JP6756558B2 - How to build a tank - Google Patents

Description

The present invention relates to a method of constructing a tank.

Patent Document 1 below discloses a method for constructing a cylindrical tank used for storing low-temperature liquids such as LNG (liquefied natural gas) and LPG (liquefied petroleum gas). The method of constructing this cylindrical tank includes a process of assembling the side wall of the outer tank at the outer peripheral edge of the bottom of the outer tank and a process of assembling the roof of the outer tank on the bottom of the outer tank other than the outer peripheral edge. In the process of assembling the side wall of the outer tank, the roof of the outer tank on the bottom of the outer tank is raised by a jack-up device and held by the side wall of the outer tank, and the roof of the outer tank caused by the rise. It has a process of assembling the inner tank independently of the roof of the outer tank in the space below. In this method, the side wall of the outer tank is assembled by placing concrete with the outer tank side plate as an inner formwork.

International Publication No. 2014/073239

By the way, the outer tank is formed by joining a plurality of side plates in a cylindrical shape by a vertical joint in the circumferential direction of the tank and laminating them in a plurality of stages. Conventionally, the vertical joint of the side plate has been formed by butt welding with a backing. The assembly accuracy of the side plate is controlled by the circumference. As this management method, there are a method of adjusting the length and position of the side plate one by one, and a method of adjusting the length of the side plate one by one without adjusting the length of the side plate with the last one.

For example, as in Patent Document 1, when concrete is cast with the side plate as the inner formwork and the side wall is constructed, the side plate has a connection with the outer formwork arranged on the outside of the tank, so the latter management method is used. It cannot be adopted, and the length and position of the side plates must be adjusted one by one. This adjustment is performed using the groove gap of the vertical joint, but in the case of the butt joint, the accuracy of the groove gap is only about ± 1 mm, and the adjustment is difficult. Further, when the gap accuracy is relaxed and the groove is widened, there is a problem that the welding amount increases and the cost increases.

The present invention has been made in view of the above problems, and even when the length and position of the side plates are adjusted one by one, the assembly accuracy of the tank can be easily controlled at no cost. The purpose is to provide a construction method.

In order to solve the above problems, the present invention is a method for constructing a tank having a side wall construction step of constructing a side wall formed by arranging a plurality of side plates on an inner wall surface of concrete, and the side wall construction step is a tank. It has a vertical joint forming step of forming a plurality of vertical joints for joining the side plates in the circumferential direction, and the vertical joint forming step includes at least one of the plurality of vertical joints of the side plates adjacent to each other in the circumferential direction of the tank. A method of forming by fillet welding on both sides of the cover plate covering the gap is adopted.

Further, in the present invention, the side wall construction step includes a concrete placing step of placing the concrete using the side plate as an inner formwork, and the vertical joint forming step includes all of the plurality of vertical joints. A method of forming by fillet welding on both sides is adopted.

Further, in the present invention, the fillet welding on both sides is performed on the cover plate that covers the gap between the side plates adjacent to each other in the circumferential direction of the tank from the inside of the tank.

Further, in the present invention, the method that the cover plate is longer than the total height of the side plate is adopted.

Further, in the present invention, the side wall construction step is a first vertical joint forming step of performing fillet welding on both sides of the cover plate arranged so as to project from the upper end of the side plate, except for the upper portion of the side plate. After the first vertical joint forming step, a horizontal joint forming step of forming a horizontal joint for joining the side plates in the tank height direction, and after the horizontal joint forming step, both side fillets on the upper part of the side plate. A method of having a second vertical joint forming process for welding is adopted.

Further, in the present invention, inside the side wall, the raising of the inner tank side plate by the jack-up device and the attachment of the next inner tank side plate to the lower side of the raised inner tank side plate are alternately repeated inside. A method of having an inner tank jack-up step of constructing a tank and a cold insulating material arranging step of arranging a cold insulating material between the inner tank and the side wall is adopted.

In the present invention, in the vertical joint forming step of forming a plurality of vertical joints for joining the side plates in the tank circumferential direction, at least one of the plurality of vertical joints is provided on both sides of the cover plate covering the gap between the adjacent side plates in the tank circumferential direction. Formed by fillet welding. According to this double-sided fillet welding, joining is possible even if the gap between the side plates becomes wide in the tank circumferential direction. In addition, if the gap between the side plates is widened, the amount of welding increases in the conventional butt welding, which increases the cost.However, according to this double-sided fillet welding, the welding amount does not change even if the gap between the side plates is widened. The gap accuracy of the side plate can be relaxed at almost the same cost.
Therefore, in the present invention, the assembly accuracy can be easily controlled at no cost even when the length and position of the side plates are adjusted one by one.

It is explanatory drawing which shows the 1st step (side wall construction step) of the construction method in embodiment of this invention. It is explanatory drawing which shows the 2nd step of the construction method in embodiment of this invention. It is explanatory drawing which shows the 3rd step (inner tank jack-up step) of the construction method in embodiment of this invention. It is explanatory drawing which shows the 4th process of the construction method in embodiment of this invention. It is explanatory drawing which shows the 5th process (the cold insulation material arrangement process) of the construction method in embodiment of this invention. It is a developed view of the side wall seen from the inside of the tank in embodiment of this invention. It is an enlarged view of the region A shown in FIG. FIG. 7 is a cross-sectional view taken along the line BB shown in FIG. It is explanatory drawing which shows the formation procedure of the vertical joint and the horizontal joint of the side wall construction process in embodiment of this invention. It is sectional drawing which shows the modification of the vertical joint in embodiment of this invention.

Hereinafter, the method for constructing the tank of the present invention will be described with reference to the drawings. In the following description, a method for constructing a ground-based PC (prestressed concrete) double-shell storage tank for storing LNG will be illustrated.

FIG. 1 is an explanatory diagram showing a first step (side wall construction step) of the construction method according to the embodiment of the present invention.
In this method, first, as shown in FIG. 1, a substantially disk-shaped basic plate 1 is constructed. An inner tank anchor strap (not shown) is embedded in the outer peripheral edge of the basic plate 1. Next, the side wall 3 is constructed on the outer peripheral edge of the basic plate 1 (side wall construction step). The side wall 3 is a PC wall in which a plurality of outer tank side plates 4 are arranged on the inner wall surface 5a of the concrete 5.

In the side wall construction step, the side wall 3 is raised by assembling the outer tank side plate 4 (side plate) on the foundation plate 1 and placing concrete 5 using the outer tank side plate 4 as an inner formwork. The outer tank side plate 4 is a steel liner and also serves as a concrete formwork, and the side wall 3 is lowered by placing the concrete 5 following the assembly of the outer tank side plate 4 while installing the outer scaffolding 6. Assemble in order from. Assembling the outer tank side plate 4 is performed by joining a plurality of outer tank side plates 4 in a cylindrical shape in the circumferential direction of the tank and laminating them one by one. After assembling the outer tank side plate 4 in one stage, the concrete 5 is placed using the outer tank side plate 4, and this is repeated to assemble the side wall 3.

In this method, the bottom liner 7 is laid on the base plate 1 in parallel with the assembly of the side wall 3. After that, the roof pedestal 8 is assembled in the central portion on the basic plate 1. Further, a pedestal 9 with legs is installed along the inside of the base end portion of the outer tank side plate 4. Then, the outer tank roof (roof portion of the outer tank) 10 is assembled on the roof stand 8 and the legged stand 9. The outer tank roof 10 is assembled by mounting an aerial work platform or the like on the basic plate 1, assembling a steel frame, and mounting a roof block on the steel frame.

After assembling the outer tank roof 10 to some extent, the jack-up device 11 is next installed on the side wall 3 during assembly. First, a plurality of suspension-side jack mounts (suspension points) 12 are installed on the side wall 3 above the basic plate 1 and above the outer peripheral edge of the outer tank roof 10 in the tank circumferential direction. The hanging-side jack stand 12 is firmly and detachably fixed to an anchor plate (not shown) embedded in the side wall 3. Further, a plurality of suspended side jack mounts 16 are installed on the outer peripheral edge of the outer tank roof 10. The suspended side jack stand 16 is detachably fixed to the outer peripheral edge of the outer tank roof 10. The suspended side jack stand 16 may be installed above the outer tank roof 10 instead of below the outer tank roof 10.

Next, the jack-up device 11 is installed between the hanging-side jack pedestal 12 and the suspended-side jack pedestal 16. The jack-up device 11 is configured as, for example, a center hole jack, and has a jack main body 11a installed on the suspended side jack stand 16 and a jack main body 11a extending vertically and being held by the jack main body 11a so as to be strokeable and having an upper end portion. It has a jack-up rod 17 that engages with the suspension-side jack stand 12 via an equalizer 17a.

A plurality of jack-up devices 11 having the above configuration are installed at predetermined intervals in the circumferential direction of the tank. The roof pedestal 8 can be removed when the roof steel frame portion of the outer tank roof 10 is assembled, and a part of the legged pedestal 9 can be removed when the jack-up device 11 is installed as described above. it can. When a part of the roof pedestal 8 and the pedestal with legs 9 is removed, the weight of the outer tank roof 10 is supported by the plurality of jack-up devices 11.

FIG. 2 is an explanatory diagram showing a second step of the construction method according to the embodiment of the present invention.
Next, in this method, as shown in FIG. 2, the outer tank roof 10 assembled on the basic plate 1 is raised by the jack-up device 11. Specifically, when the jack body 11a is driven, the jack body 11a rises along with the suspended side jack mount 16 along the jack-up rod 17, and jacks up the outer tank roof 10 in the process of assembly.

By jacking up the outer tank roof 10, the inner tank side plate 20 can be carried under the outer tank roof 10 and a work space for assembling the inner tank can be secured. To assemble the inner tank, first, a plurality of inner tank side plates 20 are erected on the pedestal 9 with legs along the tank circumferential direction, and adjacent ones of these inner tank side plates 20 are integrally welded in the tank circumferential direction. As a result, these inner tank side plates 20 are assembled in an annular shape. The inner tank side plate 20 assembled here corresponds to the uppermost stage.

FIG. 3 is an explanatory diagram showing a third step (inner tank jack-up step) of the construction method according to the embodiment of the present invention.
In this method, first, as shown in FIG. 3, the outer tank roof 10 raised by the jack-up device 11 is held by the side wall 3. Specifically, the holding pedestal 21 is installed in the middle stage of the side wall 3, and the outer tank roof 10 is held by the side wall 3 via the holding pedestal 21. The holding pedestal 21 is projected substantially horizontally from the side wall 3 having a predetermined height toward the inside of the tank. The holding base 21 is firmly and detachably fixed to, for example, an anchor plate (not shown) embedded in the side wall 3 in advance.

After the holding pedestal 21 is installed, the hanging side jack pedestal 16 is released from being fixed to the outer tank roof 10. When the hanging side jack pedestal 16 is released from the fixing, the weight of the outer tank roof 10 is supported by the holding pedestal 21. After the outer tank roof 10 is held by the side wall 3 via the holding stand 21 in this way, the jack main body 11a and the suspended side jack stand 16 are lowered, and the jack-up device 11 is placed inside the space below the outer tank roof 10. It can be used for assembling the tank side plate 20.

In this method, next, a plurality of suspended side jack mounts 16 are installed on the inner tank side plate 20 assembled in an annular shape. As a result, all or part of the weight of the inner tank side plate 20 assembled in an annular shape is supported by the jack-up device 11. When the inner tank side plate 20 is supported by the jack-up device 11 in this way, the jack-up device 11 raises the inner tank side plate 20 and attaches the next inner tank side plate to the lower side of the raised inner tank side plate 20. Assemble the inner tank by alternately repeating (inner tank jack-up process).

Specifically, first, the inner tank side plate 20 assembled in a ring shape by jacking up the jack-up device 11 is raised by an amount corresponding to the vertical width of the inner tank side plate 20 alone. Next, the next inner tank side plate 20 is carried into the space created under the inner tank side plate 20 by jacking up through a construction port (not shown) provided on the side wall 3, and the inner tank side plate 20 is mounted on a pedestal with legs. 9 It is lowered onto the inner tank side plate 20 and arranged in a ring shape below the jacked up inner tank side plate 20.

Then, the plurality of inner tank side plates 20 arranged in an annular shape are welded to each other, and the inner tank side plates 20 arranged vertically are welded to each other to form these inner tank side plates 20 into an integral cylindrical shape. In this way, the raising of the inner tank side plate 20 by the jack-up device 11 and the attachment of the next inner tank side plate 20 to the lower side of the raised inner tank side plate 20 are alternately repeated under the inner tank side plate 20. By adding the next inner tank side plate 20 to the side, it is possible to safely assemble the inner tank in a low place while avoiding interference with the outer tank roof 10 held in the middle stage of the side wall 3. ..

FIG. 4 is an explanatory diagram showing a fourth step of the construction method according to the embodiment of the present invention.
As shown in FIG. 4, when the assembly of the side wall 3 is completed, the fixing of the middle stage of the side wall 3 of the hanging side jack pedestal 12 is released, and the hanging side jack pedestal 12 is fixed to the top of the side wall 3 via the temporary pedestal. Further, the suspended side jack stand 16 is fixed to the outer peripheral edge portion of the outer tank roof 10 by releasing the fixing of the inner tank side plate 20. Then, a jack-up device 11 is installed between the hanging side jack pedestal 12 and the suspended side jack pedestal 16, the outer tub roof 10 is raised, and the outer tub roof 10 is installed on the top of the side wall 3. The holding stand 21 can be removed by pulling up the outer tank roof 10 with the jack-up device 11.

After installing the outer tank roof 10 on the side wall 3, the next step is to assemble the inner tank to the end. That is, as described above, the raising of the inner tank side plate 20 by the jack-up device 11 and the attachment of the next inner tank side plate 20 to the lower side of the raised inner tank side plate 20 are alternately repeated, and the inner tank side plate 20 is repeated. Assemble from the top to the bottom. In addition, under the legged pedestal 9, in parallel with the above-mentioned steps, a cold insulation work for laying a cold insulation material 41 (see FIG. 5) on the foundation plate 1 can be performed.

FIG. 5 is an explanatory diagram showing a fifth step (cold insulation material arranging step) of the construction method according to the embodiment of the present invention.
After assembling the inner tank 30 to the end, as shown in FIG. 5, the pedestal 9 with legs is removed, and the inner tank 30 is lowered and connected to the inner tank anchor strap (not shown). When the inner tank is lowered, the jack-up device 11 can be removed. Further, an elevating staircase 50 is provided along the side wall 3, a roof frame 51, a barrel nozzle 52, and the like are provided on the outer tank roof 10, and concrete is poured on the outer tank roof 10.

After that, the tension work of the side wall 3 is performed. Then, after installing the pump barrel 53 and closing the inner tank construction port (not shown), water filling is performed and a pressure resistance / airtightness test is performed. Finally, a cold insulating material 42 (for example, pearlite) is arranged between the inner and outer tanks 18 between the inner tank 30 and the side wall 3 to perform cold insulation work between the inner and outer tanks, and a suspension deck 43 provided on the attic of the outer tank roof 10. A cold insulation material 44 (for example, glass wool) is laid on the roof to perform attic cold insulation work.
After that, the construction of the LNG tank 100 accommodating the LNG 101 is completed through painting work, pipe cold insulation work, and the like.

Subsequently, the side wall construction step in the above-mentioned method for constructing the LNG tank 100 will be described in detail with reference to FIGS. 6 to 9.

FIG. 6 is a developed view of the side wall 3 viewed from the inside of the tank according to the embodiment of the present invention. FIG. 7 is an enlarged view of the region A shown in FIG. FIG. 8 is a cross-sectional view taken along the line BB shown in FIG.
As shown in FIG. 6, the outer tank side plate 4 is joined by a vertical joint 60 in the tank circumferential direction and is joined by a horizontal joint 70 in the tank height direction. An L-shaped angle member 80 for engaging with the outer tank roof 10 is joined to the uppermost stage of the outer tank side plate 4.

A plurality of vertical joints 60 are formed in the circumferential direction of the tank, and the outer tank side plates 4 are joined in an annular shape. At least one of these plurality of vertical joints 60 (all in the present embodiment) is formed by fillet welding on both sides of the cover plate 61. As shown in FIG. 7, the cover plate 61 is a strip-shaped plate that covers the gap S between adjacent outer tank side plates 4 in the tank circumferential direction. The cover plate 61 has a width that allows the gap S of the outer tank side plate 4 to be covered with a margin even if there is a gap of, for example, several tens of mm. This gap S serves as a gap accuracy for adjusting the length and position of the outer tank side plate 4 one by one.

As shown in FIG. 7, the cover plate 61 is longer than the total height of the outer tank side plate 4 alone. The upper end 61a of the cover plate 61 is arranged so as to project upward from the upper end 4a of the outer tank side plate 4. Further, the upper end 61a of the cover plate 61 is joined to the surface 4A (tank inward facing surface) of the upper outer tank side plate 4. On the other hand, the lower end 61b of the cover plate 61 is arranged so as to project downward from the lower end 4b of the outer tank side plate 4. Further, the lower end 61b of the cover plate 61 is also joined to the surface 4A (tank inward facing surface) of the lower outer tank side plate 4. The cover plates 61 are arranged so as to be shifted in the tank circumferential direction at the upper and lower stages of the outer tank side plate 4 so as not to be continuously overlapped in the tank height direction.

As shown in FIG. 8, the cover plate 61 is applied to the surface 4A of the outer tank side plate 4 so as to cover the gap S from the inside of the tank, and joint portions 62 by welding are formed on both sides in the width direction thereof. .. The cover plate 61 has a rectangular shape in cross section and can be formed of the same material as the outer tank side plate 4. The side end portion 4c of the outer tank side plate 4 is formed in a flat shape, and a groove or the like conventionally formed for butt welding is not formed. Further, the length of the outer tank side plate 4 in the tank circumferential direction (longitudinal direction) is slightly shorter than that of the conventional butt-welded one.

The back surface 4B (tank outward surface) of the outer tank side plate 4 is embedded in concrete 5. A plurality of separator cones (not shown) are joined to the back surface 4B of the outer tank side plate 4. The separator cone is for connecting an outer form (not shown) for placing concrete 5 with a separator. Further, a vertical stiffener may be provided on the back surface 4B of the outer tank side plate 4 to withstand the placing pressure of the concrete 5. Further, since the placing pressure of the concrete 5 is applied to the cover plate 61, the size of the gap S (gap accuracy) and the like should be set after examining the details by simulation analysis and confirming that there is no problem. Is preferable.

Returning to FIG. 7, the joint portion 62 has a first joint portion 62A and a second joint portion 62B. The first joint portion 62A is formed by the first welding to form the vertical joint 60. Further, the second joint portion 62B is formed by the second welding for forming the vertical joint 60. The first joint portion 62A is formed from the lower end 61b of the cover plate 61 to the front of the upper portion 4a1 of the outer tank side plate 4. Further, the second joint portion 62B is formed from the upper portion 4a1 of the outer tank side plate 4 and the upper portion 4a1 of the outer tank side plate 4 to the upper end 61a of the cover plate 61. The upper portion 4a1 of the outer tank side plate 4 is a range from the upper end 4a of the outer tank side plate 4 to the distance X. The distance X is set to at least a length that allows the cover plate 61 to be deformed (bent) so as not to interfere with the formation of the horizontal joint 70 after the first joint portion 62A is formed.

FIG. 9 is an explanatory view showing a procedure for forming the vertical joint 60 and the horizontal joint 70 in the side wall construction process according to the embodiment of the present invention.
In this method, first, as shown in FIG. 9A, both side fillets are welded to the cover plate 61 arranged so as to protrude from the upper end 4a of the outer tank side plate 4 except for the upper portion 4a1 of the outer tank side plate 4. (First vertical joint forming step). That is, in this first vertical joint forming step, up to the first joint portion 62A (up to the middle of the vertical joint 60) is formed.

Next, in this method, as shown in FIG. 9B, a horizontal joint 70 for joining the outer tank side plates 4 in the tank height direction is formed (horizontal joint forming step). Specifically, the upper end 4a of the outer tank side plate 4 and the lower end 4b of the next outer tank side plate 4 are butt welded. A groove 4b1 is formed at the lower end 4b of the outer tank side plate 4. The butt welding of the outer tank side plate 4 is preferably performed by one-side welding from the inside of the tank, and as shown in FIG. 9B, the butt welding with the backing using the backing metal 71 is performed.

Here, since the cover plate 61 is not joined to the upper portion 4a1 of the outer tank side plate 4, it is deformed to, for example, below the upper end 4a of the outer tank side plate 4 so as not to interfere with the formation of the horizontal joint 70 ( Can be bent). It is preferable that this deformation is performed within the elastic region of the cover plate 61.
After the horizontal joint 70 is formed, as shown in FIG. 9C, the cover plate 61 is returned to the original position, and both side fillet welding of the upper portion 4a1 of the outer tank side plate 4 is performed (second vertical joint forming step). That is, in this second vertical joint forming step, the second joint portion 62B is formed. From the above, the vertical joint 60 can be completed.

As described above, the side wall construction step of the present method includes a vertical joint forming step of forming a plurality of vertical joints 60 for joining the outer tank side plates 4 in the tank circumferential direction. In this method, in this vertical joint forming step, at least one of the plurality of vertical joints 60 is formed by fillet welding on both sides with respect to the cover plate 61 covering the gap S of the outer tank side plates 4 adjacent to each other in the tank circumferential direction. According to the fillet welding on both sides, as shown in FIGS. 7 and 8, joining is possible even if the gap S of the outer tank side plate 4 is widened to several tens of mm in the tank circumferential direction. Further, if the gap S of the outer tank side plate 4 becomes wide, the welding amount increases and the cost increases in the conventional butt welding, but according to this double-sided fillet welding, the gap S of the outer tank side plate 4 is widened. However, since the welding amount does not change, the gap accuracy of the outer tank side plate 4 can be relaxed at almost the same cost.

Further, the side wall construction step of this method includes a concrete placing step of placing concrete 5 using the outer tank side plate 4 as an inner formwork, and the vertical joint forming step includes a plurality of vertical joints as shown in FIG. All of 60 are formed by fillet welding on both sides via the cover plate 61. In this method, since concrete 5 is cast using the outer tank side plate 4 as an inner formwork to construct the side wall 3, the outer tank side plate 4 is engaged with an outer formwork (not shown) arranged on the outside of the tank via a separator. There is. Therefore, it is necessary to adjust the length and position of the outer tank side plate 4 one by one. However, in this method, all of the vertical joints 60 are fillet welded on both sides via the cover plate 61, and the outer tank side plate 4 has to be adjusted. Since each can be adjusted with a wide gap accuracy of several tens of mm, it becomes easy to manage the circumference of the outer tank side plate 4.

Further, as shown in FIG. 8, the fillet welding on both sides is performed on the cover plate 61 that covers the gap S between the outer tank side plates 4 adjacent to each other in the tank circumferential direction from the inside of the tank. In this way, by forming the vertical joint 60 of the outer tank side plate 4 by single-sided metal fillet welding from the inside of the tank, it is possible to avoid interference with the concrete 5 placing work on the outside of the tank.
Further, as shown in FIG. 7, the cover plate 61 is longer than the total height of the outer tank side plate 4. Therefore, the cover plate 61 can cover the entire gap S of the outer tank side plate 4 from the top to the bottom, and can prevent the moisture and the like of the cast concrete 5 from leaking to the inside of the tank.

Further, in the side wall construction step of this method, as shown in FIG. 9, the cover plate 61 arranged so as to project from the upper end 4a of the outer tank side plate 4 is filled with fillets on both sides except for the upper portion 4a1 of the outer tank side plate 4. A first vertical joint forming step for welding, a horizontal joint forming step for forming a horizontal joint 70 for joining the outer tank side plates 4 in the tank height direction after the first vertical joint forming step, and a horizontal joint forming step. After that, it has a second vertical joint forming step of performing fillet welding on both sides of the upper portion 4a1 of the outer tank side plate 4. According to this method, the vertical joint 60 can be formed by the cover plate 61 which is longer than the total height of the outer tank side plate 4 without interfering with the work of forming the horizontal joint 70.

As described above, according to the above-described embodiment, there is a method for constructing the LNG tank 100 having a side wall construction step of constructing a side wall 3 in which a plurality of outer tank side plates 4 are arranged on the inner wall surface 5a of the concrete 5. The side wall construction step includes a vertical joint forming step of forming a plurality of vertical joints 60 for joining the outer tank side plates 4 in the tank circumferential direction, and the vertical joint forming step includes at least one of the plurality of vertical joints 60. When adjusting the length and position of the outer tank side plates 4 one by one by adopting a method of forming by fillet welding on both sides of the cover plate 61 that covers the gap S of the outer tank side plates 4 adjacent to each other in the tank circumferential direction. Even so, the assembly accuracy can be easily controlled at no cost.

Although the preferred embodiment of the present invention has been described above with reference to the drawings, the present invention is not limited to the above embodiment. The various shapes and combinations of the constituent members shown in the above-described embodiment are examples, and can be variously changed based on design requirements and the like without departing from the gist of the present invention.

For example, in the above embodiment, a method of forming all of the plurality of vertical joints 60 by fillet welding on both sides via a cover plate 61 has been described, but the present invention is not limited to this method. For example, as a result of adjusting the length and position of the outer tank side plate 4 one by one, if the gap S of a specific outer tank side plate 4 has a width suitable for butt welding, the vertical joint 60 at that location is formed by butt welding. You may. That is, the plurality of vertical joints 60 may be formed by fillet welding on both sides via the cover plate 61 and butt welding between the outer tank side plates 4.

Further, for example, in the above embodiment, in the fillet welding on both sides, as shown in FIG. 8, with respect to the cover plate 61 that covers the gap S between the outer tank side plates 4 adjacent to each other in the tank circumferential direction from the inside (surface 4A) of the tank. However, the present invention is not limited to this method. For example, as shown in FIG. 10, the cover plate 61 may be arranged on the back surface 4B side of the outer tank side plate 4. According to this method, if the gap S of the outer tank side plate 4 is wide, both side fillet welding can be performed on the cover plate 61, and if the gap S of the outer tank side plate 4 is narrow, the cover plate 61 is backed. Can be used as a backing metal for butt welding. This method has an advantage that the construction procedure can be unified because the cover plate 61 is installed regardless of the size of the gap S of the outer tank side plate 4.

Further, for example, in the above embodiment, the case where the present invention is applied to an LNG tank is illustrated, but the present invention can also be applied to a tank for storing other low-temperature liquids (for example, LPG and the like).

3 Side wall 4 Outer tank side plate (side plate)
4a Upper end 4a1 Upper part 5 Concrete 5a Inner wall surface 11 Jack-up device 20 Inner tank side plate 30 Inner tank 42 Cold insulation material 60 Vertical joint 61 Cover plate 62 Joint 62A First joint 62B Second joint 70 Horizontal joint 100 LNG tank (tank) )
S Gap X Distance

Claims (6)

It is a method of constructing a tank having a side wall construction step of constructing a side wall formed by arranging a plurality of side plates on an inner wall surface of concrete.
The side wall construction step includes a vertical joint forming step of forming a plurality of vertical joints for joining the side plates in the tank circumferential direction.
In the vertical joint forming step, both side fillets are welded to only the cover plate that covers at least one of the plurality of vertical joints from either the inside or the outside of the tank so as to cover the gap between the side plates adjacent to each other in the tank circumferential direction. A method of constructing a tank, characterized in that it is formed. The side wall construction step includes a concrete placing step of placing the concrete using the side plate as an inner formwork.
The method for constructing a tank according to claim 1, wherein in the vertical joint forming step, all of the plurality of vertical joints are formed by fillet welding on both sides. The method for constructing a tank according to claim 1 or 2, wherein the fillet welding on both sides is performed on the cover plate that covers the gap between the side plates adjacent to each other in the circumferential direction of the tank from the inside of the tank. The method for constructing a tank according to any one of claims 1 to 3, wherein the cover plate is longer than the total height of the side plates. The side wall construction step is
A first vertical joint forming step of performing fillet welding on both sides of the cover plate arranged so as to protrude from the upper end of the side plate, except for the upper portion of the side plate.
After the first vertical joint forming step, a horizontal joint forming step of forming a horizontal joint for joining the side plates in the tank height direction, and a horizontal joint forming step.
The method for constructing a tank according to claim 4, further comprising a second vertical joint forming step of performing the fillet welding on both sides of the upper portion of the side plate after the horizontal joint forming step. Inside the side wall, an inner tank jack that constructs an inner tank by alternately repeating raising the inner tank side plate by a jack-up device and attaching the next inner tank side plate to the lower side of the raised inner tank side plate. Up process and
The method for constructing a tank according to any one of claims 1 to 5, further comprising a cold insulating material arranging step of arranging a cold insulating material between the inner tank and the side wall.

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