JP2001020555A - Construction method of storage tank roof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a construction method of a storage tank roof capable of reducing the cost and a construction period when constructing the storage tank roof. SOLUTION: A roof of an underground storage tank 10 is constituted by combining plural roof units R, and the respective roof units R are constituted as an integral unit without being divided into plural parts in the radial direction of a roof 14. When arranging the respective roof units R, a central side end part of the respective roof units R is swingably joined to a joint metal fitting arranged in a ridge ring 22, and thereafter, an outer peripheral part end part of the roof units R is lowered on an outer peripheral joint bracket 37 to be supported by a central column 50 and the side wall 13 side to be joined to the ridge ring 22 and the outer peripheral joint bracket 37.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for constructing a storage tank roof suitable for use in constructing a storage tank for storing a cryogenic liquid such as liquefied natural gas.

[0002]

2. Description of the Related Art Conventionally, as shown in FIG. 11, a storage tank (tank) 1 for storing various cryogenic liquids including, for example, liquefied natural gas, liquefied propane gas, liquefied nitrogen, liquefied oxygen, etc. After constructing the cylindrical tank body 2 with a bottom, a circular dome-shaped roof 3 is erected on the upper opening of the tank body 2, and further, on the inner peripheral surface of the tank body 2, a cold insulator and a membrane membrane are provided. And was built by attaching.

The storage tank 1 as described above may be constructed underground or on the ground. In any case, when constructing the circular dome-shaped roof 3, the previously constructed tank is constructed. The roof 3 is assembled on the bottom plate 2a of the body 2. Then, as shown in FIG. 12, the assembled roof 3 is jacked up by the jack device 6, or the lower surface of the roof 3 in a state where the outer peripheral surface of the assembled roof 3 and the tank body 2 are sealed. By the air laying method that sends air to the side and lifts the roof 3,
It is lifted to a predetermined position and attached and fixed on the tank body 2.

[0004]

However, in the conventional construction method of the storage tank roof described above, since the roof 3 is assembled on the bottom slab, the support 7, the temporary scaffold 8, and the assembled roof 3 are mounted on the bottom slab 2a. It is necessary to bring in various equipments and the like for lifting, and it takes time and effort to install and remove the equipment, which hinders cost reduction and shortening of the construction period. The present invention has been made in consideration of the above points, and has an object to provide a construction method of a storage tank roof that can reduce the cost and the construction period when the storage tank roof is constructed.

[0005]

The invention according to claim 1 is
In constructing a storage tank including a bottom plate, a substantially cylindrical side wall constructed on the bottom plate, and a roof covering the entire upper side of the side plate, after constructing the bottom plate and the side wall, On the other hand, a center post is erected at the center of the bottom slab, and a center ring located at the center of the roof is placed on the center post, and the roof is divided in a circumferential direction into a predetermined shape. The roof unit, which is substantially fan-shaped in plan view, which has been assembled in the above manner, is suspended from the outside of the side wall, and one end of the roof unit on the center side is supported by the center support, and the other end on the outer peripheral side is After being supported on the side wall, each of the roof units is attached to a predetermined position by joining the one end and the other end to the center ring and the side wall.

By constructing the roof as a unit in this way, construction efficiency can be improved. In addition, since each roof unit is supported by the center support and the side wall, the roof unit is not divided into a plurality of units in the radial direction of the roof, and is a large unit integrated. Thereby, it is only necessary to erect the central support on the bottom plate, and it is possible to reduce the number of temporary scaffolds. Also, for example, the uniting and dismantling work of the central support can be made more efficient by unitizing it.

[0007] The invention according to claim 2 is that the roof unit is formed of a frame of the roof assembled into a predetermined shape and a roof plate attached to the frame to form a surface of the roof. Features.

[0008] By forming the roof unit with the frame and the roof shingle in this way, if the roof units are sequentially installed, the installation work of the roof shingle becomes unnecessary, and the roof can be efficiently installed. And work at height can be reduced.

According to a third aspect of the present invention, a joint fitting is provided on the centering side so as to be able to swing one end of each of the roof units in a substantially vertical plane so as to be swingable. First, in a state where the other end is lifted above the side wall, the one end is jointed to the joint fitting so as to be able to swing in a substantially vertical plane, and thereafter, the joint joined to the joint fitting is provided. The roof unit is swung about one end, the other end is lowered on the side wall, and then the roof unit is joined to the side wall.

In this manner, while the other end of the roof unit is lifted, one end of the roof unit is connected to the joint fitting using a pin or the like so as to be swingable. By swinging the roof unit around the portion and lowering the other end on the side wall, the installation of the roof unit can be performed smoothly. In this case, if the roof unit is provided with a stiffener for preventing deformation in the radial direction due to its own weight, a dimensional change when the other end of the roof unit is lowered on the side wall is suppressed. It becomes possible.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the construction method of a storage tank roof according to the present invention will be described below with reference to FIGS. Here, as an example of a storage tank to be constructed, an underground storage tank is taken as an example.

In FIG. 1, reference numeral 10 denotes an underground storage tank (storage tank) to be constructed, reference numeral 11 denotes a concrete cylindrical bottomed tank constructed in the ground, reference numeral 12 denotes a bottom plate of the tank body 11, and reference numeral 13 denotes a bottom plate.
Is a cylindrical side wall that forms the tank body 11, 14 is a circular dome-shaped roof that covers the upper opening of the side wall 13, and 15 is the tank body 11.
Reference numeral 16 denotes a membrane provided along the inner wall surface for maintaining liquid-tightness and air-tightness of liquefied natural gas and the like to be filled therein.

In addition, the underground storage tank 10 is provided with piping and various devices for taking in and out the stored liquid as required. A suspension deck 17 is provided below the roof 14 via a plurality of suspension rods 17a. The roof 14 may be configured without the hanging deck 17.

The roof 14 has an outer peripheral portion fixed to an upper portion of the side wall 13 via a ring-shaped thick plate 18. The ring-shaped thick plate 18 is made of steel and has a lower end portion 18a formed on the side wall 13.
The upper part 18b is a circular dome-shaped roof 14
Is formed to be curved inward in accordance with the curved shape.

The roof 14 is made of a steel frame 2.
0 and a roof plate 21 provided on the upper surface of the frame 20
It is composed of As shown in FIGS. 2 and 3,
The frame 20 includes a ring-shaped ridge ring (center ring) 22 located at the top of the roof 14 and a ridge ring 22.
Pieces of rough material 23 radially arranged on the outer peripheral side of
And a plurality of ring members 24 extending in the circumferential direction of the roof 14
(Shown only in FIG. 2).

As shown in FIG.
Is configured by combining a plurality of substantially fan-shaped roof units R. For example, here, the entire roof 14 is constituted by a total of 21 roof units R. As shown in FIG. 5, each roof unit R
The roof 14 is divided into a plurality of pieces in the circumferential direction and has a substantially fan shape in a plan view. A predetermined number of the rougher members 23 and ring members 24 constituting the frame 20 and the roof plate 21 attached to the upper surface thereof are integrally formed. It is a unitized one.

Here, as shown in FIG. 6 (a), the roughing members 23 at both end portions of each roof unit R are formed by jointing roughing members 27 having a C-shaped cross section. The joint rougher member 27 has a portion corresponding to the web facing the outside of the roof unit R, and this is used as a joint surface 27a with another roof unit R. At this time, at the end portion of each roof unit R, the joint rougher material 27 and the roof plate 21 on the upper surface thereof are attached with a predetermined offset from each other.
The joint between the roof plates 21 and 21 does not overlap with the joint between the joint rafter members 27 and 27 at the joint between the R members.

As shown in FIG. 6 (b), when joining the roof units R, R adjacent to each other, the joining surfaces 27a, 27a of the two joint roughing members 27, 27 are brought into contact with each other. In this state, both are joined by joining means such as bolts and nuts 28. In this way, by joining the roughing members 27 for joints having a C-shaped cross section back to back, they function as a roughing member 23 having an H-shaped synthetic cross section.

As shown in FIG. 7, each roof unit R is joined to a ridge ring 22 via a joint bracket 30 at an end on the center side. The joint bracket 30 is integrally provided on the ridge ring 22 at a position corresponding to at least one rafter member 23 of each roof unit R. This joint bracket 3
Numeral 0 includes a rougher material receiver 30A provided on the lower surface side of the ridge ring 22 and a joint fitting 30B provided on the upper surface side of the ridge ring 22.

The rougher material receiver 30A is provided so as to protrude from the lower surface side of the ridge ring 22 to the outer peripheral side. On the upper surface side of the protruding portion, an inclined surface 31 corresponding to the inclination of the circular dome-shaped roof 14 is provided. Are formed. Then, by placing the rougher material 23 on the inclined surface 31,
The roughing member 23 is supported by being inclined at a predetermined angle.

The joint fitting 30B is provided by welding to a roof plate 21 provided on a ridge ring 22.
A joint hole 32 for joining the rougher member 23 is formed at a predetermined position in the joint fitting 30B. On the other hand, at the end 23a of the rougher material 23,
The connecting plate 3 extending toward the joint fitting 30B is placed on the roof plate 21 provided integrally with the roughing member 23.
3 are provided in pairs. Pin holes 34 are formed in these connection plates 33. By inserting a pin or a bolt into the pin hole 34 and the joint hole 32 with the joint fitting 30B sandwiched between the pair of two connection plates 33, the rougher member 23, that is, the roof unit R is connected to the pin hole. The center ring 34 is connected to the ridge ring 22 so as to be able to swing in a substantially vertical plane.

A gap having a predetermined size is formed between the end of the roughing member 23 and the ridge ring 22, and the joint plate 35 is welded to the gap.
The end of the rougher member 23 and the ridge ring 22 are integrally joined.

As shown in FIG. 8, on the outer peripheral side of each roof unit R, each rougher member 23 is joined to an outer peripheral joint bracket 37 provided on the ring-shaped thick plate 18. . Each outer joint bracket 37 is provided by being welded to the inner peripheral surface of the ring-shaped thick plate 18, and has a rougher material receiving portion 37 a projecting inward in the horizontal direction. And the roof unit R
A leg 23b is integrally provided on the lower surface of the end of the rough material 23 which constitutes the above, and the leg 23b stands on the rough material receiving portion 37a. The outer joint bracket 37 is integrally formed with a joint portion 37b and a stiffener 37c that are continuous with the web 23w of the rougher member 23 and the lower flange 23f.

The roughing member 23 of the roof unit R is placed on the roughing member receiving portion 37a of the outer peripheral joint bracket 37.
The joint plate 39 is welded to a gap between the end of the joint 37 and the joint 37c. Thus, the rougher member 23, that is, the roof unit R, is joined to the ring-shaped thick plate 18 via the outer peripheral joint bracket 37.

In order to construct the roof 14 using the above-described roof unit R, first, each roof unit R as shown in FIG. 5 is formed into a predetermined shape in a factory or an assembly yard provided near the construction site. Assemble to At this time, in each roof unit R, the rough material 23 and the ring material 24 are assembled in a predetermined shape in advance, and the roof plate 21 is attached to the upper surface thereof. The hanging rod 1 shown in FIG.
7a, the suspension deck 17 is attached with a size substantially equal to that of the roof unit R.

Further, for example, a truss-like stiffener 40 is attached to both ends of each roof unit R. The stiffener 40 includes, for example, a channel material 41 having a C-shaped cross section, which is disposed substantially in parallel with the joint rougher material 27, a lattice material 42 assembled between the joint rougher material 27 and the channel material 41, and the like. It is composed of At this time,
Rafter material 27 for joints constituting roof unit R
Function as the upper chord of the truss-like stiffener 40.

In addition, on the inner side of the stiffener 40, columns 45 are attached to the lower surface of the rougher member 23 at predetermined intervals, and a scaffold plate 46 is laid between the column 45 and the channel member 41. A work scaffold 47 is provided here.

While assembling each roof unit R in this manner, as shown in FIG.
Inside 1, a center support 50 is assembled at the center of the bottom plate 12. It is preferable that the central support 50 is constructed in advance by unitizing it in terms of construction efficiency and by sequentially stacking the unit.

At this time, the ridge ring 22 of the roof is installed above the central support 50. On the other hand, the ring-shaped thick plate 18 and the outer joint bracket 37 are attached to the upper part of the tank body 11.

Then, in this state, the roof unit R previously assembled into a predetermined shape is suspended by a crane or the like. Subsequently, as shown in FIG. 7, the outer peripheral end of the roof unit R is lifted (in a state shown by a two-dot chain line in FIG. 7B), and the connection plate 33 is placed on the center side of the roof unit R. Then, it is joined to a joint fitting 30B of a joint bracket 30 provided on the ridge ring 22 with a pin or a bolt. As a result, the roof unit R is swingably connected to the ridge ring 22 at the center end, and is supported by the center support 50 shown in FIG.

Next, the roof unit R is swung, and its outer peripheral end is lowered onto the outer peripheral joint bracket 37 as shown in FIG. Subsequently, the outer joint bracket 37 and the rougher member 23 are joined by welding a joint plate 39 to a gap therebetween.
Thereby, the outer peripheral side of the roof unit R is joined to the side wall 13 side. At this time, as shown in FIG. 5, since each roof unit R is provided with a truss-like stiffener 40, the rougher member 23 at the outer end is used.
The amount of deformation (along the radial direction of the roof 14) is, for example, 100 mm or more without the stiffener 40, but is suppressed to about several mm. As a result, the dimension adjustment and joining of the gap by the joint plate 39 as shown in FIG. 8 can be easily performed.

At the same time, as shown in FIG. 7, on the center side of the roof unit R, a joint plate 35 is welded to the gap between the end of the roughing member 23 and the ridge ring 22 to thereby form the joint between the roughing member 23 and the ridge ring. 22 are integrally joined.

As a result, the roof unit R is joined at its center end to the ridge ring 22 on the center column 50, and has its outer end on the side wall via the outer joint bracket 37 and the ring-shaped thick plate 18. 13 is joined.

The installation of such a roof unit R is performed, for example, in the order shown by circled numbers in FIG. At this time, as shown in FIG. 6, since the joint rougher material 27 at the end of each roof unit R has a C-shaped cross section, the joining surfaces 27a, 27a are put together and bolts and nuts 28 are used. By fastening, the roof units R adjacent to each other can be directly joined to each other. The joint work of the roof units R, R can be performed on a temporary work scaffold 47 provided inside the stiffener 40.

Then, as shown in FIG. 4, after the installation of all the roof units R is completed, at two places on the roof 14, a portion serving as an adjustment margin (margin) 51 is replaced with a loose ring material 24 '. Then, by installing a roof plate (not shown) on the upper surface, the roof construction of this portion is performed while adjusting the dimensions.

As a result, as shown in FIG.
4, the stiffener 40 and the scaffold plate 4 provided on the lower surface side of each roof unit R are provided.
The roof 14 of the underground storage tank 10 has been constructed by removing the support 6, the support 45 (see FIG. 5), and the central support 50. Therefore, after that, as shown in FIG. 1, the underground storage tank 10 is completed by installing the cold insulator 15, the membrane 16, and the like inside the tank body 11.

As described above, the roof 1 of the underground storage tank 10
4 as a unit, and each roof unit R is
Since the unit is not divided into a plurality in the radial direction and is formed as an integrated unit, construction can be performed efficiently. As a result, it is possible to reduce the cost and the construction period for constructing the roof 14.

Further, each roof unit R is connected to the frame 2
Since the construction is made by integrating the roof 0 and the roof plate 21, the efficiency of the construction is also improved. Also, the installation work of the roof slab 21 becomes unnecessary, and the work at high places can be reduced.

In addition, when installing each roof unit R, the joint bracket 3
Since the roof units R are swingably joined to the joint fitting 30B of No. 0, and the outer peripheral end of the roof unit R is then lowered onto the outer joint bracket 37 and joined, the installation of each roof unit R is performed. Can be performed smoothly.

Further, since each roof unit R is provided with a truss-like stiffener 40 on the lower surface of the joint rougher member 27 at both end portions thereof, radial deformation due to its own weight of each roof unit R is prevented. Therefore, the installation work can be performed easily and reliably.

As described above, by applying the unitized construction method of the roof 14, joint work at the site can be reduced, work efficiency can be greatly improved, and safety due to the reduction of work at high places can be reduced. It can be improved.

In the above embodiment, the underground storage tank 10 has been described as an example. However, the same construction method of the roof 14 can be applied to the above-ground storage tank. The effect is obtained.

Although the truss-shaped stiffener 40 is provided on the lower surface of the roof 14, the truss type is not limited. For example, the truss may be formed into a three-dimensional truss shape. is there. Further, the stiffener 40 may be provided not only at both end portions of each roof unit R but also at other portions as long as sufficient rigidity can be secured. It may be provided.

In addition, the stiffener 40 is removed after the roof 14 is installed. However, if necessary, the stiffener 40 can be left as the main stiffener 40 as it is.

In the above embodiment, the roof plate 21
And the frame 20 are unitized, but the roof panel 21 is not unitized, only the frame 20 is unitized, and after installing this, the roof panel 2
1 can be attached.

Other than this, any configuration may be adopted as long as it does not deviate from the gist of the present invention, and it is needless to say that the above-described configurations may be appropriately selectively combined. No.

[0047]

As described above, according to the construction method of the storage tank roof according to the first aspect, the efficiency of construction can be improved by constructing the roof as a unit. In addition, since each roof unit is supported by the center pillar and the side wall, the roof unit is not divided into a plurality of units in the radial direction of the roof, but is formed as an integral large unit. This allows
It is only necessary to set up a central support on the bottom slab, and temporary scaffolds and the like can be reduced. Therefore, it is possible to reduce the cost and the construction period for constructing the roof.

According to the construction method of the storage tank roof according to the second aspect, since the roof unit is formed of the frame and the roof plate, the installation work of the roof plate becomes unnecessary, so that the roof is efficiently installed. And work at height can be reduced.

According to the construction method of the storage tank roof according to the third aspect, while the other end of the roof unit is lifted, one end of the roof unit is joined to the joint fitting so as to be swingable, and thereafter, Since the roof unit is swung and the other end is lowered on the side wall, the installation of the roof unit can be performed smoothly.

[Brief description of the drawings]

FIG. 1 is a perspective sectional view showing an example of an underground storage tank constructed by applying a construction method of a storage tank roof according to the present invention.

FIG. 2 is a plan view showing a roof of the underground storage tank.

FIG. 3 is a vertical sectional view of the roof.

FIG. 4 is a diagram showing a construction order when the roof is unitized.

FIG. 5 is a perspective view showing a roof unit constituting the roof.

FIG. 6 is a perspective view showing a structure of a joint between the roof units.

FIG. 7 is a plan view and a side sectional view showing a joint structure of the roof unit to a ridge ring.

FIG. 8 is a side sectional view showing a joint structure to the ring-shaped thick plate side of the roof unit.

FIG. 9 is a vertical sectional view showing a state in which the roof is constructed using the roof unit.

FIG. 10 is an elevational sectional view showing a state where the entire roof is constructed.

FIG. 11 is a sectional view showing an example of a conventional construction method of a storage tank roof, showing a state where the roof is assembled on a bottom plate.

FIG. 12 is an elevational sectional view showing a state in which the assembled roof is jacked up.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Underground storage tank (storage tank) 12 Bottom plate 13 Side wall 14 Roof 20 Frame 21 Roof board 22 Building ring (Center ring) 30B Joint fitting 50 Central support R Roof unit

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Hidetoshi Kashima 12 Nishikicho, Naka-ku, Yokohama-shi, Kanagawa Prefecture Inside Mitsubishi Heavy Industries, Ltd. F-term (reference) in Zineering Co., Ltd. 3E073 AA01 AB03 BA03

Claims (3)

[Claims] In constructing a storage tank comprising a bottom plate, a substantially cylindrical side wall constructed on the bottom plate, and a roof covering the entire upper side of the side wall, after constructing the bottom plate and the side wall, Inside the side wall, a central support is erected at the center of the bottom slab, and a center ring located at the center of the roof is placed on the central support, and the roof is divided in the circumferential direction. A roof unit having a substantially fan shape in plan view, which has been assembled in a predetermined shape in advance, is hung from the outside of the side wall, and one end serving as the center side of the roof unit is supported by the center support, and becomes the outer periphery side. After the other end is supported on the side wall, the roof unit is attached to a predetermined position by joining the one end and the other end to the center ring and the side wall. Construction method of that storage tank roof. 2. The roof unit according to claim 1, wherein the roof unit is formed of a frame of the roof assembled into a predetermined shape and a roof plate attached to the frame to form a surface of the roof. The construction method of the storage tank roof described. 3. The centering side is provided with a joint fitting for jointing one end of each of the roof units so as to be able to swing in a substantially vertical plane. In a state where the portion is lifted above the side wall, the one end is joined to the joint fitting so as to be able to swing in a substantially vertical plane, and thereafter, the one end joined to the joint fitting is centered on the one end. 3. The construction method for a storage tank roof according to claim 1, wherein the roof unit is swung to lower the other end on the side wall, and then joined to the side wall.