JP2015040380A - Method for constructing tank - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for constructing a tank, capable of facilitating a finishing step, reducing cost, and shortening a construction period.SOLUTION: A method for constructing a tank includes the steps of: forming a base slab 5; and forming a tank body having a cylindrical outer tank 4 on the base slab 5. In the step of forming the base slab 5, a drain pipe 10 of which one end side is opened in a top face of the base slab 5 at a position inside the outer tank 4 formed on the base slab 5 and of which other end side is opened on an outer peripheral surface 5a side of the base slab 5 is buried, a portion where the other end side of the drain pipe 10 is positioned is formed in a state dented from the outer peripheral surface 5a of the base slab 5, and an opening 10b of the other end side of the drain pipe 10 is arranged in the dented portion (dent part 11). After the step of forming the base slab 5, the method has a step of burying the dented portion (dent part 11) of the outer peripheral surface 5a of the base slab 5 to cover and conceal the other end side of the drain pipe 10.

Description

  The present invention relates to a tank construction method.

Conventionally, as a low-temperature tank that stores low-temperature liquefied gas such as LNG (Liquefied Natural Gas), for example, a metal inner tank that stores liquefied gas and a metal that surrounds this inner tank, or a concrete that has a steel plate attached to the inner surface A double-shell tank with an outer tank is used.
When constructing such a tank, in order to discharge rainwater and the like accumulated in the outer tank to the outside of the outer tank, a drain pipe is usually buried when the foundation is formed.

  As a drain pipe, for example, a pipe formed in an L shape as shown in FIG. The drain pipe of this patent document 1 is formed and arranged so that one end side opens to the bottom part in the outer tub and the other end side extends outward from the outer peripheral surface of the bottom base so that a large amount of stored liquid can be recovered when it is leaked. Has been.

  On the other hand, the drain pipe is also formed in an L shape for discharging rainwater and the like, and one end side opens to the upper surface of the foundation, and the other end projects from the outer peripheral surface of the foundation. It arrange | positions outside the outer peripheral surface.

  Then, in the construction of the tank, when a roof is attached to the outer tank of the tank and drainage of rainwater or the like in the outer tank is no longer necessary, the portion of the outer peripheral surface of the foundation where the other end side of the drain pipe is located is scraped, and the drain Fully expose the other end of the tube. Subsequently, the other end side of the drain pipe is cut at the site where the foundation is scraped off. After that, by filling the scraped portion with mortar or the like, the other end of the drain pipe is backfilled in the foundation and covered so as not to be exposed on the outer peripheral surface of the foundation. In this way, by finishing the outer peripheral surface of the foundation, the appearance of the outer peripheral surface of the foundation is improved and the landscape is not impaired.

Japanese Patent Publication No.61-31359

  However, in the finishing process of backfilling the other end side of the drain pipe into the foundation, the outer peripheral surface side of the foundation is cut off, the drain pipe is cut off, the mortar is filled, and so on. The finishing process becomes complicated due to the time and effort required for the side scraping process and the drain pipe cutting process. Therefore, conventionally, the time required for the finishing process becomes longer, which is one factor that impairs cost reduction and shortening of the construction period.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a tank construction method that facilitates the finishing process and enables cost reduction and shortening of the construction period. .

  The tank construction method of the present invention includes a step of forming a foundation and a step of forming a tank body having a cylindrical tank on the foundation. In the step of forming the foundation, the tank is formed on the foundation. A drain pipe having one end opened on the upper surface of the foundation at the inner side of the tank and the other end opened on the outer peripheral surface of the foundation, and a portion where the other end of the drain pipe is located And forming an opening on the other end side of the drain pipe in the recessed portion. After the step of forming the foundation, a recessed portion on the outer peripheral surface of the foundation is formed. It has the process of filling and concealing the other end side of the said drain pipe.

  Moreover, in the construction method of the tank, a step of detachably connecting a joint pipe to the other end side of the drain pipe is provided, and the step of connecting the joint pipe is opposite to the drain pipe of the joint pipe. It is preferable that the step of disposing the side projecting from the outer peripheral surface of the foundation and filling the depressed portion of the outer peripheral surface of the foundation is performed after removing the connecting pipe from the other end side of the drain pipe.

  In the tank construction method, it is preferable that the joint pipe is connected to the drain pipe through a joint having a screw portion.

  According to the tank construction method of the present invention, in the step of forming the foundation, the portion where the other end side of the drain pipe is located is formed in a depressed state from the outer peripheral surface of the foundation, and the other end of the drain pipe is formed in this recessed portion. Since the opening on the side is arranged, in the step of finishing the outer peripheral surface of the foundation after the step of forming the foundation, the process of scraping the outer peripheral surface side of the foundation and the process of cutting the drain pipe as in the past are not performed. By simply filling the recessed portion of the outer peripheral surface of the foundation with mortar or the like, the other end side of the drain pipe can be covered and the outer peripheral surface of the foundation can be finished. Therefore, the finishing process can be facilitated as compared with the prior art, and the cost can be reduced and the construction period can be shortened.

It is side sectional drawing which shows schematic structure of an example of the tank obtained by the construction method of this invention. (A) is sectional drawing to which the A section of FIG. 1 was expanded, (b), (c) is the enlarged view which concerns on the A section of FIG. 1 for demonstrating the construction method of this invention.

Hereinafter, the tank construction method of the present invention will be described in detail with reference to the drawings. In the following drawings, the scale of each member is appropriately changed to make each member a recognizable size.
First, an example of a tank obtained by the construction method of the present invention will be described with reference to FIG. Reference numeral 1 in FIG. 1 is a ground type low temperature tank (hereinafter referred to as a low temperature tank) as a tank according to the present invention.

  The low temperature tank 1 is provided on the ground 2 and includes a metal inner tank 3 for storing a low temperature liquefied gas (such as LNG) and an outer tank 4 covering the periphery of the inner tank 3. It has a double shell structure. That is, a concrete base plate (foundation) 5 is installed on the ground 2, and a cylindrical outer tank (tank) 4 is installed on the base plate 5. A tank bottom 6 is formed on the base plate 5, and a cylindrical inner tank 3 is installed on the tank bottom 6.

The inner tub 3 is formed of a steel plate or the like, and is installed in the outer tub 4 via the cold insulation layer 7. The outer tub 4 is formed by an outer wall 4a made of concrete and an outer tub main body 4b made of a steel plate pasted on the inner peripheral surface thereof. The outer tank 4 and the inner tank 3 form a tank body according to the present invention.
The inner tank 3 is provided with an inner tank roof 8, and the outer tank 4 is provided with an outer tank roof 9. The outer tub roof 9 is installed on the inner tub roof 8 via the cold insulation layer 7.

  A drain pipe 10 is embedded in the foundation plate 5. One end side of the drain pipe 10 is open to the surface (upper surface) of the base plate 5 between the outer tub 4 and the inner tub 3, that is, inside the outer tub 4. Further, the other end side of the drain pipe 10 is formed toward the outer peripheral surface 5a of the base plate 5, and therefore the drain pipe 10 is formed in an L shape in a side view. Note that the opening 10b on the other end side of the drain pipe 10 is disposed on the inner side of the outer peripheral surface 5a of the base plate 5 as shown in FIG. Hidden without.

Further, the drain pipe 10 is filled with mortar or the like, and is thus closed without forming a space. As a result, the drain pipe 10 also functions substantially as a part of the basic version 5.
However, the original function of the drain pipe 10 is, in particular, from the initial stage to the middle stage of the low temperature tank 1, that is, after the outer tank 4 and the base plate 5 are installed, the outer tank roof 9 is levitated by, for example, the air lasing method. The rainwater collected in the outer tub 4 is discharged outside the outer tub 4 until it is attached to the outer tub 4.

Next, an embodiment of the construction method of the low-temperature tank 1 having the above configuration will be described focusing on construction relating to the drain pipe 10 in particular.
First, as shown in FIG. 2B, a concrete base plate 5 is formed in the same manner as in the prior art, and an outer tub 4 comprising a concrete outer wall 4a and a steel plate outer tub body 4b is formed thereon. .

  At that time, particularly in the step of forming the base plate 5, when the drain pipe 10 is embedded in the base plate 5, as shown in FIG. 4 is embedded so that one end side is open on the upper surface of the base plate 5 at a position inside 4 and a position outside the inner tank (not shown). That is, the opening 10 a on one end side of the drain pipe 10 is disposed on the upper surface of the foundation plate 5 so as to be exposed on the foundation plate 5.

On the other hand, the opening 10b on the other end side of the drain pipe 10 is arranged on the inner side of the outer peripheral surface 5a of the foundation plate 5 unlike the conventional case.
Also, regarding the formation of the base plate 5, unlike the conventional case, the portion where the other end side of the drain pipe 10 is located is formed in a state of being recessed from the outer peripheral surface 5 a of the base plate 5. That is, for example, a truncated cone-shaped depression 11 is formed in a portion where the other end side of the drain pipe 10 is disposed. Such depressions 11 are formed by providing a filling (not shown) corresponding to the depressions 11 in a mold for placing concrete, or forming a direct projection on the inner surface side of the mold. It can be done by keeping it.

  In the present embodiment, the drain pipe 10 to be embedded is a drain pipe body 12 with a joint pipe (joint) 13 attached to the other end side. The joint pipe 13 is formed with female screw parts (not shown) at both ends thereof, and one female screw part is screwed into a male screw part (not shown) formed on the other end side of the drain pipe body 12. As a result, the drain pipe main body 12 is connected and integrated.

Therefore, the opening 10b on the other end side of the drain pipe 10 in the present embodiment is formed by the opening on the other side of the joint pipe 13, and the opening (10b) on the other side of the joint pipe 13 is a recessed portion. 11 is exposed.
And in this embodiment, after forming the base plate 5 in the state which buried the drain pipe 10 in this way, the joint pipe 14 is detachably connected to the other side of the joint pipe 13.

  The joint pipe 14 has a male thread portion (not shown) on one side, and this male thread portion is screwed to the other female thread portion of the joint pipe 13. That is, the joint pipe 14 is detachably connected to the other end side of the drain pipe 10 by screwing the male thread part of the joint pipe 14 with the other female thread part of the joint pipe 13.

  At that time, as the connecting pipe 14, a pipe whose length opposite to the drain pipe 10, that is, the tip side protrudes from the outer peripheral surface 5 a of the foundation plate 5 is used. In other words, in the step of forming the base plate 5, when the joint pipe 14 prepared in advance is connected to the drain tube 10, the drain tube is positioned so that the tip side is located outside the outer peripheral surface 5 a of the base plate 5. 10 is embedded, and the recess 11 is formed. In addition, such a drain pipe 10 and the hollow part 11 corresponding to this are provided in the outer peripheral part of the base plate 5, for example, eight places at equal intervals in the circumferential direction.

  When the foundation plate 5 is formed with the drain pipe 10 buried in this manner, and the connecting pipe 14 is connected to the other end side of the drain pipe 10, it rains during the construction, and therefore the foundation plate in the outer tub 4. Even if rainwater accumulates on 5, rainwater can be easily discharged from the drain pipe 10 to the outside of the base plate 5. In other words, the base plate 5 is usually provided with a predetermined gradient so that the height decreases from the center to the outside.

  Therefore, the rainwater collected on the base plate 5 due to this gradient flows to the outer peripheral side of the base plate 5 and is blocked by the outer tub 4 to flow into the opening 10a on one end side of the drain tube 10, and into the drain tube 10 and It is discharged from the opening 14a through the connecting pipe 14. At that time, the joint pipe 14 is connected to the drain pipe main body 12 via the joint pipe 13, and the distal end side of the joint pipe 14 is located outside the outer peripheral surface 5 a of the foundation plate 5. It flows directly out of the base plate 5 without passing through the outer peripheral surface 5a of the plate 5. Therefore, there is no possibility that the outer peripheral surface 5a of the foundation plate 5 is soiled by the drained rainwater. That is, since the discharged rainwater contains various foreign matters generated by construction, if such foreign matters adhere to the outer peripheral surface 5a of the base plate 5, the outer peripheral surface 5a may be contaminated.

  Moreover, after attaching the outer tank roof 9 to the outer tank 4, rainwater does not accumulate in the outer tank 4, and therefore the drain pipe 10 becomes unnecessary. Therefore, in order to fill the hollow portion 11 as a finishing process of the outer peripheral surface 5a of the base plate 5, prior to this, the joint pipe 14 is removed from the joint pipe 13 of the drain pipe 10 as shown in FIG. By removing the joint pipe 14 from the joint pipe 13, the drain pipe 10 returns to a state where it is retracted into the original recess 11 without protruding from the outer peripheral surface 5 a.

Then, by filling the hollow 11 with mortar or the like and filling the hollow 11, the other end of the drain pipe 10 is covered and hidden so as not to be exposed as shown in FIG. The outer peripheral surface 5a is finished. Moreover, also about the one end side of the drain pipe 10, after pouring mortar etc. from the opening 10a similarly to the past and filling the drain pipe 10, the opening 10a is covered.
Hereinafter, construction is continued in the same manner as in the past, and the low temperature tank 1 shown in FIG. 1 is constructed.

  In such a tank construction method, in the step of forming the base plate 5, a portion where the other end side of the drain pipe 10 is located is formed in a state of being recessed from the outer peripheral surface 5 a of the base plate 5, and the recess 11 Since the opening 10b on the other end side of the drain pipe 10 is disposed in the inside, in the step of finishing the outer peripheral surface 5a of the base plate 5 after the step of forming the base plate 5, the outer peripheral surface of the base plate 5 as in the prior art The base plate is covered with the other end side of the drain tube 10 by simply filling the recess 11 of the outer peripheral surface 5a of the base plate 5 with mortar or the like without performing the processing of scraping the 5a side and the processing of cutting the drain tube. 5 can be finished. Therefore, the finishing process can be facilitated as compared with the prior art, and the cost can be reduced and the construction period can be shortened.

The connecting pipe 14 is detachably connected to the other end side of the drain pipe 10. In the connecting step of the connecting pipe 14, the leading end side of the connecting pipe 14 protrudes from the outer peripheral surface 5 a of the foundation plate 5. Therefore, the rainwater discharged by the drain pipe 10 can be discharged directly to the outside of the base plate 5 without being transmitted to the outer peripheral surface 5a of the base plate 5, and therefore, the base plate is discharged by the drained rainwater. There is no risk of soiling the outer peripheral surface 5a.
Moreover, since the hollow part 11 is filled after removing the connecting pipe 14 from the other end side of the drain pipe 10, the drain pipe 10 can be easily covered in the outer peripheral surface 5a.

  Further, since the joint pipe 14 is connected to the drain pipe main body 12 via a joint 13 having a screw part, a screw part (male thread part) of the joint pipe 14 and a screw part (female thread part) of the joint 13 The joint pipe 14 can be easily connected to the drain pipe main body 12 (drain pipe) and can be easily detached from the connected state.

The present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the gist of the present invention.
For example, in the above embodiment, the joint pipe 13 is connected to the drain pipe body 12 in advance and embedded in the foundation plate 5. However, after forming the foundation plate 5 with the drain pipe body 12 buried, the drain pipe is formed. The joint pipe 13 may be connected to the main body 12 by screwing. However, in that case, it is necessary to form the recessed portion 11 deeper than the example shown in FIG. 2B and to sufficiently expose the other end side of the drain pipe body 12 in the recessed portion 11. is there. In this case, the joint pipe 14 may be connected to the joint pipe 13 in advance, and the joint pipe 13 and the joint pipe 14 that have been integrated may be connected to the drain pipe body 12.

Further, the joint pipe 13 does not have a female thread portion (screw portion), but simply has an inner diameter that substantially matches the outer diameter of the drain pipe main body 12, and is fitted to the drain pipe main body 12 by extrapolation. A structure to be connected may be adopted by combining.
Moreover, in the said embodiment, after forming the foundation plate 5 in the state where the drain pipe 10 is buried, the joint pipe 14 is connected to the other side of the joint pipe 13. The joint pipe 14 may be connected to the drain pipe 10 in advance, and the base plate 5 may be formed in this state, and the drain pipe 10 and the joint pipe 14 may be embedded in the base plate 5.

  Further, in the above-described embodiment, the connecting pipe 14 is connected to the drain pipe 10, but drainage such as rain water may be performed only by the drain pipe 10 without connecting such a connecting pipe 14. In that case, since the joint pipe 13 is also unnecessary, the drain pipe 10 can be configured only by the drain pipe main body 12.

  In the above embodiment, the case where the tank construction method of the present invention is applied to the construction of a ground type low temperature tank has been described. However, the present invention is not limited to this, for example, the construction of an underground type low temperature tank or a silo. It can be applied to the construction of tanks.

1 Low temperature tank 3 Inner tank 4 Outer tank (tank)
5 Basic version (basic)
5a Outer peripheral surface 10 Drain pipe 10a Opening 10b Opening 11 Recessed part 12 Drain pipe main body 13 Joint pipe 14 Joint pipe 14a Opening

Claims (3)

A step of forming a foundation, and a step of forming a tank body having a cylindrical tank on the foundation,
In the step of forming the foundation, a drain pipe having one end opened on the foundation upper surface at a position inside the tank formed on the foundation and the other end opened on the outer peripheral surface of the foundation is embedded, and the drain Forming a portion where the other end side of the tube is located in a depressed state from the outer peripheral surface of the foundation, and arranging an opening on the other end side of the drain tube in the depressed portion;
After the step of forming the foundation, the method for constructing a tank includes a step of filling a depressed portion of the outer peripheral surface of the foundation and covering the other end side of the drain pipe. A step of detachably connecting the connecting pipe to the other end side of the drain pipe, and in the step of connecting the connecting pipe, the side opposite to the drain pipe of the connecting pipe protrudes from the outer peripheral surface of the foundation. And place
The method for constructing a tank according to claim 1, wherein the step of filling the depressed portion of the outer peripheral surface of the foundation is performed after removing the connecting pipe from the other end side of the drain pipe. 3. The tank construction method according to claim 2, wherein the connecting pipe is connected to the drain pipe through a joint having a screw portion.

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