than the other end of the other brace member 44, thereby arranging the one brace member 44 and the other brace member 44 in a V-shape when viewed from the side. The present invention as described in claim 3 is characterized in that, in the rectangular steel tank described in claim 2, an anchor 46 is arranged outside the side plate 10 at the lower part of the one vertical flange plate 11 that connects the other end of the one brace member 44, and at the lower part of the other vertical flange plate 11 that connects the other end of the other brace member 44. The present invention as described in claim 4 is characterized in that, in the rectangular steel tank described in claim 1, stainless steel is used as the brace material 44. [Effects of the Invention]

[0007] According to the present invention, a one-sided brace member and a other-sided brace member are placed at all steps that are partitioned from the bottom plate to the top plate by horizontal members in the long-side direction and horizontal members in the short-side direction. All one-sided brace members in the step direction are inclined in the first direction, and all other-sided brace members in the step direction are inclined in the second direction. In the event of an earthquake, when a compressive force is applied to one-sided brace members, a tensile force is applied to the other-sided brace members, and when a compressive force is applied to the other-sided brace members, a tensile force is applied to one-sided brace members. For seismic motion below a predetermined level, the brace members undergo elastic buckling (stable buckling) in response to compressive force and elastic deformation in response to tensile force, thereby preventing damage to the tank body accompanied by water leakage. For seismic motion above a predetermined level, the brace members undergo elastic buckling in response to compressive force and plastic deformation in response to tensile force. Damage to the plastically deformed brace members prevents the eigenvalue from changing and resonance from occurring, thereby preventing damage to the tank body accompanied by water leakage. Furthermore, according to the present invention, by using a flat bar as a bracing material, even when unexpected seismic forces are applied, the energy of the seismic motion can be absorbed by undergoing plastic deformation in response to the tensile force. [Brief explanation of the drawing]

[0008] [Figure 1] Partially fractured perspective view of a rectangular steel tank according to one embodiment of the present invention, viewed from the short side. [Figure 2] Partially broken perspective view from a higher position than Figure 1. [Figure 3] Partial fracture perspective view from Figure 2, with internal reinforcing material removed. [Figure 4] Partially fractured perspective view of the rectangular steel tank, seen from the long side. [Figure 5] Side view showing internal reinforcing material for a rectangular steel tank according to another embodiment of the present invention. [Figure 6] Figure 5(a) shows a diagram illustrating the action of forces. [Figure 7] Figure illustrating the principle of the present invention. [Modes for carrying out the invention]

[0009] In the rectangular steel tank according to the first embodiment of the present invention, flat bars are used as bracing members, a pair of opposing side plates are designated as one side plate and the other side plate, a vertical flange plate on one side plate is designated as the one vertical flange plate, a vertical flange plate on the other side plate is designated as the other vertical flange plate, a bracing member connecting the other end to the one vertical flange plate is designated as the one bracing member, and a bracing member connecting the other end to the other vertical flange plate is designated as the other bracing member. One bracing members and other bracing members are placed at all stages partitioned from the bottom plate to the top plate by horizontal members in the long side direction and horizontal members in the short side direction, all one bracing members in the stage direction are inclined in the first direction, and all other bracing members in the stage direction are inclined in the second direction, and in the event of an earthquake, when a compressive force is applied to one bracing member, a tensile force is applied to the other bracing member, and when a compressive force is applied to the other bracing member, a tensile force is applied to one bracing member. Therefore, in the event of seismic motion below a predetermined level, the brace material 44 will elastically buckle (stable buckling) against compressive forces and elastically deform against tensile forces, thereby preventing damage to the tank body. In the event of seismic motion above a predetermined level, the brace material 44 will elastically buckle against compressive forces and plastically deform against tensile forces. It is. According to this embodiment, one brace member and the other brace member are placed at all steps that are partitioned from the bottom plate to the top plate by horizontal members in the long side direction and horizontal members in the short side direction. All one brace members in the step direction are inclined in the first direction, and all other brace members in the step direction are inclined in the second direction. In the event of an earthquake, when a compressive force is applied to one brace member, a tensile force is applied to the other brace member, and when a compressive force is applied to the other brace member, a tensile force is applied to one brace member. For seismic motion below a predetermined level, the brace members undergo elastic buckling (stable buckling) in response to compressive force and elastic deformation in response to tensile force, thereby preventing damage to the tank body. For seismic motion above a predetermined level, the brace members undergo elastic buckling in response to compressive force and plastic deformation in response to tensile force. Damage to the plastically deformed brace members does not change their eigenvalues ​​and cause resonance, thus preventing damage to the tank body accompanied by water leakage. Furthermore, according to this embodiment, by using flat bars as bracing materials, even when unexpected seismic forces are applied, the energy of the seismic motion can be absorbed by undergoing plastic deformation in response to the tensile force.

[0010] A second embodiment of the present invention is a rectangular steel tank according to the first embodiment, wherein one end of one brace member is positioned higher than the other end of the one brace member, and one end of the other brace member is positioned higher than the other end of the other brace member, so that when viewed from the side, the one brace member and the other brace member are arranged in a V-shape. According to this embodiment, the upward force generated by the tensile force during an earthquake is applied to the vertical flange plate, so that the upward force due to the tensile force can be received at the position of the side plate.

[0011] A third embodiment of the present invention is a rectangular steel tank according to the second embodiment, wherein anchors are positioned outward from the side plate at the lower part of one vertical flange plate connecting the other end of one brace member, and at the lower part of the other vertical flange plate connecting the other end of the other brace member. According to this embodiment, by positioning the anchor outside the tank body, there is no need to consider the impact on tap water caused by installing the anchor inside the tank body.

[0012] In the fourth embodiment of the present invention, stainless steel is used as the brace material in the rectangular steel tank according to the first embodiment. According to this embodiment, by adopting a stainless steel material with high elongation performance and high toughness as the brace material, the strength increases even when entering the plastic region, and the toughness is high, so it exhibits the performance of being difficult to break. As a result, it is possible to more effectively prevent the damage of the tank body accompanied by water leakage.

Example

[0013] Hereinafter, a rectangular steel tank according to an embodiment of the present invention will be described. FIG. 1 is a partially broken perspective view of the rectangular steel tank according to this embodiment as seen from the short side, FIG. 2 is a partially broken perspective view seen from a position higher than FIG. 1, FIG. 3 is a partially broken perspective view excluding the internal reinforcing material from FIG. 2, and FIG. 4 is a partially broken perspective view of the same rectangular steel tank as seen from the long side.

[0014] The rectangular steel tank according to this embodiment has a tank body formed by a side plate 10, a ceiling plate 20 (see FIG. 5), a bottom plate 30, and an internal reinforcing material 40. [[ID=!19]]The internal reinforcing material 40 includes a long-side horizontal member 41 arranged in the long-side direction of the tank body, a short-side horizontal member 42 arranged in the short-side direction of the tank body, a vertical member 43 arranged vertically between the bottom plate 30 and the ceiling plate 20, and a brace material 44 connecting one end to the intersection of the long-side horizontal member 41, the short-side horizontal member 42, and the vertical member 43. A plurality of vertical flange plates 11 continuous from the bottom plate 30 to the ceiling plate 20 are provided on the side plate 10 at a predetermined pitch. In addition, a plurality of horizontal flange plates 12 are provided on the side plate 10 at a predetermined pitch in the height direction.

[0015] It should be noted that in the translation of the content you provided, I have tried my best to ensure the accuracy and compliance with the requirements. However, in the process of translation, due to the complexity of patent texts, there may still be some areas that need further review and adjustment in actual applications. If you have any other questions or need further assistance, please feel free to let me know.In this embodiment, the rectangular steel tank has two vertical members 43 between a pair of side plates 10 that are facing each other in the short-side direction of the tank body, and four vertical members 43 between a pair of side plates 10 that are facing each other in the long-side direction of the tank body. In other words, the rectangular steel tank in this embodiment has eight vertical members 43 inside the tank body. Furthermore, in this embodiment, the rectangular steel tank is provided with two layers of horizontal members 41 in the long-side direction and horizontal members 42 in the short-side direction between the bottom plate 30 and the top plate 20.

[0016] In Figures 1 and 2, the brace material 44ARD is shown as a brace material 44 that is positioned on the lower level, with its other end connected to the vertical flange plate 11 of one side plate 10 which is positioned opposite to the short side of the tank body. Furthermore, the brace material 44ARM indicates a brace material 44 that is positioned in the middle section, with its other end connected to the vertical flange plate 11 of one side plate 10, which is arranged opposite to the short side of the tank body. Furthermore, the brace material 44ARU indicates a brace material 44 that is positioned on the upper level by connecting its other end to the vertical flange plate 11 of one side plate 10, which is arranged opposite to the short side direction of the tank body.

[0017] Furthermore, the brace material 44ALD indicates a brace material 44 that is positioned lower, with its other end connected to the vertical flange plate 11 of the other side plate 10, which is positioned opposite to the short side of the tank body. Furthermore, the brace material 44ALM indicates a brace material 44 that is positioned in the middle section, with its other end connected to the vertical flange plate 11 of the other side plate 10, which is positioned opposite to the short side of the tank body. Furthermore, the brace material 44ALU indicates a brace material 44 that is positioned on the upper level by connecting its other end to the vertical flange plate 11 of the other side plate 10, which is arranged opposite to the short side direction of the tank body.

[0018] As shown in Figures 1 and 2, all one-sided brace members 44 in the step direction, namely brace members 44ARD, 44ARM, and 44ARU, are tilted in the first direction, and all other-sided brace members 44 in the step direction, namely brace members 44ALD, 44ALM, and 44ALU, are tilted in the second direction. In this embodiment, the first direction is the direction in which one end of one brace member 44 is positioned higher than the other end of the one brace member 44, and the second direction is the direction in which one end of the other brace member 44 is positioned higher than the other end of the other brace member 44, so that in a side view, the one brace member 44 and the other brace member 44 are arranged in a V shape. Alternatively, the first direction may be the direction in which one end of one brace member 44 is positioned lower than the other end of the one brace member 44, and the second direction may be the direction in which one end of the other brace member 44 is positioned lower than the other end of the other brace member 44, so that in a side view, the one brace member 44 and the other brace member 44 are arranged in a V shape. The one brace member 44 and the other brace member 44 are arranged symmetrically with respect to the center line between a pair of side plates 10 that are arranged opposite each other in the short side direction of the tank body.

[0019] In this way, all one-sided brace members 44 in the step direction are inclined in the first direction, and all other-sided brace members 44 in the step direction are inclined in the second direction, and the one-sided brace members 44 and the other-sided brace members 44 are arranged symmetrically with respect to the center line between a pair of side plates 10 that are arranged opposite each other in the short-side direction of the tank body. As a result, during an earthquake, when a compressive force is applied to one-sided brace member 44, a tensile force is applied to the other-sided brace member 44, and when a compressive force is applied to the other-sided brace member 44, a tensile force is applied to one-sided brace member 44.

[0020] In Figure 4, the brace material 44BRD is shown as a brace material 44 that is positioned in the lower section, with its other end connected to the vertical flange plate 11 of one side plate 10, which is positioned opposite to the long side of the tank body. Furthermore, the brace material 44BRM indicates a brace material 44 that is positioned in the middle section, with its other end connected to the vertical flange plate 11 of one side plate 10, which is arranged opposite to the long side of the tank body. Furthermore, the brace material 44BRU indicates a brace material 44 that is positioned on the upper level by connecting its other end to the vertical flange plate 11 of one side plate 10, which is arranged opposite to the long side of the tank body.

[0021] Furthermore, the brace material 44BLD indicates a brace material 44 that is positioned in the lower section, with its other end connected to the vertical flange plate 11 of the other side plate 10, which is positioned opposite to the long side of the tank body. Furthermore, the brace material 44BLM indicates a brace material 44 that is positioned in the middle section, with its other end connected to the vertical flange plate 11 of the other side plate 10, which is positioned opposite to the long side of the tank body. Furthermore, the brace material 44BLU indicates a brace material 44 that is positioned on the upper level by connecting its other end to the vertical flange plate 11 of the other side plate 10, which is arranged opposite to the long side of the tank body.

[0022] As shown in Figure 4, all one-sided brace members 44 in the step direction, namely brace members 44BRD, 44BRM, and 44BRU, are inclined in the first direction, and all other-sided brace members 44 in the step direction, namely brace members 44BLD, 44BLM, and 44BLU, are inclined in the second direction. In this embodiment, the first direction is the direction in which one end of one brace member 44 is positioned higher than the other end of the one brace member 44, and the second direction is the direction in which one end of the other brace member 44 is positioned higher than the other end of the other brace member 44, so that in a side view, the one brace member 44 and the other brace member 44 are arranged in a V shape. Alternatively, the first direction may be the direction in which one end of one brace member 44 is positioned lower than the other end of the one brace member 44, and the second direction may be the direction in which one end of the other brace member 44 is positioned lower than the other end of the other brace member 44, so that in a side view, the one brace member 44 and the other brace member 44 are arranged in a V shape. The one brace member 44 and the other brace member 44 are arranged symmetrically with respect to the center line between a pair of side plates 10 that are arranged opposite each other in the short side direction of the tank body.

[0023] In this way, all one-sided brace members 44 in the step direction are inclined in the first direction, and all other-sided brace members 44 in the step direction are inclined in the second direction, and the one-sided brace members 44 and the other-sided brace members 44 are arranged symmetrically with respect to the center line between a pair of side plates 10 that are arranged opposite each other in the short-side direction of the tank body. As a result, during an earthquake, when a compressive force is applied to one-sided brace member 44, a tensile force is applied to the other-sided brace member 44, and when a compressive force is applied to the other-sided brace member 44, a tensile force is applied to one-sided brace member 44.

[0024] Figure 5 is a side view showing an internal reinforcing member for a rectangular steel tank according to another embodiment of the present invention, where Figure 5(a) is a side view of the tank body in the direction of the short side, and Figure 5(b) is a side view of the tank body in the direction of the long side. The rectangular steel tank according to this embodiment differs from the embodiment shown in Figures 1 to 4 in that it has four vertical members 43 between a pair of side plates 10 facing each other in the short-side direction of the tank body, nine vertical members 43 between a pair of side plates 10 facing each other in the long-side direction of the tank body, and additional optional bracing members 45, but the other basic configurations are the same. Although the partition wall 43x shown in Figure 5(b) is a different member from the vertical members 43, in this embodiment it is described as one of the vertical members 43 in terms of its function against seismic motion. Also, although the description was omitted in the embodiment shown in Figures 1 to 4, the anchor 46 described using this embodiment is also placed in the same position in the rectangular steel tank shown in Figures 1 to 4. In the description of this embodiment, the same functional members as in the embodiment shown in Figures 1 to 4 are denoted by the same reference numerals and their descriptions are omitted.

[0025] As shown in Figure 5(a), between a pair of side plates 10 that are positioned opposite each other in the short-side direction of the tank body, there are two optional bracing members 45: one optional bracing member 45AR and the other optional bracing member 45AL. On the other hand, the optional brace member 45AR is positioned parallel to the optional brace member 44ARD, at the same level (lower level) as the optional brace member 44ARD, between the vertical member 43AR1 that connects one end of the optional brace member 44ARD and the vertical member 43AR2 adjacent to the vertical member 43AR1. In other words, the optional brace member 45AR is inclined in the first direction. On the other hand, the optional brace member 45AL is positioned parallel to the other brace member 44ALD, at the same level (lower level) as the other brace member 44ALD, between the vertical member 43AL1 that connects one end of the other brace member 44ALD and the vertical member 43AL2 adjacent to the vertical member 43AL1. In other words, the other optional brace member 45AL is inclined in the second direction. In this manner, all one arbitrary brace members 45 are inclined in the first direction, and all other arbitrary brace members 45 are inclined in the second direction, and the one arbitrary brace member 45 and the other arbitrary brace member 45 are arranged symmetrically with respect to the center line between a pair of side plates 10 that are arranged opposite each other in the short-side direction of the tank body.

[0026] Furthermore, as shown in Figure 5(b), between a pair of side plates 10 arranged opposite each other in the long direction of the tank body, optional bracing members 45 are provided: on one side, optional bracing members 45BR1, 45BR2, 45BR3, and 45BR4; and on the other side, optional bracing members 45BL1, 45BL2, 45BL3, and 45BL4. On the other hand, the optional brace member 45BR1 is positioned parallel to the optional brace member 44BRD, on the same level (lower level) as the optional brace member 44BRD, between the vertical member 43BR1 that connects one end of the optional brace member 44BRD and the vertical member 43BR2 adjacent to the vertical member 43BR1. In other words, the optional brace member 45BR1 is inclined in the first direction. Furthermore, the optional brace member 45BR2 is positioned parallel to the optional brace member 44BRD, on the same level (lower level) as the optional brace member 44BRD, between the vertical member 43BR2 to which one end of the optional brace member 45BR1 is connected and the vertical member 43BR3 adjacent to the vertical member 43BR2. In other words, the optional brace member 45BR2 is inclined in the first direction. Furthermore, the optional brace member 45BR3 is positioned parallel to the optional brace member 44BRD, on the same level (lower level) as the optional brace member 44BRD, between the vertical member 43BR3 that connects one end of the optional brace member 45BR2 and the vertical member 43BR4 adjacent to the vertical member 43BR3. In other words, the optional brace member 45BR3 is inclined in the first direction. Furthermore, the optional brace member 45BR4 is positioned parallel to the optional brace member 44BRD, on the same level (lower level) as the optional brace member 44BRD, between the vertical member 43BR4 that connects one end of the optional brace member 45BR3 and the vertical member 43x adjacent to the vertical member 43BR4. In other words, the optional brace member 45BR4 is inclined in the first direction.

[0027] On the other hand, the optional brace member 45BL1 is positioned parallel to the other brace member 44BLD, on the same level (lower level) as the other brace member 44BLD, between the vertical member 43BL1 that connects one end of the other brace member 44BLD and the vertical member 43BL2 adjacent to the vertical member 43BL1. In other words, the other optional brace member 45BL1 is inclined in the second direction. Furthermore, the other arbitrary brace member 45BL2 is positioned parallel to the other arbitrary brace member 44BLD, on the same level (lower level) as the other arbitrary brace member 44BLD, between the vertical member 43BL2 that connects one end of the other arbitrary brace member 45BL1 and the vertical member 43BL3 adjacent to the vertical member 43BL2. In other words, the other arbitrary brace member 45BL2 is inclined in the second direction. Furthermore, the other arbitrary brace member 45BL3 is positioned parallel to the other arbitrary brace member 44BLD, on the same level (lower level) as the other arbitrary brace member 44BLD, between the vertical member 43BL3 that connects one end of the other arbitrary brace member 45BL2 and the vertical member 43BL4 adjacent to this vertical member 43BL3. In other words, the other arbitrary brace member 45BL3 is inclined in the second direction. Furthermore, the other arbitrary brace member 45BL4 is positioned parallel to the other arbitrary brace member 44BLD, on the same level (lower level) as the other arbitrary brace member 44BLD, between the vertical member 43BL4 that connects one end of the other arbitrary brace member 45BL3 and the vertical member 43x adjacent to this vertical member 43BL4. In other words, the other arbitrary brace member 45BL4 is inclined in the second direction.

[0028] In this manner, all one arbitrary brace members 45 are inclined in the first direction, and all other arbitrary brace members 45 are inclined in the second direction, and the one arbitrary brace member 45 and the other arbitrary brace member 45 are arranged symmetrically with respect to the center line between a pair of side plates 10 that are arranged opposite each other in the long direction of the tank body.

[0029] As shown in Figure 5, the anchor 46 is positioned at the lower part of one vertical flange plate 11 that connects the other end of one brace member 44, and at the lower part of the other vertical flange plate 11 that connects the other end of the other brace member 44, and is located outward from the side plate 10.

[0030] Figure 6 is a diagram showing the action of forces in Figure 5(a). Figure 6 shows the case where seismic force is applied in the direction of arrow X. On the one hand, a compressive force is applied to the brace members 44, namely brace members 44ARD, 44ARM, and 44ARU, and one arbitrary brace member 45AR, while on the other hand, a tensile force is applied to the brace members 44, namely brace members 44ALD, 44ALM, and 44ALU, and one arbitrary brace member 45AL. When tensile force is applied to brace members 44ALD, 44ALM, and 44ALU, an upward reaction force is applied to the vertical flange plate 11 of the other side plate 10. Therefore, an anchor 46 is provided at the lower part of the vertical flange plate 11 of the other side plate 10.

[0031] Thus, since the upward force generated by the tensile force during an earthquake is applied to the vertical flange plate 11, anchors 46 are placed at the lower part of the one vertical flange plate 11 to which the other end of the one brace member 44 is connected, and at the lower part of the other vertical flange plate 11 to which the other end of the other brace member 44 is connected. Furthermore, by placing the anchors 46 on the outside of the tank body, there is no need to consider the impact on the tap water caused by installing the anchors 46 inside the tank body.

[0032] Figure 7 shows the principle of the present invention. In Figure 7, seismic motion below a predetermined level is shown as Level 1 seismic motion, and seismic motion above a predetermined level is shown as Level 2 seismic motion. As shown in Figure 7(a), in the present invention, when the seismic motion is below a predetermined level, the brace material 44 elastically buckles under compressive force and elastically deforms under tensile force, and when the seismic motion is above a predetermined level, the brace material 44 elastically buckles under compressive force and plastically deforms under tensile force. In the case of seismic motion below a predetermined level, damage to the tank body is eliminated, and in the case of seismic motion above a predetermined level, the damage to the plastically deformed brace material 44 changes the eigenvalue and prevents resonance, thereby preventing damage to the tank body accompanied by water leakage. As shown in Figure 7(b), the brace member 44 with length "l" shrinks to "l-α" when subjected to compressive force, as shown in Figure 7(c). However, because this is elastic buckling, it returns to its original length "l" when subjected to tensile force. As shown in Figure 7(d), when the earthquake is below a predetermined level, the brace member 44 stretches by "l + Δl1" when subjected to tensile force, but since this is an elongation within the elastic range, it returns to its original length "l" when the tensile force is removed. On the other hand, as shown in Figure 7(e), when the earthquake is above a certain level of ground motion, the brace member 44 stretches by "l + Δl2" due to the tensile force, which lowers its natural frequency and allows it to escape the resonance state.

[0033] In this embodiment, by using flat bars for the brace material 44 and optional brace material 45, even when unexpected seismic forces are applied, the energy of the seismic motion can be absorbed by undergoing plastic deformation in response to the tensile force. Note that a flat bar is a flat steel plate, not a round bar, shaped steel (L-beam, C-beam, H-beam, etc.), or steel pipe. Furthermore, it is preferable to use stainless steel for the brace material 44 and optional brace material 45. By using stainless steel, the strength increases even when it enters the plastic region, and its high toughness makes it less prone to fracture. As a result, damage to the tank body accompanied by water leakage can be prevented more effectively.

[0034] Thus, according to this embodiment, one brace member 44 and the other brace member 44 are placed at all steps that are partitioned from the bottom plate 30 to the ceiling plate 20 by the horizontal members 41 in the long side direction and the horizontal members 42 in the short side direction, all one brace members 44 in the step direction are tilted in the first direction, and all other brace members 44 in the step direction are tilted in the second direction, and in the event of an earthquake, when a compressive force is applied to one brace member 44, a tensile force is applied to the other brace member 44, and when a compressive force is applied to the other brace member 44 On the other hand, when tensile force is applied to the brace member 44, in the event of seismic motion below a predetermined level, the brace member 44 will elastically buckle (stable buckling) against compressive force and elastically deform against tensile force, thereby preventing damage to the tank body. In the event of seismic motion above a predetermined level, the brace member 44 will elastically buckle against compressive force and plastically deform against tensile force. Damage to the plastically deformed brace member 44 will change its eigenvalue and prevent resonance, thereby preventing damage to the tank body accompanied by water leakage. [Industrial applicability]

[0035] The rectangular steel tank according to the present invention is suitable as a water reservoir for temporarily storing water produced at a water treatment plant. [Explanation of Symbols]

[0036] 10 Side panels (one side panel, the other side panel) 11. Vertical flange plate (one vertical flange plate, the other vertical flange plate) 12 Side flange plate 20 Ceiling panels 30 Bottom plate 40 Internal reinforcement 41 Horizontal member in the direction of the long side 42 Horizontal members in the short-side direction 43, 43AR1, 43AR2, 43AL1, 43AL2, 43BL1, 43BL2, 43BL3, 43BL4, 43BR1, 43BR2, 43BR3, 43BR4 Vertical material 43x Vertical material (partition board) 44 bracing material 44ARD, 44ARM, 44ARU, 44BRD, 44BRM, 44BRU bracing material (one-sided bracing material) 44ALD, 44ALM, 44ALU, 44BLD, 44BLM, 44BLU bracing material (other bracing material) 45 Optional bracing material 45AR, 45BR1, 45BR2, 45BR3, 45BR4 Optional bracing material (one side is optional bracing material) 45AL, 45BL1, 45BL2, 45BL3, 45BL4 (Optional bracing material) (Other optional bracing material) 46 Anchors

Claims

1. The tank body is formed from side plates, a top plate, a bottom plate, and internal reinforcing materials. Multiple vertical flange plates are provided on the side plate at predetermined intervals, extending from the bottom plate to the top plate. The aforementioned internal reinforcing material A horizontal member arranged in the direction of the long side of the tank body, A horizontal member in the direction of the short side of the tank body, A vertical member positioned vertically between the base plate and the ceiling plate, A rectangular steel tank comprising a horizontal member in the direction of the long side, a horizontal member in the direction of the short side, and a brace member having one end connected to the intersection of the vertical members, Using a flat bar as the bracing material, The pair of side plates that are arranged opposite each other are referred to as one side plate and the other side plate. The vertical flange plate on one side plate is referred to as the one vertical flange plate, and the vertical flange plate on the other side plate is referred to as the other vertical flange plate. If the brace member connecting the other end to the one vertical flange plate is called the one-side brace member, and the brace member connecting the other end to the other vertical flange plate is called the other-side brace member, The one brace member and the other brace member are placed at all the steps that are partitioned from the bottom plate to the ceiling plate by the horizontal members in the long side direction and the horizontal members in the short side direction. All of the aforementioned one-sided brace members in the step direction are inclined in the first direction, All of the other brace members in the step direction are inclined in the second direction, A rectangular steel tank characterized in that, during an earthquake, when a compressive force is applied to one brace member, a tensile force is applied to the other brace member, and when a compressive force is applied to the other brace member, a tensile force is applied to the one brace member, thereby preventing damage to the tank body in the event of seismic motion below a predetermined level, by elastic buckling (stable buckling) against the compressive force and elastic deformation against the tensile force, and in the event of seismic motion above the predetermined level, the brace member elastic buckles against the compressive force and plastically deforms against the tensile force.

2. The one end of the aforementioned brace member is positioned higher than the other end of the aforementioned brace member. By positioning one end of the other brace member higher than the other end of the other brace member, the two braces are arranged in a V-shape when viewed from the side. A rectangular steel tank according to feature 1.

3. The lower part of the one vertical flange plate connecting the other end of the one brace member, and the lower part of the other vertical flange plate connecting the other end of the other brace member, wherein the anchor is positioned outward from the side plate. The rectangular steel tank according to feature 2.

4. Stainless steel is used as the brace material. A rectangular steel tank according to feature 1.

Images