TWI628128B - Method for constructing double shell tank - Google Patents

Abstract

The present invention is a construction method of a double-shell groove (1) provided with a supporting metal member (3a3) embedded in the outer groove side wall (3a) and supported by a supporting metal member (3a3) Supported metal trough top (3a1), the method of constructing the double-shell trough (1) has a step of forming an outer trough side wall, such that the top surface becomes a water guiding surface that descends toward the outer side of the outer trough (3) (3a5 The concrete is formed by filling the concrete to form the outer groove side wall (3a); and the metal groove top forming step is to form the metal groove top (3b1) connected to the supporting metal member (3a3).

Description

Construction method of double shell groove

The present invention relates to a method of constructing a double-shell tank. The present application claims priority on Japanese Patent Application No. 2016-007722, filed on Jan.

For example, as disclosed in Patent Document 1, in order to store LNG (Liquefied Natural Gas), a double groove having a groove mainly composed of concrete and a metal inner groove disposed inside the outer groove is used. Shell groove. Such a technique is also disclosed in Patent Documents 2 to 4.

[Previous Technical Literature] (Patent Literature)

(Patent Document 1) Japanese Patent Laid-Open Publication No. 2005-247324

(Patent Document 2) Japanese Patent Laid-Open Publication No. 2003-292091

(Patent Document 3) Japanese Unexamined Gazette No. 55-041653

(Patent Document 4) Japanese Unexamined Patent Publication No. 03-084557

However, at the time of the construction of the double-shell groove as described above, the bottom cold-retaining layer supporting the inner groove is formed inside the outer groove. Such a bottom cold layer must be protected from rain by the rain in order to maintain the cooling function. Therefore, in the construction of the double-shell groove, a part of the outer groove ceiling portion is formed first to prevent rainwater from intruding into the outer groove, and then the formation of the bottom cold-retaining layer is performed. More specifically, the groove side wall is formed in a state in which the support metal member is buried at the top, and then the metal groove top which is the skeleton portion of the outer groove ceiling portion is lifted by air raising or the like and then fixed. To support the metal part, thereby forming a part of the outer trough ceiling portion.

However, the top of the side wall of the outer tank was exposed for several months until the concrete was poured over the metal trough top of the skeleton portion of the outer trough ceiling portion. Therefore, there is a case where rainwater permeates from the boundary portion between the concrete portion of the side wall of the outer tank and the embedded supporting metal member, and then oozes out on the inner surface of the side wall of the outer tank. In such a case, it is necessary to take measures to prevent the bottom cold-retaining layer from being wetted, etc., and it is necessary to extend the construction period.

The present invention has been made in view of the above problems, and is a construction method of a double-shell groove having an outer groove made of concrete, the object of which is to: a metal up to a bone portion as an outer groove During the period before the concrete is poured on the top of the trough, the rainwater is prevented from seeping out to the inner surface of the side wall of the outer trough.

The present invention adopts the following constitution as a solution to the above The means of the subject.

The present invention is a method for constructing a double-shell groove having a supporting metal member embedded in an inner surface of a groove side wall formed of concrete in a partially exposed state, and supported by a supporting metal member and formed a metal trough top of a lower portion of the outer trough ceiling portion, the method for constructing the double trough groove has a step of forming an outer trough side wall, and the top surface is lowered toward the outer side of the outer trough in a state in which the supporting metal member is embedded The water guiding surface is formed by pouring concrete to form the outer groove side wall; and the metal groove top forming step is to form a metal groove top connected to the supporting metal piece.

According to the invention, the top surface of the side wall of the outer groove is formed as a water guiding surface which is lowered toward the outer side of the outer groove. Therefore, the rainwater on the top surface of the side wall of the outer tank is discharged from the side wall of the outer tank along the water guiding surface and the outer side of the side wall of the outer tank. Therefore, a large amount of rainwater does not accumulate on the top surface of the side wall of the outer tank, and it is possible to suppress the rainwater from penetrating into the boundary portion of the supporting metal member embedded in the side wall of the outer tank and the concrete portion around it. Therefore, the construction method of the double-shell groove provided with the outer groove made of concrete according to the present invention can be prevented until the concrete is poured on the top of the metal groove as the skeleton portion of the outer groove. Rainwater seeps out to the inner side of the side wall of the outer tank.

1‧‧‧double shell slot

2‧‧‧Basic flooring

3‧‧‧ outer trough

3a‧‧‧ outer groove sidewall

3a1‧‧‧ concrete layer

3a2‧‧ ‧ steel bars

3a3‧‧‧Support metal parts

3a4‧‧‧ Waterstop

3a5‧‧‧ water guide

3b‧‧‧ outer trough ceiling

3b1‧‧‧Metal roof

3b2‧‧‧ concrete layer

3b3‧‧‧ shoulder

3b4‧‧‧Central Department

3b5‧‧‧ lower

3b6‧‧‧ upper

4‧‧‧Bottom cold insulation layer

5‧‧‧ Inside slot

5a‧‧‧ bottom of the inner trough

5b‧‧‧ inner groove sidewall

6‧‧‧Side cold insulation

7‧‧‧ Ceiling

8‧‧‧Boom

9‧‧‧Retaining wall

10‧‧‧Upper cold insulation layer

K1‧‧‧ outside template

K2‧‧‧ inside template

Fig. 1 is a longitudinal cross-sectional view showing a schematic configuration of a double-shell groove which is constructed by a construction method of a double-shell groove according to an embodiment of the present invention.

Fig. 2 is an enlarged view of a region A in Fig. 1.

Fig. 3 is a schematic view showing the steps of a method of constructing a double-shell groove according to an embodiment of the present invention, and is a view showing a state after a steel bar is assembled.

Fig. 4 is a schematic view showing the steps of a method of constructing a double-shell groove according to an embodiment of the present invention, and is a view showing a state after the inner template and the outer template are set.

Fig. 5 is a schematic view showing the steps of a method of constructing a double-shell groove according to an embodiment of the present invention, and is a view showing a state after concrete is poured between the inner formwork and the outer formwork.

Fig. 6 is a schematic view showing the steps of a method of constructing a double-shell groove according to an embodiment of the present invention, and is a view showing a state after the metal groove top is set.

Hereinafter, an embodiment of the construction method of the double-shell groove of the present invention will be described with reference to the drawings. In the following drawings, the scale dimensions of the respective members are appropriately changed in order to make each member a viewable size.

Fig. 1 is a longitudinal cross-sectional view showing a schematic configuration of a double-shell groove 1 which is completed by the construction method of the double-shell groove of the present embodiment. As shown in Fig. 1, the double-shell groove 1 of the present embodiment is a PC (Prestressed Concrete) type storage tank, and includes a base floor 2, an outer tank 3, a bottom cold-retaining layer 4, and an inner tank 5. a side cold insulation layer 6, a suspended deck 7, a hanger 8, a retaining wall 9, and an upper cold insulation layer 10.

The base floor 2 is a member that supports the outer groove 3, the inner groove 5, and the like from below, and has a substantially disk shape having a larger diameter than the outer groove 3 as viewed from above. A heater (not shown) is provided in the base floor 2 to suppress the transfer of cold heat of the stored LNG to the ground. The outer tub 3 is a container made of pre-stressed concrete and is erected on the foundation floor 2 so as to cover the inner tub 5. Further, the groove 3 is mainly formed of concrete, and has a cylindrical outer groove side wall 3a and a groove ceiling portion 3b which is connected to the upper edge portion of the outer groove side wall 3a.

Fig. 2 is a schematic cross-sectional view showing, in an enlarged manner, a connecting portion (region A in Fig. 1) of the outer groove side wall 3a and the outer groove ceiling portion 3b. As shown in Fig. 2, the outer groove side wall 3a has a reinforcing bar 3a2 embedded in the concrete layer 3a1, a supporting metal member 3a3 embedded in the inner surface of the outer groove side wall 3a in a partially exposed manner, and a supporting metal member. The water stop material 3a4 at the boundary portion between the 3a3 and the concrete layer 3a1. Further, although not shown in the first and second drawings, a sheath for applying a pre-stress is also provided in the outer groove side wall 3a.

The plurality of reinforcing bars 3a2 are provided so as to be erected from the base floor 2, and are disposed in the entire height direction of the outer groove side wall 3a. The plurality of reinforcing bars 3a2 support the strength members of the concrete layer 3a1 as the skeleton portions of the outer groove side walls 3a. The supporting metal member 3a3 is a substantially annular member which is embedded in the top of the outer groove side wall 3a in such a manner that the inner surface thereof is flush with the inner surface of the concrete layer 3a1 (that is, the inner surface of the outer groove side wall 3a). This supporting metal piece 3a3 is connected to the reinforcing bar 3a2. Such a supporting metal member 3a3 is a portion to which the metal trough top 3b1, which will be described later, of the outer trough ceiling portion 3b is to be connected. stop The water material 3a4 is used to prevent rainwater from penetrating into the joint portion of the concrete layer 3a1 and the supporting metal member 3a3 during the construction of the double-shell tank 1. Such a water stop material 3a4 can be, for example, a water-swellable water stop material which is expanded by sucking water.

The outer trough ceiling portion 3b has a metal trough top 3b1 and a concrete layer 3b2. The metal trough top 3b1 is a steel skeleton member that forms a lower portion of the outer trough ceiling portion 3b, and has a shoulder portion 3b3 and a central portion 3b4 as shown in Fig. 2 . The shoulder portion 3b3 is an outer peripheral edge portion of the metal groove top 3b1, and is welded to the supporting metal member 3a3. Such a shoulder portion 3b3 has a lower portion 3b5 which is concentric with the supporting metal member 3a3 and which is directly joined to the supporting metal member 3a3, and is supported from below by the lower portion 3b5 and protrudes outward from the radially outer side of the outer groove 3 beyond the lower portion 3b5. Upper part 3b6. The central portion 3b4 is welded to the upper portion 3b6 of the shoulder portion 3b3. The concrete layer 3b2 is supported by the metal trough top 3b1 from below and connected to the concrete layer 3a1 of the outer trough side wall 3a to form an upper portion of the outer trough ceiling portion 3b.

Returning to Fig. 1, the bottom cold insulation layer 4 is placed on the upper surface of the base floor 2, and the inner tank 5 is supported from below. The bottom cold insulation layer 4 is formed in a substantially disk shape having a diameter smaller than that of the base floor 2, and is disposed coaxially with the base floor 2 as viewed from above. The bottom cold insulation layer 4 is formed of, for example, perlite concrete, sand, or the like. The inner tank 5 is a metal container placed on the bottom heat retaining layer 4, and has a shape formed into a bottomed cylinder having an open end at the upper end. The inside of this inner tank 5 stores LNG. The inner groove 5 has an inner groove bottom portion 5a and an inner groove side wall 5b which is erected on the edge portion of the inner groove bottom portion 5a.

The side cold insulation layer 6 is disposed on the outer groove side wall 3a and the inner groove The side walls 5b are formed by filling in granular perlite. Further, as shown in Fig. 1, the side cold retaining layer 6 is disposed so as to be formed to the upper portion of the inner tank 5, and is supported by the retaining wall 9 formed on the upper portion of the ceiling 7 from the side to be filled to the ceiling 7 The upper part of the outer circumference.

The ceiling 7 is a disk-shaped member made of metal, and is suspended by a boom 8 to seal the upper end of the inner groove 5 formed as an open end from above. The upper end portion of the boom 8 is fixed to the outer groove ceiling portion 3b, and the lower end portion is fixed to the ceiling 7. As shown in Fig. 1, such a boom 8 is provided with a plurality of branches between the outer tank ceiling portion 3b and the ceiling 7, to suspend the ceiling 7.

The retaining wall 9 is disposed substantially in a cylindrical shape along the outer edge portion of the ceiling 7, and is formed from the outer groove ceiling portion 3b to the ceiling 7. Such a retaining wall 9 is for preventing the side cold retaining layer 6 formed of the granular perlite from intruding above the ceiling 7 (inside of the groove). The upper cold insulation layer 10 is placed on the upper surface of the ceiling 7 and disposed on the inner side of the retaining wall 9. Such an upper heat retaining layer 10 is formed of a polyurethane foam or the like.

Next, a construction method of the double-shell groove 1 of the present embodiment will be described with reference to Figs. In the following description, it is assumed that the base floor 2 has been formed.

First, as shown in Fig. 3, the reinforcing bars 3a2 are assembled, and then the supporting metal members 3a3 to which the water stopping material 3a4 is adhered are attached to the assembled reinforcing bars 3a2. Next, as shown in Fig. 4, the outer template K1 and the inner template K2 are provided so as to sandwich the group of reinforcing bars 3a2. That is, the outer template K1 is disposed outside the formation region of the outer groove side wall 3a, on the outer groove side. The inner template K2 is disposed inside the formation region of the wall 3a. Here, the inner side template K2 is disposed such that the supported metal piece 3a3 abuts from the inner side of the outer groove forming region, and the upper end is formed at the same position as the upper end of the supporting metal piece 3a3, and the upper end of the outer side plate K1 is made. The height is lower than the inner template K2.

Next, as shown in Fig. 5, concrete is poured between the outer formwork K1 and the inner formwork K2. At this time, the water-conducting surface 3a5 which consists of an inclined surface is formed in the top surface of the concrete which the upper end of the inner side form K2 (that is, the upper end of the support metal member 3a3) is connected to the upper end of the outer form K1. Such a water guiding surface 3a5 is an inclined surface that is lowered toward the radially outer side of the outer groove side wall 3a.

Through the steps shown in Figs. 3 to 5, the groove side wall 3a is formed by the water guiding surface 3a5 which is formed by the inclined surface in a state in which the supporting metal member 3a3 is fitted. In other words, the steps shown in Figs. 3 to 5 correspond to the outer groove side wall forming step in the present invention.

Next, as shown in Fig. 6, the outer template K1 and the inner template K2 are removed and the metal groove top 3b1 is attached to the supporting metal member 3a3. Here, the shoulder 3b3 of the metal trough top 3b1 is first welded to the supporting metal piece 3a3. Then, the center portion 3b4 of the metal groove top 3b1 is formed inside the outer groove side wall 3a, and the formed central portion 3b4 is lifted up and welded to the shoulder portion 3b3. By the step shown in Fig. 6, the metal trough top 3b1 is connected to the supporting metal member 3a3. In other words, the step shown in Fig. 6 corresponds to the metal groove top forming step in the present invention.

As shown in Fig. 6, it will be relative to the supporting metal piece 3a3 The metal trough top 3b1 is connected, and the metal trough top 3b1 covers the space surrounded by the outer trough side wall 3a. In the space covered by the metal trough top 3b1 in this manner, the bottom cold-retaining layer 4, the inner tank 5, the side cold-storage layer 6, the ceiling 7, the boom 8, the retaining wall 9, and the upper cold-preserving layer 10 are formed. After the work in the space covered by the metal trough top 3b1 or the operation of pouring the concrete on the upper portion of the metal trough top 3b1, the concrete layer 3b2 of the outer trough ceiling portion 3b is formed. In addition to the steps described above, the piping operation is performed again, and the double-shell tank 1 is completed.

Here, according to the construction method of the double-shell groove 1 of the present embodiment, the top surface of the outer groove side wall 3a is oriented outward until the concrete layer 3b2 is formed on the metal groove top 3b1. The state of the water guiding surface 3a5 which is lowered radially outward of the groove 3. Therefore, the rainwater falling on the top surface of the outer groove side wall 3a is discharged from the outer groove side wall 3a along the water guiding surface 3a5 and the outer side of the outer groove side wall 3a. Therefore, a large amount of rainwater does not accumulate on the top surface of the outer tank side wall 3a, and it is possible to suppress the rainwater from penetrating into the boundary portion between the supporting metal member 3a3 buried in the outer tank side wall 3a and the surrounding concrete layer 3a1. Therefore, according to the double-shell groove 1 of the present embodiment, rainwater can be prevented from seeping into the outer groove side wall 3a until the concrete is poured on the metal groove top 3b1 which is the skeleton portion of the outer groove 3. The situation.

Further, in the method of constructing the double-shell groove 1 of the present embodiment, the water guiding surface 3a5 is formed as an inclined surface that is inclined outward in the radial direction of the outer groove side wall 3a. Therefore, the entire surface of the top surface of the outer groove side wall 3a can surely guide the rainwater toward the outer side of the outer groove side wall 3a. Therefore, according to the construction method of the double-shell tank 1 of the present embodiment, the rainwater infiltration support gold can be more reliably suppressed. The boundary between the member 3a3 and the surrounding concrete layer 3a1.

Further, in the method of forming the double-shell groove 1 of the present embodiment, in the outer groove side wall forming step, the inner side plate K2 which is in contact with the support metal piece 3a3 from the inner side of the outer groove side wall forming region is disposed, and is disposed on the outer groove side wall. The outer side of the region is formed and the upper end is made lower than the upper end of the supporting metal piece 3a3 by the outer side form K1, and then the concrete is poured between the outer formwork K1 and the inner side formwork K2. Therefore, the water guiding surface 3a5 can be easily formed by forming the inclined surface connecting the upper ends of the upper end of the supporting metal member 3a3 and the upper end of the outer template K1. Therefore, the water guiding surface 3a5 having a uniform inclination can be formed on the entire circumference of the outer groove side wall 3a.

Further, in the method of constructing the double-shell groove 1 of the present embodiment, in the step of forming the outer groove side wall, the concrete is poured after the supporting metal member 3a3 is adhered to the water stopping member 3a4. Therefore, the water stop member 3a4 can be easily disposed at the boundary portion between the support metal member 3a3 and the concrete layer 3a1. When such a water stop material 3a4 is provided, even if rainwater intrudes into the boundary portion between the support metal member 3a3 and the concrete layer 3a1 around it, the rainwater can be prevented from seeping out to the inner surface of the outer tank side wall 3a.

Further, in the method of constructing the double-shell groove 1 of the present embodiment, the upper portion 3b6 of the shoulder portion 3b3 of the metal groove top 3b1 protrudes outward beyond the lower portion 3b5. Therefore, it is possible to suppress the rainwater flowing down to the metal tank top 3b1 from flowing to the lower portion 3b5 and falling to the vicinity of the supporting metal member 3a3. Therefore, it is possible to more reliably suppress the penetration of rainwater into the boundary portion between the supporting metal member 3a3 and the surrounding concrete layer 3a1.

The preferred embodiment of the present invention has been described above with reference to the drawings. Although the form has been described, the present invention is not limited to the above embodiment. The various shapes, combinations, and the like of the respective components disclosed in the above-described embodiments are merely examples, and various modifications may be made in accordance with design requirements and the like within the scope of the gist of the invention.

For example, in the above-described embodiment, the configuration of the inclined surface of the water guiding surface 3a5 has been described. However, the present invention is not limited thereto, and may be formed as a stepped surface that is stepped downward toward the outer side of the outer groove side wall 3a. The composition. With such a configuration, it is possible to prevent rainwater flowing from the outer side of the top surface of the outer groove side wall 3a toward the outer side of the supporting metal member 3a3, and to prevent rainwater from intruding into the supporting metal member 3a3. The interface with the surrounding concrete layer 3a1. Further, the water guiding surface 3a5 may be formed in a shape in which a slope, a step surface, or the like is combined.

Further, in the above embodiment, a configuration in which the guide grooves are formed in the water guiding surface 3a5 may be employed. With such a configuration, the guide groove can be used to more accurately guide the flow of the rainwater, and for example, the rainwater can be concentrated from a desired position.

Further, in the above-described embodiment, the outer template K1 is disposed lower than the upper end of the supporting metal member 3a3, and the upper end of the supporting metal member 3a3 and the upper end of the outer template K1 are formed as the reference. The slope is formed to form the water guiding surface 3a5. However, the present invention is not limited thereto, and the configuration in which the outer template K1 and the inner template K2 are the same height may be employed, and then the inclined surface may be formed by another method.

Moreover, in the above embodiment, although Before the concrete is poured, the water stop material 3a4 is adhered to the support metal member 3a3 in advance. However, the present invention is not limited thereto, and a configuration in which the water stop member 3a4 is not provided or a configuration in which the water stop member 3a4 is placed at another position after the concrete is poured may be employed.

(industrial availability)

According to the present invention, it is possible to prevent the rainwater from oozing out to the inner surface of the side wall of the outer groove until the concrete is poured on the top of the metal groove as the skeleton portion of the outer groove.

Claims (8)

A method for constructing a double-shell groove, the double-shell groove having a supporting metal member embedded in an inner surface of a groove side wall formed by concrete in a partially exposed state, and supported by the supporting metal member and formed a metal trough top of a lower portion of the outer trough ceiling portion, the double shell trough construction method having an outer trough side wall forming step in which the supporting metal member is embedded and the top surface is oriented toward the outer trough The outwardly descending water guiding surface forms concrete to form the outer groove side wall; and the metal groove top forming step forms a metal groove top connected to the supporting metal member. The method for constructing a double-shell groove according to claim 1, wherein the water guiding surface is inclined toward the outer side of the outer groove. The method for constructing a double-shell groove according to the first aspect of the invention, wherein in the outer groove side wall forming step, the inner side plate which is abutted by the inner side of the outer groove side wall forming region by the supporting metal member is disposed, And an outer side plate disposed at an outer side of the outer groove side wall forming region and having an upper end lower than an upper end of the supporting metal member, and concrete is poured between the inner side plate and the outer side plate. The method for constructing a double-shell groove according to claim 2, wherein in the step of forming the outer groove sidewall, the arrangement is: The inner template that abuts the inner side of the outer groove side wall forming region, and the outer side plate disposed at the outer side of the outer groove side wall forming region, and the upper end has a lower height than the upper end of the supporting metal member, and the outer side plate and the outer side are Concrete is poured between the templates. The method for constructing a double-shell groove according to the first aspect of the invention, wherein in the step of forming the outer groove side wall, the concrete is poured after the supporting metal member is adhered to the water stop material. The method for constructing a double-shell groove according to claim 2, wherein in the step of forming the outer groove side wall, the concrete is poured after the supporting metal member is adhered to the water stop material. The method for constructing a double-shell groove according to claim 3, wherein in the step of forming the outer groove side wall, the concrete is poured after the supporting metal member is adhered to the water stop material. The method for constructing a double-shell groove according to claim 4, wherein in the step of forming the outer groove side wall, the concrete is poured after the supporting metal member is adhered to the water stop material.