Water tank structure and method for constructing water tank structure

Abstract

To provide a water tank structure and a method for constructing the water tank structure, which can more reliably ensure watertightness and maintain watertight performance.SOLUTION: The present invention relates to a water tank structure (1) and a construction method for the water tank structure (1), which includes a foundation top waterproof layer (23) formed on leveled concrete (5), a base slab (2) formed on the foundation top waterproof layer (23), side walls (3) erected on a base slab (2), a bottom waterproof layer (22) formed on a top surface of the base slab (2), an outer surface waterproof layer (31) formed on the outer surface of the side walls (3), and an inner surface waterproof layer (32) formed on the inner surface of the side walls (3).SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a water tank structure and a method for constructing the water tank structure. [Background technology]

[0002] Water tanks must be waterproof to prevent the stored water from leaking. In particular, underground water tanks must be able to prevent the stored water from seeping out and also prevent groundwater from seeping in. For example, if water seeps out of the tank or groundwater seeps into the tank, it may be impossible to accurately determine the amount of water in the tank.

[0003] For this reason, water tanks constructed underground may be subjected to a water-stopping treatment during construction to prevent the outflow of stored water and the infiltration of groundwater. For example, in Patent Document 1, a water-stopping layer is formed by coating the inner surface of a concrete structure with a resin material. The resin material of the water tank in Patent Document 1 has a flexible primer layer coated on the surface of the concrete structure and a resin water-stopping layer coated on the primer layer. In the water tank in Patent Document 1, even if the concrete structure is deformed, such as by cracking, the primer layer follows and maintains water-stopping properties. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2016-160572 Summary of the Invention [Problem to be solved by the invention]

[0005] The water-stopping layer formed on the surface of the tank may lose its water-stopping ability due to contact with the stored material or deterioration. If the water-stopping ability of the tank decreases, it must be repaired immediately to prevent the stored material from seeping out and groundwater from seeping in. However, it is difficult to detect the deterioration of the tank's water-stopping ability.

[0006] An object of the present invention is to provide an aquarium structure and a construction method for the aquarium structure that can more reliably ensure watertightness and maintain watertight performance. [Means for solving the problem]

[0007] In order to solve the above problem, the aquarium structure of the present invention comprises a foundation top waterproof layer formed on the top surface of the leveled concrete, a bottom slab formed on the foundation top waterproof layer, side walls erected on the bottom slab, a bottom waterproof layer formed on the top surface of the bottom slab, an outer surface waterproof layer formed on the outer surface of the side walls, and an inner surface waterproof layer formed on the inner surface of the side walls.

[0008] This aquarium structure has a high level of watertightness because waterproof layers are formed on both the inner and outer surfaces of the bottom slab and side walls. Even if the watertight performance of one of the waterproof layers on the inner or outer surfaces of the bottom slab or side walls deteriorates, the watertightness is maintained by the other waterproof layer.

[0009] In addition, the aquarium structure may be formed by having a plurality of precast members connected in one direction, each having a base portion that forms part of the bottom plate and a wall portion that forms part of the side wall, and by interposing a sealing material between adjacent precast members. The water tank structure may also include a top plate disposed above the bottom plate, and a top waterproof layer formed on the upper surface of the top plate.

[0010] The construction of such a water tank structure may be carried out by the following steps: an excavation step of excavating the ground to form a recess; a leveling concrete pouring step of pouring leveling concrete into the bottom of the recess; a foundation waterproofing step of forming a foundation top waterproof layer on top of the leveling concrete; a wall formation step of arranging multiple precast members on the foundation top waterproof layer to form side walls; a base slab formation step of pouring concrete on the foundation top waterproof layer to form a base slab; an inner surface waterproofing step of forming a bottom waterproof layer on the top of the base slab and an inner surface waterproofing layer on the inner surface of the side walls; an outer surface waterproofing step of forming an outer surface waterproofing layer on the outer surface of the side walls; and a backfilling step of filling in the periphery of the side walls. In the base slab formation step, the concrete is poured so as to be integrated with the base. [Effects of the Invention]

[0011] According to the aquarium structure and the construction method for the aquarium structure of the present invention, it is possible to more reliably ensure watertightness and maintain watertight performance. [Brief explanation of the drawings]

[0012] [Figure 1] 1 is a cross-sectional view showing an aquarium structure according to an embodiment of the present invention. [Figure 2] FIG. 1 is a perspective view showing a precast member. [Figure 3] 10 is a flowchart showing the steps of a construction method for a water tank structure. [Figure 4] This is a cross-sectional view showing the construction status of a water tank structure, where (a) is the excavation process, (b) is the leveling concrete pouring process and foundation waterproofing process, and (c) is the wall formation process. [Figure 5] 1A and 1B are cross-sectional views showing the construction status of a water tank structure, in which (a) is the bottom slab forming process, (b) is the top slab forming process, and (c) is the backfilling process. DETAILED DESCRIPTION OF THE INVENTION

[0013] An embodiment of the present invention will be described in detail with reference to the drawings as appropriate. In this embodiment, a water tank structure 1 for storing water formed underground will be described. FIG. 1 shows the water tank structure 1. The water tank structure 1 is formed in a recess 7 formed by excavating the ground G. As shown in FIG. 1, the water tank structure 1 is formed in a box shape with a bottom slab 2, side walls 3, and a top slab 4. The water tank structure 1 is placed on leveling concrete 5 poured on the bottom surface 71 of the recess 7. The water tank structure 1 also has multiple (three in this embodiment) middle walls 30, 30, 30 inside. An upper portion of the water tank structure 1 protrudes from the upper end of the recess 7, and the remaining portion is buried underground.

[0014] A foundation top waterproof layer 23 is formed on the upper surface of the leveling concrete 5. The base slab 2 is formed on the foundation top waterproof layer 23, and the side walls 3 and middle walls 30 are erected on the base slab 2. In this embodiment, the side walls 3 and middle walls 30 are formed from a plurality of precast members 6 arranged in one direction.

[0015] The precast member 6 is shown in Figure 2. As shown in Figure 2, the precast member 6 is made of reinforced concrete and has a base portion 62 that becomes part of the bottom slab 2, and a wall portion 63 that becomes part of the side wall 3 or the middle wall 30. A sealing material 64 is interposed between adjacent precast members 6.

[0016] As shown in Figures 1 and 2, the side wall 3 is formed by wall portions 63 of connected precast members 6. As shown in Figure 1, an outer surface waterproof layer 31 is formed on the outer surface of the side wall 3, and an inner surface waterproof layer 32 is formed on the inner surface of the side wall 3. The side wall precast member 61, which is the precast member 6 that constitutes the side wall 3, has a wall portion 63 erected from one end (outer end) of a base portion 62, and is L-shaped in cross section.

[0017] As shown in FIG. 2 , an insertion hole 65 for inserting a connecting member penetrates the other end (inner end) of the base portion 62 of the side wall precast member 61. A bolt box 66 is formed in the base portion 62, opening at the end surface of the base portion 62 facing the interior space at an axially intermediate portion of the insertion hole 65. A fixing member for fixing the connecting member is provided within the bolt box 66 at a position corresponding to the insertion hole 65. Similarly to the base portion 62, insertion holes 65 for inserting the connecting member penetrate the lower and upper ends of the wall portion 63, and a bolt box 66 is formed at the axial center of the insertion hole 65. The bolt box 66 formed in the lower portion of the wall portion 63 opens to the inner surface of the wall portion 63. Meanwhile, the bolt box 66 (not shown) formed in the upper end of the wall portion 63 opens to the upper surface of the wall portion 63.

[0018] Anchor reinforcement (not shown) protrudes from the end surface of the base portion 62 facing the interior space. The upper end of the wall portion 63 is widened inward to allow the top slab 4 to be placed on it. A sealing material 64 is attached to the axial end surface of the side wall precast member 61 (the boundary surface with another adjacent side wall precast member 61) continuously from the base portion 62 to the wall portion 63. The sealing material 64 is attached at a predetermined distance from the outer surface of the wall portion 63 and the underside of the base portion 62, and is L-shaped when viewed from the front. The sealing material 64 is also attached continuously to the end surface of the base portion 62 facing the interior space (towards the concrete 21).

[0019] 1 and 2, the middle wall 30 is formed by wall portions 63 of connected precast members 6. The middle wall precast member 60, which is the precast member 6 that constitutes the middle wall 30, has the wall portion 63 erected from the center in the width direction of the base portion 62, and has an inverted T-shape in cross section.

[0020] As shown in FIG. 2 , insertion holes 65 for inserting connecting members penetrate through both ends of the base portion 62 of the inner wall precast member 60. A bolt box 66 is formed in the base portion 62 at the axial middle of the insertion hole 65, opening at an end face (the face that abuts against the concrete 21) parallel to the axial direction of the base portion 62. A fixing member for fixing the connecting member is provided within the bolt box 66 at a position corresponding to the insertion hole 65. Similarly to the base portion 62, an insertion hole 65 for inserting the connecting member also penetrates through the upper end of the wall portion 63, and a bolt box 66 is formed at the axial center of the insertion hole 65. The bolt box 66 formed at the upper end of the wall portion 63 opens at the upper surface of the wall portion 63.

[0021] Anchor reinforcement (not shown) protrudes from the end face (contact surface with concrete 21) parallel to the axial direction of base portion 62. The upper end of wall portion 63 is widened to the left and right to accommodate top slab 4. Furthermore, sealing material 64 is provided around the periphery of base portion 62 of middle wall precast member 60 at a predetermined distance from the underside.

[0022] As shown in Figure 1, the base slab 2 is formed in a plate shape by the base portions 62 of the precast members 6 and concrete 21 poured between the base portions 62 of the opposing precast members 6. A bottom waterproof layer 22 is formed on the upper surface of the base slab 2 (the base portions 62 and the concrete 21).

[0023] As shown in Figure 1, the top slab 4 is disposed above the bottom slab 2, and a top waterproof layer 41 is formed on the upper surface of the top slab 4. The top slab 4 is formed of precast top slab members 42, 42, ... that are laid horizontally between the upper ends of the side walls 3 and the upper ends of the middle walls 30. Joints 43 are formed in the gaps between the top slab members 42.

[0024] Next, a construction method for the water tank structure 1 will be described. Figure 3 shows the steps of the construction method for the water tank structure 1. As shown in Figure 3, the water tank structure 1 includes an excavation step S1, a leveling concrete pouring step S2, a foundation waterproofing step S3, a wall formation step S4, a bottom slab formation step S5, an inner surface waterproofing step S6, a top slab formation step S7, an outer surface waterproofing step S8, and a backfilling step S9. Figure 4 shows the excavation step S1 to the foundation waterproofing step S3.

[0025] In the excavation step S1, as shown in FIG. 4(a), the ground is excavated to form a recess 7. In the excavation step S1, first, an earth-retaining wall 72 is formed around the planned construction location of the water tank structure 1. The earth-retaining wall 72 is formed by driving steel pipe sheet piles or steel sheet piles. Next, the area surrounded by the earth-retaining wall 72 is excavated to form the recess 7.

[0026] In the leveling concrete pouring step S2, as shown in FIG. 4(b), leveling concrete 5 is poured on the bottom surface 71 of the recess 7. The leveling concrete 5 is cured until it develops a predetermined strength. In this embodiment, protective mortar and bedding mortar (not shown) are spread on the leveling concrete 5 to make it flat.

[0027] In the foundation waterproofing step S3, as shown in FIG. 4(b), a foundation top waterproof layer 23 is formed on the leveled concrete 5. The foundation top waterproof layer 23 is formed in the area where the aquarium structure 1 will be formed, and has a larger area than the bottom slab 2 so that its edges extend beyond the bottom slab 2 in a plan view. The foundation top waterproof layer 23 is formed by spraying a water-stopping material on top of the bedding mortar. In this embodiment, polyurethane resin is used as the water-stopping material. In this embodiment, the water-stopping material is sprayed multiple times and layers of the water-stopping material are stacked to form a foundation top waterproof layer 23 of a predetermined thickness.

[0028] In the wall formation process S4, a plurality of precast members 6 are connected together on the foundation top waterproof layer 23 to form the side walls 3 and middle walls 30. Adjacent precast members 6 are connected together via connecting members inserted into insertion holes 65 (see FIG. 2). The connecting members are inserted into the insertion holes 65 so as to straddle adjacent precast members 6, and the ends are fixed by fixing members inside bolt boxes 66. In this manner, adjacent precast members 6 are connected together. At this time, a sealing material 64 is interposed between the precast members 6 (see FIG. 2). In this embodiment, a sheath packing is used as the sealing material 64.

[0029] Figure 5 shows the base slab forming step S5 to the backfilling step S9. In the base slab forming step S5, as shown in Figure 5(a), concrete 21 is poured onto the foundation top waterproof layer 23 to form the base slab 2. The concrete 21 is poured between opposing precast members 6 (base portions 62) so as to be integrated with the base portions 62 of the precast members 6. The concrete 21 is poured so as to wrap around the anchor reinforcement protruding from the end faces of the base portions 62.

[0030] In the inner surface waterproofing process S6, a bottom waterproof layer 22 is formed on the upper surface of the bottom slab 2, and an inner surface waterproof layer 32 is formed on the inner surface of the side wall 3. The bottom waterproof layer 22 and the inner surface waterproof layer 32 are formed by spraying a waterproofing material onto the upper surface of the bottom slab 2 and the inner surface of the side wall 3. In this embodiment, polyurethane resin is used as the waterproofing material that makes up the bottom waterproof layer 22 and the inner surface waterproof layer 32. The waterproofing material is applied so that the finished surface is flat. The bottom waterproof layer 22 and the inner surface waterproof layer 32 are applied by first preparing the upper surface of the bottom slab 2 and the inner surface of the side wall 3 and then spraying the waterproofing material. In this embodiment, an epoxy resin is applied as the preparation.

[0031] In the top plate forming step S7, as shown in Figure 5(b), top plate members 42 are laid on the upper ends of the side walls 3 and the middle wall 30 to form the top plate 4. Joints 43 are formed in the gaps between the top plate members 42 so that the upper surface of the top plate 4 is flat.

[0032] In the exterior waterproofing step S8, an exterior waterproof layer 31 is formed on the exterior surface of the side wall 3, and a top waterproof layer 41 is also formed. The exterior waterproof layer 31 is formed by spraying a waterproofing material onto the exterior surface of the side wall 3, and the top waterproof layer 41 is formed by spraying a waterproofing material onto the upper surface of the top slab 4. In this embodiment, polyurethane resin is used as the waterproofing material that constitutes the exterior waterproof layer 31 and the top waterproof layer 41. The waterproofing material is sprayed so that the finished surface is flat. The exterior waterproof layer 31 and the top waterproof layer 41 are constructed by first preparing the exterior surface of the side wall 3 and the upper surface of the top slab 4, and then spraying the waterproofing material. In this embodiment, an epoxy-based resin is applied as the preparation. The exterior waterproofing step S8 may be performed in parallel with the interior waterproofing step S6, or may be performed before the interior waterproofing step S6.

[0033] In the backfilling step S9, as shown in Fig. 5(c), the area around the side wall 3 is backfilled (see Fig. 1). In this embodiment, concrete is poured as backfilling material 73 between the side wall 3 and the retaining wall 72. The backfilling material 73 is backfilled down to the ground surface.

[0034] As described above, the aquarium structure 1 of this embodiment has high water-stopping properties because waterproof layers are formed on both the outer and inner surfaces of the base slab 2 and side walls 3 by the foundation top waterproof layer 23, bottom waterproof layer 22, outer surface waterproof layer 31, and inner surface waterproof layer 32. Furthermore, even if the water-stopping performance of one of the waterproof layers on the outer and inner surfaces of the base slab 2 or side walls 3 deteriorates, the water-stopping properties are maintained by the other waterproof layer.

[0035] Furthermore, the top surface waterproof layer 41 prevents rainwater and the like from penetrating. Since it is formed using precast members 6, the labor required during construction can be reduced and the construction period can be shortened.

[0036] Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and each of the above-described components can be appropriately modified within the scope of the present invention. The upper part of the water tank structure 1 does not necessarily have to protrude above the ground surface. In the above embodiment, the water tank structure 1 is formed using the precast members 6, but the water tank structure 1 may also be formed using cast-in-place concrete.

[0037] The shape and dimensions of the aquarium structure 1 are not limited and may be determined appropriately. Although the aquarium structure 1 of the above embodiment has the middle wall 30, the middle wall 30 may be formed as needed. The top plate 4 may be formed as needed.

[0038] In the above embodiment, the retaining wall 72 is formed, but the retaining wall 72 may be formed as needed. Furthermore, the structure of the retaining wall 72 is not limited to steel sheet piles or steel pipe sheet piles. The material constituting the backfill material 73 is not limited to concrete, and for example, mortar, liquefied soil, soil generated at the site, etc. may also be used as the backfill material 73.

[0039] The material constituting each waterproof layer is not limited to polyurethane resin, and the material constituting the base material is not limited to epoxy resin. Furthermore, the method for forming the waterproof layer is not limited, and the waterproof layer may be formed by coating, for example. [Explanation of symbols]

[0040] 1. Tank structure 2 bottom plate 21 Concrete 22 Bottom waterproof layer 23 Foundation top waterproof layer 3 side wall 30 Middle wall 31 External waterproof layer 32 Inner waterproof layer 4 Top plate 41 Top waterproof layer 42 Top plate member 43 Joint 5. Leveling concrete 6 Precast members 60 Precast members for inner walls 61 Precast members for side walls 62 Base 63 Wall 64 Sealing material 65 Insertion hole 66 Bolt Box 67 Anchor Bar 7. Recess 71 bottom 72 Earth retaining wall 73 Backfill material

Claims

1. A foundation top waterproof layer formed on the leveled concrete; A base plate formed on the top waterproof layer of the foundation; A side wall erected on the bottom plate; A bottom waterproof layer formed on the top surface of the bottom slab; An outer surface waterproof layer formed on the outer surface of the side wall; An aquarium structure characterized by comprising an inner surface waterproof layer formed on the inner surface of the side wall.

2. It has multiple precast members connected in one direction, The precast member has a base portion that becomes part of the bottom slab and a wall portion that becomes part of the side wall, 2. The water tank structure according to claim 1, wherein a sealing material is interposed between adjacent precast members.

3. a top plate disposed above the bottom plate; 2. The aquarium structure according to claim 1, further comprising a top waterproof layer formed on the top surface of the top plate.

4. an excavation step of excavating the ground to form a recess; A leveling concrete pouring process for pouring leveling concrete onto the bottom surface of the recess; A foundation waterproofing process of forming a foundation top waterproof layer on the leveling concrete; a wall forming process in which a plurality of precast members are connected to the foundation top waterproof layer to form a side wall; A bottom slab forming process in which concrete is poured onto the foundation top waterproof layer to form a bottom slab; an inner surface waterproofing process of forming a bottom surface waterproof layer on the upper surface of the bottom slab and forming an inner surface waterproof layer on the inner surface of the side wall; an outer surface waterproofing step of forming an outer surface waterproof layer on the outer surface of the side wall; A backfilling step of backfilling the periphery of the side wall, The precast member has a base portion that becomes part of the bottom slab and a wall portion that becomes part of the side wall, A construction method for a water tank structure, characterized in that in the bottom slab forming step, the concrete is poured so as to be integrated with the base portion.

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