JP2012052349A - Rainwater storage tank and filling structure of rainwater storage tank - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a filling structure of a rainwater storage tank capable of effectively enhancing strength in a horizontal direction using a box-shaped filling component, and a rainwater storage tank using the filling structure of a rainwater storage tank.SOLUTION: A filling structure 18 of a rainwater storage tank 10 comprises a lower stage block assembly 60 and an upper stage block assembly 62 which are formed of a plurality of arranged box type blocks 30 and stacked so as to sandwich a horizontal reinforcement part 50. A plate face part 52 of the horizontal reinforcement part 50 has an outer peripheral rib 54 projecting from each side of the plate face and a reinforcement rib 56. The reinforcement rib 56 has an outer peripheral part 56A with a shape along an opening 34 of the box type blocks 30 in a plan view, and comprises a plurality of linear ribs extending in the depth direction W and a plurality of linear ribs extending in the width direction L to form a lattice inside the outer peripheral part 56A. The reinforcement rib 56 has a continuous shape to form a bridge from one side of the outer peripheral part 56A to the other opposing side in the depth direction and in the width direction.

Description

  The present invention relates to a rainwater storage tank used for storing rainwater or penetrating into the ground, and a rainwater storage tank filling structure constituting the rainwater storage tank.

  In recent years, a large amount of rainwater has been stored underground, and facilities that infiltrate this rainwater into the strata gradually, in order to compensate for the decrease in water retention capacity of the strata especially in urban areas and factory areas. Development of facilities that discharge to rivers over a sufficient amount of time and facilities that pump up stored rainwater and use it as fire prevention water (collectively, these facilities are called “rainwater storage tanks”) are under development. .

  As such a rainwater storage tank, what was described in patent document 1 is known, for example. Patent Document 1 discloses a technique for arranging an underground water storage system by arranging opening portions of box-shaped filling members on the lower side. As described above, when the box-shaped filling member is used, there is a problem that the opening portion of the filling member is easily crushed by the earth pressure in the horizontal direction.

  Therefore, in Patent Document 2, a flat reinforcing material is used in order to reinforce in the horizontal direction. The reinforcing material of Patent Document 2 is provided with a concave portion on the upper and lower surfaces of the reinforcing material to engage a filling member, and is a plate filled with a portion other than the concave portion or a lattice-like plate. Thus, the strength in the horizontal direction can be increased by using the reinforcing material. However, if the portion other than the concave portion of the reinforcing material is a grid-like plate, the strength in the vertical direction is reduced. Further, if the plate other than the concave portion is filled, a large amount of material for the filling member is required.

JP 2008-223418 A JP 2002-235361 A

  The present invention has been made in consideration of the above facts, and when a box-shaped filling member is used, a rainwater storage tank filling structure capable of effectively increasing the strength in the horizontal direction, and It aims at providing the rainwater storage tank using this rainwater storage tank filling structure.

  In order to solve the above-described problem, the rainwater storage tank filling structure according to claim 1 is configured such that an opening is formed on one surface, and an opposing surface of the opening is a box bottom, and the inlet enters the box inside the outer periphery of the side surface. A lower block group configured by arranging a plurality of openings in the box-shaped block, an upper block group configured by arranging a plurality of the openings in the box-shaped block, and the upper block group. And an opening of the upper block group and the lower block group from both sides and a portion corresponding to the contact position of the opening. A horizontal reinforcing member formed with reinforcing ribs extending from one end to the other end of the box and projecting from the plate surface of the plate surface portion.

  In the rainwater storage tank filling structure according to the first aspect, the horizontal reinforcing member is disposed between the lower block group and the upper block group. The horizontal reinforcing member has a plate-like plate surface portion, and openings of the upper block group and the lower block group are brought into contact with the plate surface portion from both sides. A reinforcing rib protruding from the plate surface of the plate surface portion is formed from one end inside the box to the other end of the portion corresponding to the contact position of the opening.

  In this way, by forming the reinforcing rib from the one end inside the box at the contact position of the opening of the box-shaped block to the other end, the opposing surface of the opening is supported by the reinforcing rib, and the horizontal strength is increased. Can be high. Also, since the outer side from the part corresponding to the outer side of the opening of the horizontal reinforcing member is plate-shaped, the strength in the vertical direction of the part with which the opening is abutted compared to the case of the grid shape Can also be maintained. Further, the horizontal reinforcing member can be effectively reinforced by the reinforcing rib without increasing the overall thickness.

  The rainwater storage tank filling structure according to claim 2 is characterized in that the reinforcing ribs are formed in a lattice shape.

  In this way, by forming the reinforcing ribs in a lattice shape, the horizontal direction of the opening can be reinforced in a balanced manner.

  The rainwater storage tank filling structure according to claim 3 further includes a horizontal connector for connecting the adjacent horizontal reinforcing members.

  Thus, the connection of filling members can be strengthened by connecting the horizontal reinforcing members adjacent to each other using a horizontal connector.

  The rainwater storage tank according to claim 4 is provided with a water shielding sheet laid so as to cover an inner surface of a concave pit formed on the ground, and the rainwater storage tank filling according to any one of claims 1 to 3 And a filling structure that is configured by stacking a plurality of structures in the vertical direction and is disposed in the pit via the water shielding sheet.

  According to the rainwater storage tank of claim 4, since the rainwater storage tank filling structure according to any one of claims 1 to 3 is used, a concave pit formed on the ground, that is, formed on the ground. The strength in the horizontal direction can be improved with respect to the filling structure filled in the recessed portion through the water shielding sheet.

  The rainwater storage tank which concerns on Claim 5 is equipped with the up-down connection tool which connects the box bottom parts which the said rainwater storage tank filling structure laminated | stacked by the up-down direction adjoins.

  According to the rainwater storage tank of claim 5, since the box bottoms of the filling members of the lower block group and the upper block group adjacent to each other are connected by the upper and lower connectors, the upper and lower parts of the stacked rainwater storage tank filling structure Directional connection can be strengthened.

  As described above, according to the rainwater storage tank filling structure of the present invention, the opposing surface of the opening is supported by the reinforcing ribs of the horizontal reinforcing member, and the strength in the horizontal direction can be increased. Also, since the outer side from the part corresponding to the outer side of the opening of the horizontal reinforcing member is plate-shaped, the strength in the vertical direction of the part with which the opening is abutted compared to the case of the grid shape Can also be maintained. Further, the horizontal reinforcing member can be effectively reinforced by the reinforcing rib without increasing the overall thickness.

It is sectional drawing which shows typically the structure of the rainwater storage penetration tank which concerns on embodiment of this invention. It is sectional drawing which shows the structure of the water-blocking protective layer in the rainwater storage tank shown by FIG. It is the perspective view seen from the bottom part side which shows the structure of the box-shaped block used for the rainwater storage tank of this invention. It is the perspective view seen from the opening side which shows the structure of the box-shaped block used for the rainwater storage tank of this invention. It is a perspective view which shows the relationship between the several box-shaped block laminated | stacked in this embodiment, and a horizontal reinforcement member. It is a perspective view which shows a part of structure of the filling structure used for the rainwater storage tank of this invention. It is a perspective view which shows the relationship between the several box-shaped block laminated | stacked in this embodiment, and a horizontal reinforcement member. It is a partial cross section figure which shows the connection state in an up-and-down connection tool. It is a partial cross section figure which shows the connection state in a horizontal connector. It is a side view which shows the relationship between the several box-shaped block laminated | stacked and a horizontal reinforcement member. It is a perspective view which shows the modification of the horizontal reinforcement member based on this embodiment.

  Hereinafter, a rainwater storage tank according to an embodiment of the present invention will be described with reference to the drawings.

(Configuration of rainwater storage tank and filling structure)
FIG. 1 schematically shows a rainwater storage tank according to an embodiment of the present invention. As shown in FIG. 1, the rainwater storage tank 10 is embedded in the underground F and includes an inflow rod 12 and an outflow rod 14 as its incidental facilities.

  When the rainwater storage tank 10 shown in FIG. 1 is installed, first, rainwater is collected and a concave pit P is dug from the ground surface of the site to be stored, and the inner surface of the pit P is protected against water. After covering with the layer 16 without a gap, a filling structure 18 having a predetermined volume formed in a substantially rectangular parallelepiped shape is constructed in the pit P covered with the water shielding protective layer 16.

  Next, the top surface side of the filling structure 18 is covered with the water shielding sheet 20 without a gap, and the outside of the filling structure 18 is sealed with the water shielding protective layer 16 and the water shielding sheet 20, and then the filling structure 18 is placed inside. The arranged pits P are backfilled with soil, and the upper side of the filling structure 18 is covered with the soil covering layer 22. In addition, in the site where the rainwater storage tank 10 is installed in the basement, most of the ground surface is usually covered with a non-immersible pavement material such as concrete or asphalt.

  In the site, an inflow dredging 12 formed in a container shape with reinforced concrete is embedded around the rainwater storage tank 10, and an outflow dredging 14 formed in a container shape with reinforced concrete adjacent to the rainwater storage tank 10. Buried. For example, the inflow rod 12 divides the site into a plurality of regions having a predetermined area, and the inflow rod 12 is installed for each region, and rainwater flows into each of the inflow rods 12. Here, the one or more inflow troughs 12 closest to the rainwater storage tank 10 are connected to other inflow troughs 12 through the water conduits 24. As a result, rainwater that has fallen on the entire site is once collected in the inflow trough 12 that is closest to the rainwater storage tank 10.

  One end portion of the inflow pipe 26 is connected to a portion of the inflow rod 12 near the lower end of the side wall portion, and one end portion of the overflow pipe 28 is connected to the upper side of the connection portion with the inflow pipe 26 in the side wall portion. . The other end side of the inflow pipe 26 passes through the water shielding protective layer 16 and communicates with the inside of the rainwater storage tank 10, and the other end portion of the overflow pipe 28 is connected to a portion near the upper end of the side wall portion of the outflow raft 14. ing.

  One end portion of the orifice pipe 25 is connected to the lower end portion of the side wall portion of the outflow soot 14, and one end portion of the overflow pipe 27 is connected to the upper end portion of the side wall portion. The other ends of the orifice pipe 25 and the overflow pipe 27 are connected to drainage paths such as water pipes connected to rivers, rivers, etc., drainage culverts, and sewers, respectively. Here, the rainwater overflowed from the rainwater storage tank 10 flows into the spillway 14 and is temporarily stored. In addition, the orifice pipe 25 has a function as an orifice for restricting the flow rate of rainwater flowing out from the inside of the outflow basin 14 to the drainage path.

  As shown in FIG. 2, the water shielding protective layer 16 has a three-layer structure including an outer protective mat 16A, a water shielding sheet 20, and an inner protective mat 16B. The outer protective mat 16A and the inner protective mat 16B are made of non-woven fabric having a sufficient flexibility, using polyester short fibers as raw materials. The outer protective mat 16 </ b> A and the inner protective mat 16 </ b> B protect the filling structure 18 and the water shielding sheet 20 from loads caused by earth pressure and the weight of the filling structure 18 by alleviating stress concentration.

  The filling structure 18 of the rainwater storage tank 10 is formed by laminating a lower block group 60 and an upper block group 62 (see FIG. 6) in which a plurality of box-shaped blocks 30 shown in FIG. It is configured. Details of the lower block group 60, the upper block group 62, and the horizontal reinforcing member 50 will be described later.

(Configuration of box block)
As a molding material of the box-shaped block 30, polyolefin resin such as polypropylene (PP) and polyethylene (PE) (especially high density polyethylene (HDPE)) is used in terms of chemical stability, mechanical strength, and price. preferable. Here, the melt flow rate (MFR) (JIS K7210) of the resin is preferably 10 (F / 10 minutes) to 15 (F / 10 minutes) in consideration of workability and mechanical strength. Moreover, you may improve light resistance by adding 1-3% of carbon black as a filler to these. In addition, since an installation place is not a place where it becomes high temperature, an antioxidant may not be added. Further, FRP based on unsaturated polyester may be used.

  The box-shaped block 30 is formed in a hollow container shape. The thickness of the box-shaped block 30 is set to 2 mm to 3 mm in consideration of the weight per product, mechanical strength, and the like. The box block 30 can be formed by an injection molding method.

  As shown in FIG. 3 and FIG. 4, the box-shaped block 30 is formed in a substantially rectangular parallelepiped box shape (hollow container shape) as a whole. A cylindrical side plate 32 is formed in the box-shaped block 30, and a bottom plate 40 that closes the bottom side of the side plate 32 is integrally formed. As shown in FIG. 4, the box-shaped block 30 has an opening 34 formed by opening a box surface facing the bottom plate 40, and has an L-shaped cross section extending from the lower end of the side plate 32 to the outer peripheral side. Thru | or the J-shaped folding | returning part 34A is formed over the perimeter. Here, the box-shaped block 30 is substantially rectangular with the width direction (arrow L direction) as a longitudinal direction in plan view, and the dimension along the width direction is the dimension along the depth direction (arrow W direction). It has doubled.

  The box-shaped block 30 is formed with a cove portion 38 in which the side plate 32 is recessed toward the inside of the box. A total of eight inlets 38 are formed, one on each of two sides in the width direction (arrow L direction) and one on two sides in the depth direction (arrow W direction). By forming the inlet 38, the side plate 32 has an outer surface 38A that constitutes the outer peripheral surface of the box-shaped block 30, an inner surface 38B that is substantially U-shaped in plan view on two side surfaces in the width direction L, and An arcuate curved surface portion 38C is formed on two side surfaces in the depth direction W in plan view. In addition, a space 38R is formed in the inlet 38 in the vertical direction, and an inlet connecting plate 35 is provided on the opening 34 side of the space 38R formed on the two side surfaces in the width direction L. The inlet connection plate 35 is provided so as to connect the lower ends of the side plates 32 at the inlet portion 38. A hole 35 </ b> A is formed in the inlet connecting plate 35.

  On the side of the opening 34 in the vertical direction of the side plate 32, a plate-like rib 36 is provided so that the plate surface is substantially orthogonal to the folded portion 34A. In the present embodiment, a portion (convex portion) in which the inlet 38 in the depth direction W is not formed, one in each square of the side plate 32 and one in the side plate 32 of the inlet 38 formed in the depth direction W. ), A total of 26 are provided, one at a time, and two at a portion (convex portion) where the inlet 38 in the width direction L is not formed. The ribs 36 may be provided at other positions, or may be provided in a number smaller than 26.

  The bottom plate 40 is formed with a substantially rectangular center plate portion 42 extending elongated along the symmetry line CL1, and a cover plate portion 44 extending from the center plate portion 42 to the end of the outer surface portion 38A is integrally formed. Is formed. These cover plate portions 44 close the other surface side of the box-shaped block 30 as the bottom plate 40 of the portion where the inlet portion 38 is not formed.

  The lid plate portion 44 is disposed at a position protruding from the center plate portion 42 to the outside of the box-shaped block 30. Accordingly, the bottom plate 40 is formed with standing wall portions 43 along the width direction L at both ends in the depth direction W of the center plate portion 42. Thus, each of the standing wall portions 43 rises at a substantially right angle with respect to the center plate portion 42, and the upper end thereof coincides with the upper surface of the lid plate portion 44.

  In the box-shaped block 30, by forming the inlet portion 38 on the side plate 32, a large number of corner portions are formed by the side plate 32, the corner portions function as reinforcing ribs against an external load, and the side plate 32 forms irregularities. Compared with the case where it is formed in a flat plate shape that is not made, a high strength is secured against an external load.

  In the center plate portion 42 of the bottom plate 40, four openings 42B are formed in a rectangular shape along the width direction L, and a plurality of openings 44B are formed in the lid plate portion 44. The openings 42 </ b> B and 44 </ b> B formed in the box-shaped block 30 in this way have good water permeability to the inside and outside of the box-shaped block 30, whereby the filling structure 18 constituted by the box-shaped block 30. Water permeability to the inside and outside is also improved.

  In addition, the upper and lower connecting holes 44 </ b> A are formed in four of the lid plate portions 44 provided in the squares of the box-shaped block 30. As shown in FIG. 8, the upper and lower connecting holes 44A have a large-diameter taper T on the outside.

(Configuration of horizontal reinforcing member)
As shown in FIG. 5, the horizontal reinforcing member 50 has a substantially rectangular plate shape, and as shown in FIG. The plate surface portion 52 is formed with an outer peripheral rib 54 and a reinforcing rib 56 protruding from each side of the plate surface. The outer peripheral rib 54 is formed along the outer periphery of the plate surface portion 52, and a gap S is formed at the center in the width direction L and the depth direction W. The reinforcing rib 56 has a shape in which an outer peripheral portion 56A is formed along the opening 34 of the box-shaped block 30 in a plan view, and a plurality of linear ribs extending in the depth direction W on the inner side of the outer peripheral portion 56A, and a width A plurality of linear ribs extending in the direction L are formed in a lattice shape. In the depth direction W and the width direction L, the reinforcing rib 56 has a continuous shape extending from one side of the outer peripheral portion 56A to the opposite side.

  A holding groove 58 that holds the box-shaped block 30 by fitting the opening 34 of the box-shaped block 30 is formed between the outer peripheral rib 54 and the outer peripheral portion 56 </ b> A of the horizontal reinforcing member 50. In a portion corresponding to the inlet portion 38 formed along the width direction L of the holding groove 58, an inlet holding portion 58A into which the inlet connecting plate 35 can be fitted is configured. In the inlet holding portion 58A, a hole 58B is formed at a position corresponding to the hole 35A of the inlet connecting plate 35. An outer plate portion 58 </ b> C is configured at a portion corresponding to the inlet portion 38 formed along the depth direction W of the holding groove 58. A hole 58D is formed in the outer plate portion 58C.

(Lower block group and upper block group)
As shown in FIG. 6, the lower block group 60 is configured by arranging a plurality of box-shaped blocks 30 in the horizontal and vertical directions with the opening 34 facing upward. The upper block group 62 includes a plurality of box-shaped blocks 30 arranged in a horizontal and vertical direction with the opening 34 facing downward. A horizontal reinforcing member 50 is disposed between the lower block group 60 and the upper block group 62. As shown in FIG. 7, each box-shaped block 30 of the lower block group 60 has an opening 34 fitted into a holding groove 58 on one side (lower surface side) of the horizontal reinforcing member 50 so as to contact the plate surface portion 52. The horizontal movement is restricted and held. Also, for each box-shaped block 30 of the upper block group 62, the opening 34 is fitted into the holding groove 58 on the other surface side (upper surface side) of the horizontal reinforcing member 50 and is brought into contact with the plate surface portion 52, so that the horizontal direction Movement is restricted and held.

  As shown in FIG. 9, the horizontal reinforcing members 50 adjacent to each other in the horizontal direction are connected by a horizontal connector 64. The horizontal connector 64 has a shape in which both ends of a long plate member are bent at a substantially right angle to form a bent portion 64A. With respect to the horizontal reinforcing members 50 adjacent to each other in the depth direction W, as shown in FIG. 9A, the horizontal coupling member 64 is bent in the state where the horizontal reinforcing member 50 is disposed on the box-shaped block 30. The box-shaped block 30 in which the other bent portion 64A is adjacent to the hole 58B and the depth direction W of the horizontal reinforcing member 50 so that the portion 64A penetrates the hole 58B of the horizontal reinforcing member 50 and the hole 35A of the box-shaped block 30 from above. It is attached so as to penetrate the hole 35A from above.

  Further, for the horizontal reinforcing members 50 adjacent in the width direction L, as shown in FIG. 9B, the horizontal coupler 64 is configured outside the curved surface portion 38C of the box-shaped block 30 adjacent in the width direction L. The recessed portion and the hole 58D of the horizontal reinforcing member 50 are attached so as to penetrate from above.

  Thereby, the horizontal reinforcement members 50 adjacent to each other in the depth direction W and the width direction L are restricted from moving in a direction away from each other, and are connected. The horizontal coupler 64 may be provided only in one of the depth direction W and the width direction L.

  As shown in FIG. 10, a lower block group 60, a horizontal reinforcing member 50, and an upper block group 62 are sequentially stacked on the upper block group 62. Lamination of the lower block group 60 to the upper block group 62 is performed by overlapping the cover plate portions 44 of the box-shaped blocks 30, and the upper and lower box-shaped blocks 30 are connected by the upper and lower connecting members 66. As shown in FIG. 8, the upper and lower coupling member 66 is configured such that a substantially conical insertion portion 66 </ b> A is abutted at the bottom with the flange 66 </ b> B interposed therebetween.

  When connecting the upper and lower box-shaped blocks 30 to each other, first, one insertion portion 66A side is inserted into the upper and lower connection holes 44A of the box-shaped blocks 30 of the upper block group 62 from the upper side. As a result, the upper and lower couplers 66 are in a state in which the flange portion 66B is supported by the tapered portion T and the upper half protrudes upward from the lid plate portion 44. The protruding portion (upper half) of the upper and lower coupling tool 66 is inserted into the upper and lower coupling hole 44A of the box-shaped block 30 of the lower block group 60, and the box-shaped block 30 is stacked. Thereby, the upper and lower box-shaped blocks 30 are connected.

(Method for constructing filling structure and rainwater storage tank)
Next, a method for constructing the filling structure 18 in the pit P whose inner surface is covered with the water shielding protective layer 16 will be described. When the filling structure 18 is constructed using the box-shaped blocks 30, the box-shaped blocks 30 are arranged via the water-blocking protective layer 16.

  An operator who constructs the filling structure 18 arranges a lower block group 60 that is the lowermost layer (first stage) of the filling structure 18. The lower block group 60 has a plurality of box-shaped blocks 30 arranged so that the opening 34 faces upward and the width direction L and the depth direction W are in the same direction so as to contact each other. Cover the entire bottom.

  Next, the worker arranges the same number of horizontal reinforcing members 50 as the box-shaped blocks 30 on the lower block group 60. The horizontal reinforcing member 50 is disposed while fitting the opening 34 of the box-shaped block 30 into the lower holding groove 58. Then, the horizontal reinforcing members 50 adjacent to each other in the width direction L and the depth direction W are connected by the horizontal connector 64.

  Next, the worker arranges the upper block group 62 on the horizontal reinforcing member 50 in a stacked manner. The upper block group 62 has a plurality of box-shaped blocks 30 with the opening 34 facing downward, and the box blocks 30 and the openings 34 of the lower block group 60 are associated with each other so that the upper block group The opening 34 of the box-shaped block 30 is fitted into the holding groove 58.

  Next, the worker places the lower block group 60 on the upper block group 62 in a stacked manner. The lower block group 60 is formed by laminating a plurality of box-shaped blocks 30 with the opening 34 facing upward, and the box-shaped blocks 30 and the cover plate portions 44 of the upper block group 62 corresponding to each other. At this time, the upper and lower box-shaped blocks 30 are connected by the upper and lower connecting members 66 with the cover plate portion 44 interposed therebetween.

  Further, in the same manner as described above, the horizontal reinforcing member 50, the upper block group 62, and the lower block group 60 are repeatedly stacked on top of each other, and stacked by the number of steps corresponding to the depth of the pit P (rainwater storage tank 10). Thus, the filling structure 18 is constructed in the pit P.

  After the construction of the filling structure 18 in the pit P, the operator covers the upper surface side of the filling structure 18 with the water shielding sheet 20 without gaps, and after performing necessary piping work and the like, The upper soil layer 22 is formed by refilling the upper side with soil. The ground surface of the site is paved with a paving material such as concrete or asphalt as necessary, or a block or the like is laid.

(Operation of rainwater storage tank)
Next, the effect | action of the rainwater storage tank 10 comprised as mentioned above is demonstrated.

  In the site where the rainwater storage tank 10 is installed, when it rains, rainwater once flows into the inflow trough 12 from the ground surface of the site, and the rainwater stored in the inflow trough 12 passes through the inflow pipe 26 in the rainwater storage tank 10. Flow into. At this time, if the water level in the inflow trough 12 becomes higher than the connection part of the overflow pipe 28, the rain water in the inflow trough 12 flows out directly to the outflow trough 14 through the overflow pipe 28 and prevents the rain water from overflowing from the inflow trough 12. ing.

  Rainwater that has flowed into the rainwater storage tank 10 flows out from the rainwater storage tank 10 to the outflow rod 14 through an orifice (not shown) provided between the rainwater storage tank 10 and the outflow rod 14. The orifice restricts the flow rate of water so that the flow rate of rainwater balances with the flow rate of rainwater in the orifice pipe 25 connected to the spillway 14. Moreover, when rainwater exceeding the amount of rainwater outflow from the rainwater storage tank 10 continuously flows into the rainwater storage tank 10 and the rainwater storage tank 10 becomes nearly full, the rainwater in the rainwater storage tank 10 overflows into the outflow basin 14. In addition, overflow of rainwater from the rainwater storage tank 10 is prevented.

  Rainwater that has flowed into the spillway 14 flows out through the orifice pipe 25 to a drainage channel such as a water pipe, drainage culvert, and sewer, and is finally discharged into a river, the sea, or the like. When rainwater exceeding the amount of rainwater flowing through the orifice pipe 25 continuously flows into the outflow basin 14 and the outflow basin 14 becomes nearly full, the rainwater in the outflow basin 14 flows out through the overflow pipe 27 to the drainage path, Rainwater is prevented from overflowing from the inside of the spillway 14.

  According to the rainwater storage tank 10 as described above, by setting the internal volume according to the site area, the rain that has fallen on the site does not flow directly from the ground surface into the river, sewage, etc. After storing the corresponding amount of rainwater in the rainwater storage tank 10, rainwater can be drained from the rainwater storage tank 10 to the river, sewage, etc. Even in the case of heavy rain, it is possible to prevent rainwater exceeding the allowable flow volume from flowing into the river and sewage, and effectively prevent flooding such as flooding and flooding.

  Moreover, in this embodiment, since the horizontal reinforcement member 50 is provided, the horizontal strength in the opening 34 of the hollow box-shaped block 30 can be reinforced, and the collapse against the earth pressure in the horizontal direction is suppressed. be able to.

  In the present embodiment, the reinforcing rib 56 of the horizontal reinforcing member 50 is formed from one end side to the other end side of the portion corresponding to the inside of the opening portion 34 of the box-shaped block 30, so The opposing surface is supported, and the collapse of the opening 34 with respect to the earth pressure in the horizontal direction can be effectively suppressed.

  Further, in the present embodiment, the reinforcing ribs 56 of the horizontal reinforcing member 50 are formed in a lattice shape at a portion corresponding to the inside of the opening 34 of the box-shaped block 30, and therefore receive horizontal earth pressure in a balanced manner. Can do.

  Moreover, in this embodiment, since the horizontal reinforcement member 50 has the plate | board surface part 52, compared with the case where the whole horizontal reinforcement member is formed with the mesh-shaped rib, the intensity | strength with respect to the earth pressure of a perpendicular direction Can also be maintained.

  In addition, the filling structure 18 constituting the rainwater storage tank 10 according to the present embodiment is such that the openings 34 of the box-shaped block 30 face each other in the vertical direction, or the cover plate portions 44 of the box-shaped block 30 are arranged with each other. They are stacked to face each other. Therefore, the strength against the pressure in the vertical direction can be increased at the boundary between the upper and lower box-shaped blocks 30. Moreover, in the boundary part laminated | stacked so that the cover plate parts 44 may face each other, a horizontal reinforcement member becomes unnecessary and can reduce a number of members.

  In the present embodiment, the horizontal reinforcing member 50 is integrally formed in a rectangular plate shape corresponding to the opening 34 of one box-shaped block 30, but as shown in FIG. You may comprise by the 2 member divided into 2 parts.

DESCRIPTION OF SYMBOLS 10 Rainwater storage tank 20 Water-impervious sheet 30 Box-shaped block 34 Opening part 38 Cove part 50 Horizontal reinforcement member 52 Plate surface part 54 Peripheral rib 56 Reinforcement rib 60 Lower block group 62 Upper block group 64 Horizontal connector 66 Vertical connector P Pit

Claims (5)

An opening is formed on one side and a box-shaped block in which an opposing surface of the opening is a box bottom and a cove portion is formed on the outer periphery of the side is formed inside the box. Lower block group,
An upper block group configured by arranging a plurality of the openings of the box-shaped blocks downward,
The openings of the upper block group and the lower block group are abutted from both sides to a plate-shaped plate surface portion arranged between the upper block group and the lower block group, and the contact position of the opening portion A horizontal reinforcing member formed with reinforcing ribs projecting from the plate surface of the plate surface portion extending from one end to the other end inside the box corresponding to
Rainwater storage tank filling structure with   The rainwater storage tank filling structure according to claim 1, wherein the reinforcing ribs are formed in a lattice shape.   The rainwater storage tank filling structure according to claim 1, further comprising a horizontal connector that connects the horizontal reinforcing members adjacent to each other. A water shielding sheet laid so as to cover the inner surface of the concave pit formed on the ground;
A plurality of rainwater storage tank filling structures according to any one of claims 1 to 3 are stacked in a vertical direction, and a filling structure disposed in a pit via the water shielding sheet;
Rainwater storage tank with   The rainwater storage tank of Claim 4 provided with the upper-lower connection tool which connects the adjacent box bottom parts of the said rainwater storage tank filling structure laminated | stacked by two or more up and down directions.

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