JP2019070294A - Construction method of tank, and tank - Google Patents

Abstract

To provide a construction method of a tank which can suppress generation of floated distortion of a bottom liner when installing a bottom cold insulation material, and a tank.SOLUTION: A cold insulation construction of a tank bottom comprises: a first welding step of a bottom liner plate of welding a plurality of bottom liner plates laid on a base slab, except a part, to form a welded region and a non-welded region of the bottom liner plates; a first installation step of a bottom cold insulation material, after the first welding step of a bottom liner plate, of installing a bottom cold insulation material on the welded region; a second welding step of a bottom liner plate, after the first installation step of a bottom cold insulation material, of welding the bottom liner plates neighboring in the non-welded region with each other; and a second installation step of a bottom cold insulation material, after the second welding step of a bottom liner plate, of installing the bottom cold insulation material on the non-welded region.SELECTED DRAWING: Figure 6

Description

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

  A double shell tank having an inner tank and an outer tank is used for storage of low temperature liquids such as LNG (liquefied natural gas) and LPG (liquefied petroleum gas). Patent Document 1 below discloses a method of constructing a cylindrical tank having an inner tank made of metal and an outer tank made of concrete. According to the method of constructing this cylindrical tank, in order to shorten the construction period of the cylindrical tank, a metal inner tank and a concrete outer tank are simultaneously applied.

  Specifically, in the method of constructing the cylindrical tank, the side wall of the outer tank is assembled at the outer peripheral edge of the bottom of the outer tank, and the roof of the outer tank is formed on the bottom of the outer tank other than the outer peripheral edge. Assembling the side wall of the outer tank, raising the roof of the outer tank on the bottom of the outer tank with a jack-up device, and holding the outer tank on the side wall of the outer tank; And a step of assembling the inner tub independently of the roof of the outer tub in the space under the roof of the

JP, 2014-92004, A

  By the way, such a tank has a structure capable of storing a low temperature liquid by laying a cold insulating material at the bottom and filling the cold insulating material between the inner and outer tanks. The bottom insulation of this tank is cast on the bottom liner laid on the foundation plate. The bottom liner is, for example, fixed by welding on the base plate, but when the bottom cold insulator is placed on the bottom liner, the bottom liner may be wrinkled to cause floating distortion. . When such an upset distortion occurs, the uplifted bottom liner has to be cut off and repaired so as to be flat, which takes time and effort.

  The present invention has been made in view of the above problems, and it is an object of the present invention to provide a method of constructing a tank and a tank capable of suppressing the occurrence of the rise distortion of the bottom liner when placing the bottom heat insulating material. .

  In order to solve the above-mentioned subject, the present invention is a construction method of a tank which carries out bottom part cold preservation construction which lays a bottom part liner on a foundation version, and places a bottom part cold storage material on the laid bottom part liner. The bottom insulation work is performed by welding the adjacent bottom liner plates together except for a part of the plurality of bottom liner plates laid as the bottom liner on the foundation plate. A first bottom liner plate welding step for forming a welded region and a non-welded region, and a first bottom cold insulator material for placing the bottom cold insulator on the welded region after the first bottom liner plate welding step And a second bottom liner plate welding step of welding the bottom liner plates adjacent to each other in the non-welding region after the first bottom cold-storage material placing step and the placing step. After the second bottom liner plate welding process, said having a second bottom cold insulating material striking setting step of pouring said bottom cold insulator on the non-welded regions, employing a technique called.

  Further, in the present invention, the first bottom liner plate welding step includes a first welding step of forming a first region of the welding region in a straight line passing through the center of the base plate, and after the first welding step A second welding step of forming a second region of the welding region in each of the regions divided on the basic plate by the first region, and the second region comprising the first region and the second region A method is adopted in which the non-welding region is formed in between.

  Further, in the present invention, a method is adopted in which the first region is formed so that straight lines intersect at the center of the basic plate.

  In the present invention, in the non-welding region, the end of the second region is over the first region, and in the second bottom liner plate welding step, the end of the second region is Adopt a method of fillet welding a portion on the first area.

  Further, in the present invention, in the first bottom cold-storage material placing step, the bottom cold-storage material is hit onto the second region toward the end of the second region overlapping the first region. Adopt the method of setting up.

  Also, the present invention is a tank having a bottom liner laid on a foundation plate and a bottom heat insulator placed on the bottom liner, the bottom liner comprising a plurality of bottom liner plates And the plurality of bottom liner plates are joined at a first area joined so that straight lines intersect at the center of the base plate and an area divided on the base plate by the first area. And an end portion of the second region overlapping with the first region is formed, and the end portion of the second region is joined onto the first region. .

  According to the present invention, when laying the bottom liner on the foundation plate, the welding area and the non-welding area are formed, and the strain accumulated when the bottom heat insulator is cast is absorbed in the non-welding area. As a result, it is possible to suppress the occurrence of floating distortion of the bottom liner.

It is an explanatory view showing the 1st process of a construction method in an embodiment of the present invention. It is an explanatory view showing the 2nd process of a construction method in an embodiment of the present invention. It is explanatory drawing which shows the 3rd process of the construction method in embodiment of this invention. FIG. 6 is a plan view of a bottom liner laid on a foundation plate in an embodiment of the present invention. It is explanatory drawing which shows the 1st bottom part liner plate welding process of the bottom part cold preservation work in embodiment of this invention. It is explanatory drawing which shows the 1st bottom part cold-storage material placement process of the bottom-part cold storage construction in embodiment of this invention. It is explanatory drawing which shows the (a) 2nd bottom part liner plate welding process of the bottom part cold storage construction in embodiment of this invention, and the (b) 2nd bottom part cold-storage material pouring process. It is explanatory drawing which shows the 4th process of the construction method in embodiment of this invention. It is an explanatory view showing the 5th process of a construction method in an embodiment of the present invention. It is explanatory drawing which shows the 6th process of the construction method in embodiment of this invention. It is explanatory drawing which shows the 1st bottom part cold-storage material placement process of the bottom-part cold storage construction in embodiment of this invention.

  Hereinafter, the tank and the method of constructing the tank according to the present invention will be described with reference to the drawings. The following description exemplifies a method of constructing a land-based PC (prestressed concrete) double shell storage tank for storing LNG. In the following drawings, some parts are enlarged or omitted for convenience of explanation, and the dimensional ratio of each component shown in the drawings is not necessarily the same as the actual one.

FIG. 1 is an explanatory view showing a first step of a construction method in the embodiment of the present invention. 1 (a) is an overall view, and FIG. 1 (b) is an enlarged view of a region A shown in FIG. 1 (a).
First, in the present method, as shown in FIG. 1 (a), a substantially disk-shaped basic version 1 is constructed (basic version construction step). The base plate 1 is made of concrete, and the inner tank anchor strap 4 and the corner angle 100 are embedded in the outer peripheral edge thereof.

  Next, in the present method, the outer tank 2 is constructed on the basic version 1 (outer tank construction step). As shown in FIG. 1A, the outer tank 2 is constructed at the peripheral portion of the substantially disk-shaped base plate 1. The outer tank 2 is a PC (prestressed concrete) constructed by placing the outer tank side plate 3 (side plate) on the upper end of the corner angle 100 by welding while placing the outer tank side plate 3 as an inner formwork. ) It is a wall. Therefore, a plurality of outer tank side plates 3 are arranged on the inner wall surface 2 a of the outer tank 2.

  As shown in FIG. 1 (b), the corner angle 100 is formed in an L-shape in cross section. At the lower part of the corner angle 100, a head stud 101 for applying a pull-out load to the base plate 1 is joined so that the outer tank side plate 3 welded to the upper end is not inclined. A separator cone 102 for installing the outer frame 200 may be joined to the rear surface of the corner angle 100.

  The outer tank side plate 3 is formed in a rectangular plate shape. A stiffener 110 is joined to the surface 3a of the outer tank side plate 3 facing the inner side of the tank and the back surface 3b on the opposite side. The stiffener 110 is embedded in the concrete 5. Further, a separator cone 120 for installing the outer frame 200 is joined to the back surface 3 b of the outer tank side plate 3. The outer mold frame 200 is connected to the outer tank side plate 3 via the separator 201 connected to the separator cone 120.

  The outer tank side plate 3 has a lateral stiffener 110A and a longitudinal stiffener 110B as stiffeners 110. The lateral stiffener 110A is embedded in the concrete 5 so as to extend in the horizontal direction, and increases the shear resistance of the outer tank side plate 3 due to prestress. The longitudinal stiffener 100B is embedded in the concrete 5 so as to extend in the vertical direction, and suppresses the expansion of the outer tank side plate 3 to the inside of the tank due to the placing pressure of the concrete 5.

  The assembling of the outer tank side plate 3 and the placing of the concrete 5 are parallel operations at a fixed interval. Thereby, the protrusion part P of the outer tank side plate 3 of the height which is not pouring concrete 5 can be restrained to a certain fixed range. Since the protruding portion P is a portion that receives the wind load by the outer tank side plate 3 alone, it is possible to prevent the buckling of the outer tank side plate 3 due to the wind load by thus suppressing the protruding portion P within a certain range.

FIG. 2 is an explanatory view showing a second step of the construction method in the embodiment of the present invention.
In the present method, the bottom liner 6 is laid on the base plate 1 in parallel with the assembly of the outer tank 2. Moreover, the roof mount 7 is assembled in the center part of the foundation version 1. Further, a construction port 8 for taking in the inner tank side plate 9 and the like is formed at the base end of the outer tank 2. Moreover, along the inside of the base end part of the outer tank 2, multiple gate type mount frames 10 for inner tank side plate assembly are installed. The portal type gantry 10 is installed so as to straddle an annular region X, which is a region where a cylindrical inner tank formed by combining a plurality of inner tank side plates 9 is to be finally lowered onto the base plate 1.

  Under the portal frame 10, a cold storage structure 12 such as a pearlite concrete block or a lightweight structural concrete block is temporarily placed in the annular area X. Further, on the portal frame 10, a plurality of jackup devices 19 are installed in the outer tank 2. Specifically, the suspension-side gantry 70 is installed in the middle portion of the outer tank 2 above the installation position of the portal-type gantry 10. The suspension-side gantry 70 is detachably fastened and fixed to an anchor plate (not shown) embedded in the outer tank 2. Further, the suspended support frame 80 is installed on the knuckle plate 11 assembled on the portal frame 10.

  The jack main body 19 a of the jack-up device 19 is connected to the to-be-suspended side support frame 80. In addition, a jack rod 19b which is stroked by the operation of the jack main body 19a is connected to the suspension stand 70. After the jack-up device 19 is thus installed, the knuckle plate 11 is lifted from the portal frame 10, the inner tank side plate 9 is carried into the lower space created by the jack up, and adjacent inner tank side plates 9 are welded to each other. The pieces are joined together in the circumferential direction so that they become cylindrical as a whole. Next, the upper end portion of the inner tank side plate 9 is assembled to the lower end portion of the knuckle plate 11. Further, the upper end portion of the knuckle plate 11 is assembled to the outer peripheral edge portion of the inner tank roof 14 which has been folded on the roof mount 7.

FIG. 3 is an explanatory view showing a third step of the construction method in the embodiment of the present invention.
Thereafter, when the lifting body 60 including the inner tank roof 14, the knuckle plate 11 and the inner tank side plate 9 is lifted by the jack-up device 19, the roof mount 7 is removed as shown in FIG. Repeat alternately (attachment of upper and lower width of inner tank side plate 9) and the next inner tank side plate 9 to the lower end of inner body 60 (inner tank side plate 9) (welding), and hang up jack point The first structure 9a except the lowermost stage of the inner tank side plate 9 is assembled while being reheated upward.

Also, during this process, the outer tub roof 22 is assembled on the inner tub roof 14. The outer tank roof 22 is connected to the inner tank roof 14 by a connecting member (not shown), and is integrally assembled with the inner tank roof 14.
Under the portal frame 10, a cooling work of the annular portion 13 by the temporarily placed cold storage structure 12 is performed. When the cold insulation work of the annular portion 13 is completed, as shown in FIG. 3, the leg portion 10 a of the portal type gantry 10 arranged on the tank inner side than the annular portion 13 is replaced on the annular portion 13.

As a result of such replacement, no interference is present on the inner side of the tank with respect to the annular portion 13, so that the cooling work of the central portion on the basic version 1 can be performed. In the central cold storage construction, a bottom cold storage material 39 (for example, a pearlite concrete block) serving as a bottom cold heat resistance reducing material is placed on the bottom liner 6, and the foam glass 40 is placed thereon. Furthermore, an ALC (light-weight cellular concrete) (not shown) and an inner tank bottom plate (not shown) are sequentially laid on top of that.
Then, the bottom part cold-packing work of such a foundation version 1 is demonstrated in detail with reference to FIGS. 4-7.

FIG. 4 is a plan view showing the bottom liner 6 laid on the foundation plate 1 in the embodiment of the present invention.
The bottom liner 6 has an outer annular plate 61, a bottom liner plate 62, and an inner annular plate 63, as shown in FIG. The outer annular plate 61 is fan-shaped in plan view. On the outer diameter side of the outer annular plate 61, a plurality of holes 61a are formed at intervals along the arc shape on the outer diameter side. While the inner tank anchor strap 4 mentioned above is penetrated by the hole 61a, the anchor box not shown which accommodates the lower end part of the inner tank anchor strap 4 engages.

  The outer annular plate 61 is annularly laid along the outermost peripheral portion 1 a of the base plate 1 (inside of the outer tank 2). A bottom liner plate 62 is laid on the central portion 1b of the base plate 1 surrounded by the annularly laid outer annular plate 61. The bottom liner plate 62 has an outer contour laid in a polygonal shape in plan view. An inner annular plate 63 is laid in an intermediate gap portion 1 c between the outer annular plate 61 laid in an annular shape and the bottom liner plate 62 laid in a polygonal shape. The inner annular plate 63 is a plate for adjustment that covers the intermediate gap portion 1 c, and is laid across the outer annular plate 61 and the bottom liner plate 62. In this manner, the bottom liner 6 is laid on the entire surface of the base plate 1.

  The bottom liner plate 62 has a first region 62A joined in a straight line passing through the center O of the base plate 1 and a second region joined in each of the regions divided on the base plate 1 by the first region 62A. And 62B. The first region 62A is formed such that straight lines intersect at the center O of the base plate 1. The first region 62A of the present embodiment is formed such that two straight lines intersect at right angles and a cross at the center O of the base plate 1. The second area 62B is formed in a quadrant shape in each of the four areas divided by the first area 62A.

  In the first region 62A, a rectangular bottom liner plate 62 (hereinafter, may be referred to as a corridor plate 62a) is formed by welding and joining in a straight line. On the other hand, in the second region 62B, two rectangular bottom liner plates 62 (hereinafter, may be referred to as a tatami board 62b1 and a corridor board 62b2) are joined together by welding to form a quarter circle. . The directions of the longitudinal direction of the tatami board 62b1 and the corridor board 62b2 are laid orthogonal to each other, and they are joined so as to avoid the cross joint.

  The first area 62 </ b> A and the second area 62 </ b> B are joined by the joining portion 64. The joint portion 64 is formed by fillet welding an end 62B1 of the second region 62B onto the first region 62A. Specifically, the end 62B1 of the second area 62B overlaps the first area 62A, and the overlapped end 62B1 is fillet-welded on the first area 62A (so-called lap welding). .

  A bottom heat insulating material 39 shown in FIG. 3 is placed on the bottom liner plate 62 thus laid. Next, the process of bottom part cold insulation construction of this foundation version 1 will be described with reference to FIGS. 5 to 7.

FIG. 5 is an explanatory view showing a first bottom liner plate welding step of the bottom part cooling work in the embodiment of the present invention.
In the bottom portion cold insulation construction of the foundation plate 1, first, a first bottom liner plate welding step shown in FIG. 5 is performed. In the first bottom liner plate welding process, adjacent bottom liner plates 62 are welded together except for a part of the plurality of bottom liner plates 62 laid as the bottom liner 6 on the base plate 1 to form a bottom liner. This is a step of forming the welding area (first area 62A, second area 62B) of the plate 62 and the non-welding area 65.

In the first bottom liner plate welding process, first, as shown in FIG. 5A, a first area 62A (welding area) is formed in a straight line passing through the center O of the base plate 1 (first welding process). The first region 62A is formed so that straight lines intersect at the center O of the base plate 1.
Next, in the first bottom liner plate welding step, as shown in FIG. 5B, the second region 62B (welded region) is formed in each of the regions divided on the base plate 1 by the first region 62A. (2nd welding process).

  The second area 62B is formed in the shape of a quadrant in each of the areas divided into four by the first area 62A, and the quadrant-shaped radially extending end 62B1 overlaps the first area 62A. Is formed. In the first bottom liner plate welding step, the end 62B1 of the second region 62B is not yet welded to the first region 62A. That is, the non-welding area 65 is formed between the first area 62A and the second area 62B.

FIG. 6 is an explanatory view showing a first bottom portion cold-insulating-material placing step of the bottom portion cold-holding work in the embodiment of the present invention.
In the bottom part cold storage construction of the foundation plate 1, next, a first bottom cold storage material placement step shown in FIG. 6 is performed. The first bottom cold storage material casting step is a step of casting a bottom cold storage material 39a on the second region 62B, which is a welding region, after the first bottom liner plate welding step.

  In the first bottom portion cold insulating material placing step, as shown in FIG. 6A, the bottom portion cold insulating material 39a is placed on each of the four second regions 62B. Although the direction in which the bottom portion cold storage material 39a is cast is not particularly limited, in the present embodiment, it is difficult to take a structure to release the floating strain of the bottom liner plate 62 in the prior art. The bottom portion cold insulating material 39a is to be placed. In addition, conversely, in the case where the bottom portion cold-storage material 39a is placed from the center O of the base plate 1 toward the outer periphery, it is possible to absorb the distortion in the intermediate gap portion 1c shown in FIG.

  The distortion of the second region 62B accumulated toward the center O of the foundation plate 1 by the placement of the bottom portion cold insulator 39a is absorbed in the non-welded region 65, as shown in the B-B cross section of FIG. 6 (b). Be done. That is, in the non-welding region 65, since the end 62B1 of the second region 62B overlaps the first region 62A, the end 62B1 of the second region 62B slides on the first region 62A (slip) Thus, the distortion of the second region 62B is absorbed. That is, the area where the end 62B1 of the second area 62B overlaps the first area 62A is increased, and the generation of the floating distortion of the second area 62B is suppressed.

FIG. 7 is an explanatory view showing (a) a second bottom liner plate welding step and a (b) second bottom cold-storage material placing step in the bottom-side cold-holding work according to the embodiment of the present invention.
Next, a second bottom liner plate welding step shown in FIG. 6A is performed in the bottom portion cold insulation construction of the foundation plate 1. The second bottom liner plate welding step is a step of welding adjacent bottom liner plates 62 in the non-welding region 65 after the first bottom cold-storage material placement step. That is, the joint portion 64 is formed by fillet welding the end 62B1 of the second region 62B onto the first region 62A.

In the bottom part cold storage construction of the foundation plate 1, finally, a second bottom part cold insulating material placement step shown in FIG. 6 (b) is performed. The second bottom portion cold-storage material placing step is a step of placing a bottom-portion cold-storage material 39 b on the non-welding region 65 after the second bottom liner plate welding step. That is, in order to absorb the distortion of the second region 62B, the remaining region (the non-welded region 65 (joint portion 64), the end 62B1 of the second region 62B, and the The bottom portion cold-insulating material 39b is placed in the first region 62A).
By the above, the bottom part cold-packing construction of basic version 1 is completed.

FIG. 8 is an explanatory view showing a fourth step of the construction method in the embodiment of the present invention.
In this method, after completion of the bottom portion cooling work of the foundation plate 1, the lowermost step of the inner tank side plate 9 is assembled on the annular portion 13 separately from the first structure 9a assembled in FIG. Specifically, after dismantling the portal type gantry 10, when the lowermost step of the inner tank side plate 9 is placed on the annular portion 13, adjacent inner tank side plates 9 are welded to form a cylindrical shape as a whole. Connect in the direction to assemble the second structure 9b. After the second structure 9 b is assembled, the inner tank anchor strap 4 installed on the foundation plate 1 is attached. In addition, the elevating stairs 23 are provided outside the outer tank 2. In addition, the pump barrel 25 is carried into the outer tank 2.

FIG. 9 is an explanatory view showing a fifth step of the construction method in the embodiment of the present invention.
Next, in the present method, as shown in FIG. 9, the first structure 9a is jacked down, and the lower end of the first structure 9a is lowered to the upper end of the second structure 9b. The structure 9 a and the second structure 9 b are welded to assemble the inner tank 30. In this method, the assembly of the lowermost part of the inner tank 30 is separated from the assembly of the inner tank 30 by the jack-up device 19, and the second structure 9 b which is the lowermost part of the inner tank 30 is fixed on the annular portion 13. Are moving ahead of time. Therefore, in the present method, fixing of the inner tank 30 on the annular portion 13 which takes about one month, for example, does not become a critical path, and the construction period can be shortened compared to the conventional method.

When the inner tank 30 is completed, the outer tank roof 22 releases the connection with the inner tank roof 14 by a connecting material (not shown), and is installed at the upper end of the outer tank 2 assembled up to the uppermost stage. In addition, a roof stairway 24 is provided on the outer tank roof 22. Also, the pump barrel 25 is installed.
Thereafter, the suspended base 80 is removed and the jack-up device 19 is removed. Then, the tension work of the outer tank 2 is performed. Then, after closing the construction opening 8, water pressure is applied to carry out a pressure and air tightness test.

FIG. 10 is an explanatory view showing a sixth step of the construction method in the embodiment of the present invention.
Finally, as shown in FIG. 10, a cold insulating material 44 is disposed between the inner and outer tanks 15 between the inner tank 30 and the outer tank 2 and also between the inner tank roof 14 and the outer tank roof 22. 44 is arrange | positioned and cold insulation construction is performed, Then, painting construction, piping cold insulation construction are passed, and the LNG tank 50 is constructed | assembled.

  As described above, according to the above-described embodiment, the bottom liner 6 is laid on the foundation plate 1, and the LNG tank 50 is subjected to the bottom portion cooling construction in which the bottom portion cold insulator 39 is cast on the laid bottom liner 6. In the bottom portion cold-keeping work, adjacent bottom portion liner plates 62 are welded together except for a part of the plurality of bottom portion liner plates 62 laid as the bottom portion liner 6 on the foundation plate 1. A first bottom liner plate welding step forming a welded region (first region 62A, second region 62B) of the bottom liner plate 62 and a non-welded region 65, and after the first bottom liner plate welding step, The bottom liner plates 62 adjacent to each other in the non-welding region 65 after the first bottom cold insulator placing step of placing the bottom cold insulator 39a on the top and the first bottom cold insulator placing step Method of having the second bottom liner plate welding step in contact and the second bottom cold-storage material driving step of placing the bottom cold-storage material 39b on the non-welding region 65 after the second bottom liner-plate welding step By adopting this, it is possible to suppress the occurrence of the upset distortion of the bottom liner 6.

  As mentioned above, although the suitable embodiment of the present invention was described referring to drawings, the present invention is not limited to the above-mentioned embodiment. The shapes, combinations, and the like of the constituent members shown in the above-described embodiment are merely examples, and various changes can be made based on design requirements and the like without departing from the spirit of the present invention.

FIG. 11 is an explanatory view showing a first bottom cold-insulating-material placing step of the bottom cold-insulating work according to another embodiment of the present invention. Note that, in FIG. 11, the same or equivalent configuration as that of the above-described embodiment is denoted by the same reference numeral, and the description thereof is simplified or omitted.
In the first bottom cold-insulating-material placing step shown in FIG. 11, a bottom cold-insulating material 39a is cast on the second region 62B toward the end 62B1 of the second region 62B overlapping the first region 62A. There is. According to this method, strain is accumulated toward the end 62B1 of the second region 62B, so that the strain can be easily absorbed in the non-welding region 65.

  Further, as shown in FIG. 1, if the bottom portion cold-insulating material 39a is cast from both sides of the first region 62A toward the first region 62A, even if the first region 62A has a single linear shape. Good. In this method, since the direction in which the bottom portion cold insulating material 39a is cast is limited, in the case where the casting work of the bottom portion cold insulator 39a has a degree of freedom, it is shown in FIG. As shown, it is preferable to form the first region 62A so that straight lines intersect at the center O of the base plate 1. According to the first area 62A, distortion of the second area 62B can be absorbed in all directions (at least the tank radial direction and the tank circumferential direction).

  Further, for example, in the above-described embodiment, the bottom heat insulating material 39a is cast on the second region 62B in the first bottom heat insulating material placing step, but the width in the first region 62A is sufficiently ensured. The bottom part cold-storage material 39a may be cast on a part of the first area 62A while avoiding the non-welding area 65.

  For example, although the case where the present invention was applied to the LNG tank was illustrated in the above-mentioned embodiment, the present invention is applicable also to the tank which stores other low temperature liquids (for example, LPG etc.).

  Also, for example, the present invention can be applied not only to the method of constructing a tank using a jack-up device, but also to the method of constructing a tank using an air laying method.

Reference Signs List 1 base plate 39 bottom cold storage material 39a bottom cold storage material 39b bottom cold storage material 62 bottom liner plate 62A first area 62B second area 62B1 end 65 non-welding area O center

Claims (6)

It is a construction method of a tank which performs bottom part cold insulation construction which lays a bottom part liner on a foundation version and places a bottom part cold storage material on the laid bottom part liner,
The said bottom part cold construction is
Among the plurality of bottom liner plates laid as the bottom liner on the foundation plate, the adjacent bottom liner plates are welded together except for a part of the bottom liner plates to form a welded area and a non-welded area of the bottom liner plate A first bottom liner plate welding step to form
A first bottom cold storage material casting process in which the bottom cold storage material is placed on the welding area after the first bottom liner plate welding process;
A second bottom liner plate welding step of welding the bottom liner plates adjacent to each other in the non-welding region after the first bottom cold-storage material driving step;
And b. A second bottom heat insulating material placing process for placing the bottom heat insulating material on the non-welding region after the second bottom liner plate welding process. The first bottom liner plate welding process comprises
A first welding step of forming a first region of the welding region in a straight line passing through the center of the foundation plate;
After the first welding step, a second welding step of forming a second region of the welding region by each of the regions divided on the base plate by the first region;
The method according to claim 1, wherein the non-welding region is formed between the first region and the second region.   The method according to claim 2, wherein the first region is formed to cross a straight line at the center of the base plate. In the non-welding region, the end of the second region is over the first region, and
The tank according to any one of claims 1 to 3, wherein in the second bottom liner plate welding step, an end of the second region is fillet-welded on the first region. How to build.   In the first bottom portion cold-insulating-material placing step, the bottom portion cold-insulating material is placed on the second region toward an end of the second region overlapping the first region. The method of constructing a tank according to claim 4. A tank having a bottom liner laid on a foundation plate and a bottom heat insulator driven on said bottom liner,
The bottom liner comprises a plurality of bottom liner plates,
The plurality of bottom liner plates are joined at a first area joined in a straight line at the center of the base plate and at a divided area above the base plate by the first area. Forming a second region whose end overlaps the first region;
A tank, wherein an end of the second area is joined onto the first area.

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