JP5791287B2 - Rainwater storage facility - Google Patents

Description

  The present invention relates to a rainwater storage facility provided under a ground such as a park, a parking lot, or a road.

  Rainwater that falls on residential areas and roads is discharged into rivers through side ditches and drainage grooves with little penetration into the ground, but if a large amount of rainfall such as torrential rain occurs in a short time, Flooding causes traffic paralysis. For this reason, rainwater storage facilities have been provided under the ground such as parks, parking lots, or roads from the past, and when a large amount of rainfall occurs, rainwater is temporarily returned to this rainwater storage facility through side grooves and drainage grooves. It is done to store.

  As such a rainwater storage facility, for example, as described in Patent Document 1, a resin block body having an internal space for storing rainwater in a water storage recess formed by digging the ground vertically and horizontally. A water storage tank is formed by laying and stacking in multiple stages, and the water storage tank is covered with a laminated covering material such as a sheet material or a paving material. It is introduced and stored in the tank. At this time, if solids such as earth and sand and stone flow into the water tank together with rainwater, these solids may accumulate on the bottom of the water tank, reducing the volume of water that can be stored, and clogging the drain pipes and the like. In addition, it is difficult to remove the solid matter accumulated at the bottom of the water tank.

  For this reason, in this Patent Document 1, by providing a small sand settling tank adjacent to the water storage tank, the rainwater from the side ditch or drainage ditch is once introduced into the sand settling tank and the stones contained in the rainwater A relatively large solid material such as gravel is settled and removed, and a U-shaped partition wall is disposed on the rainwater inlet side in the water storage tank so as to surround the rainwater inlet side. A settling tank part is formed by laminating the above block bodies in a set of four in a flat rectangular shape in multiple layers and providing a work hole penetrating vertically in the center of these laminated block bodies By allowing the rainwater to overflow from the settling tank into the water storage tank while sedimenting fine components called sediment and silt that could not be removed by the sand settling tank provided adjacent to the water storage tank. Like It is configured.

Japanese Patent No. 4163088

  However, according to such a rainwater storage facility, since the sedimentation tank portion is formed adjacent to the rainwater inlet, the strength tends to be insufficient with respect to the side earth pressure from the inlet, such as during an earthquake. Since the partition wall is arranged in a plane U shape so as to enclose the inflow port side, rainwater that has flowed into this storage tank is from three sides of the partition wall. It overflows and flows into the water tank. Therefore, if the volume of the sedimentation tank is not enough with respect to the amount of rainwater flowing into the sedimentation tank, the silt that should be precipitated in the sedimentation tank is stirred without precipitation, and is moved from the sedimentation tank to the water storage tank. On the other hand, there is a problem that it is difficult to collect the precipitate if the volume of the water storage tank is sufficiently secured.

  In addition, if rainwater introduced into the settling tank from the rainwater inlet side is retained in the settling tank until it overflows from the partition wall, the pressure in the settling tank becomes higher than in the water storage tank and the partition wall is destroyed. For this reason, a plurality of water outlets are provided in the partition wall so that the water level inside and outside the partition wall is adjusted to the same level. There is a problem that before the water settles, it flows out from the water outlet to the water tank side together with rain water and cannot be effectively precipitated in the precipitation tank portion.

  Furthermore, since the partition wall is disposed between the block body stacked in the storage tank and the block body stacked in the settling tank section, as well as maintenance inspection, It is extremely difficult to replace, and even if part of it is damaged by an earthquake, etc., it is difficult to confirm the damaged part and it will be used as it is, so that gravel, mud, silt, etc. will settle and deposit in the sedimentation tank. If the muddy soil or silt accumulates in the sedimentation tank and a permeable sheet is laid at the bottom of the storage tank, the permeation function is reduced due to clogging. Cause.

  The present invention has been made in view of the above-described problems, and its object is to reliably and efficiently separate earth and sand, silt, and the like contained in rainwater flowing into a water tank from rainwater. An object of the present invention is to provide a rainwater storage facility including a filtration and sedimentation tank section that can be easily collected and removed, and that can be easily maintained and inspected, and has a simple structure and can be constructed easily and firmly.

In order to achieve the above object, a rainwater storage facility according to the present invention comprises a rainwater storage unit member having an internal space for storing rainwater in a water storage recess formed by excavating the ground. A reservoir is formed by laying vertically and horizontally and stacking in multiple stages, and the upper surface of the reservoir is covered with a covering material, and a rainwater inflow pipe for introducing rainwater from outside the reservoir is arranged on one end of the reservoir. In the rainwater storage facility that is provided, the rainwater storage unit member includes a rectangular bottom plate and a plurality of hollow mountain portions having a trapezoidal cross-section with a constant height and having a lower end that is entirely open downward from the bottom plate. In the uppermost rainwater storage unit member row that is projected in a parallel state and stacked, it passes through the inside of the water storage space that communicates straightly between the adjacent hollow ridges of the rainwater storage unit members. Rainwater inflow pipe is a pipe, Yes to face the opening frame through the top opening of the opening frame facing the tip end side of the reservoir, further, the rainwater storage unit member in a portion of the water tank A flat rectangular space not provided is provided, and a rectangular parallelepiped opening frame having open sides and upper and lower ends is inserted and installed in the space, and a water-permeable sheet is provided on all sides of the opening frame. Yes forms a filtered settling tank unit by lining, characterized in that through the dressing is provided with a check port communicating with the opening frame of the filtered settling tank unit.

  In the rainwater storage facility constructed as described above, the invention according to claim 2 is characterized in that a filtration / precipitation tank portion formed by lining a water-permeable sheet on the four opening surfaces of the opening frame is disposed in the central portion of the water storage tank. It is characterized by being.

  Invention of Claim 3 is the structure of the said opening frame, Comprising: By the height which reaches the upper end from the inner bottom face of a water storage tank along the four inner corners of the space part of the plane rectangular shape provided in the water storage tank It is composed of four standing pillars and a rectangular frame member attached at regular intervals in the length direction of the pillars with the four corners in contact with these pillars. To do.

Invention, the filtered precipitation tank portion disposed in several places of the water storage tank, rainwater storage in the water tank rainwater inlet tube communicating with the opening frame of the filtration precipitation tank unit from outside the water storage tank according to claim 4 Each unit is arranged through a water storage space provided in the unit member.

Moreover, the invention which concerns on Claim 5 provides the sand-sink tank which accepts the rainwater from a side ditch or a drain ditch in the ground adjacent to the said water tank, and the filtration provided in the said water tank through the rainwater introduction pipe | tube from this sand-sink tank It is characterized by introducing rainwater into the settling tank.

  According to the first aspect of the present invention, a storm water storage unit member is provided in a part of a water storage tank in which a number of storm water storage unit members are laid vertically and horizontally in a water storage recess excavated in the ground. A rectangular parallelepiped opening frame with four sides and upper and lower ends opened is inserted and installed in the space, and a permeable sheet is lined on the four sides of the opening frame. In addition, a filtration and precipitation tank section is formed, and the discharge port of the rainwater introduction pipe for introducing rainwater from the outside of the water storage tank faces the opening of the opening frame of the filtration and precipitation tank section. Rainwater that has flowed into the filtration and precipitation tank through the introduction pipe is filtered by a water-permeable sheet stretched on the opening frame of the filtration and precipitation tank, so that earth and sand, silt, etc. contained in this rainwater are reliably and efficiently separated from the rainwater. Water storage Can be transmitted to the side, it is possible to provide a possible and may rainwater storage facilities prolonged use without hardly deposited sediment and silt at the bottom of the reservoir.

  Furthermore, since the filtration / sedimentation tank is formed by stretching water-permeable sheets on the four sides of the opening frame, even if a large amount of rainwater flows into the filtration / sedimentation tank, it is stretched on the four sides of the opening frame. The water permeable sheet surface allows the filtration treatment to be performed uniformly and efficiently toward the water storage tank outside the filtration sedimentation tank section, and sediment, silt, etc. can be precipitated while staying in the filtration sedimentation tank section. Even if the volume of the filtration / sedimentation tank is relatively small, it is possible to filter and settle sediment, silt, etc. contained in the rainwater against a large amount of rainwater, and it is filtered from the filtration / sedimentation tank by a permeable sheet. The water pressure acting on the inner surface of the permeable sheet due to the rainwater that rises while acting in the outer surface of the permeable sheet by acting on the outer surface of the permeable sheet due to the rainwater flowing into the water storage tank can be offset. In addition to being lined with the opening frame, it can sufficiently withstand the water pressure in the filtration and precipitation tank section, and the opening frame is formed in a rectangular parallelepiped shape and has a shape retaining strength. Can withstand vibrations such as earthquakes and earthquakes.

  In addition, there is no rainwater storage unit member or the like in the filtration / sedimentation tank part, and the interior is a completely open space, so that sediment, silt, etc. accumulated at the bottom of the filtration / sedimentation tank part The sediment collection and removal work can be performed reliably and efficiently through the inspection port, and the water permeable sheet stretched on the opening frame from the inside of the filtration and sedimentation tank can be directly viewed, so that the water permeable sheet is maintained and inspected. Can be easily and reliably performed, and the permeable sheet is lined on the opening frame as described above, so if the permeable sheet becomes clogged or damaged due to long-term use, work The water permeable sheet can be easily replaced when an operator enters the filtration and precipitation tank through the inspection port.

  In addition, when constructing a rainwater storage facility, a plane rectangular space portion not provided with a rainwater storage unit member is provided in a part of the water tank, and the four sides and upper and lower ends are opened in this space portion. By inserting and installing a rectangular parallelepiped shaped opening frame, the construction of the filtration / precipitation tank can be performed easily and accurately, and the cost can be reduced.

Furthermore, according to the invention which concerns on Claim 1, the said rainwater storage unit member is a rectangular-shaped bottom plate, and a hollow mountain part of the cross-section isosceles trapezoid shape of the fixed height which the lower end opened completely downward from a bottom plate In the uppermost rainwater storage unit member row, the rainwater inflow pipe passes through the straight storage water space provided between the adjacent hollow ridges of the rainwater storage unit member in the uppermost rainwater storage unit member row. Since the front end of the pipe faces the inside of the opening frame through the upper opening of the opening frame facing one end of the water storage tank, the space for piping the rainwater introduction pipe from the outside of the water storage tank to the filtration and precipitation tank section Without providing a separate section, the rainwater introduction pipe can be easily and accurately piped to the filtration and precipitation tank section using the water storage space of the rainwater storage unit member.

  Furthermore, according to the invention according to claim 2, since the filtration sedimentation tank section is disposed in the central part of the water storage tank, the influence of the lateral earth pressure acting on the water storage tank can be reduced and the filtration is performed. The rainwater thus made can flow into the water storage tank in a well-balanced manner from the four sides of the filtration and precipitation tank section.

  According to the invention which concerns on Claim 3, the opening frame of the said filtration sedimentation tank part is on the upper end from the inner bottom face of a water storage tank along the four inner corners of the plane rectangular-shaped space part provided in the water storage tank. It consists of four struts erected up to the height to reach, and a rectangular frame member that is attached at regular intervals in the length direction of the struts with the four corners in contact with these struts Therefore, it is possible to produce an opening frame that is firmly framed in a rectangular parallelepiped shape by the four pillars and these rectangular frame members, and to attach rainwater sheets that are lined in four directions to the inner surfaces of a plurality of rectangular frame members. It is possible to form a filtration / precipitation tank that can sufficiently withstand the water pressure acting on the water-permeable sheet during filtration, and to filter rainwater by exposing the water-permeable sheet to a large area between the upper and lower rectangular frame members. To enhance the action Kill.

Further, according to the invention according to claim 4 , the filtration / sedimentation tanks are arranged at several locations of the water storage tank, and the rainwater introduction pipes communicating from the outside of the water storage tank to the openings of these filtration / sedimentation tanks are provided in the water storage tank. Since it is arranged through the water storage space provided in the rainwater storage unit member, even if the rainfall per unit time is extremely large, such as torrential rain, etc., a large amount of rainwater can be supplied through multiple rainwater introduction pipes. Can be separated and introduced into the filtration / precipitation tank section, and a large amount of rainwater can be precipitated and filtered in these filtration / precipitation tank sections, and the filtered rainwater can be stored in the storage tank. Can do.

According to the fifth aspect of the present invention, a sand settling tank is provided in the ground adjacent to the water storage tank to receive rainwater from a side ditch or a drainage ditch, and the filtration provided from the sand settling tank to the water storage tank through a rainwater introduction pipe. Since rainwater is introduced into the sedimentation tank, gravel and clay contained in the rainwater are introduced by flowing rainwater that flows into the storage tank from the side ditch and drainage into the storage tank. In this case, rainwater is introduced from the sand basin into the water storage tank through the rainwater introduction pipe and is contained in the rainwater. Sediment and clay can be precipitated in the filtration and sedimentation tank, and rainwater is filtered by the water-permeable sheet stretched on the opening frame in the filtration and precipitation tank to capture fine sediment and silt in the water-permeable sheet. Can be , The water tank can be stored rain water sediment or silt is hardly included.

A simplified longitudinal side view of a rainwater storage facility. The simplified plan view. The expanded vertical side view of a rainwater storage facility. The expansion perspective view of a part of filtration precipitation tank part. The perspective view of a rainwater storage unit member. The longitudinal section front view of the state which has accumulated. The simplified top view which shows another Example of this invention.

  Next, a specific embodiment of the present invention will be described with reference to the drawings. In FIGS. 1 to 3, the rainwater storage facility creates a rectangular rectangular water storage recess 1 by digging the ground such as a park into a predetermined depth. It is formed by laying the rainwater storage unit members 3 made of synthetic resin having a flat rectangular shape having a constant thickness in the water storage recess 2 and having a constant thickness in a horizontal and vertical direction and stacked in multiple stages. The water storage tank 1, the covering material 4 covering the upper surface of the water storage tank 1, and a part of the water storage tank 1 are not provided with the rainwater storage unit member 3 from the inner bottom surface to the upper end of the water storage tank 1. A rectangular rectangular space 5 is provided, and a rectangular parallelepiped opening frame 7 having openings in the space 5 that are connected to the inside and outside is inserted and installed in the space 5. Permeability on all sides A filtration / sedimentation tank 6 formed by lining the tank 8, an inspection port 9 communicating from the ground surface of the coating material 4 to the upper end of the filtration / sedimentation tank 6, and one end of the water storage tank 1 And a rainwater introduction pipe 10 for introducing rainwater from the outside of the water storage tank 1 to the upper end opening of the opening frame 7 in the filtration and precipitation tank section 6.

  The structure of the rainwater storage facility constructed as described above will be described in more detail. After the bottom surface of the water storage recess 2 is formed on a flat horizontal surface, the water is shielded from the bottom surface of the water storage recess 2 to the entire surface of the four excavation walls. A water storage tank 1 is formed by covering the sheet 11 and arranging the rainwater storage unit members 3 in multiple rows and multiple stages in the water storage recess 2 covered by the water shielding sheet 11. A rainwater lead-out pipe 12 for discharging rainwater in the water storage tank 1 to the outside is communicated with an upper end portion on the other end side of the tank 1. A water permeable sheet may be laid instead of the water shielding sheet 11.

  For example, as shown in FIGS. 5 and 6, the rainwater storage unit member 3 constituting the water storage tank 1 has a bottom plate portion 31 having a flat rectangular shape and a lower end that opens downward from the bottom plate portion 31. A plurality of hollow ridges 32 having a constant height cross-section with a constant height in the front-rear direction or the left-right direction at regular intervals, and projecting until both ends in the length direction reach parallel sides of the bottom plate part 31. In addition, projecting tops 32a having a planar rectangular shape are provided on the upper end surfaces of these hollow ridges 32 at the same interval as the hollow ridges 32, and the lengths of these projecting ridges 32a are the hollow ridges. When the upper rainwater storage unit member 3 is stacked so that the hollow ridges 32 are perpendicular to each other, the upper rainwater storage unit member 3 is formed so as to be equal to the opening width of the lower end portion of 32. The protruding top portion 32a of the hollow mountain portion 32 of the lower rainwater storage unit member 3 is the upper step. It fits into the lower end opening of the hollow peak portion 32 of the rainwater storage unit member 3, and both lower end surfaces of the inclined wall of the hollow peak portion 32 are supported on the upper surface of the hollow peak portion 32 of the lower rainwater storage unit member 3. In such a state, it is configured to be stacked accurately and reliably.

  Further, all the projecting top portions 32a are provided with several water passage holes 34 communicating with the inside of the hollow ridge portion 32, and the hollow valley portion between the adjacent hollow ridge portions 32, 32 has a constant width. It is formed in the water storage space part 35 which consists of a straight groove.

  A large number of rainwater storage unit members 3 configured in this way, first, all the rainwater storage unit members 3 are arranged in series with each other on the water shielding sheet 11 laid on the bottom surface of the water storage recess 2. It is installed vertically and horizontally over the entire surface of the water storage recess 2 so as to be continuous to form a first-stage rainwater storage unit member row. At this time, a space where the rainwater storage unit member 3 is not provided is provided in a part of the rainwater storage unit member row, for example, in the center of the water storage recess 2. The space 5 is formed in a width (about 1000 mm square) corresponding to one rainwater storage unit member.

  Similarly, a large number of second-stage rainwater storage unit members 3 are sequentially placed on all the rainwater storage unit members 3 in the first-stage rainwater storage unit member row, and the hollow ridges 32 are disposed in the lower-stage rainwater. By superimposing the storage unit member 3 so as to be orthogonal to the hollow crest portion 32, the lower end opening of the hollow crest portion 32 is fitted onto the protruding top 32a of the hollow crest portion 32 of the lower rainwater storage unit member 3. A second-stage rainwater storage unit member row is formed. At this time, the second stage rainwater storage unit member row also has a rainwater reservoir so as to overlap the space portion on the space portion where the rainwater storage unit member 3 in the first stage rainwater storage unit member row is not provided. A space where no unit member 3 is provided is formed.

  In this manner, the upper rainwater storage unit member 3 is superposed on the lower rainwater storage unit member 3 so that the hollow ridges 32 and 32 are perpendicular to each other, and the rainwater storage unit member row is covered with rainwater. Water shielding which forms a rectangular space where no storage unit member 3 is provided and is stacked on the bottom surface of the water storage recess 2 in a part of the water storage recess 2 by stacking a number of steps up to the vicinity of the upper end of the water storage recess 2 From the upper surface of the sheet 11 to the vicinity of the upper end of the water storage recess 2, a water storage tank 1 having a planar rectangular space 5 in which no rainwater storage unit member 3 is provided is constructed.

  After that, in the space 5 in the water tank 1, a water-permeable sheet 8 made of a filter sheet material (filter material) is formed on the inner surfaces of the four open surfaces except for the upper end portion as shown in FIG. 4. A filtration and precipitation tank section 6 is formed by inserting and installing a rectangular parallelepiped opening frame 7 that is stretched over the entire surface. In addition, the water-permeable sheet 8 is stretched over the entire opening surface of the opening frame 7 and the upper end portion of the water-permeable sheet 8 is partially cut to form an overflow space that overflows rainwater. You may keep it. Further, when the amount of rainwater filtered by the water-permeable sheet 8 stretched on the four sides of the opening frame is larger than the amount of rainwater flowing into the filtration / sedimentation tank section 6 per unit, the water-permeable sheet 8 is used. May be stretched over the entire opening surface of the four sides of the opening frame 7.

  The opening frame 7 is formed in a bar shape having four columns 7a having a height equal to the depth of the space 7 along the four corners of the space 5 and the length between the adjacent columns 7a and 7a. The four frame members are combined to form a plurality of rectangular frame members 7b having a rectangular shape formed so as to surround the support columns 7a. The rectangular frame members 7b are formed at the four corners. It has a structure in which the right inner surface is in contact with the right outer surface of the four columns 7a and fixed to the columns 7a with screws or the like, and is attached at regular intervals in the length direction of the columns 7a. Is open almost entirely.

  A large number of water-permeable sheets 8 stretched on the four sides of the opening frame 7 are obtained by heat-sealing the overlapping portions in a state in which nonwoven fabrics or randomly split yarns arranged in parallel are orthogonal to each other. The water-permeable sheet 8 is superposed on the four opening surfaces of the opening frame 7 and the portion facing the rectangular frame material 7b is formed on the inner surface of the rectangular frame material 7b. Installed by lining. In addition, as the lining structure of the water-permeable sheet 8 with respect to the opening frame 7, for example, a plurality of locking pins (not shown) are projected from the inner surface of the rectangular frame material 7a, and the locking pins are made water-permeable. A structure in which the water-permeable sheet 8 is detachably stretched on the opening frame 7 by being penetrated through the sheet 8 can be employed, other mounting members can be employed, or an adhesive is used. And may be attached in a peelable manner.

  On the other hand, a rainwater introduction pipe 10 is arranged from the ground outside the water storage tank 1 on one end side of the water storage tank 1 to the upper end opening of the opening frame 7 in the filtration and precipitation tank section 6. This rainwater introduction pipe 10 has a piping structure through a straight water storage space 35 provided between adjacent hollow ridges 32, 32 of the rainwater storage unit member 3 in the uppermost rainwater storage unit member row. The discharge port faces the inside of the opening frame 7 through the upper end opening of one surface of the opening frame 7 facing the one end side of the water storage tank 1 and the base end of the rainwater introduction pipe 10 The side is buried in the ground outside the water tank 1 through the upper end portion of the sheet portion on one end side of the water tank 1 in the water shielding sheet 11 covering the four excavated wall surfaces of the water reservoir recess 2.

  The base end of the rainwater introduction pipe 10 may be directly connected to the side groove or drainage groove side, but as shown in FIG. It is preferable that a sand settling tank 13 for receiving rainwater from the groove is provided, and the base end portion of the rainwater introduction pipe 10 is communicated with the sand settling tank 13. When the rainwater introduction pipe 10 is piped from the sand settling tank 13 to the opening frame 7 in the filtration / precipitation tank section 6, between the adjacent hollow mountain parts 32, 32 in the rainwater storage unit member 3 for piping the rainwater introduction pipe 10. If the water storage space 35 is small and it is difficult to pipe a large-diameter rainwater introduction pipe, several rainwater introduction pipes 10 may be piped between the sand settling tank 13 and the filtration settling tank section 6. In the figure, reference numeral 14 denotes a rainwater inflow pipe for introducing rainwater into the upper end of the sand settling tank 13 from a side groove or a drainage groove.

  On the entire upper surface of the uppermost rainwater storage unit member row in the water storage tank 1 and on the upper end opening of the filtration / sedimentation tank section 6, a large number of small water holes 15a penetrating in the vertical direction (shown in FIG. 6). A reinforcing plate is formed by laying the partition plate 15 having the vertical and horizontal directions, and the water storage tank 1 is covered with the covering material 4 through the reinforcing layer. The covering material 4 includes a water permeable sheet 4a laid on the reinforcing layer and a water permeable pavement layer 4b composed of a soil layer provided on the water permeable sheet 4a. Permeable sheet 4a and water penetration hole 15a provided in partition plate 15 constituting the reinforcing layer are made to pass through water storage tank 1, but asphalt instead of permeable pavement layer 4b As the pavement layer, a water shielding sheet may be employed instead of the water permeable sheet 4a. In this case, it is not necessary to provide the water flow holes 15a in the partition plate 15.

The partition plate 15 is a rectangular plate that fits into the rainwater storage unit member 3, and overlaps the upper surface of all the uppermost rainwater storage unit members 3, and the upper end opening of the filtration sedimentation tank section 6. A through-hole 15b made of a circular hole or a rectangular hole having a size allowing an operator communicating with the inside of the opening frame 7 to enter and exit is provided at the center of the partition plate 15 laid on the part. An inspection port 9 communicating from the ground surface to the through hole 15b is formed by removing the portion of the covering material 4 on 15b, and the upper end opening of the inspection port 9 is closed by a lid 16 so as to be opened and closed. When a plurality of partition plates 15 are disposed on the upper end opening of the filtration / precipitation tank section 6, the upper and lower openings of the opening frame 7 constituting the filtration / precipitation tank section 6 are arranged vertically and horizontally. Several horizontal reinforcement frames (not shown) are attached, and the partition plate 15 is received on the horizontal reinforcement frames and the upper end surface of the opening frame 7 to support the load applied on the pavement layer. It is configured as follows. In this case, a through hole 15b through which the inspection port 9 is communicated is provided at the center of the combined partition plate 15.

  The operation of the rainwater storage facility constructed as described above will be described. Rainwater that has flowed into the side ditch and drainage ditch at the time of rainfall is sent into the sand settling tank 13 through the inflow pipe 14 and is relatively large in the sand settling tank 13. Solids such as stones and lumps of sediment settle on the bottom of the sand settling tank 13 and part of the solids such as gravel and small foreign matter also settle and accumulate on the bottom of the sand settling tank 13. The accumulated solid matter is inhaled and removed at a later date using a suction hose from the ground side.

  On the other hand, fine earth and sand and silt contained in rainwater flow into the rainwater introduction pipe 10 and enter the water tank 1 through the water storage space 35 in the rainwater storage unit member row of the water tank 1 in which the rainwater introduction pipe 10 is disposed. It flows out in the filtration precipitation tank part 6 provided in this.

  When the amount of rainwater flowing in is small, the rainwater that has flowed into the filtration / sedimentation tank 6 is finely soiled or silted by the water-permeable sheet 8 stretched on the four openings of the opening frame 7 of the filtration / settlement tank 6. While being filtered, the rainwater storage unit members 3 enter the water storage tanks 1 arranged in multiple rows and stages from four sides of the filtration and precipitation tank unit 6 and are stored in the water storage space of the rainwater storage unit member 3.

  When there is a large amount of rainwater flowing in, the rainwater that has flowed into the filtration / sedimentation tank 6 once stays in the filtration / sedimentation tank 6 and sediments sediment and the like while the water level rises, and the sedimentation tank. The rainwater storage unit members 3 are arranged in multiple rows and multiple stages from the four sides of the filtration sedimentation tank 6 while fine earth and sand and silt are filtered by the water-permeable sheet 8 stretched on the four sides of the opening frame 7 of the portion 6. It enters into the water storage tank 1 provided and is stored in the water storage space of the rainwater storage unit member 3.

  At this time, the amount of rainwater filtered by the water-permeable sheet 8 stretched on the four opening surfaces of the opening frame 7 in the filtration / sedimentation tank 6 is the amount of rainwater flowing into the filtration / sedimentation tank 6 from the rainwater introduction pipe 10. Or more than this amount, the water level in the water storage tank 1 in the inside and outside of the filtration sedimentation tank section 6 rises while being equal, and the rainwater does not overflow from the filtration sedimentation tank section 6 and the water storage tank 1, the flow rate is adjusted by the orifice 18 in the drainage tank 17 through the rainwater outlet pipe 12, and is gradually discharged from the drainage pipe 19 to the river or the like.

  On the other hand, the amount of rainwater filtered by the water-permeable sheet 8 stretched on the four opening surfaces of the opening frame 7 in the filtration / sedimentation tank 6 is greater than the amount of rainwater flowing into the filtration / settlement tank 6 from the rainwater introduction pipe 10. In the case where the water level is too low, the water level in the filtration / sedimentation tank unit 6 rises prior to the water level of the water storage tank 1 outside the filtration / sedimentation tank unit 6, and before rainwater is stored in the uppermost rainwater storage unit member row. The inside of the filtration / sedimentation tank 6 becomes full and overflows from the upper part of the filtration / sedimentation tank 6 and flows into the water storage tank 1, and the flow rate is adjusted by the orifice 18 in the drainage tank 17 through the rainwater outlet pipe 12 and gradually drained. 19 is discharged into rivers. Further, when the rainwater becomes full in the water storage tank 1, it overflows from the spillway 20 provided in the drainage tank 17 and is discharged to a river or the like through the drainage pipe 19.

  Furthermore, a pump can be installed in the drainage tank 17, and the stored water can be pumped up and used for watering a park or the ground. Also, when removing solids such as gravel and mud that have settled and accumulated in the bottom of the filtration sedimentation tank 6, drain the rainwater in the water storage tank 1 to the extent that the work can be performed, and then from the ground side. A suction pipe (not shown) is inserted through the inspection port 9, and the gravel and mud are sucked and removed.

  In addition, when the water-permeable sheet 8 lining the opening frame 7 in the filtration / sedimentation tank section 6 is clogged with earth or sand or silt and the filtration function is lowered, the water-permeable sheet 8 is removed from the opening frame 7. After washing away dirt and silt trapped in the water-permeable sheet 8 by backwashing from the side facing the rainwater storage unit member 3 stacked in the water storage tank 1, the lining is again placed on the opening frame 7. On the other hand, when the water-permeable sheet 8 does not recover or is damaged due to long-term use even though the water-permeable sheet 8 is washed, a lifting platform or the like is provided in the filtration settling tank 6. And the water permeable sheet 8 is exchanged and replaced by an operator.

  In addition, in the above Example, although the filtration precipitation tank part 6 is provided in one place in the water storage tank 1, as shown in FIG. 7, it may be provided in several places, These filtration precipitation tank parts 6, 6 and 6, a rainwater introduction pipe 14 is piped from the sand settling tank 13 through the water storage space 35 in the uppermost rainwater storage unit member row of the water tank 1 and above the filtration settling tank parts 6, 6, 6. Inspection ports 9, 9, and 9 communicating with the respective filtration and precipitation tank sections 6, 6, and 6 from the ground side may be formed in the covering material 4 respectively, and if configured in this way, A large amount of rainwater can be precipitated and filtered in these filtration / precipitation tank sections 6, 6, 6, and a large amount of rainwater can be stored in the water storage tank 1 in a short time.

DESCRIPTION OF SYMBOLS 1 Water storage tank 2 Water storage recessed part 3 Rainwater storage unit member 4 Coating | covering material 6 Filtration precipitation tank part 7 Opening frame 8 Water-permeable sheet 9 Inspection port
10 Rainwater introduction pipe
11 Water shielding sheet
12 Rainwater outlet pipe
13 Settling tank
14 Rainwater inflow pipe
15 divider
16 Lid
17 Drainage tank
18 Orifice
19 Drain pipe
20 Spillway

Claims (5)

A rainwater storage unit member having an internal space for storing rainwater is laid vertically and horizontally in a water storage recess formed by excavating the ground, and a water tank is formed by stacking in multiple stages, and the upper surface of this water tank is covered with a covering material In the rainwater storage facility in which a rainwater inflow pipe for introducing rainwater from the outside of the water tank is provided on one end side of the water tank, the rainwater storage unit member has a rectangular bottom plate and a lower end from the bottom plate. The rainwater storage unit member of the uppermost rainwater storage unit member row in which a plurality of hollow crests having a constant height cross-section with a constant height opening in a downward direction and protruding in a parallel state are stacked. The rainwater inflow pipe is piped through the straight water storage space provided between the adjacent hollow ridges, and the upper end opening of the opening frame faces the one end of the water storage tank. Through Yes to face in the opening frame, the further square faces and upper and lower ends to the space portion provided space portion plane rectangular not provided with rainwater storage unit member in the water tank is opened to insert the opening frame of the rectangular shape is, Yes to form a filtered settling tank unit by lining the water permeable sheet in all directions of the opening frame with are installed, the filtered precipitate through the dressing A rainwater storage facility characterized in that an inspection port communicating with the inside of the opening frame of the tank portion is provided.   The rainwater storage facility according to claim 1, wherein a filtration / precipitation tank portion formed by lining a water-permeable sheet on the four opening surfaces of the opening frame is disposed at a central portion of the water storage tank.   The opening frame has four struts erected from the inner bottom surface of the water tank to the height reaching the upper end along the inner corners of the four sides of the planar rectangular space provided in the water tank. The rainwater according to claim 1 or 2, comprising a rectangular frame member attached at regular intervals in the length direction of the column with the four-sided corners in contact with the column. Storage facility. Reservoir space provided with rainwater introduction pipes in the rainwater storage unit member in the water storage tank, which is provided with filtration and precipitation tanks at several locations in the water tank and communicates from outside the water tank to the opening frame of these filtration and precipitation tanks. The rainwater storage facility according to claim 1, wherein the rainwater storage facility is disposed respectively.   A sedimentation tank is provided in the ground adjacent to the water storage tank to receive rainwater from the side gutter and drainage ditch, and rainwater is introduced from the sand storage tank through the rainwater introduction pipe into the filtration / sedimentation tank. The rainwater storage facility according to claim 1 or 4, wherein the rainwater storage facility is provided.

Images