JP7189787B2 - Tank construction method - Google Patents

Description

The present invention relates to a tank construction method.

For example, Patent Literature 1 discloses a method for constructing a cylindrical tank. In such a cylindrical tank, a frame may be provided on the upper part of the roof. The frame is provided with piping equipment, passages through which workers can walk, etc., and is fixed to one side of the roof.

Japanese Unexamined Patent Application Publication No. 2014-92004

During construction of the tank, the roof will be flexed and deformed due to movement, concrete placement, etc., so the frame cannot be constructed until the construction and fixing of the roof are completely completed. Therefore, when constructing a tank with a frame, the construction period tends to be greatly extended.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-described problems, and an object of the present invention is to shorten the construction period at the time of constructing a tank on which a frame is provided.

The present invention employs the following configurations as means for solving the above problems.

A first means is a construction method for a tank in which a frame is formed on the roof, comprising a roof lifting step of lifting the roof of the tank vertically upwards, and supporting the pillars of the frame against the roof of the tank. A base construction step for supporting from below in the vertical direction and fixing a vertically expandable temporary support, a height adjustment step for adjusting the height of the temporary support after the base construction process, and construction of the frame. and a frame construction step for

A second means adopts a configuration in which the base building step is performed before the roof lifting step and the height adjusting step in the first means.

A third means is, in the first or second means, having a concrete placing step of placing concrete on the roof after the roof lifting step, and the height adjusting step comprises the A configuration is adopted in which it is performed after the concrete placing process.

A fourth means is any one of the first to third means, wherein the roof lifting step is performed using a jack device, and the frame building step is performed before the roof lifting step. configuration is adopted.

A fifth means is, in the fourth means, after the height adjustment step, a fixing step of fixing the column to the roof, and in the fixing step, the jack device is removed. configuration is adopted.

According to the present invention, the processing is constructed after installing the pillars of the frame on the temporary pillars that can be expanded and contracted in the vertical direction. As a result, even if the roof is deformed or bent, the height of the support can be adjusted according to the deformation or deflection of the roof by adjusting the length of the temporary support. Therefore, it is possible to construct the frame in parallel with constructing the roof, and it is possible to shorten the construction period of the tank.

1 is a schematic cross-sectional view of a tank in one embodiment of the present invention; FIG. FIG. 3 is a schematic diagram showing a frame attachment position on the tank roof in one embodiment of the present invention. Fig. 4 is a flow chart illustrating a construction procedure when installing a frame of a tank roof in one embodiment of the present invention. FIG. 4 is a schematic diagram illustrating a construction procedure when installing the frame of the roof of the tank in one embodiment of the present invention.

An embodiment of a construction method for a tank 1 according to the present invention will be described below with reference to the drawings. In the drawings below, the scale of each member is appropriately changed so that each member has a recognizable size.

The tank 1 includes a base floor slab 2, an outer tank 3, a bottom cold insulation layer 4, an inner tank 5, and a frame 6, as shown in FIG.

The base slab 2 is a foundation for supporting the outer tank 3, the inner tank 5, and the like from below, and has a substantially disk shape with a larger diameter than the outer tank 3 when viewed from above. A heater (not shown) is installed on the base slab 2 to prevent cold heat from the stored LNG from being transferred to the ground.

The outer tank 3 is a container made of prestressed concrete and erected on the base floor slab 2 so as to cover the inner tank 5 . The outer tank 3 is mainly made of concrete, and has a cylindrical outer tank side wall 3a and an outer tank roof portion 3b connected to the upper edge of the outer tank side wall 3a. At the time of assembly, the outer tank roof portion 3b is constructed by lifting the roof frame 3b1 (roof) upward, fixing it to the outer tank side wall 3a, and pouring concrete.

The bottom cold insulation layer 4 is placed on the upper surface of the base floor slab 2 and supports the inner tank 5 from below. The bottom cold insulation layer 4 has a substantially disk-like shape with a smaller diameter than the base floor slab 2 and is arranged coaxially with the base floor slab 2 when viewed from above. The bottom cold insulation layer 4 is made of perlite concrete, sand, or the like, for example.

The inner tank 5 is a metal container placed on the bottom cold insulation layer 4, and has a bottomed cylindrical shape with an open top end. LNG is stored inside the inner tank 5 . The inner tank 5 has an inner tank bottom 5a (floor surface) and an inner tank side wall 5b erected on the edge of the inner tank bottom 5a. The inner tank side wall 5b is constructed by connecting a plurality of rectangular side plates in the circumferential direction and the vertical direction so as to form a cylindrical shape.

The frame 6 is a frame provided on the upper part of the outer tank roof portion 3b, and includes facilities such as a passage where workers can walk and pipes through which LNG or the like flows, as shown in FIG. As shown in FIG. 2, such a frame 6 is constructed in the area surrounded by the dashed line of the outer tank roof portion 3b. Therefore, the weight of the frame 6 causes the outer tank roof portion 3b to bend. Further, the frame 6 supports the load by a frame support 6a provided on the outer tank roof portion 3b.

Next, a tank construction method according to the present embodiment will be described with reference to FIGS. 3 and 4. FIG.
First, after the roof frame 3b1 of the outer tank roof portion 3b is assembled on the floor surface, a base construction step is performed (step S1). In the base construction step, as shown in FIG. 4(a), a plurality of temporary fixing struts 6b are fixed to the roof frame 3b1. This temporary fixing support|pillar 6b is made expandable-contractible in a longitudinal direction, and is fixed with respect to the roof frame 3b1 by a lever etc., for example. Further, the base 6c is mounted and fixed to the temporary fixing support 6b. Then, the frame support 6a is formed on the base 6c. A jack J is arranged below the base 6c (in the space between the temporary fixing struts 6b). The jack J is a manually operable jack device having a curved upper portion, and is mounted on a pedestal 3b2 constructed on the roof frame 3b1. The pedestal 3b2 is set to a height that protrudes from the outer surface of the outer tank roof portion 3b when concrete is poured.

Next, a roof frame lifting process (roof lifting process) is performed (step S2). In the roof frame lifting process, the roof frame 3b1 of the outer tank roof portion 3b is lifted vertically upward from the floor surface by a plurality of hydraulic jacks. At this time, each hydraulic jack is controlled by a control device (not shown). Specifically, the controller controls the full hydraulic jack to lift the roof until the load/inclination exceeds an allowable value or the number of strokes reaches a set number. When the load/inclination exceeds the allowable value, the attitude of the outer tank roof 3b is adjusted manually by the operator or by controlling a hydraulic jack. When the number of strokes reaches the set number, the operator welds and fixes the roof frame 3b1 of the outer tank roof portion 3b to the upper end of the outer tank side wall 3a. In such a construction method, when the roof frame 3b1 of the outer tank roof portion 3b is lifted, if a large load is applied to some of the hydraulic jacks, the stroke amount of the hydraulic jacks decreases, and when the next hydraulic jacks are operated, By transferring the load to the other hydraulic jacks, the load is gradually dispersed, and the difference between the loads of the hydraulic jacks becomes smaller. Therefore, it is possible to carry out the lifting operation of the roof frame 3b1 of the outer tub roof portion 3b in a short period of time.

Then, a concrete placing step is performed (step S3). In the concrete placing step, concrete is placed on the roof frame 3b1. At this time, since the jack J is placed on the pedestal 3b2 as shown in FIG. 4B, it is exposed above the outer surface of the concrete. Due to the concrete placing process, the outer tank roof portion 3b is slightly deformed by its own weight.

Subsequently, a height adjustment process is performed (step S4). In the height adjustment process, the jack J is used to adjust the height and the horizontal position of the frame support 6a in accordance with the deformation or the like that occurs in the concrete placing process. The position adjustment in the horizontal direction changes the position of the frame support 6a by adjusting the position of the load using the fact that the upper part of the jack J is curved. Moreover, according to such adjustment of the jack J, the length of the temporary fixing support|pillar 6b is adjusted.

Then, a post fixing step is performed (step S5). In the post fixing step, first, as shown in FIG. 4(c), the jack J is removed from the pedestal 3b2. Then, as shown in FIG. 4(d), concrete is placed in a region including the temporary fixing support 6b, the base 6c, and the lower part of the frame support 6a. As a result, the frame support 6a is fixed to the outer tank roof portion 3b.

Further, a frame construction step is performed (step S6). In the frame construction process, the frame 6 as shown in FIG. 1 is constructed using the frame pillars 6a placed on the base 6c.

According to this embodiment, the frame 6 is constructed so as to be vertically movable by means of the jack J. As shown in FIG. Therefore, it is possible to adjust the height of the frame 6 so as to follow the bending and deformation of the roof frame 3b1. That is, the construction of the frame 6 can be started before the construction and attachment of the outer tank roof 3b are completed, and the work can be performed in parallel. Therefore, it is possible to shorten the construction period of the tank 1 .

In particular, in this embodiment, the base construction process is performed before the roof frame lifting process. Therefore, before lifting the roof frame 3b1, the frame support 6a of the frame 6 can be constructed in parallel, and the tank construction period can be further shortened.

Furthermore, in this embodiment, there is a concrete placing step of placing concrete on the roof frame 3b1. When pouring concrete, it takes time for the concrete to harden, so the construction period tends to be long. However, in the present embodiment, since the frame 6 can be constructed before concrete is poured into the roof frame 3b1, the work can be performed without waiting for the concrete to harden. Therefore, it is possible to effectively shorten the construction period of the tank.

Further, in this embodiment, the height adjusting process is performed by adjusting using a jack J. As shown in FIG. Since the upper portion of the jack J is curved, it is possible to adjust the position not only in the height direction of the frame support 6a but also in the horizontal direction.

Further, in this embodiment, in the post fixing step, the post is fixed to the roof frame 3b1 after the jack J is removed. Therefore, the jack J can be reused, and this construction method does not increase the construction cost.

Although the preferred embodiments of the present invention have been described above with reference to the drawings, the present invention is not limited to the above embodiments. The various shapes, combinations, and the like of the constituent members shown in the above-described embodiment are merely examples, and can be variously changed based on design requirements and the like without departing from the gist of the present invention.

In the above embodiment, the concrete placing step is provided, but the present invention is not limited to this. The present invention can also be applied to a tank having a structure in which concrete is not placed on the outer tank roof portion 3b.

In the above embodiment, the frame building process is performed after the roof frame lifting process, but the present invention is not limited to this. The frame building process may be performed before the roof frame lifting process.

In the above embodiment, the jack J is used to lift the roof frame 3b1 in the roof frame lifting process, but the present invention is not limited to this. For example, the roof frame 3b1 may be lifted by aeration.

1 Tank 2 Base slab 3 Outer tank 3a Outer tank side wall 3b Outer tank roof 3b1 Roof frame 3b2 Pedestal 4 Bottom cold insulation layer 5 Inner tank 5a Inner tank bottom 5b Inner tank side wall 6 Frame 6a Frame support 6b Support 6c Base J Jack

Claims (5)

A construction method for a tank in which a frame is formed on the roof,
a roof lifting step of lifting the roof of the tank vertically upward;
a base construction step of supporting the support columns of the frame from below the roof of the tank and fixing temporary support columns that can be expanded and contracted in the vertical direction;
A construction method for a tank, comprising: a height adjustment step of adjusting the height of the temporary support; and a frame construction step of constructing the frame after the base construction step. 2. The tank construction method according to claim 1, wherein the base construction step is performed before the roof lifting step and the height adjustment step. After the roof lifting step, having a concrete placing step of placing concrete on the roof,
3. The tank construction method according to claim 1, wherein the height adjusting step is performed after the concrete placing step. The roof lifting step is performed using a jack device,
The tank construction method according to any one of claims 1 to 3, wherein the frame construction step is performed after the base construction step and before the roof lifting step. A jack is arranged vertically below the pillar supported by the temporary pillar,
Adjustment of the height of the temporary support in the height adjustment step is performed using the jack,
After the height adjustment step, a fixing step of fixing the support to the roof,
The tank construction method according to any one of claims 1 to 4 , wherein the jack is removed in the fixing step.

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