WO2017043567A1

WO2017043567A1 - Cylindrical tank construction method

Info

Publication number: WO2017043567A1
Application number: PCT/JP2016/076428
Authority: WO
Inventors: 寿一郎山田; 成貴加藤
Original assignee: 株式会社Ihi
Priority date: 2015-09-11
Filing date: 2016-09-08
Publication date: 2017-03-16
Also published as: TWI620861B; JP6465488B2; TW201713835A; JP2017053182A

Abstract

This construction method for a cylindrical tank having a metal inner tank and a concrete outer tank involves an outer tank side wall construction step in which a PC wall 2 is constructed in that steel side liners 2a are built up from a base plate and, following the building up of the side liners 2a, concrete 2b is laid with the side liners 2a as the inside frame. In the outside tank side wall construction step, a method is adopted that involves a scaffolding unit linking step in which multiple scaffolding units 100 comprising a beam member 110 are hung on multiple beam receivers 101 installed on the inward-facing plate surface 102 of previously built-up side liners 2a, and the beam members 110 of the scaffolding units 100 hung on the beam receivers 101 are linked together in a ring shape along the inward-facing plate surface 102 of the side liners 2a.

Description

Construction method of cylindrical tank

The present disclosure relates to a method for constructing a cylindrical tank.
This application claims priority based on Japanese Patent Application No. 2015-179734 for which it applied to Japan on September 11, 2015, and uses the content here.

A cylindrical shell with a double shell structure having an inner tank and an outer tank is used for storing low-temperature liquids such as LNG (liquefied natural gas) and LPG (liquefied petroleum gas). Patent Document 1 discloses a cylindrical tank having a metal inner tank and a concrete outer tank.

Patent Document 1 discloses a technique in which a metal inner tank and a concrete outer tank are simultaneously constructed in order to shorten the construction period of a cylindrical tank. Specifically, a jack stand is erected at the bottom of the outer tub, and the jack-up device is supported at a predetermined height (see FIG. 4B of Patent Document 1). And when performing the side wall construction of the outer tub, the inner tub roof and the outer tub roof are assembled on the bottom of the outer tub, and then the inner tub roof and the outer tub roof are raised by the jack-up device, By attaching the inner tank side plates to the tank roof in order from the top to the bottom, simultaneous construction of the metal inner tank and the concrete outer tank is realized.

Japanese Unexamined Patent Publication No. 7-62924

By the way, the side wall of the outer tank is constructed as follows, for example. First, the bottom of the outer tub is constructed, and steel liner materials are sequentially stacked in layers on the bottom and fixed by welding. When the liner material has been assembled, the outer mold is then installed, and concrete is cast using the liner material as the inner mold to construct the sidewall of the outer tub. In this method, in order to prevent buckling due to wind load of an independent and independent liner material, the thickness of the liner material must be increased, and the amount of construction cannot be minimized.

Therefore, the inventors of the present invention have assembled a liner material from the bottom of the outer tub, followed by assembling the liner material using the liner material as an inner mold, and assembling the side walls of the outer tub. Devised. According to this method, the assembling of the liner material and the placing of the concrete are performed in parallel with a certain interval, and the liner material is supported by the concrete within a certain range, so that buckling due to the wind load of the liner material can be suppressed. . In addition, it is possible to minimize the amount of construction by optimizing the thickness of the liner material.

However, even in this method, the liner material (the uppermost liner material) assembled prior to the concrete is not supported by the concrete, and is independent and independent. For this reason, it is necessary to weld, for example, a yoke material or the like as a strong ring to the uppermost liner material. However, since this yoke material gets in the way of the cold insulation work between the inner and outer tubs, it must be finally removed from the liner material. Therefore, a great deal of work is required to attach and remove the yoke material.

The present disclosure has been made in view of the above problems, and an object thereof is to provide a method for constructing a cylindrical tank that can easily maintain the shape of a liner material assembled prior to placing concrete.

The first aspect according to the present disclosure is a method for constructing a cylindrical tank having a metal inner tank and a concrete outer tank. In this cylindrical tank construction method, the steel liner material is assembled in advance from the bottom of the outer tub, and the concrete is cast using the liner material as the inner mold following the assembly of the liner material. An outer tank side wall constructing step for constructing the side wall of the outer tank. In the outer tank side wall construction process, a plurality of scaffolding units including beam members are hooked on a plurality of receiving beams installed on an inward plate surface facing the inside of a tank of liner material assembled in advance. A scaffold unit connecting step of connecting the beam members of the suspended scaffold units in an annular manner along the inward plate surface of the liner material;

According to the present disclosure, a plurality of scaffolding units including beam members are hooked on a plurality of receiving beams installed on an inward plate surface of a liner material assembled prior to placing concrete, and the beams of the scaffolding unit The members are connected in a ring shape. Thereby, an annular strong ring can be formed along the inward plate surface of the liner material. The annularly connected beam members maintain the shape of an independent and self-supporting liner material and function as a buckling prevention material (so-called stiffener) due to wind load. Furthermore, since the scaffold units are connected in the circumferential direction of the tank by connecting the beam members, and the scaffold can be formed over the entire circumference of the tank, the construction of the liner material is facilitated. Further, since the scaffold unit is hooked on the receiving beam of the liner material, the attachment and removal work of the scaffold unit is easy.
Therefore, in the present disclosure, the shape of the liner material assembled prior to the concrete placement can be easily maintained.

It is a figure which shows the 1st process of the construction method in embodiment of this indication. It is a side view which shows the installation state of the scaffold unit in embodiment of this indication. It is arrow A figure shown in FIG. FIG. 3 is an arrow B view shown in FIG. 2. It is a figure which shows the 2nd process of the construction method in embodiment of this indication. It is a figure showing the 3rd process of the construction method in the embodiment of this indication. It is a figure which shows the 4th process of the construction method in embodiment of this indication. It is a figure which shows the 5th process of the construction method in embodiment of this indication. It is a figure which shows the 6th process of the construction method in embodiment of this indication. It is a side view which shows the installation state of the scaffold unit in another embodiment of this indication.

Hereinafter, the construction method of the cylindrical tank according to the present disclosure will be described with reference to the drawings. In the following description, a ground type PC (prestressed concrete) double-shell storage tank for storing LNG is exemplified as the cylindrical tank.

FIG. 1 is a diagram illustrating a first step of a construction method according to an embodiment of the present disclosure.
As shown in FIG. 1, in this method, first, construction of a substantially disk-shaped foundation plate 1 made of concrete (the bottom of the outer tub) is performed. Next, the bottom liner 6 is laid on the foundation plate 1. Then, the roof pedestal 7 is assembled at the center of the base plate 1. Moreover, the PC wall 2 (side wall of the outer tub) is constructed at the outer peripheral edge of the base plate 1 (outer tub side wall construction step).

The PC wall 2 is constructed by placing the side liner 2a (steel liner material) in advance from the base plate 1 and following the assembling of the side liner 2a to place concrete 2b using the side liner 2a as an inner mold. It is constructed by. The side liner 2a is, for example, a large steel plate having a length of 4.5 m, a width of 12 m, and a thickness of 8 mm. An outer scaffold 5 is installed on the outside of the side liner 2a, an outer mold (not shown) is assembled so as to face the side liner 2a, and concrete 2b is placed.

The side liner 2a is joined by welding in the circumferential direction so as to be cylindrical as a whole. The next side liner 2a is welded to the upper part of the side liner 2a joined in a cylindrical shape, and similarly, the next side liner 2a is joined in a circumferential direction so as to be cylindrical as a whole. Match. In addition, it is preferable to perform welding of the side liners 2a by one-side welding from the inside of the tank. For example, it is preferable to perform backing butt welding using a backing metal. In this way, by making the welding of the side liners 2a one-sided welding from the inside of the tank, interference with the concrete 2b placing work on the outside of the tank can be avoided.

The assembly of the side liner 2a and the placement of the concrete 2b are performed alternately. That is, when the side liner 2a is assembled in advance, the concrete 2b is placed using the lower side liner 2a as the inner mold. For this reason, the assembling of the side liner 2a and the placing of the concrete 2b are parallel operations with a certain interval. Thereby, the protrusion part L of the side liner 2a of the height which is not placing concrete 2b can be restrained to a certain fixed range. For this reason, when designing the side liner 2a, the thickness of the side liner 2a may be set so that the side liner 2a can stand independently in the projecting portion L, and the design amount is optimized to minimize the amount of construction. And cost can be reduced.

Incidentally, there is no structure for positioning (particularly positioning in the tank radial direction) around the side liner 2a (the uppermost side liner 2a) assembled in advance. Further, the protruding portion L of the side liner 2a receives a wind load alone. Moreover, in order to perform the welding operation | work of the side liner 2a, an inner side scaffold is also required. Therefore, in this method, in the construction of the PC wall 2, the shape of the side liner 2a is maintained, used as a welding work scaffold for the side liner 2a, and also functions as a buckling prevention material (so-called stiffener) due to wind load. The scaffold unit 100 is installed.

FIG. 2 is a side view showing an installation state of the scaffold unit 100 in the present embodiment. FIG. 3 is an arrow A view shown in FIG. 4 is an arrow B view shown in FIG.
As shown in FIG. 2, a plurality of receiving beams 101 are installed on the side liner 2a. The receiving beam 101 is a steel material assembled in an L shape that extends in the horizontal direction from the side liner 2a and then rises in the vertical direction. The receiving beam 101 is fixed to the inward plate surface 102 facing the tank inside of the side liner 2a by welding.

As shown in FIG. 3, a plurality of receiving beams 101 are arranged at intervals in the longitudinal direction of the side liner 2a. A plurality of receiving beams 101 are arranged so as to be hooked at three places in the longitudinal direction with respect to one scaffold unit 100. The receiving beams 101 according to the present embodiment are arranged in two upper and lower rows, and are hooked to a total of six places on one scaffold unit 100. The receiving beam 101 is preferably welded to the side liner 2a in advance on the ground before assembling the side liner 2a.

As shown in FIG. 2, the scaffold unit 100 includes a beam member 110 that can be hooked on the receiving beam 101, and a scaffold 120 that is integrally fixed to the beam member 110. The beam member 110 extends along the inward plate surface 102 in the longitudinal direction of the side liner 2a (the paper depth direction shown in FIG. 2). The beam member 110 forms a stronger ring of the side liner 2a by being connected in an annular shape as will be described later, and maintains the shape of the side liner 2a. In the present embodiment, as the beam member 110, for example, an H-shaped steel having a cross-sectional dimension of 200 mm long × 200 mm wide is used.

The scaffold unit 100 includes two beam members 110 arranged one above the other. Each of the upper and lower beam members 110 is hooked on the receiving beam 101 at three locations as shown in FIG. The scaffold unit 100 includes two scaffolds 120 that are fixed to the upper and lower beam members 110, respectively. The scaffold 120 is supported by a plurality of projecting members 121 (see FIG. 4) welded to the beam member 110, a cross member 122 fixed to the ends of the plurality of projecting members 121, and the projecting member 121 and the cross member 122. Scaffolding plate 123.

An oblique member 124 is connected to the bottom of the scaffold 120 as shown in FIG. One end of the oblique member 124 is fixed to the overhanging member 121 with a bolt or the like, and the other end of the oblique member 124 contacts the inward plate surface 102 of the side liner 2a. The other end of the diagonal member 124 that supports the bottom of the upper scaffold 120 is fixed to a vertical member 125 that connects the upper and lower beam members 110 with a bolt or the like. The other end of the diagonal member 124 that supports the bottom of the lower scaffold 120 is fixed to a vertical member 126 that extends downward from the lower beam member 110 with a bolt or the like.

In addition, the scaffold unit 100 includes a vertical member 126 that connects the upper and lower scaffolds 120. As shown in FIG. 3, a cross member 127 serving as a handrail is fixed to the vertical member 126.
As shown in FIG. 3, a plurality of scaffold units 100 having the above configuration are attached to the side liner 2a. Specifically, a plurality of scaffold units 100 are attached by hooking the beam members 110 of the scaffold unit 100 to the receiving beam 101 as shown in FIG. The beam member 110 and the receiving beam 101 are preferably connected with a bolt or the like in order to maintain the hooked state. Note that the scaffold unit 100 may be attached to the side liner 2a in advance on the ground.

Next, as shown in FIG. 3, the beam members 110 of the scaffold unit 100 hooked to the receiving beam 101 are connected in an annular shape along the inward plate surface 102 of the side liner 2a (scaffold unit connecting step). . As shown in FIG. 4, the beam members 110 are preferably connected to each other using a connection plate 130 such as a face plate to which a plurality of bolts can be fastened. Moreover, it is preferable to connect the upper and lower sides of the flange of the beam member 110 (H-section steel) using the connection plate 130 as shown in FIG. The beam member 110 is connected by the connection plate 130 to form a strong ring having an annular shape (in detail, a polygonal annular shape close to a circle) that goes around the tank.

According to this method, a plurality of scaffold units 100 including beam members 110 are hooked on a plurality of receiving beams 101 installed on the inward plate surface 102 of the side liner 2a assembled prior to the placing of the concrete 2b. To do. By connecting the beam members 110 of the scaffold unit 100 in an annular shape, an annular strong ring is formed along the inward plate surface 102 of the side liner 2a. As shown in FIG. 2, the beam members 110 connected in an annular shape maintain the shape of the independent side liner 2a and function as a buckling prevention material (so-called stiffener) due to wind load. Furthermore, since the scaffold unit 100 is connected in the circumferential direction of the tank by connecting the beam member 110 and can form a scaffold over the entire circumference of the tank, the side liner 2a can be easily constructed (welded or the like).

Moreover, since the scaffold unit 100 is hooked on the receiving beam 101 of the side liner 2a as shown in FIG. 2, the attachment and removal work of the scaffold unit 100 is easy.
For example, if the bolting that maintains the hooked state of the beam member 110 and the receiving beam 101 is released, the scaffold unit 100 can be easily removed (lifted) from the side liner 2a with a crane or the like. In addition, since the receiving beams 101 are dotted and welded to the side liner 2a and each receiving beam 101 is small in a piece shape, the receiving beams 101 can be easily excised when disturbing during the cold insulation work described later. Thus, according to this method, the shape of the side liner 2a assembled prior to the placement of the concrete 2b can be easily maintained.

Also, the scaffold unit 100 includes beam members 110 that are arranged above and below, and in the scaffold unit coupling step, each of the upper and lower beam members 110 is annularly coupled along the inward plate surface 102 of the side liner 2a. According to this method, since the independent and independent side liner 2a is supported by the two upper and lower strong rings, the shape of the side liner 2a can be maintained with higher accuracy. For example, the radial position of the side liner 2a can be accurately adjusted by moving the side liner 2a in the radial direction with reference to the beam member 110 connected in an annular shape. Further, according to this method, since the size of the cross section per beam member 110 can be reduced as compared with the case where the rigidity of the side liner 2a is ensured by using one beam member 110, the assembly work of the scaffold unit 100 is performed. Etc. becomes easy.

The scaffold unit 100 includes a scaffold 120 fixed to each of the upper and lower beam members 110. According to this configuration, operations such as welding (vertical seam welding) between the side liners 2a adjacent to each other in the circumferential direction and inspection related to the welding are facilitated.
Moreover, since the beam member 110 is H-shaped steel, the manufacturing cost of the scaffold unit 100 can be reduced as compared with the case where a custom-made steel material is used.

FIG. 5 is a diagram illustrating a second step of the construction method according to the embodiment of the present disclosure.
As shown in FIG. 5, in this method, the PC wall 2 is constructed while attaching the scaffold unit 100 to the side liner 2a as described above. In addition, an inner tank anchor strap 4 is installed on the base plate 1 inside the PC wall 2. Moreover, the construction port 8 for taking in the inner tank side plate 9 one by one in the base end part of the PC wall 2 is formed. A plurality of gate-type mounts 10 for assembling the inner tank side plate are installed along the inside of the base end of the PC wall 2. The gate-type gantry 10 is installed so that a cylindrical inner tank formed by combining a plurality of inner tank side plates 9 straddles the annular area X, which is an area to be finally lowered on the base plate 1.

Next, the inner tank side plate 9 is placed on the gate-type gantry 10 and the inner tank side plates 9 adjacent in the circumferential direction are welded to each other so as to form a cylindrical shape as a whole. Further, the knuckle plate 11 is assembled to the upper end portion of the inner tank side plate 9. In addition, the structural member 12 of the annular portion 13 (see FIG. 6) such as a pearlite concrete block or a structural lightweight concrete block is temporarily placed in the annular region X under the portal frame 10. Further, the inner tank roof 14 is assembled on the roof mount 7. Further, the knuckle plate 11 is assembled to the outer peripheral edge portion of the inner tank roof 14.

Next, between the inner and outer tubs 15 above the base plate 1 (between the PC wall 2 and the inner tub side plate 9), the suspending side jack mount 16 (hanging point) is placed on the PC wall 2 above the knuckle plate 11. Are installed along the circumferential direction of the tank. The suspension-side jack mount 16 is installed so as to protrude substantially horizontally from the PC wall 2 having a predetermined height toward the inside of the tank. The suspension-side jack mount 16 is fastened and fixed firmly, for example, to an anchor plate embedded in the PC wall 2 or the like.

Also, a plurality of knuckle reinforcements 17 facing the plurality of suspension-side jack mounts 16 are installed on the knuckle plate 11. The knuckle reinforcement member 17 projects from the knuckle plate 11 toward the inner / outer tank 15. Further, the knuckle reinforcing member 17 serves as a suspended base. A jack-up device 18 is installed across the suspension-side jack mount 16 and the knuckle reinforcement member 17. The jack-up device 18 is a center hole jack. The device main body is installed on the suspension-side jack mount 16 and the lower end of the jack-up rod 19 is attached to the knuckle reinforcement member 17.

When the jack-up device 18 is installed in this way, the roof mount 7 is removed, and the knuckle plate 11 is lifted by the jack-up device 18 to raise the inner tank side plate 9. When the inner tank side plate 9 is raised by the jack-up device 18 by one stroke of the jack-up rod 19 (corresponding to the vertical width of the inner tank side plate 9 alone in this embodiment), the jack-up device 18 lowers the inner tank side plate 9 by this jack-up. The inner tank side plate 9 of the next stage is carried into the space formed.

FIG. 6 is a diagram illustrating a third step of the construction method according to the embodiment of the present disclosure.
When the inner tank side plate 9 of the next stage is connected in the tank circumferential direction, the upper end thereof and the lower end of the raised inner tank side plate 9 are welded. Next, the inner tank side plate 9 integrated by this welding is jacked up by the jack-up device 18, and the next stage of the inner tank side plate 9 is carried into the space formed by the jack up in the lower part of the inner tank side plate 9. To do. Thus, the raising of the inner tank side plate 9 by the jack-up device 18 and the welding of the inner tank side plate 9 of the next stage to the lower part of the raised inner tank side plate 9 are alternately repeated (inner tank side wall construction step). . In this method, the inner tank side plate 9 is attached in order from the uppermost stage, and the first structure 9a excluding the lowermost stage of the inner tank side plate 9 is assembled.

In addition, during this process, the cold insulation work of the annular portion 13 is performed in parallel under the portal frame 10.
When the cold insulation work of the annular portion 13 is completed, as shown in FIG. 6, the leg portion 10 a disposed on the inner side of the tank than the annular portion 13 is moved onto the annular portion 13. By such relocation, there is no interfering substance inside the tank with respect to the annular portion 13, so that the cold insulation work at the central portion on the foundation plate 1 can be performed. In the cold insulation work in the center, the foam glass 40 is placed on the bottom cooling resistance reducing material 39. Then, a pearlite concrete block (not shown) and an inner tank bottom plate (not shown) are laid on top of each other in this order.

FIG. 7 is a diagram illustrating a fourth step of the construction method according to the embodiment of the present disclosure.
In the present embodiment, as shown in FIG. 7, the lowermost stage of the inner tank side plate 9 is assembled on the annular portion 13 separately from the first structure 9a. After disassembling the portal frame 10, when the lowermost stage of the inner tank side plate 9 is placed on the annular portion 13, the inner tank side plates 9 adjacent to each other in the circumferential direction are welded together and joined together so as to be cylindrical. The second structure 9b is assembled. When the second structure 9b is assembled, the inner tank anchor strap 4 installed on the foundation plate 1 is attached to the second structure 9b.

Moreover, as shown in FIG. 7, the outer tank roof 22 is assembled on the inner tank roof 14. The outer tank roof 22 is connected to the inner tank roof 14 by a connecting material (not shown), and is assembled integrally with the inner tank roof 14. Further, an elevating staircase 23 is provided outside the PC wall 2. Further, the pump barrel 25 is carried inside the PC wall 2.

FIG. 8 is a diagram illustrating a fifth step of the construction method according to the embodiment of the present disclosure.
Next, in this method, as shown in FIG. 8, the first structure 9a is jacked down, the lower end portion of the first structure 9a is lowered to the upper end portion of the second structure 9b, and the first structure 9a is lowered. The structure 9a and the second structure 9b are welded, and the inner tank 30 is assembled. In this method, the assembly of the lowermost stage of the inner tank 30 is separated from the assembly of the inner tank 30 by the jack-up device 18, and the second structure 9 b that is the lowermost stage of the inner tank 30 is fixed on the annular portion 13. (See FIG. 7). Therefore, in this method, for example, fixing the inner tank 30 on the annular portion 13 which takes about one month does not become a critical path, and the construction period can be shortened compared to the conventional method.

When the inner tub 30 is completed, the outer tub roof 22 is disconnected from the inner tub roof 14 by a connecting material (not shown) and installed on the upper end of the PC wall 2 assembled to the top. A roof staircase 24 is provided on the outer tank roof 22. A pump barrel 25 is also installed.
Thereafter, the knuckle reinforcement member 17 is cut off and the jackup device 18 is removed. After that, tension work on the PC wall 2 is performed. Then, after the construction port 8 is closed, it is filled with water and a pressure and airtight test is performed.

FIG. 9 is a diagram illustrating a sixth step of the construction method according to the embodiment of the present disclosure.
Finally, as shown in FIG. 9, the cold insulation material 44 is arranged between the inner and outer tanks 15 and the cold insulation material 44 is arranged between the inner tank roof 14 and the outer tank roof 22 to perform the cold insulation work. The cylindrical tank 50 is constructed through painting work and pipe cooling work.

The above-described embodiment is a method for constructing a cylindrical tank 50 having a metal inner tank and a concrete outer tank. In this cylindrical tank construction method, while assembling the steel side liner 2a in advance from the base plate 1, following the assembly of the side liner 2a, the concrete 2b is driven using the side liner 2a as the inner mold, It has an outer tank side wall construction process of constructing the PC wall 2. The outer tub side wall construction step hangs a plurality of scaffold units 100 including beam members 110 on a plurality of receiving beams 101 installed on the inward plate surface 102 of the side liner 2a assembled in advance. A scaffold unit connecting step of connecting the beam members 110 of the scaffold unit 100 hooked to 101 in a ring shape along the inward plate surface 102 of the side liner 2a is included. By adopting the above method, the shape of the side liner 2a assembled prior to the placing of the concrete 2b can be easily maintained.

The preferred embodiments of the present disclosure have been described above with reference to the drawings, but the present disclosure is not limited to the above embodiments. Various shapes, combinations, and the like of the constituent members shown in the above-described embodiments are examples, and various modifications can be made based on design requirements and the like without departing from the gist of the present disclosure.

For example, as in another embodiment shown in FIG. 10, the direction of the beam member 110A (H-shaped steel) may be rotated by 90 ° with respect to the beam member 110 of the above embodiment. In this case, since the web connecting the flanges of the H-shaped steel is disposed perpendicular to the inward plate surface 102 (that is, the web extends in the horizontal direction), the beam member 110A is provided on the inward plate surface of the side liner 2a. It becomes strong against the load received from 102. Since it is difficult to connect the beam member 110A in this direction to the receiving beam 101 with a bolt or the like, it is preferable to fix the beam member 110A by driving a wedge member 140 into the gap as shown in FIG.

According to the present disclosure, it is possible to provide a method for constructing a cylindrical tank that can easily maintain the shape of the liner material assembled prior to placing concrete.

1 Basic version (bottom of outer tank)
2 PC wall (side wall of outer tank)
2a Side liner (steel liner)
2b Concrete 50 Cylindrical tank 100 Scaffolding unit 101 Receiving beam 102 Inward plate surface 110 Beam member 120 Scaffolding

Claims

A construction method of a cylindrical tank having a metal inner tank and a concrete outer tank,
While assembling the steel liner material in advance from the bottom of the outer tub, following the assembling of the liner material, the concrete is cast using the liner material as an inner mold, and the side wall of the outer tub is constructed. A tank side wall construction process,
The outer tub side wall construction step includes hooking a plurality of scaffolding units including beam members to a plurality of receiving beams installed on an inward plate surface facing the inside of the tank of the liner material assembled in advance, A construction method of a cylindrical tank including a scaffold unit coupling step of annularly coupling the beam members of the scaffold unit hooked to a receiving beam along the inward plate surface of the liner material.
The scaffold unit includes the beam members arranged above and below,
The method for constructing a cylindrical tank according to claim 1, wherein in the scaffold unit connecting step, each of the upper and lower beam members is connected annularly along the inward plate surface of the liner material.
The construction method of a cylindrical tank according to claim 2, wherein the scaffold unit includes a scaffold fixed to each of the upper and lower beam members.
The method for constructing a cylindrical tank according to any one of claims 1 to 3, wherein the beam member is H-shaped steel.
Inside the side wall of the outer tank, the inner tank side plate is lifted by a jack-up device and the welding of the inner tank side plate of the next stage to the lower portion of the raised inner tank side plate is alternately repeated. The cylindrical tank construction method according to claim 1, further comprising an inner tank side wall construction step of constructing the side wall.
Inside the side wall of the outer tank, the inner tank side plate is lifted by a jack-up device and the welding of the inner tank side plate of the next stage to the lower portion of the raised inner tank side plate is alternately repeated. The cylindrical tank construction method according to claim 2, further comprising an inner tank side wall construction step of constructing the side wall.
Inside the side wall of the outer tank, the inner tank side plate is lifted by a jack-up device and the welding of the inner tank side plate of the next stage to the lower portion of the raised inner tank side plate is alternately repeated. The method for constructing a cylindrical tank according to claim 3, further comprising an inner tank side wall construction step of constructing the side wall.
Inside the side wall of the outer tank, the inner tank side plate is lifted by a jack-up device and the welding of the inner tank side plate of the next stage to the lower portion of the raised inner tank side plate is alternately repeated. The construction method of the cylindrical tank according to claim 4, further comprising an inner tank side wall construction step of constructing the side wall.