JP6389411B2 - Concrete structure, method for forming concrete structure, structure - Google Patents

Description

  The present invention relates to a concrete structure having a concrete portion and a steel plate.

  A PC (prestressed concrete) tank is a facility for storing liquids such as LNG (liquefied natural gas) and LPG (liquefied petroleum gas). FIG. 7 shows an example of an LNG tank 100 that stores LNG as a PC tank. The LNG tank 100 of FIG. 7 is provided with a liquid breakwater 2 on a bottom slab 5 supported by a pile 4 in the ground 7, and an inner tank 3 a and an outer tank 3 b made of steel plates or the like are installed on the inside. The roof portion of the outer tub 3b is made of steel or reinforced concrete, and the inner side of the side portion of the outer tub 3b has a shape in which a steel liner plate is attached to the liquid barrier 2. 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 cold insulation.

  The breakwater 2 is a concrete side wall provided to prevent leakage of LNG to the outside when the inner tank 3a is damaged, and is generally cylindrical. The breakwater 2 needs to have a structure capable of withstanding the hydraulic pressure of LNG, and therefore prestress is introduced by tension of a tension material (not shown) in the circumferential direction and the vertical direction.

  In order to construct the breakwater 2 efficiently, various methods using a precast (PCa) member have been proposed. For example, when the precast member is assembled to construct the breakwater 2, the concrete placement of the breakwater 2 can be omitted. In addition, by attaching a steel plate to the precast member in advance, it is possible to save labor for constructing the breakwater 2 that forms the side portion of the outer tub 3b.

  FIG. 8 is a diagram showing a precast block 10 (hereinafter referred to as a block 10) which is an example of a precast member. FIG. 8A is a vertical section of the block 10, and FIG. 8B is a diagram showing the anchor arrangement on the plate 12. FIG. 8A is a cross-section at a position along the line aa in FIG.

  In this block 10, one surface of a steel plate 12 is arranged along a block main body 11 (hereinafter referred to as a main body 11) made of concrete. In the main body 11, a sheath tube (not shown), a reinforcing bar (not shown) and the like for passing a tendon are also provided.

  A large number of headed studs 13 are welded and attached to the plate 12 as fixed anchors, and these headed studs 13 are embedded in the main body 11. The headed stud 13 prevents the plate 12 from being separated from the main body 11 or being displaced in a direction parallel to the surface of the plate 12 (hereinafter referred to as a surface direction). As the fixed anchor, L-shaped steel or the like can be used in addition to the headed stud 13.

  Patent Documents 1 and 2 describe examples in which a headed stud is provided in a steel material and the headed stud is embedded in a concrete member. In Patent Documents 1 and 2, by providing a delayed-setting type synthetic resin mortar around the shaft portion of the headed stud, the effect of the steel material restraining the concrete against deformation due to shrinkage at the time of hardening of the concrete is affected. Make it smaller.

  In order to construct the breakwater 2, the block 10 is carried into the site, and then the block 10 is assembled vertically and horizontally with the plate 12 inside as shown in FIG. In this way, the liquid breakwater 2 is constructed, and a tension material (not shown) is tensioned through the sheath tube in the main body 11 to introduce prestress into the liquid breakwater 2. Then, the sides of the plates 12 of the adjacent blocks 10 are welded together to form the side portion of the outer tub 3b.

JP 2001-11938 A Japanese Patent Laid-Open No. 2002-4475

  FIG. 10A shows a cross section in the vicinity of the weld connection portion 14 between the sides of the plate 12. FIG. 10B shows the weld connection 14 together with the anchor arrangement on the plate 12 as in FIG. 8B.

  In the vicinity of the weld connection portion 14 of the plate 12, the plate 12 is once exposed to a high temperature of about 1500 ° C. due to heat at the time of welding, and then returns to the normal temperature.

  The outermost headed stud 13 of the plate 12 is disposed at the end of the plate 12 and is located close to the weld connection 14. Since the displacement in the surface direction of the plate 12 is constrained at the position of the headed stud 13, the above contraction is within a short range D (for example, a range of about 25 cm) between the outermost headed studs 13 of both plates 12. And a large tensile stress is generated on the plate 12 in this range D.

  Therefore, a large residual tensile stress remains on the outer peripheral portion of the plate 12, and in some cases, measures such as increasing the plate thickness of the plate 12 are required. In addition, weld cracks may occur. The methods of Patent Documents 1 and 2 did not consider the influence of shrinkage during plate welding.

  An object of this invention is to provide the concrete structure etc. which can reduce the tensile stress of the plate by the shrinkage | contraction after welding.

1st invention for solving the subject mentioned above is a concrete structure which has a concrete part and the steel plate arrange | positioned by matching one surface to the said concrete part, Comprising: The fixing provided in the said plate An anchor part and a movable anchor part are embedded in the concrete part, the fixed anchor part is provided near a center part of the surface, and the movable anchor part is provided outside the fixed anchor part on the surface, structure der the plate is allowed to displace to the surface in a direction parallel to said concrete portion is, the movable anchor portion is obtained by inserting a runner attached to the plate in the groove of the guide rail, wherein guide rails, are arranged radially from the central portion near the surface is a concrete structure characterized Rukoto.
2nd invention is a concrete structure which has a concrete part and the steel plate arrange | positioned by matching one surface to the said concrete part, Comprising: The fixed anchor part provided in the said plate and the movable anchor part are the said Embedded in the concrete portion, the fixed anchor portion is provided near the center of the surface, the movable anchor portion is provided outside the fixed anchor portion on the surface, and the plate is The movable anchor portion is a structure in which a runner attached to the plate is inserted into a groove of a guide rail, and a headed stud is provided outside the guide rail. It is a concrete structure characterized by being provided.
3rd invention is a concrete structure which has a concrete part and the steel plate arrange | positioned by aligning one surface to the said concrete part, Comprising: The fixed anchor part provided in the said plate and the movable anchor part are the said Embedded in the concrete portion, the fixed anchor portion is provided near the center of the surface, the movable anchor portion is provided outside the fixed anchor portion on the surface, and the plate is The movable anchor portion is a structure in which a headed stud attached to the plate is inserted into an internal space of the housing, and the side surface of the headed stud is It is provided apart from the inner surface of the housing, and a headed stud is provided outside the housing. That is a concrete structure.

In the third invention, it is also desirable that a ring-shaped elastic member is provided on the side surface of the headed stud attached to the plate .

According to a fourth aspect of the present invention, concrete is placed on one surface of a steel plate, and a fixed anchor portion and a movable anchor portion provided on the plate are embedded in the concrete portion. A structure provided near the center of the surface, and the movable anchor portion is provided outside the fixed anchor portion in the surface, and allows the plate to be displaced in a direction parallel to the surface with respect to the concrete portion. der is, the movable anchor portion is obtained by inserting a runner attached to the plate in the groove of the guide rail, said guide rail, characterized in Rukoto arranged radially from the central portion near the surface This is a method for forming a concrete structure.
According to a fifth aspect of the present invention, concrete is placed on one surface of a steel plate, and a fixed anchor portion and a movable anchor portion provided on the plate are embedded in the concrete portion. A structure provided near the center of the surface, and the movable anchor portion is provided outside the fixed anchor portion in the surface, and allows the plate to be displaced in a direction parallel to the surface with respect to the concrete portion. The movable anchor portion is formed by inserting a runner attached to the plate into a groove of a guide rail, and a stud with a head is provided outside the guide rail. Is the method.
According to a sixth aspect of the present invention, concrete is placed on one surface of a steel plate, and a fixed anchor portion and a movable anchor portion provided on the plate are embedded in the concrete portion. A structure provided near the center of the surface, and the movable anchor portion is provided outside the fixed anchor portion in the surface, and allows the plate to be displaced in a direction parallel to the surface with respect to the concrete portion. The movable anchor portion is a headed stud attached to the plate inserted into an internal space of the housing, and a side surface of the headed stud is provided apart from an inner side surface of the housing, It is a method for forming a concrete structure characterized in that a headed stud is provided on the outside of a housing.

A seventh invention is a cylindrical structure in which the concrete structure according to any one of the first to third inventions is used, wherein the plates are arranged inside, and the sides of adjacent plates are welded together. It is a structure characterized by being joined.

  In the present invention, when the temperature drops after welding of the plates, the movable anchor portion located near the weld connection portion does not restrain the displacement of the plate. Therefore, the contraction when the temperature of the plates decreases is generated within the long distance between the fixed anchor portions near the center of both plates, and the contraction amount per unit length is reduced and is generated in the plates. Tensile stress can be greatly relaxed. Therefore, no large residual tensile stress remains on the outer periphery of the plate, no measures such as increasing the plate thickness are required, and no weld cracks are generated on the plate.

  The present invention can provide a concrete structure or the like that can reduce the tensile stress of a plate due to shrinkage after welding.

Diagram showing block 10a Diagram showing production of block 10a The figure which shows the welding connection part 14 between plates 12 The figure which shows the block 10b The figure which shows the block 10c The figure which shows the precast formwork 10d and the breakwater 2b Diagram showing LNG tank 100 Diagram showing block 10 Diagram showing breakwater 2 The figure which shows the welding connection part 14

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings.

[First embodiment]
FIG. 1 is a view showing a precast block 10a (hereinafter referred to as a block 10a) which is a concrete structure according to the first embodiment of the present invention. FIGS. 1A and 1B are views showing a vertical section of the block 10a, and FIG. 1C is a view showing an anchor arrangement on the plate 12. FIG. FIGS. 1A and 1B show cross sections at positions indicated by lines AA and BB in FIG. 1C, respectively.

  Similarly to the block 10 (see FIG. 8), the block 10a is a structure in which one surface of a steel plate 12 is aligned with a main body 11 (concrete portion) made of concrete. Similarly to the above, a sheath tube (not shown), a reinforcing bar (not shown) and the like for passing a tension material are embedded in the main body 11. However, the block 10a of the present embodiment is different from the block 10 in the anchor arrangement on the plate 12.

  That is, in the present embodiment, the fixed anchor portion 20 by the headed stud 13 is provided in the vicinity of the center portion on the above-described surface of the plate 12, and the movable anchor portion 21 is provided outside the fixed anchor portion 20.

  The movable anchor portion 21 has a structure that allows the plate 12 to be displaced in the surface direction with respect to the main body 11. The movable anchor portion 21 includes a runner 13a, a guide rail 15, a headed stud 16, and the like.

  The runner 13a has the same shape as the headed stud 13, and has a shaft portion and a head portion that is wider than the shaft portion. The shaft portion of the runner 13a is attached to the plate 12 by welding.

  The guide rail 15 has a groove 152 having a substantially C-shaped cross section that opens to the plate 12 side. The runner 13 a is inserted into the groove 152 of the guide rail 15. The runner 13 a has a shaft portion passed through a slit-like opening on the lower surface of the groove 152 and a head portion disposed in the groove 152. The width of the head is larger than the width of the opening. The runner 13a is movable along the guide rail 15 in the surface direction of the plate 12 indicated by the arrow d.

  As shown in FIG. 1C, a plurality of guide rails 15 are arranged radially from the vicinity of the central portion of the plate 12, and one or a plurality of runners 13 a are inserted into each guide rail 15. Further, a plurality of headed studs 16 are attached to the outside of each guide rail 15, whereby the guide rail 15 is firmly fixed to the concrete of the main body 11.

  In order to manufacture the block 10a at the factory, as shown in FIG. 2 (a), a fixed anchor portion 20 with a headed stud 13 is provided near the center of one surface, and a runner 13a, a guide rail 15, The plate 12 provided with the movable anchor portion 21 by the headed stud 16 is disposed.

  Then, as shown in FIG. 2 (b), the concrete of the main body 11 is placed on the surface of the plate 12. A fixed anchor portion 20 and a movable anchor portion 21 are embedded in the concrete. A sheath tube (not shown) is also embedded in the concrete of the main body 11. Thus, the block 10a is manufactured.

  As in FIG. 9, the block 10 a is arranged in the vertical and horizontal directions with the plates 12 arranged inside, and the sides of the plates 12 of the adjacent blocks 10 a are welded to each other, whereby the cylindrical liquid barrier 2 of the LNG tank 100 is connected. (Structure) can be constructed as a side part of the outer tub 3b. In the liquid breakwater 2, circumferential and vertical tension members are arranged through the sheath tube in the main body 11, and prestress due to tension of the tension members is also introduced.

  FIG. 3 shows the weld connection portion 14 between the sides of the plate 12 in the same manner as in FIG. In the present embodiment, unlike the block 10, the movable anchor portion 21 (runner 13 a, guide rail 15, headed stud 16, etc.) located at a position close to the weld connection portion 14 when the temperature of the plates 12 is lowered after welding. ) Does not restrain the displacement of the plate 12.

  Therefore, the contraction when the temperature of the plates 12 is reduced occurs in a long distance range D (for example, a range of about 2-3 m) between the fixed anchor portions 20 (headed studs 13) in the vicinity of the center portions of both plates 12. As a result, the amount of shrinkage per unit length is reduced, and the tensile stress generated in the plate 12 can be greatly relieved.

  Therefore, in this embodiment, a large residual tensile stress does not remain on the outer peripheral portion of the plate 12, and measures such as increasing the plate thickness of the plate 12 are unnecessary, and no weld cracks are generated in the plate 12. . Further, the work after the on-site assembly of the block 10a is only the welding of the plate 12, so that the work can be greatly shortened, and the construction period at the time of construction of the liquid barrier 2 can be shortened. The guide rail 15 is firmly fixed to the concrete of the main body 11 by the headed stud 16.

  However, the present invention is not limited to this. For example, in this embodiment, the breakwater 2 of the LNG tank 100 is constructed by the block 10a, but the present invention is not limited to this. For example, it can be used when constructing the side walls of various tanks.

[Second Embodiment]
FIG. 4 is a diagram showing a precast block 10b (hereinafter referred to as a block 10b) which is a concrete structure according to the second embodiment. 4A and 4B are views showing a cross section in the vertical direction of the block 10b, and FIG. 4C shows an anchor arrangement on the plate 12. FIG. 4 (a) and 4 (b) show cross sections at the positions of line CC and line DD in FIG. 4 (c), respectively.

  This embodiment differs in the structure of the movable anchor part 21a compared with 1st Embodiment. That is, the movable anchor portion 21a of the present embodiment includes the headed studs 13b and 16, the housing 17, and the like.

  The headed stud 13b, like the headed stud 13 and the runner 13a, has a shaft part and a head part that is wider than the shaft part, and the shaft part is attached to the plate 12 by welding.

  The housing 17 has an internal space 172, and a hole 171 leading to the internal space 172 is provided on the surface on the plate 12 side. The headed stud 13 b is inserted into the internal space 172 of the housing 17. The shaft portion of the headed stud 13 b is passed through the hole 171, and the head portion is disposed in the internal space 172. The width of the head is larger than the width of the hole 171.

  The widths of the hole 171 and the internal space 172 are larger than the width of the shaft portion and the head portion of the headed stud 13b, respectively, and the side surfaces of the head portion and the shaft portion of the headed stud 13b are respectively inside the housing 17. The space 172 is separated from the inner surface of the hole 171. Around the head of the headed stud 13b in the internal space 172, a rubber ring 18 which is a ring-shaped elastic member is disposed.

  A headed stud 16 is provided outside the housing 17 in the same manner as described above, whereby the housing 17 is firmly fixed to the concrete of the main body 11.

  Also in the second embodiment, the headed stud 13b is movable in the surface direction of the plate 12 indicated by the arrow d, and the movable anchor portion 21a allows the plate 12 to be displaced in the surface direction with respect to the main body 11. It becomes. Therefore, the second embodiment can provide the same effects as those of the first embodiment.

[Third embodiment]
FIG. 5 is a diagram showing a precast block 10c (hereinafter referred to as a block 10c) which is a concrete structure according to the third embodiment. 5A and 5B are views showing a cross section in the vertical direction of the block 10c, and FIG. 5C shows the anchor arrangement on the plate 12. FIG. FIGS. 5A and 5B show cross sections at the positions of line EE and line FF in FIG. 5C, respectively.

  This embodiment differs in the structure of the movable anchor part 21b compared with 1st, 2nd embodiment. That is, in the present embodiment, the movable anchor portion 21b includes the headed stud 13c and the rubber tube 19 (cylindrical elastic member).

  The headed stud 13c has a shaft portion and a head having a width wider than the shaft portion, like the headed studs 13 and 13b and the runner 13a, and the shaft portion is attached to the plate 12 by welding.

  The rubber tube 19 is a cylindrical elastic member fitted around the shaft portion of the headed stud 13c. The thickness of the rubber tube 19 is, for example, about 5 mm. One end of the rubber tube 19 in the axial direction is in contact with the plate 12.

  In the third embodiment, since the shaft portion of the headed stud 13c can bend and deform in the surface direction of the plate 12 indicated by the arrow d in the rubber tube 19, the movable anchor portion 21b is formed so that the plate 12 faces the main body 11. The structure allows displacement in the direction. Therefore, the third embodiment can provide the same effects as those of the first embodiment.

[Fourth Embodiment]
The concrete structure of the fourth embodiment is a precast formwork at the time of placing concrete. FIG. 6A shows the precast form 10d. The precast mold 10d is configured by aligning one surface of a steel plate 12 with a concrete mold body 11a (concrete member).

  As in any of the first to third embodiments, the plate 12 is provided with a fixed anchor portion and a movable anchor portion, and is embedded in the concrete of the mold body 11a.

  As shown in FIG. 6 (a), in this embodiment, at the time of construction of the breakwater 2a, the precast form 10d is arranged vertically and horizontally so that the inside becomes the plate 12, and the cast-in-place concrete 22 is provided on the outside. To cast. The concrete 22 is placed, for example, in several lots in the height direction.

  After introducing prestress by a tension material (not shown) in the circumferential direction and the vertical direction of the liquid barrier 2a, the sides of the plates 12 of the adjacent precast formwork 10d are welded together. In this way, the liquid breakwater 2a which formed the plate 12 of the side part of the outer tank 3b inside is built.

[Fifth Embodiment]
The concrete structure of the fifth embodiment is a liquid breakwater constructed using the plate 12 as a remaining formwork. FIG.6 (b) is a figure which shows this liquid breakwater 2b.

  At the time of construction of the breakwater 2b, the steel plate 12 is arranged vertically and horizontally to form a formwork, and cast-in-place concrete 22 is placed on the outside thereof. As in any of the first to third embodiments, a fixed anchor portion and a movable anchor portion are provided on the surface of the plate 12 on the concrete 22 (concrete member) side, and are embedded in the concrete 22 of the liquid barrier 2b. The The concrete 22 is placed, for example, in several lots in the height direction.

  When prestress by a tension material (not shown) is introduced in the circumferential direction and the vertical direction of the liquid barrier 2b and the sides of the vertical and horizontal plates 12 are welded and connected, the side portion of the outer tub 3b is formed inside. The liquid bank 2b is constructed.

  Also in the fourth and fifth embodiments described above, the anchor arrangement of the plate 12 is the same as that of any of the first to third embodiments, and thus the same effects as those described in the first embodiment can be obtained.

  The preferred embodiments of the present invention have been described above with reference to the accompanying drawings, but the present invention is not limited to such examples. It will be apparent to those skilled in the art that various changes or modifications can be conceived within the scope of the technical idea disclosed in the present application, and these are naturally within the technical scope of the present invention. Understood.

2, 2a, 2b; breakwater 3a; inner tub 3b; outer tub 4; pile 5; bottom slab 7; ground 10, 10a, 10b, 10c; precast block 10d; precast form 11; block body 11a; 12; Plates 13, 13b, 13c, 16; Stud 13a with head; Runner 14; Weld connection 15; Guide rail 17; Housing 18; Rubber ring 19; Rubber tube 20; Fixed anchor part 21, 21a, 21b; Part 22; Cast-in-place concrete

Claims (8)

A concrete structure having a concrete portion and a steel plate arranged on one side of the concrete portion,
The fixed anchor portion and the movable anchor portion provided in the plate are embedded in the concrete portion,
The fixed anchor portion is provided near the center of the surface,
Said movable anchor portion is provided on the outside of the stationary anchor portion in the surface, Ri structures der that the plate is allowed to displace to the surface in a direction parallel to said concrete portion,
The movable anchor portion is a runner attached to the plate inserted into a groove of a guide rail,
The guide rails, concrete structure characterized Rukoto arranged radially from the central portion near the surface. A concrete structure having a concrete portion and a steel plate arranged on one side of the concrete portion,
The fixed anchor portion and the movable anchor portion provided in the plate are embedded in the concrete portion,
The fixed anchor portion is provided near the center of the surface,
Said movable anchor portion is provided on the outside of the stationary anchor portion in the surface, Ri structures der that the plate is allowed to displace to the surface in a direction parallel to said concrete portion,
The movable anchor portion is a runner attached to the plate inserted into a groove of a guide rail,
The outside guide rails, concrete structure characterized Rukoto headed stud is provided. A concrete structure having a concrete portion and a steel plate arranged on one side of the concrete portion,
The fixed anchor portion and the movable anchor portion provided in the plate are embedded in the concrete portion,
The fixed anchor portion is provided near the center of the surface,
Said movable anchor portion is provided on the outside of the stationary anchor portion in the surface, Ri structures der that the plate is allowed to displace to the surface in a direction parallel to said concrete portion,
The movable anchor part is obtained by inserting a headed stud attached to the plate into the internal space of the housing,
A side surface of the headed stud is provided apart from an inner side surface of the housing;
Outside the housing, the concrete structure characterized Rukoto headed stud is provided. The concrete structure according to claim 3, wherein a ring-shaped elastic member is provided on a side surface of the headed stud attached to the plate . Concrete is placed on one surface of a steel plate, and a fixed anchor portion and a movable anchor portion provided on the plate are embedded in the concrete portion,
The fixed anchor portion is provided near the center of the surface,
Said movable anchor portion is provided on the outside of the stationary anchor portion in the surface, Ri structures der that the plate is allowed to displace to the surface in a direction parallel to said concrete portion,
The movable anchor portion is a runner attached to the plate inserted into a groove of a guide rail,
The guide rail, the method of forming the concrete structure characterized Rukoto arranged radially from the central portion near the surface. Concrete is placed on one surface of a steel plate, and a fixed anchor portion and a movable anchor portion provided on the plate are embedded in the concrete portion,
The fixed anchor portion is provided near the center of the surface,
Said movable anchor portion is provided on the outside of the stationary anchor portion in the surface, Ri structures der that the plate is allowed to displace to the surface in a direction parallel to said concrete portion,
The movable anchor portion is a runner attached to the plate inserted into a groove of a guide rail,
The outside of the guide rails, the method of forming the concrete structure characterized Rukoto headed stud is provided. Concrete is placed on one surface of a steel plate, and a fixed anchor portion and a movable anchor portion provided on the plate are embedded in the concrete portion,
The fixed anchor portion is provided near the center of the surface,
Said movable anchor portion is provided on the outside of the stationary anchor portion in the surface, Ri structures der that the plate is allowed to displace to the surface in a direction parallel to said concrete portion,
The movable anchor part is obtained by inserting a headed stud attached to the plate into the internal space of the housing,
A side surface of the headed stud is provided apart from an inner side surface of the housing;
Outside the housing, the method of forming the concrete structure characterized Rukoto provided headed studs. A cylindrical structure in which the concrete structure according to any one of claims 1 to 4 is used,
The plate is arranged inside,
A structure characterized in that the sides of adjacent plates are joined together by welding.

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