JP2014084592A - Method for constructing ground type low temperature tank - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for constructing a ground type low temperature tank, enabling a construction period to be shortened.SOLUTION: A method for constructing a ground type low temperature tank having a side wall part 4b, a roof part 4c, and a bottom slab part includes: a roof part forming step for forming the roof part; a slip form step for constructing the side wall part 4b by continuously placing concrete between concrete forms 11, 11 while lifting up the pair of concrete forms 11, 11 disposed opposite to each other, and lifting up the roof part 4c formed in the roof part forming step while supporting it by a support part 12 provided on the concrete forms; and a cold insulation treatment step for performing cold insulation treatment of the bottom slab part surrounded by the concrete forms 11, 11. The cold insulation treatment step is carried out in parallel with and during the slip form step.

Description

  The present invention relates to a method for constructing a ground-type cryogenic tank.

  Conventionally, to construct a ground-type cryogenic tank, for example, the concrete is cast on the side wall (cylindrical wall) by the jump foam method, and then the steel roof that has been assembled in the tank at the same time as the concrete placing is installed. The air rises by air rising method (Air Raising method). And after making a steel roof reach | attain to predetermined height, this steel roof is fixed to a side wall part by welding to the embedding hardware which embedded the side wall part.

However, in such a construction method, after performing the concrete placement which is the work on the civil engineering side to complete the side wall part, the steel roof is raised and the steel roof is fixed to the uppermost part of the side wall part. There exists a subject that the construction period of a tank becomes long on a process.
Therefore, as a construction method for solving such problems, a slip foam construction method that is generalized as a technique is used instead of the jump foam construction method, and a steel roof is attached to the side wall during construction of the side wall portion by this slip foam construction method. A construction method has been proposed in which jack-up is performed together with a slip-form device used for construction of a part, and the roof is raised (see, for example, Patent Document 1).

Japanese Patent No. 3412505

  By the way, in the construction of a low temperature tank, it is indispensable to cool the bottom plate part, etc., but in such a cold holding process, if the processing part gets wet with rainwater, its cooling performance may be lowered, so the cold processing part is wetted with rainwater. There is a restriction that it must not be. Therefore, conventionally, after the roof is finally attached on the side wall portion and the roof is completed, the cold insulation processing of the bottom plate portion or the like is performed. It is getting longer.

  This invention is made | formed in view of the said situation, The place made into the objective is to provide the construction method of the ground type low temperature tank which enabled shortening of the construction period.

The construction method of the above-mentioned ground type cryogenic tank of the present invention is a construction method of the above ground type cryogenic tank having a side wall portion, a roof portion, and a bottom plate portion,
A roof portion forming step for forming the roof portion;
The roof part formed in the roof part forming step while constructing the side wall part by continuously placing concrete between the molds while lifting up a pair of molds arranged to face each other A slip-form step of lifting up while supporting by a support provided in the mold,
A cold insulation treatment step for carrying out a cold insulation treatment of the bottom plate portion surrounded by the mold,
The cold insulation process is performed during the slip foam process in parallel with the slip foam process.

  Moreover, in the construction method of the above-mentioned ground-type cryogenic tank, it is preferable that the cold insulation process and the construction thereof are performed in the cold insulation process.

  Further, in this method for constructing a ground type low temperature tank, the low temperature tank has a double shell structure of an inner tank and an outer tank covering the inner tank, and the side wall portion is a side wall of the outer tank, and the cold insulation of the annular portion is performed. It is preferable to provide the inner tank formation process which constructs the side wall of the said inner tank on this annular part after a process and its construction.

  Moreover, in the construction method of the above-mentioned ground-type cryogenic tank, the roof portion is provided with a damming portion for collecting rainwater on the upper surface side of the outer peripheral portion thereof, and the rainwater accumulated in the damming portion is disposed outside the side wall portion. It is preferable to provide a discharge pipe for discharging.

  According to the construction method of the above ground type cryogenic tank of the present invention, since the cold insulation process is performed during the slip foam process in parallel with the slip foam process, the roof part is finally attached on the side wall part. Thus, the construction of the cold insulation treatment can be started before the roof is completed, and therefore the construction period can be shortened.

It is side sectional drawing which shows schematic structure of an example of the ground-type cryogenic tank obtained by the construction method of this invention. It is process explanatory drawing of one Embodiment of the construction method of the ground type cryogenic tank which concerns on this invention. It is process explanatory drawing of one Embodiment of the construction method of the ground type cryogenic tank which concerns on this invention. It is process explanatory drawing of one Embodiment of the construction method of the ground type cryogenic tank which concerns on this invention. It is process explanatory drawing of one Embodiment of the construction method of the ground type cryogenic tank which concerns on this invention. It is process explanatory drawing of one Embodiment of the construction method of the ground type cryogenic tank which concerns on this invention. It is process explanatory drawing of one Embodiment of the construction method of the ground type cryogenic tank which concerns on this invention. It is process explanatory drawing of one Embodiment of the construction method of the ground type cryogenic tank which concerns on this invention. It is process explanatory drawing of one Embodiment of the construction method of the ground type cryogenic tank which concerns on this invention. It is process explanatory drawing of one Embodiment of the construction method of the ground type cryogenic tank which concerns on this invention.

Hereinafter, the construction method of the above-mentioned ground type cryogenic tank 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 ground type cryogenic tank obtained by the construction method of the present invention will be described with reference to FIG. In FIG. 1, reference numeral 1 denotes a ground type low temperature tank (hereinafter referred to as a low temperature tank).

  The low-temperature tank 1 is provided on the ground 2 and includes a metal (for example, iron) inner tank 3 for storing a low-temperature liquefied gas (such as LNG) L and an outer tank 4 that covers the inner tank 3. It has a double-shell structure. That is, a concrete foundation floor slab 5 is installed on the ground 2, and an outer tub 4 having a bottom slab 4 a, a side wall plate 4 b, and a roof plate 4 c is installed on the foundation floor slab 5. An inner tank 3 composed of a bottom plate portion 3 a and a side wall portion 3 b is installed on a bottom plate 4 a in 4 via a bottom cool layer 6. The bottom plate 4a, the side wall plate 4b, and the roof plate 4c of the outer tub 4 are formed of a thin steel plate. A side wall portion (not shown) made of concrete is formed so as to cover the side wall plate 4b, thereby forming a side wall. Also, a concrete roof portion (not shown) is formed so as to cover the roof plate 4c, thereby forming a roof. In FIG. 2 and subsequent figures, a concrete side wall portion covering the side wall plate 4b is denoted by reference numeral 4b. Further, not only the roof plate 4c but also a concrete roof portion covering the roof plate 4c may be indicated by reference numeral 4c. The ground type cryogenic tank in FIG. 1 has a so-called floating foundation structure in which the foundation bottom plate is floating, but there is a type in which there is no gap between the foundation bottom plate and the ground surface. The construction method can be applied.

The inner tub 3 is provided with a lid 7 that covers the upper opening thereof, and the lid 7 is a roof portion of the inner tub 3. Further, glass wool 8 is laid as a lightweight cold insulation material on the lid material 7.
Between the side wall part 3b of the inner tank 3 and the side wall part 4b of the outer tank 4, for example, a gap of about 1 m is formed, and this gap is filled with granular pearlite 9 as a cold insulating material.

Next, based on the construction method of the low temperature tank 1 which consists of such a structure, one Embodiment of the construction method of the ground type low temperature tank of this invention is described.
First, as shown in FIG. 2, the foundation floor slab 5 is formed on the ground 2, and then a pair of molds 11 are arranged at predetermined positions on the foundation floor slab 5 at predetermined intervals.

  And the outer side of each of a pair of formwork 11 and 11 is inserted | pinched with the yoke 12 used as the support part in this invention, and it hold | maintains. The yoke 12 is arranged between the pair of vertical plate portions 12a and 12a that are disposed outside the mold frames 11 and 11 and holds the mold frames 11 and 11, and the upper end portions of the vertical plate portions 12a and 12a. And a horizontal plate portion 12b. A plurality of such yokes 12 are installed at predetermined intervals in the length direction (circumferential direction) of the molds 11 and 11. The jacks 13 are attached to the yokes 12 on the horizontal plate portions 12b.

  The jack 13 is attached so as to be able to rise with respect to the pole 14 standing between the molds 11 and 11 so that the yoke 12 can be pulled up by the jack 13. That is, the yoke 12 is configured to be raised, and the molds 11 and 11 held by the yoke 12 are also raised at the same time.

  Further, a scaffold 15 is assembled on the foundation floor slab 5, and the scaffold 15 is fixed to the mold 11. Therefore, as the yoke 12 and the molds 11 and 11 are raised, the scaffold 15 is also raised. Then, concrete is placed between the molds 11 and 11, and the pole 14 is embedded by embedding the pole 14 in the concrete. An embedded metal fitting for bottom plate welding (not shown) is arranged on the inner surface of the inner mold 11 (the surface facing the other mold), and after the side wall 4b is formed, the side wall 4b. A predetermined portion of the inner surface is made to be exposed if necessary.

  Next, as shown in FIG. 3, the trolley beam 17a is fixed to the inner side of the horizontal plate portion 12b of the yoke 12, that is, the inner side of the low-temperature tank 1 to be formed. Further, a temporary support 16 is attached to the inner end of the horizontal plate portion 12b with bolts while projecting inwardly of the horizontal plate portion 12b, and then a trolley beam 17b is mounted on the temporary support 16. The trolley beams 17a and 17b are welded to each other adjacent trolley beams 17a (17b) after leveling. Moreover, it fixes to the horizontal plate part 12b and the temporary support 16 with a volt | bolt.

  In addition to the assembly of the mold 11 as described above, the roof portion 4c of the outer tub 4 is formed on the foundation floor slab 5 (roof portion forming step). When the roof portion 4c is formed, the load on the central portion is received by the center support 18 and the load on the outer peripheral side is received by the intermediate support 19 as shown in FIG. At this stage, the roof portion 4 is not completed, and a plurality of roof blocks (not shown) are temporarily fixed without being fixed to each other.

  Further, as shown in FIG. 5, the compression ring 20 is attached to such a roof portion 4c in a block form in advance at its outer peripheral end portion. And a support (not shown) is installed between the yokes 12 and 12 adjacent in the length direction (circumferential direction) of the molds 11 and 11, and the roof portion 4c is held by this support. Moreover, H steel 21 is attached to the inside of the compression ring 20, thereby preventing falling. Further, a stopper 22 is attached to the outer side of the compression ring 20 on the horizontal plate portion 12b, thereby preventing positional displacement on the support.

  Next, the roof blocks 4c are assembled and fixed to each other. Subsequently, as shown in FIG. 6, the trolley beam 17 a on the horizontal plate portion 12 b and the trolley beam 17 b on the temporary support 16 and the roof portion 4 c are connected by the connecting member 23. Thereby, attachment and fixing of the roof part 4c by the support part to the formwork 11 are completed.

  When the fixing of the roof part 4c via the support part to the formwork 11 is completed, the center support 18 and the intermediate support 19 that supported the load of the roof part 4c are removed as shown in FIG.

  Next, as shown in FIG. 8, the side walls 4 b are constructed by continuously placing concrete between the molds 11, 11, and the roof 4 c is provided with the yoke 12 provided on the molds 11, 11. Lifting up while supporting by a support portion such as (slip foam process). That is, when the concrete placed between the molds 11 and 11 is strong enough to be self-supporting, the jacks 13 are sequentially pulled up by the jacks 13 to pull up the molds 11 and 11 through the yokes 12. The roof part 4c is also pulled up.

  Further, as shown in FIG. 7, after the center support 18 and the intermediate support 19 are removed, the lower side of the roof 4c is parallel to the lifting (jacking up) of the molds 11 and 11 and the roof 4c by the slip form process. Then, the cold insulation process (cold insulation treatment process) for the bottom slab portion 4 a of the outer tub 4 is started on the foundation floor slab 5. Also, the suspended deck 24 is assembled and suspended from the roof portion 4c.

  Here, as shown by a two-dot chain line in FIG. 6, the roof portion 4 c is provided with a damming portion 25 for collecting rainwater on the upper surface side of the outer peripheral portion (for example, on the compression ring 20). The damming portion 25 is a plate-like one provided in a cylindrical shape (annular) around the entire outer periphery of the roof portion 4c, and dams and collects rainwater that has flowed down to the outer periphery along the inclination of the roof portion 4c. It is supposed to leave. Further, a discharge pipe 26 for discharging the accumulated rainwater is connected to the damming unit 25.

  That is, a through hole (not shown) is formed in the damming portion 25, and one end of the discharge pipe 26 is attached in communication with the through hole. The other end side of the discharge pipe 26 is positioned outside the side wall portion 4b (outside the molds 11 and 11). In that case, since the roof part 4c is supported on the formwork 11, the discharge pipe 26 is naturally arranged on the side wall part 4b. Therefore, the discharge pipe 26 can be passed over the side wall portion 4b, and the other end side can be easily disposed outside the side wall portion 4b. As a result, the rain that has fallen on the roof portion 4 c can be dammed and collected by the damming portion 25, and the accumulated rainwater can be discharged to the outside of the side wall portion 4 b by the discharge pipe 26. Therefore, the interior surrounded by the side wall 4b, that is, the foundation floor slab 5 surrounded by the mold 11 is covered with the roof 4c, so that it is reliably prevented from getting wet by rain.

  Further, as the cold insulation process for the bottom plate part 4a on the foundation floor slab 5, the cold insulation process and the construction of the annular part 27 shown in FIG. 7 are performed. This annular part 27 is a place where the side wall part 3b of the inner tub 3 shown in FIG. 1 is constructed. In order to construct this annular portion 27, first, as shown in FIG. 9, a block-like pearlite concrete 28 is laid on the foundation floor slab 5, and then a ring concrete 29 made of reinforced concrete is placed thereon. An annular plate 30 made of nickel steel is laid on the ring concrete 29.

  The pearlite concrete 28 contains pearlite, which is a cold insulator, and has good cold insulation performance. Therefore, the cold treatment of the annular portion 27 can be performed by spreading such pearlite concrete 28. In addition, instead of the pearlite concrete 28, the cold insulation process of the annular portion 27 may be performed by laying a block-shaped foam glass, for example. Foam glass also has a cold insulation performance equivalent to that of perlite concrete 28.

  When the annular portion 27 is thus constructed, the side wall portion 3b of the inner tub 3 is subsequently formed on the outer peripheral portion of the annular portion 27 (inner tub forming step).

  On the other hand, when the molds 11 and 11 and the roof portion 4c are pulled up to the top in the slip-form process, and concrete is placed in the molds 11 and 11 as shown in FIG. The steel 31 is embedded. And if concrete strength expresses, the roof part 4c will be fixed to the H steel 31. FIG. For example, a fixing member (not shown) such as H steel is fixed to the outer peripheral end of the roof portion 4c by welding or bolting, and the fixing member is welded to the H steel 31 so that the H steel 31 is bonded. The roof part 4c is fixed.

  Next, concrete (not shown) is placed and hardened so as to cover the fixed portion (welded portion) between the H steel 31 and the roof portion 4c. Thereby, between the side wall part 4b of the outer tub 4 shown in FIG. 1 and the roof part 4c (joint) can be formed with concrete, and the roof part 4c can be fixed on the side wall part 4b.

Next, the yoke 12 and the scaffold 15 are removed from the molds 11 and 11, and the molds 11 and 11 are also removed from the side wall 4b. Moreover, the damming part 25 and the discharge pipe 26 provided on the outer peripheral part of the roof part 4c are also removed.
In this manner, by removing the mold 11, the yoke 12, and the scaffold 15 from the side wall 4b, the side wall 4b is formed and the connection between the side wall 4b and the roof 4c is completed.

  Thereafter, the side wall portion 3b of the inner tub 3 on the annular portion 27 is completed (inner tub forming step), and the bottom plate portion 3a of the inner tub 3 in the side wall portion 3b is constructed (including a cold insulation process). Then, the inner surface of the side wall 4b of the outer tub 4 is subjected to a cold insulation process. Then, the lid member 7 is provided in the inner tub 3 and the glass wool 8 is laid, and the pearlite 9 is filled between the side wall 3b of the inner tub 3 and the side wall 4b of the outer tub 4, etc. The low temperature tank 1 shown in FIG.

  According to such a construction method of the low-temperature tank 1, at least the cold insulation treatment process is performed in parallel with the slip foam process on the bottom plate portion 4a of the outer tub 4, that is, the bottom plate portion 4a on the foundation floor slab 5. Since a part of the process is performed during the slip foam process, the construction of the cold insulation process can be started before the roof part 4c is finally attached to the side wall part 4b and the roof is completed. Therefore, the construction period can be shortened.

  Moreover, in the cold insulation process, since the cold insulation treatment and the construction of the annular portion 27 are performed, the start of the construction of the side wall (side wall) 3b of the inner tank 3 to be constructed thereafter can be accelerated, and therefore the low temperature tank 1 The construction period can be shortened.

  Further, the roof portion 4c is provided with a damming portion 25 for collecting rainwater on the upper surface side of the outer peripheral portion thereof, and a discharge pipe 26 for discharging the rainwater collected in the damming portion 25 to the outside of the side wall portion 4b. Therefore, the inside surrounded by the side wall 4b, that is, the foundation floor slab 5 surrounded by the mold 11 is covered with the roof 4c, so that it can be reliably prevented from getting wet by rain. Therefore, the cold insulation process on the foundation floor slab 5 can be performed without hindrance.

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, about the support of the roof part 4b with respect to the formwork 11 and 11, ie, the structure of a support part, it is not limited to the structure which has the said yoke 12 as a main, Arbitrary structures are employable.

  In addition, as a method of fixing the roof portion 4c to the side wall portion 4b after the formwork 11, 11 and the roof portion 4c are pulled up to the topmost portion in the slip-form process, the method using the H steel 31 shown in FIG. 10 is used. For example, various methods such as a method using an embedded hardware can be adopted.

DESCRIPTION OF SYMBOLS 1 ... Low temperature tank (ground type low temperature tank), 3 ... Inner tank, 3b ... Side wall part, 4 ... Outer tank, 4a ... Bottom plate, 4b ... Side wall board (side wall part), 4c ... Roof board (roof part), 5 ... Foundation floor slab, 11 ... form, 12 ... yoke (supporting part), 25 ... damming part, 26 ... discharge pipe, 27 ... annular part

Claims (4)

A method for constructing a ground-type cryogenic tank having a side wall portion, a roof portion, and a bottom plate portion,
A roof portion forming step for forming the roof portion;
While building up the side wall by continuously placing concrete between the molds while lifting up a pair of molds arranged facing each other, the roof part formed in the roof part forming step A slip-form step of lifting up while supporting by a support provided in the mold,
A cold insulation treatment step for carrying out a cold insulation treatment of the bottom plate portion surrounded by the mold,
A method for constructing a ground-type low-temperature tank, wherein the cold insulation process is performed during the slip foam process in parallel with the slip foam process.   The method for constructing a ground-type cryogenic tank according to claim 1, wherein in the cold insulation treatment step, the cold insulation treatment of the annular portion and the construction thereof are performed. The low temperature tank is a double shell structure of an inner tank and an outer tank covering the inner tank, and the side wall is a side wall of the outer tank,
The method for constructing a ground-type cryogenic tank according to claim 2, further comprising an inner tank forming step of constructing a side wall of the inner tank on the annular portion after the cold treatment and construction of the annular portion.   The roof portion is provided with a damming portion for collecting rainwater on an upper surface side of the outer peripheral portion thereof, and a discharge pipe for discharging the rainwater accumulated in the damming portion to the outside of the side wall portion. The construction method of the above-mentioned ground-type cryogenic tank as described in any one of Claims 1-3.

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