JP6502186B2 - Wall and wall construction method - Google Patents

Description

  The present invention relates to walls and wall construction methods.

  A PC (prestressed concrete) tank may be used as equipment for storing liquids such as LNG (liquefied natural gas) and LPG (liquefied petroleum gas) (see, for example, Patent Document 1).

  FIG. 8 shows an example of an LNG tank 100 storing LNG as a PC tank. In the LNG tank 100, a concrete liquid barrier 6 is fixedly provided on the bottom plate 5 supported by the pile 4 in the ground 7, and the inner tank 3a and the outer tank 3b of steel plate etc. are provided inside thereof. is there. LNG is stored in the inner tank 3a, and a heat insulating material is disposed between the inner tank 3a and the outer tank 3b to perform cooling.

  The liquid barrier 6 is a wall provided to prevent liquid leakage to the outside of the LNG when the inner tank 3a is broken, and is generally cylindrical. The liquid barrier 6 needs to have a structure capable of withstanding the hydraulic pressure of the LNG, so that prestress due to circumferential and vertical tendons (not shown) is introduced.

  Although the hydraulic pressure can be resisted by introducing prestress in the circumferential direction to the liquid barrier 6, the liquid barrier 6 is always in a state where no hydraulic pressure is applied from inside the tank. Therefore, in the bottom portion of the liquid-proof dike 6, the bending moment in the inward direction is added by the prestress in the circumferential direction, and the stress may be concentrated to cause a crack or the like. As a measure to suppress this, the bottom of the liquid protection embankment 6 is often widened outward as compared to the upper part thereof. By providing additional tension in the vertical direction in this widened portion to introduce prestress, the bottom of the liquid break ember 6 can be reinforced.

JP, 2006-83572, A

  FIG. 9 (a) schematically shows the vicinity of the bottom of the liquid break embankment 6. As shown in FIG. FIG.9 (b) shows the cross section of the horizontal direction by line AA of Fig.9 (a). The liquid barrier 6 has a shape in which the bottom portion is expanded in a step-like manner to the outside as compared with the upper portion thereof. In addition, the liquid barrier 6 is cylindrical as described above, and the outer peripheral surface 61 of the bottom portion and the outer peripheral surface 62 of the upper portion of the bottom portion are circumferential in plan view. The inner circumferential surface 63 of the liquid protection dike 6 is also circumferential.

  When constructing the liquid barrier 6, it is necessary to prepare an outer frame having a curvature according to the outer diameter of the liquid barrier 6 at the time of placing concrete, but this outer frame is another It can not be diverted to the liquid bank 6, and the efficiency is poor. Furthermore, in the case where the bottom of the liquid barrier 6 is widened, it is necessary to prepare another outer frame having a curvature different between the bottom and the upper part of the single liquid barrier 6.

  An object of the present invention is to provide a wall etc. which can be built efficiently.

A first invention for solving the above-mentioned problems is a cylindrical wall made of concrete, wherein the wall has an inner peripheral surface having a substantially circumferential shape and an outer peripheral surface having a substantially regular polygonal shape. Ah it is, the bottom of the wall has a shape which is widened outwardly with respect to portions of the upper, outer peripheral surface of the bottom portion of the wall body is substantially regular polygonal shape of the enlarged outer peripheral surface portion of the upper a wall body, wherein Rukoto Do and.

Before Kigaishu surface is preferably substantially icosahedral triangle or a substantially regular polygonal shape.

The second invention is a wall construction method for constructing a cylindrical tubular wall made of concrete, wherein the inner peripheral surface has a substantially circumferential shape by casting concrete between the inner mold and the outer mold. And the outer form has a curved surface corresponding to a part of the approximate circumference of the inner peripheral surface of the wall, formwork, have a plane corresponding to the linear portion of the substantially regular polygonal outer peripheral surface of the wall, the bottom of the wall is a widened shape on the outside with respect to portions of the upper, the the outer peripheral surface of the bottom portion of the wall is a wall construction wherein the Rukoto a substantially regular polygon of an enlarged outer peripheral surface portion of the upper.

As the outer frame of the concrete after casting before SL upper portion, it is desirable to divert the outer formwork of the concrete after casting of the bottom of the wall.
Furthermore, the outer frame may have a variable mechanism that the width is variable, the variable mechanism is preferably a hinge that allows folding the end portion of the outer frame.

The third invention is a wall construction method for constructing a cylindrical wall made of concrete, which comprises arranging a precast block made of concrete in the circumferential direction of the wall and laminating the same in the vertical direction. The wall is constructed such that the surface is substantially circumferential and the outer circumferential surface is substantially regular polygon, and the precast block corresponds to a part of the substantially circumferential of the inner circumferential surface of the wall on the inner side surface has a curved surface, have a plane corresponding to the linear portion of the substantially regular polygonal outer peripheral surface of the wall on the outer side surface, the bottom of the wall body, a shape which is widened outwardly with respect to portions of the upper and has an outer peripheral surface of the bottom portion of the wall is a wall construction wherein the Rukoto a substantially regular polygon of an enlarged outer peripheral surface portion of the upper.
According to a third aspect of the present invention, there is provided a method of constructing a wall according to the third aspect of the present invention, wherein the precast is performed by placing concrete on a form having a bottom surface having a curved surface corresponding to a part of a substantially circumference of the inner circumferential surface of the wall and a side surface It is also desirable to have the process of making blocks. It is also desirable to change the depth at which the concrete is cast in the formwork at the time of producing the precast block at the bottom of the wall and at the time of producing the precast block in the upper part thereof.

  In the present invention, by forming the outer peripheral surface of the cylindrical wall into a substantially regular polygonal shape, the outer form frame at the time of placing the concrete may be a planar one, and the outer form frame may be It can be diverted by changing the width etc. As described above, in the present invention, the conversion efficiency of the outer form is high, and it is not necessary to prepare another form entirely due to the difference in curvature as in the case where the outer peripheral surface of the wall is substantially circumferential. On the other hand, the inner circumferential surface of the wall is substantially circumferential, and the necessary inner space can be suitably secured. Also in the case where the wall is constructed by a precast block, the block formwork form can be commonly used when constructing various walls, and the wall can be efficiently constructed.

  Further, in the present invention, even when the wall thickness changes midway in the vertical direction, diversion of the outer form is easy, and the construction can be rationalized. If the above-mentioned variable mechanism is provided in the outer form, diversion is further improved. Also in the case where the wall is constructed of a precast block, a block making form can be commonly used in the same manner as described above. Further, by making the outer peripheral surface of the wall body into a substantially regular polygonal shape having a substantially regular icosagon or more, the outer peripheral surface can be brought close to the circumference, and the amount of extra concrete in design can be reduced.

  According to the present invention, it is possible to provide a wall that can be efficiently built.

Diagram showing the liquid break 2 Figure showing the vicinity of the bottom 201 of the liquid breakwater 2 Diagram showing the construction of the liquid barrier 2 Figure showing the outer formwork 301 ', 301 " Diagram showing the liquid breakwater 2 ' A diagram showing the vicinity of the bottom portion 201 of the liquid dike 2a Diagram showing formwork 400 Diagram showing the LNG tank 100 Diagram showing the liquid break 6

  Hereinafter, preferred embodiments of the present invention will be described in detail based on the drawings.

First Embodiment
(1. Liquid break 2)
FIG. 1 is a view showing a liquid protection dike 2 according to a first embodiment of the present invention. Fig.1 (a) is a figure which shows the structure of the perpendicular direction of the liquid protection dike 2, FIG.1 (b) is a cross section of the horizontal direction of the liquid diversion 2 in the position of line aa of Fig.1 (a) FIG.

  In the present embodiment, the liquid barrier 2 is a liquid barrier of the LNG tank 1 and is a cylindrical wall made of concrete. The configuration of the LNG tank 1 other than the liquid barrier 2 is the same as that described with reference to FIG.

  As shown to Fig.1 (a), the bottom part 201 of the liquid-proof dike 2 becomes a shape which expanded outside with respect to the intermediate part 202 which is the upper part. In the present embodiment, the top portion 203 of the liquid protection dike 2 also has a shape that is widened outward with respect to the lower middle portion 202.

  The liquid barrier 2 has a pseudo-cylindrical shape, and the bottom surface 201, the middle portion 202, and the outer peripheral surfaces 21, 22 and 23 of the top portion 203 have a substantially regular polygonal shape approximate to a circumference in plan view. On the other hand, the inner circumferential surface 24 of the liquid protection dike 2 is substantially circumferential in plan view. The following description will be mainly made on the bottom portion 201 and the middle portion 202 of the liquid-proof wall 2. The configuration of the top portion 203 is substantially the same as that of the bottom portion 201, and thus will not be described in the following.

  FIG. 2A is a view schematically showing the vicinity of the bottom portion 201 of the liquid dike 2. As shown in FIG. The bottom portion 201 of the dike 2 widens in a step-like manner outward with respect to the middle portion 202.

  FIG.2 (b) is a figure which shows the cross section of the horizontal direction by line bb of FIG. 2 (a). The outer peripheral surfaces 21 and 22 of the liquid protection dike 2 are defined as a substantially regular polygonal shape circumscribing the circumferential outer peripheral surface (shown by a dotted line) in the case of designing the liquid protection dike as a cylindrical shape.

  Therefore, in the corner portions 21a and 22a of the outer peripheral surfaces 21 and 22, extra concrete is required for the circumferential outer peripheral surface. Therefore, it is desirable that the outer peripheral surfaces 21 and 22 be approximated to the circumference as a substantially regular polygonal shape with a large number of angles to reduce the amount of unnecessary concrete. For example, the outer peripheral surfaces 21 and 22 may have a substantially regular polygonal shape having a substantially regular icosagon or more. In the present embodiment, the outer peripheral surfaces 21 and 22 have a substantially regular quadrilateral shape.

  For example, in the case of an outer peripheral surface having a cylindrical shape with an inner diameter of 80 m and a wall thickness of 0.7 m, the increment of concrete can be suppressed to about 12% of the original amount.

(2. Construction method of the liquid protection dike 2)
In the present embodiment, the liquid dike 2 is constructed of cast-in-place concrete. Therefore, when constructing the liquid barrier 2, first, the outer frame 301 and the inner frame 303 are disposed on the bottom plate 5, as shown in the left view of FIG. Cast 201 concrete.

  After casting the concrete of the bottom portion 201, the outer mold frame 301 and the inner mold frame 303 are moved upward and arranged as shown in the right view of FIG. 3 (a). The outer formwork 301 is disposed inside of the bottom portion 201 when concrete is cast. The inside means the center side of the tank, and the opposite is called the outside. The movement of the outer mold frame 301 and the inner mold frame 303 is performed by a slide device (not shown) or the like. Thereafter, concrete is cast between the outer mold frame 301 and the inner mold frame 303.

  After the concrete is cast, the outer mold 301 and the inner mold 303 are moved upward, and concrete is cast again between the outer mold 301 and the inner mold 303. By repeating this, concrete placement in the middle portion 202 is sequentially performed from the bottom.

  FIG. 3 (b) shows the arrangement of the outer mold frame 301 and the inner mold frame 303 from the top, and the left figure shows the concrete casting of the bottom part 201 and the right figure shows the concrete casting of the middle part 202. Show.

The outer mold frame 301 has a plane corresponding to the straight part of the substantially regular polygon of the outer peripheral surfaces 21 and 22 (see FIG. 2 (b)) of the liquid protection dike 2 on the inner side surface.
The inner formwork 303 has a curved surface corresponding to a part of the substantially circumference of the inner circumferential surface 24 (see FIG. 2B) of the liquid-proof dam 2 on the outer side surface.

  The outer formwork 301 and the inner formwork 303 are disposed along the circumferential direction of the liquid protection dike 2 with their surfaces facing each other.

  However, the outer peripheral surface 22 of the middle portion 202 of the liquid-repellent embankment 2 is on the inner side compared with the outer peripheral surface 21 of the bottom portion 201, and has a substantially regular polygon shape obtained by reducing the substantially regular polygon of the outer peripheral surface 21. Therefore, the width c ′ required for the outer form 301 at the time of concrete placing of the middle part 202 is slightly shorter than the width c required for the outer form 301 at the time of concrete placing at the bottom part 201. Here, the width refers to the length along the circumferential direction of the liquid protection dike 2.

  Therefore, in the present embodiment, for example, an end portion in the width direction of the outer mold frame 301 at the time of putting concrete in the bottom portion 201 is cut and diverted as the outer mold frame 301 at the time of putting concrete in the middle portion 202 A variable mechanism may be provided on the outer frame.

  An example thereof is an outer mold frame 301 'shown in FIG. 4A, and the outer mold frame 301' is hinged at an end portion 301a to be foldable. The end portion 301a is not folded back at the time of placing concrete at the bottom portion 201, but at the time of placing concrete at the intermediate portion 202, the end portion 301a can be folded back and the width can be shortened as shown in the figure below.

  4 (b) is provided with one or a plurality of detachable end members 301b, and is used in a state where the end members 301b are attached when concrete is placed on the bottom portion 201. When casting the intermediate portion 202, as shown in the figure below, part or all of the end members 301b can be removed and the width can be shortened.

  After concrete placement of the middle part 202, concrete placement of the top part 203 is performed. Since the outer peripheral surface 23 of the top 203 is outside the outer peripheral surface 22 of the middle 202 (see FIG. 1 (a)), when concrete is placed on the top 203, the concrete casting of the middle 202 is reversed. The outer formwork having a width greater than that of the outer formwork 301 at the time of installation may be disposed outside the concrete placement of the intermediate portion 202 and used. In the case of using an outer frame having a variable mechanism which makes the width variable, the width can be increased and diverted.

  Although illustration is omitted, the above-mentioned circumferential and vertical tendons, additional tendons and the like are also embedded in the concrete of the liquid barrier 2, and the tension of the respective tendons causes the liquid barrier 2 to be prestressed. To complete the construction of the dike 2.

  As described above, according to the present embodiment, by forming the outer peripheral surface of the liquid-proof dike 2 into a substantially regular polygonal shape, the outer form frame 301 at the time of putting concrete may be flat, and the liquid-proof dike Even when the size of 2 is different, it can be diverted by changing the width of the outer mold frame 301 or the like. As described above, in the present embodiment, the divertability of the outer mold frame 301 is high, and it is not necessary to prepare a completely different mold frame due to the difference in curvature as in the case where the outer peripheral surface of the liquid protection dike has a circumferential shape. Furthermore, the shape of the outer mold frame 301 itself is simple and the manufacturing cost is low. On the other hand, the inner peripheral surface of the liquid protection dike 2 has a substantially circumferential shape, and the inner space necessary for the tank can be suitably secured.

  Although it is ideal in terms of stress that the outer peripheral surface of the liquid protection embankment 2 is a strict regular polygon close to the circumference, in the case where the liquid protection embankment 2 has a prestressed concrete structure, the outer peripheral surface is peripheral It is necessary to arrange several fixing parts (pilaster parts) of direction tension material in the circumferential direction. It may be practically difficult to make the side length on which the pilaster portion is arranged the same as the side length of the other side. Even in such a case, in the present invention, the outer peripheral surface of the liquid-proof dike 2 does not have to be strictly a regular polygon, but taking into consideration the constraints of the actual structural form, etc. It is possible to

  Further, in the present embodiment, the wall thickness of the liquid protection dike 2 changes midway in the vertical direction, but even in this case, diversion of the outer mold frame 301 is possible, and the construction can be rationalized. If the above-described variable mechanism is provided in the outer mold, diversion is further improved. Furthermore, by making the outer peripheral surface of the liquid-proof dike 2 into a substantially regular dodecagonal shape or more, the outer peripheral surface can be brought close to the circumference, and the amount of extra concrete in design can be reduced.

  However, the present invention is not limited to this. For example, although the example which constructs the liquid barrier 2 of the LNG tank was shown in this embodiment, the application range of the present invention is not limited to the liquid barrier 2 of the LNG tank, but the cylindrical wall included in various structures. It is possible to apply to the body. It is also possible to eliminate prestressing due to the tendon.

  Further, in the present embodiment, one outer mold frame 301 is used per one side of the substantially regular polygon of the outer peripheral surface of the liquid protection embankment 2, but plural outer mold frames may be used side by side for one side. Is also possible. At the time of conversion of the outer formwork, the width of the outer formwork may be changed or the number of outer formwork used side by side may be changed according to the difference in the scale of the liquid-proof dike 2 or the like.

  Furthermore, in the present embodiment, the widening portion of the bottom portion 201 is one step, but it is also possible to widen in a plurality of steps. Further, even if the outer circumferential surface 21 'of the bottom portion 201 is inclined downward in a straight line to widen as it goes downward as shown in the liquid-proof dike 2' in FIG. It is applicable.

  Next, a second embodiment of the present invention will be described. The second embodiment will be mainly described in terms of differences from the first embodiment, and the same points will be denoted by the same reference symbols in the drawings and the like, and the description will be omitted.

Second Embodiment
Fig.6 (a) is a figure which shows typically the bottom part 201 vicinity of the liquid protection dike 2a which concerns on 2nd Embodiment. FIG. 6 (b) is a diagram showing a horizontal cross section taken along line d-d of FIG. 6 (a).

  As in the first embodiment, the bottom portion 201 of the liquid-proof dike 2a is shaped so as to be expanded stepwise outward with respect to the intermediate portion 202 which is the upper portion thereof. As in the first embodiment, the top (not shown) of the liquid-proof dike 2a is also widened outward with respect to the lower middle portion 202, but the configuration of the top is substantially the same as that of the bottom portion 201. It is the same and will be omitted in the following description.

  In the present embodiment, the liquid protection dike 2a is constructed by arranging concrete precast blocks (hereinafter referred to as blocks) in the circumferential direction of the liquid protection dike 2a and vertically laminating them. Although illustration is omitted, the above-mentioned circumferential and vertical tendons, additional tendons, etc. are disposed through a sheath pipe (not shown) in the block, and the tension of each tendon causes the liquid dike 2a to Stress is introduced.

  200 a in the figure is a block used for the bottom portion 201, and 200 b is a block used for the middle portion 202. Each of the blocks 200a and 200b has a plane corresponding to the straight part of the substantially regular polygon of the outer peripheral surface 21 or 22 of the liquid-repellent dike 2a on the outer side surface, It has a curved surface corresponding to a part on the inner side.

  Similar to the first embodiment, the outer peripheral surfaces 21 and 22 of the liquid-repellent dike 2a have a substantially regular forty-eight shape, and 48 blocks 200a and 200b are arranged side by side in the circumferential direction of the liquid-repellent dike 2a.

  The upper and lower blocks 200a and 200b are arranged in alignment with the inner side surface. The block 200b is thinner than the block 200a, and as shown in FIG. 6B, the width e 'of the outer side surface of the block 200b is slightly shorter than the width e of the outer side surface of the block 200a. Further, both end surfaces in the width direction of the blocks 200a and 200b are slightly tapered in such a manner as to converge at the center of the tank.

  FIG. 7A shows a mold 400 at the time of manufacturing the blocks 200a and 200b. In the formwork 400, the bottom surface 402 is a curved surface corresponding to a part of the approximate circumference of the inner circumferential surface 24 of the liquid-repellent dike 2a, and the side surface 401 has an inclination corresponding to the above-described tapered shape.

  By pouring concrete to the position shown by the line f1 in the formwork 400, the block 200a is manufactured as shown in FIG. 7 (b), and by placing concrete to the position shown by the line f2, which is lower than that. As shown in FIG. 7C, a block 200b is manufactured. Thus, the blocks 200a and 200b having different thicknesses and outer side surfaces can be manufactured by the mold 400. In addition, the above-mentioned sheath tube (not shown) etc. are arrange | positioned in the formwork 400 before casting of concrete.

  In addition, it is possible to change the widths of the inner and outer side surfaces of the block and the inclinations of both end surfaces in the width direction of the block by inserting side members as shown by dotted lines 401 '. In addition to the wall thickness, it is possible to cope with the case where the number of angles of the substantially regular polygon of the outer peripheral surface of the liquid protection dike 2a is different.

  As described above, even in the case where the liquid protection dike 2a is constructed of a precast block, the common formwork 400 can be used for various liquid protection dikes 2a having different wall thicknesses and the like, and the number of the formwork 400 is significantly increased. As a result, the liquid barrier 2a can be constructed efficiently. Furthermore, even when the wall thickness of the liquid protection dike 2a changes in the middle in the vertical direction, the block formwork 400 can be used in common.

  Although the preferred embodiments of the present invention have been described above with reference to the accompanying drawings, the present invention is not limited to such examples. It is apparent that those skilled in the art can conceive of various modifications or alterations within the scope of the technical idea disclosed in the present application, and of course these also fall within the technical scope of the present invention. It is understood.

2, 2 ', 2a, 6; liquid-proof walls 21, 21', 22, 23, 61, 62; outer peripheral surface 24, 63; inner peripheral surface 200a, 200b; precast block 201; bottom 202; 301, 301 ′, 301 ′ ′; outer frame 303; inner frame 400; frame

Claims (7)

It is a cylindrical wall made of concrete,
The wall has an inner peripheral surface is substantially circular, Ri substantially regular polygon der outer peripheral surface,
The bottom of the wall is widened outward with respect to the upper part thereof,
Wall of the outer peripheral surface of the bottom portion of said wall, characterized in Rukoto a substantially regular polygon of an enlarged outer peripheral surface portion of the upper. A wall construction method for constructing a concrete cylindrical wall, comprising:
By placing concrete between the inner mold and the outer mold, the wall whose inner circumferential surface is substantially circumferential and whose outer circumferential surface is substantially regular polygonal is constructed.
The inner formwork has a curved surface corresponding to a part of the substantially circumference of the inner peripheral surface of the wall,
The outer frame may have a plane corresponding to the linear portion of the substantially regular polygonal outer peripheral surface of the wall,
The bottom of the wall is widened outward with respect to the upper part thereof,
Wall construction method the outer peripheral surface of the bottom portion of said wall, characterized in Rukoto a substantially regular polygon of an enlarged outer peripheral surface portion of the upper. As the outer frame of the concrete after casting before SL upper portion, wall building method according to claim 2, characterized in that diverting outer molds concrete after casting of the bottom of the wall. The outer frame may have a variable mechanism that the width is variable,
The wall construction method according to claim 2 or 3 , wherein the variable mechanism is a hinge capable of folding an end of the outer mold frame . A wall construction method for constructing a concrete cylindrical wall, comprising:
By arranging the precast blocks made of concrete in the circumferential direction of the wall and laminating in the vertical direction, the wall whose inner circumferential surface is substantially circumferential and whose outer circumferential surface is substantially regular polygonal is constructed.
The precast block is
The inner side surface has a curved surface corresponding to a part of the approximate circumference of the inner circumferential surface of the wall,
Have a plane corresponding to the linear portion of the substantially regular polygonal outer peripheral surface of the wall to the exterior side surface,
The bottom of the wall is widened outward with respect to the upper part thereof,
Wall construction method the outer peripheral surface of the bottom portion of said wall, characterized in Rukoto a substantially regular polygon of an enlarged outer peripheral surface portion of the upper. The method further includes the step of manufacturing the precast block by casting concrete in a mold frame having a bottom surface having a curved surface corresponding to a part of the substantially circumference of the inner circumferential surface of the wall and a side surface. The wall construction method according to claim 5. 7. The method according to claim 6, wherein the depth at which the concrete is cast in the form is changed between the time of producing the precast block at the bottom of the wall and the time of producing the precast block of the upper part thereof. Wall construction method.

Images