JP2008031645A - Rainwater storage tank - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To effectively prevent an impervious sheet from being damaged by earth pressure even if irregularities are formed on the surface of a filling structure arranged in a water storage pit via the impervious sheet. <P>SOLUTION: In this rainwater storage tank 10, when pressure receiving panels 110 are mounted to side plates 44 and 90 which form the outside surface of the filling structure 18, the outside surface of the filling structure 18 can be covered with the pressure receiving panel 110. Thus, even if the outside surface of the filling structure is subjected to earth pressure via an impervious protective layer 16, the impervious sheet 20 of the impervious protective layer 16 can be supported by the pressure receiving panel 110, and can be prevented from being locally deformed into such a shape as to be fitted into the recessed portion of the outside surface of the filling structure 18 and a gap between filling blocks 40. This can prevent excessive tensile force from being locally generated on the impervious sheet 20, and can effectively prevent breakage in the impervious sheet 20. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a rainwater storage tank used for storing rainwater or infiltrating it into the ground.

  In recent years, especially in urban areas and factory zones, many portions of the formation surface are covered with a non-permeable material such as concrete, and the number of trees that increase the water retention capacity of the formation has decreased. For this reason, when a large amount of rain falls in such an area in a short period of time, the rainwater is not absorbed or retained in the formation, and flows directly into the river, sewage, etc. Immediately after that, the amount of water flowing into rivers, sewage, etc. exceeds the allowable flow rate of rivers, sewage, and often causes flooding such as flooding and flooding of rivers. In order to mitigate such flood damage, a large amount of rainwater is stored underground, and facilities that allow this rainwater to gradually penetrate into the strata, and facilities that once drain the stored large amount of rainwater into rivers, etc. Development of facilities that pump up stored rainwater and use it as fire prevention water (collectively, these facilities are referred to as “rainwater storage tanks”) is progressing.

  As such a rainwater storage tank, what was described in patent document 1 and patent document 2 is known, for example. In Patent Document 1, a pit is dug in the ground, a water-impervious sheet is laid on the outer surface, a plurality of container-like members (filling blocks) are stacked vertically and horizontally, and the top is covered with soil. A rainwater storage tank that covers and covers rainwater is described.

  Further, Patent Document 2 describes a rainwater storage tank filler (filling structure) composed of a plurality of support columns and a connecting member that vertically fixes the support columns, and the rainwater storage tank is configured using this filler. In order to do this, first, the inside of the concave pit formed by digging the ground is shielded, and then the filler is filled in the pit in the horizontal direction and stacked in the vertical direction. An earth and sand invasion prevention plate is placed on the top surface of the filling structure, and an earth and sand invasion prevention plate is attached to the outer peripheral surface of the filler located on the outer peripheral side. A rainwater storage tank is constructed by refilling earth and sand outside the earth and sand invasion prevention plate on the outer peripheral surface.

By the way, the filling structure described in Patent Document 2 is a three-dimensional structure in which two connecting members each formed in a panel shape are connected by a plurality of support columns. The filling block) has an opening between the columns on the side surface. A circular through hole is formed at the center of the connecting member. Thereby, compared with the rainwater storage tank described in Patent Document 1, according to the one described in Patent Document 2, a wide range from the outside of the rainwater storage tank through the opening of the side surface portion of the filling block and the through hole of the connecting member. Since there is an advantage that maintenance inspection of the rainwater storage tank becomes easy.
JP-A 63-268823 JP 2004-19206 A

  However, in the filling structure described in Patent Document 2, the space between the columns on the outer surface is an opening, and the through hole of the connecting member is also opened on the top surface. When the sheet is subjected to a large earth pressure, the water-impervious sheet is locally deformed so as to be fitted into the opening on the outer surface or the through hole on the top surface, and there is a possibility that a large tension is generated in the portion. When the tension generated in this way exceeds the breaking strength of the water-impervious sheet and the water-impervious sheet breaks, water leakage occurs in the rainwater storage tank.

  On the other hand, even in a container-like filling block as described in Patent Document 1, the side plate portion and the top plate are made uneven (in a broad sense, rib shape) to enhance load resistance, and the side plate portion is used for maintenance inspection. In some cases, a concave curved portion that becomes a manhole is formed. For this reason, even when a filling structure is configured by arranging and laminating filling blocks as described in Patent Document 1, the water-impervious sheet that has received earth pressure is formed on the side plate portion and the top surface of the filling structure. There is a risk that the water-impervious sheet may be torn in the vicinity of the irregularities.

  The purpose of the present invention is to take into account the above facts, even if there is unevenness on the surface of the filling structure disposed in the water storage pit via the water shielding sheet, it is effective that the water shielding sheet is damaged by earth pressure. It is in providing the rainwater storage tank which can prevent automatically.

  In order to solve the above-mentioned problem, the rainwater storage tank according to claim 1 is integrally provided with a cylindrical side plate having one end opened along the height direction and a top plate that closes the other end of the side plate, A filling block having a window opening in the side plate, a water shielding sheet laid so as to cover an inner surface of a concave water storage pit formed on the ground, and a plurality of the filling blocks in the height direction. A filling structure arranged along the orthogonal row direction and column direction and stacked along the height direction, and disposed in the water storage pit via the water shielding sheet, and the filling structure A plate that can be attached to the side plate forming the outer side surface of the body, and that covers the window portion on the outer side surface of the filling structure and a region between a pair of adjacent window portions from the outside when attached to the side plate. A pressure-receiving panel It is characterized in.

  In the rainwater storage tank according to claim 1, the plate-shaped pressure receiving panel can be attached to the side plate forming the outer surface of the filling structure, and the pressure receiving panel is attached to the side plate forming the outer surface of the filling structure. And the window part opened to the outer surface of a filling structure by this pressure receiving panel, and the area | region between a pair of adjacent window parts on the outer surface of a filling structure are each covered.

  Thereby, even if the outer surface of the filling structure is subjected to a large earth pressure through the water-impervious sheet, the water-impervious sheet can be supported by the surface (pressure-receiving surface) of the plate-shaped pressure-receiving panel, Since it is possible to prevent local deformation so as to fit into the window portion and the gap between the window portions on the outer surface of the filling structure, it is possible to prevent excessive tension from being generated locally on the water shielding sheet. It is possible to effectively prevent the water sheet from being damaged.

  The rainwater storage tank according to claim 2 is the rainwater storage tank according to claim 1, wherein the pressure receiving panel is attachable to the top plate forming the top surface of the filling structure, and is attached to the top plate. A space between a pair of adjacent top plates on the top surface of the filling structure is covered from above.

  In the rainwater storage tank according to claim 2, the plate-shaped pressure receiving panel can be attached to the top plate forming the top surface of the filling structure, and when the pressure receiving panel is attached to the top plate, the pressure receiving panel is filled. A gap between a pair of adjacent top plates on the top surface of the structure is covered from above.

  As a result, even if a large earth pressure is applied to the top surface of the filling structure via the water shielding sheet, the water shielding sheet can be supported by the front side surface (pressure receiving surface) of the pressure receiving panel, and the water shielding sheet is filled with the structure. Since it can prevent local deformation so as to fit into the gap between the pair of top plates on the top surface of the body, it can prevent excessive tension from being generated locally on the water shielding sheet, and the water shielding sheet is damaged. Can be effectively prevented.

  The rainwater storage tank according to claim 3 is the rainwater storage tank according to claim 1 or 2, wherein the pressure-receiving panel is a surface opposite to an inner mounting surface facing an outer surface or a top surface of the filling structure. Is a flat pressure-receiving surface.

  The rainwater storage tank according to claim 4 is the rainwater storage tank according to claim 3, wherein the rainwater storage tank is inserted into the mounting surface through the window portion and inside the side plate, and the peripheral edge portion of the window portion in the side plate is engaged. The latching claw which stops is formed integrally.

  The rainwater storage tank according to claim 5 is the rainwater storage tank according to claim 4, wherein the rainwater storage tank is brought into contact with the mounting surface from the outside to the side plate, and the pressure receiving surface is substantially vertical. It is characterized by integrally forming a reinforcing rib for supporting it so as to extend along.

  The rainwater storage tank according to claim 6 is the rainwater storage tank according to any one of 3 to 5, wherein a concave gap portion extends along the arrangement direction of the filling blocks on the top surface of the filling structure. A convex reinforcing rib extending along the arrangement direction of the filling blocks is formed on the mounting surface, and the reinforcing rib is inserted into the gap portion to fill the pressure receiving panel. It is characterized by positioning to a predetermined mounting position on the top surface of the structure.

  As described above, according to the rainwater storage tank of the present invention, even when the surface of the filling structure disposed in the water storage pit is provided with an unevenness through the water shielding sheet, the water shielding sheet is damaged by earth pressure. Can be effectively prevented.

  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, and FIGS. 9 to 12 show a filling block used in the rainwater storage tank according to this embodiment. 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 or the like is embedded around the rainwater storage tank 10, and an outflow dredging 14 formed in a container shape with reinforced concrete or the like 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 30 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 32 is connected to the upper end portion of the side wall portion. The other ends of the orifice pipe 30 and the overflow pipe 32 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 30 has a function as an orifice for restricting the flow rate of rainwater flowing out from the inside of the outflow trough 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 34, a water shielding sheet 20, and an inner protective mat 36. The outer protective mat 34 and the inner protective mat 36 are made of non-woven fabric having a sufficient flexibility and made of polyester short fibers. The outer protective mat 34 and the inner protective mat 36 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, respectively.

  Note that an electrode sheet 38 made of aluminum foil is sandwiched on the entire surface of the outer protective mat 34 at an intermediate portion along the thickness direction. The electrode sheet 38 is connected to an energization inspection device (not shown) when inspecting water leakage from the rainwater storage tank 10. The energization inspection device detects the current conduction state between the electrode sheet 38 and the inspection electrode installed in the rainwater storage tank 10, for example, whether or not there is water leakage in the rainwater storage tank 10, the degree of water leakage, Inspect the location.

  The filling structure 18 of the rainwater storage tank 10 includes a filling block 40 shown in FIG. 3 and an auxiliary block 42 shown in FIG. The filling block 40 and the auxiliary block 42 are molded using a fat material that does not cause hydrolysis. Specifically, as the molding material of these blocks 40 and 42, polyolefin resins such as polypropylene (PP) and polyethylene (PE) (particularly high density polyethylene (HDPE)) are chemically stable and mechanical. It is preferable in terms of strength and price. 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, it is not necessary to add an antioxidant.

  The filling block 40 and the auxiliary block 42 are each formed into a hollow container shape by an injection molding method. The thickness of the filling block 40 and the thickness of the auxiliary block 42 are substantially equal, and are set to 2 mm to 3 mm in consideration of the weight per product, mechanical strength, and the like. The projection area of the auxiliary block 42 in plan view is approximately 1/8 of the projection area of the filling block 40.

  As shown in FIGS. 3 and 4, the filling block 40 is formed in a substantially rectangular parallelepiped container shape as a whole. The filling block 40 is formed with a cylindrical side plate 44 and a top plate 46 that integrally closes the top surface side of the side plate 44. The filling block 40 has an open end on the bottom surface side (lower end side) opposite to the top plate 46, and the side plate 44 has an L-shaped or J-shaped cross section so as to extend to the outer peripheral side at the lower end portion. A folded portion 48 is formed over the entire circumference. Here, the filling block 40 has a substantially rectangular shape with the width direction (arrow W direction) as a longitudinal direction in plan view, and the dimension along the width direction is 2 which is the dimension along the depth direction (arrow D direction). It has doubled.

  The filling block 40 includes a plurality of (eight in the present embodiment) overhanging portions 50A to 50H formed in a substantially pyramid shape on the side plate 44 (in the case of comprehensively speaking, these are simply “overhanging”. Part 50 "). The overhang portions 50A to 50D and the overhang portions 50E to 50H are linearly arranged along the width direction, and the four overhang portions 50A to 50D and 50E to 50H are provided on the filling block 40, respectively. They are arranged symmetrically with respect to the symmetry line CL which is the center in the depth direction. Each of the overhanging portions 50A to 50H is formed in a substantially U shape whose cross-sectional shape along the horizontal direction opens toward the symmetry line CL. As illustrated in FIG. 10, the overhang portions 50 </ b> A to 50 </ b> H are formed in a tapered shape in which the dimensions along the width direction and the depth direction gradually decrease from the lower end side toward the upper end side. Moreover, the pitch along the width direction and depth direction of each overhang | projection part 50A-50H is respectively equal.

  In the side plate 44, connection plate portions 52A to 52C are integrally formed between the four overhang portions 50A to 50D, and the connection plate portions 52D to 52FC are respectively formed between the four overhang portions 50E to 50H. Are integrally formed. These connecting plate portions 52A to 52F (inclusive of these, simply referred to as “connecting plate portion 52”) connect a pair of projecting portions 50A to 50H adjacent to each other along the width direction. is doing. As a result, depressions 54A to 54C that are recessed toward the symmetric line CL are formed between the overhangs 50A to 50D in the side plate 44, and are recessed in a U-shape to the symmetric line CL side between the bulges 50E to 50H. The hollow portions 54D to 54F (in the case of comprehensively referring to these, simply referred to as “the hollow portion 54”) are formed.

  As shown in FIG. 4A, the side plate 44 is integrally formed with bottom plate portions 56A to 56C for closing the lower end sides of the recessed portions 54A to 54C, and the lower end sides of the recessed portions 54D to 54F are formed. Closed bottom plate portions 56D to 56F (inclusive of these, simply referred to as “bottom plate portion 56”) are integrally formed. The side plate 44 is integrally formed with a concave curved plate portion 58 between two projecting portions 50A and 50E located at one end in the width direction, and two pieces located at the other end in the width direction. A concave curved plate portion 58 is also integrally formed between the overhang portions 50C and 50H. Each of the curved plate portions 58 is formed in an arc shape in cross section, and its radius of curvature (inner diameter) gradually decreases from the upper end side toward the lower end side.

  The top plate 46 is formed with a substantially rectangular center plate portion 60 extending elongated along the symmetry line CL, and lid plate portions 62A to 62D extending outward from the center plate portion 60 in the width direction, and Lid plate portions 62E to 62H (inclusive of these, simply referred to as “lid plate portion 62”) are integrally formed. These lid plate portions 62A to 62D and lid plate portions 62E to 62H close the top surface side of the overhang portions 50A to 50D and the top surface side of the overhang portions 50E to 50H, respectively.

  In the filling block 40, overhang portions 50A to 50H are formed on the side plate 44, and the overhang portions 50A to 50H adjacent to each other are connected by connecting plate portions 52A to 52F and bottom plate portions 56A to 56F, or curved. By being connected by the plate portion 58, the overhang portions 50 </ b> A to 50 </ b> H function as reinforcing ribs with respect to an external load, and compared with a case where the side plate 44 is formed in a flat plate shape without irregularities, High strength against load is secured.

  Standing wall portions 64 and 65 are formed on the top plate 46 so as to follow both end portions in the depth direction of the center plate portion 60, respectively. The pair of standing wall portions 64 and 65 are substantially perpendicular to the center plate portion 60. It stands up and its upper end coincides with the upper surface of the top plate 46. As a result, the top plate 46 is formed with an insertion groove 66 between the standing wall portions 64 and 65 whose lower end side is closed by the center plate portion 60 and extends linearly in the width direction. The standing wall portion 64 is formed with rectangular cutouts 68A to 68C between the overhang portions 50A and 50B, between the overhang portions 50B and 50C, and between the overhang portions 50C and 50D. Rectangular cutouts 68D to 68F (between these overhangs 50E and 50F, between the overhangs 50F and 50G, and between the overhangs 50G and 50H (in order to comprehensively refer to these, the “notch 68”) Is formed). The bottom portions of these notches 68 </ b> A to 68 </ b> F are located on the same plane as the top surface of the center plate 60.

  Here, the width of the insertion groove 66 and the width of the notches 68 </ b> A to 68 </ b> F are equal to each other and slightly wider than twice the thickness of the lower end portion of the side plate 44 of the filling block 40.

  As shown in FIG. 3, three window portions 70, 72, and 74 are formed in the side walls of the overhang portions 50 </ b> A to 50 </ b> H in the filling block 40 so as to penetrate in the plate thickness direction. The window portions 70, 72, and 74 are formed in a substantially rectangular shape that is elongated along the height direction (arrow H direction). Here, the window part 70 is arrange | positioned at the edge part of the depth direction outer side in overhang | projection part 50A-50H, and the window parts 72 and 74 are the one end part and the other end part along the width direction in overhang | projection part 50A-50H. Respectively.

  In addition, four openings 76 are formed in the top plate 46 in a rectangular shape at a pitch substantially equal to the pitch along the width direction of the projecting portions 50 </ b> A to 50 </ b> H in the center plate portion 60, and these openings 76. One opening 78 is formed between the two openings 76 arranged on the center side in the width direction. Further, the cover plate portions 62A to 62H of the top plate 46 are each formed with a plurality of through holes 80A to 80H (referred to simply as “through holes 80”) in a rectangular shape. .

  As described above, the windows 70, 72, 74, the openings 76, 78 and the through holes 80 </ b> A to 80 </ b> H formed in the filling block 40 have good water permeability to the inside and outside of the filling block 40, Water permeability to the inside and outside of the filling structure 18 constituted by the filling block 40 and the auxiliary block 42 is also improved.

  As shown in FIG. 5, the auxiliary block 42 is formed in a substantially truncated cone container shape as a whole. A cylindrical side plate 90 is formed on the auxiliary block 42, and a top plate 92 that closes the top side of the side plate 90 is integrally formed. The auxiliary block 42 has an open end on the bottom side (lower end side) opposite to the top plate 92, and the side plate 90 has an L-shaped or J-shaped cross section so as to extend to the outer peripheral side at the lower end portion. A folded portion 94 is formed over the entire circumference. Here, the auxiliary block 42 has a substantially square shape with the same dimension in the width direction and the depth direction in plan view, and its vertical and horizontal dimensions are ¼ of the dimension along the width direction of the filling block 40. This is ½ of the dimension along the depth direction of the block 40.

  In the auxiliary block 42, window portions 96 are formed at both end portions along the width direction and both end portions along the depth direction of the side plate 90. The shape of these four window portions 96 is substantially the same as the shape of the window portions 70, 72, 74 in the filling block 40. The top plate 92 of the auxiliary block 42 is integrally formed with a convex insertion portion 98 at the center thereof. The fitting insertion portion 98 has a substantially square shape in a plan view, and is formed in a tapered shape in which the cross-sectional area gradually decreases from the lower end side toward the upper end side. The insertion portion 98 can be inserted into and removed from the through holes 80 </ b> A to 80 </ b> H formed in the vicinity of the center of the eight cover plate portions 62 </ b> A to 62 </ b> H in the filling block 40.

  When the auxiliary block 42 is part of the filling structure 18, the auxiliary block 42 is mounted on any one of the overhang portions 50 </ b> A to 50 </ b> H in the filling block 40 in a state where the posture shown in FIG. Placed. At this time, the auxiliary block 42 inserts the insertion portion 98 into any of the through holes 80A to 80H in the filling block 40, and brings the top plate 92 into contact with the lid plate portions 62A to 62H. As a result, the auxiliary block 42 is positioned so as to be in the same position in plan view as the overhanging portions 50A to 50H located below the through holes 80A to 80H in which the insertion portion 98 is inserted. It is also positioned at a predetermined position in the vertical direction.

(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 filling block 40 and the auxiliary block 42, first, as shown in FIG. 6, a plurality of filling blocks 40 are connected to the bottom surface of the pit P via the water shielding protective layer 16. Place on top. Here, for convenience, it is assumed that the cross-sectional shape (horizontal cross section) along the horizontal direction of the pit P is substantially rectangular, and the water flow direction in the horizontal cross section of the pit P is orthogonal to the row direction (arrow R direction). The direction is the column direction (arrow L direction), and the depth direction of the pits P is the height direction (arrow H direction).

  An operator who constructs the filling structure 18 sets the plurality of filling blocks 40 that are the lowermost layer (first stage) of the filling structure 18 in a direction in which the longitudinal direction thereof coincides with the row direction of the pits P, These filling blocks 40 are arranged so as to be in contact with each other along the column direction, and are arranged so as to be in contact with each other also in the row direction, and these filling blocks 40 cover the entire bottom surface of the pit P. Accordingly, as shown in FIG. 11, the short side portions of the side plates 44 in the filling blocks 40 adjacent to each other along the row direction are in contact with each other, and the height direction is determined by the curved plate portions 58 respectively formed on the pair of side plates 44. A substantially circular maintenance hole 100 penetrating to is formed.

  Next, as shown in FIG. 7, the operator sets the plurality of filling blocks 40 that are the second stage of the filling structure 18 in a direction in which the longitudinal direction thereof coincides with the row direction of the pits P, that is, While rotating the direction by 90 ° with respect to the first-stage filling block 40, they are stacked on the first-stage filling block 40. At this time, the worker arranges the plurality of filling blocks 40 constituting the second stage so as to contact each other along the column direction, and also arranges so as to contact each other also along the row direction. Further, the operator does not place the plurality of filling blocks 40 constituting the second stage on the outermost projecting portion 50 of the plurality of filling blocks 40 constituting the first stage. A plurality of filling blocks 40 constituting the eyes are arranged on the first stage while being shifted inward along the row direction and the column direction by a dimension corresponding to one overhang 50.

  In FIG. 11, the second-stage filling structure 18 is indicated by an imaginary line and hatching. Even in the plurality of filling blocks 40 constituting the second stage, the short side portions of the filling block 40 side plates 44 adjacent to each other in the row direction are in contact with each other, and the curved plate portions 58 formed on the pair of side plates 44 respectively. A maintenance hole 100 penetrating in the height direction is formed. These second-stage maintenance holes 100 are maintenance holes arranged at odd-numbered positions (excluding the first, 3, 5,...) From the end along the row direction of the first-stage maintenance holes 100. 100 and penetrates the filling structure 18 in the height direction.

  Among the plurality of filling blocks 40 constituting the second stage, the pair of filling blocks 40 adjacent to each other along the column direction is the top plate of the first stage filling block 40 with the long side portion of the lower end portion of the side plate 44 respectively. 46 is inserted into the cutout portion 68 of 46. Of the plurality of filling blocks 40 constituting the second stage, the pair of filling blocks 40 adjacent to each other in the row direction is such that the short side portion of the lower end portion of the side plate 44 is the same as that of the first stage filling block 40. The top plate 46 is inserted into the insertion groove 66. Thus, the plurality of filling blocks 40 constituting the second stage are positioned at predetermined positions along the row direction and the column direction (horizontal direction), respectively.

  Next, as shown in FIG. 8, the operator sets the plurality of auxiliary blocks 42, which are the second stage of the filling structure 18, upside down from the posture shown in FIG. Are stacked on the outer peripheral side on the plurality of filling blocks 40 constituting the first stage. At this time, the plurality of auxiliary blocks 42 are stacked only on the outermost protruding portion 50 of the plurality of filling blocks 40 constituting the first stage, and the second stage outer periphery of the filling structure 18. It is arranged over the entire circumference along the part. Thereby, the second stage of the filling structure 18 is constituted by the filling block 40 and the auxiliary block 42.

  Next, as shown in FIGS. 9 and 10, a plurality of filling blocks 40 constituting the third stage are stacked on the second stage filling block 40 and the auxiliary block 42. These filling blocks 40 are arranged in the same direction and at the same position as the plurality of filling blocks 40 constituting the first stage. Thereafter, similarly, the filling blocks 40 and auxiliary blocks 42 stacked in the even-numbered stages are arranged in the same direction and the same positions as the second-stage filling blocks 40 and auxiliary blocks 42, and the filling blocks 40 stacked in the odd-numbered stages are The first-stage filling block 40 is disposed in the same direction and at the same position. In this way, by filling the filling block 40 and the auxiliary block 42 by the number of stages corresponding to the depth of the pit P (rainwater storage tank 10), the filling structure 18 is constructed in the pit P as shown in FIG. Is done.

  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.

  As shown in FIG. 15, a manhole hole 102 is dug down to the impermeable sheet 20 in a region directly above the maintenance hole 100 that opens to the upper surface of the filling structure 18 in the soil covering layer 22 in the site. An opening (not shown) is formed in a portion of the sheet 20 facing the maintenance hole 100. A manhole cover 104 is fitted in the manhole hole 102 at the entrance. Thus, when it is desired to check the inside of the rainwater storage tank 10 (filling structure 18) or to remove earth and sand accumulated on the bottom surface of the rainwater storage tank 10, the manhole hole 102 and the maintenance can be performed by removing the manhole cover 104. The inside of the rainwater storage tank 10 can be inspected directly through the hole 100 or with an inspection optical scope or the like, and if the vacuum hose 106 is inserted through the maintenance hole 100 to the bottom surface of the filling structure 18 as shown in FIG. The earth and sand can be sucked and removed by the vacuum hose 106.

(Configuration and mounting method of pressure receiving panel)
In the filling structure 18 configured as described above, a pressure receiving panel 110 shown in FIG. 13 can be attached as an optional component as required. The filling structure 18 embedded in the ground is subjected to earth pressure P (see FIG. 14) on the outer side surface and top surface of the filling structure 18 via the water shielding protective layer 16 and the water shielding sheet 20. The earth pressure P acting on the outer surface of the filling structure 18 increases as the distance from the ground surface increases, and the earth pressure P acting on the top surface of the filling structure 18 increases as the thickness of the covering layer 22 increases. To increase.

  On the other hand, on the outer surface of the filling structure 18, the curved plate portion 58, the window portion 70, and the recessed portion 54 of the filling block 40 are concave with respect to the surrounding area for the odd-numbered steps, and for the odd-numbered steps, The window portion 96 of the auxiliary block 42 is concave with respect to the surrounding area. In addition, on the top surface of the filling structure 18, a gap between the fitting groove 66 and the recess 54 in the filling block 40 and the top plate 46 of the blocks 40 and 42 adjacent to each other is concave with respect to the surrounding area.

  For this reason, when the outer surface or top surface of the filling structure 18 is subjected to a large earth pressure via the water shielding protective layer 16 or the water shielding sheet 20, the water shielding protective layer 16 or the water shielding sheet together with the soil fills the structure 18. In some cases, a part of the water shielding protective layer 16 or the water shielding sheet 20 is stretched along the concave part, and an excessive tension is generated in a part of the water shielding sheet 20. Thus, when the tension | tensile_strength which arose in the water-impervious sheet 20 exceeded breaking strength, damage, such as a crack and peeling between seams, will generate | occur | produce in the water-impervious sheet 20, and it accumulates in the rainwater storage tank 10 through this damaged part. There is a risk of rainwater leaking. Moreover, when damage expands with time, the soil wall around the filling structure 18 may collapse, and soil may enter the rainwater storage tank 10 through the damaged portion.

  In the rainwater storage tank 10 according to the present embodiment, when there is a possibility that the above-described problem may occur due to earth pressure received by the filling structure 18, the pressure receiving panel 110 is provided on the outer surface or the top surface of the filling structure 18. Is installed. As shown in FIG. 13, the pressure receiving panel 110 is formed in a substantially rectangular plate shape as a whole, and the pressure receiving surface 112 (see FIG. 13A), which is a surface on the side receiving earth pressure, is flat. Is formed. The pressure receiving panel 110 has a surface opposite to the pressure receiving surface 112 as an attachment surface 114 (see FIG. 13B). A first reinforcing rib 116 is integrally formed on the mounting surface 114 so that the first reinforcing rib 116 extends in the longitudinal direction at the central portion in the direction perpendicular to the longitudinal direction, and the second reinforcing rib 118 is elongated at the central portion in the longitudinal direction. It is integrally formed so as to extend in a perpendicular direction. Thereby, in the attachment surface 114, the 1st reinforcement rib 116 and the 2nd reinforcement rib 118 cross | intersect at right angle near center part.

  The first reinforcing rib 116 includes a plurality of vertical beam portions 120 linearly extending in the longitudinal direction and a plurality of (three in the present embodiment) vertical beam portions extending along the direction perpendicular to the longitudinal direction. A plurality of horizontal crosspieces 122 connecting 120 are integrally formed. The first reinforcing rib 116 is formed in a slope shape in which the wall thickness gradually protrudes from the mounting surface 114 from one end side to the other end side along the direction perpendicular to the longitudinal direction, and the inclination angle is filled. This corresponds to the inclination angle of the side plate 44 in the block 40 and the inclination angle of the side plate 90 in the auxiliary block 42. The second reinforcing rib 118 includes a plurality of (five in the present embodiment) horizontal crosspieces 122 that extend linearly in the direction perpendicular to the longitudinal direction and cross the first reinforcing rib 116.

  Here, the width along the direction perpendicular to the longitudinal direction of the first reinforcing rib 116 in the pressure receiving panel 110 is slightly narrower than the width of the recessed portion 54 in the filling block 40, and the longitudinal direction of the second reinforcing rib 118. The along width is slightly narrower than the width of the gap formed between the pair of filling blocks 40 adjacent to each other along the row direction in the filling structure 18. Further, the dimension along the longitudinal direction of the pressure receiving panel 110 is substantially equal to the dimension along the height direction of the filling block 40 and the auxiliary block 42, and the dimension along the direction perpendicular to the longitudinal direction of the pressure receiving panel 110 is It is substantially equal to 1/4 of the dimension along the width direction of 42 and the dimension along the width direction of the filling block 40.

  As shown in FIG. 13B, the pressure receiving panel 110 is integrally provided with two locking claws 124 extending from one end of the first reinforcing rib 116 to one end of the mounting surface 114 along the longitudinal direction. Is formed. A slit-like gap 126 that is slightly wider than the wall thickness of the filling block 40 and the auxiliary block 42 is formed between the locking claw 124 and the mounting surface 114, and this gap 126 is outside in the longitudinal direction. It becomes an opening.

  First, the case where the pressure receiving panel 110 is attached to the outer surface of the filling structure 18 will be described. When the operator attaches the pressure-receiving panel 110 to the filling block 40 that forms the outer surface of the odd-numbered stages (1, 2, 3,...) Of the filling structure 18, the operator receives the pressure-receiving panel 110 with a pair of locking claws. The pair of locking claws 124 are inserted into the filling block 40 through the window portions 70, 72, 74 while making the posture such that 124 faces downward. Thereafter, the operator inserts the peripheral edge portion along the lower ends of the window portions 70, 72, 74 in the side plate 44 into the gap 126 between the pair of locking claws 124 and the mounting surface 114, and also attaches the reinforcing ribs 116, 118 to the side plate. It hits 44. Thereby, the side plate 44 is locked by the pair of locking claws 124, and the pressure receiving panel 110 is attached to the outer surface of the filling structure 18 (filling block 40). At this time, since the first reinforcing rib 116 of the pressure receiving panel 110 has an inclination opposite to that of the side plate 44 of the filling block 40, the pressure receiving surface 112 of the pressure receiving panel 110 is substantially parallel to the height direction (vertical direction). Supported by

  The operator attaches a plurality of pressure-receiving panels 110 in order from one end of the outer surface to the other end of the odd-numbered stages of the filling structure 18 so that the filling structure 18 has a structure as shown in FIG. The outer surface of the odd-numbered stages can be covered with a plurality of pressure receiving panels 110 without any substantial gap.

  Further, when the operator attaches the pressure receiving panel 110 to the auxiliary block 42 constituting the outer surface of the arithmetic stage (2, 4, 6,...) In the filling structure 18, the operator places the pressure receiving panel 110 as a pair of engagement members. The pair of locking claws 124 are inserted into the filling block 40 through the window portion 96 of the auxiliary block 42 while keeping the pawls 124 facing upward. Thereafter, the operator inserts a peripheral edge portion along the upper end of the window portion 96 in the side plate 90 into the gap 126 between the pair of locking claws 124 and the mounting surface 114 and abuts the reinforcing ribs 116 and 118 against the side plate 90. . Thereby, the side plate 90 is locked by the pair of locking claws 124, and the pressure receiving panel 110 is attached to the outer surface of the filling structure 18 (auxiliary block 42). At this time, since the first reinforcing rib 116 of the pressure receiving panel 110 has an inclination opposite to that of the side plate 90 of the auxiliary block 42, the pressure receiving surface 112 of the pressure receiving panel 110 is substantially parallel to the height direction (vertical direction). Supported by

  The operator attaches a plurality of pressure-receiving panels 110 in order from one end of the outer surface to the other end of the even-numbered stages of the filling structure 18, as shown in FIG. The outer surface of the even-numbered stage can be covered with a plurality of pressure receiving panels 110 without any substantial gap.

  Next, a case where the pressure receiving panel 110 is attached to the top surface of the filling structure 18 will be described. The operator places the pressure-receiving panel 110 in a posture such that the first reinforcing ribs 116 extend in the row direction and the second reinforcing ribs 118 extend in the column direction, and a pair of fillings adjacent to each other along the row direction. It is mounted on the pair of top plates 46 so as to straddle the block 40. At this time, the pressure receiving panel 110 inserts the first reinforcing rib 116 into the recess 54 in the pair of filling blocks 40 and inserts the second reinforcing rib 118 into the gap formed between the pair of filling blocks 40. The mounting surfaces 114 are abutted against the pair of top plates 46. Accordingly, the pressure receiving panel 110 is attached to a predetermined position on the top surface of the filling structure 18 (filling block 40), and the pressure receiving surface 112 is supported so as to be parallel to the top surface of the filling structure 18.

  The operator attaches the plurality of pressure receiving panels 110 in order from one end portion along the row direction to the other end portion on the top surface of the filling structure 18, and further from one end portion toward the other end portion along the column direction. By repeating the same operation, the region excluding the insertion groove 66 on the top surface of the filling structure 18 can be covered with the plurality of pressure receiving panels 110 without any substantial gap.

(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 30 connected to the spillway 14. Further, 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 30 to drainage channels such as water pipes, drainage culverts, and sewers, and is finally discharged into rivers, seas, and the like. When rainwater exceeding the circulation amount of rainwater in the orifice pipe 30 continuously flows into the outflow basin 14 and the outflow basin 14 is nearly full, the rainwater in the outflow basin 14 flows out through the overflow pipe 32 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 a corresponding amount of rainwater has been stored 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.

  In the rainwater storage tank 10 according to the present embodiment, the plate-shaped pressure receiving panel 110 can be attached to the side plates 44 and 90 that form the outer surface of the filling structure 18. When attached to the side plates 44 and 90 that form the outer side surfaces, the pressure receiving panel 110 can close the window portions 70, 72, 74, and 96, the curved plate portion 58, and the recessed portion 54 that open to the outer surface of the filling structure 18. At the same time, the outer surface of the filling structure 18 can be covered with the pressure receiving panel 110.

  Thereby, even if the outer surface of the filling structure is subjected to earth pressure via the water-blocking protective layer 16, the water-blocking sheet 20 of the water-blocking protective layer 16 can be supported by the flat pressure-receiving surface 112 in the pressure-receiving panel 110. The water-impervious sheet 20 is locally deformed so as to fit into the recessed portions such as the window portions 70 and 72, the recessed portion 54, and the curved plate portion 58 on the outer surface of the filling structure 18 and the gap between the filling blocks 40. Since it can prevent, it can prevent that excessive tension | tensile_strength arises locally on the water-impervious sheet 20, and can prevent effectively that the water-impervious sheet 20 is damaged.

  In the rainwater storage tank 10, the pressure receiving panel 110 can be attached to the top plate 46 that forms the top surface of the filling structure 18. When the pressure receiving panel 110 is attached to the top plate 46, the pressure receiving panel 110 fills the filling structure. Even if a large earth pressure acts on the top surface of the filling structure 18 via the water shielding sheet 20 by covering the gap between the recess 54 and the pair of top plates 46 on the top surface of the body 18 from above, The sheet 20 can be supported by the pressure receiving surface 112 of the pressure receiving panel 110, and the water shielding sheet 20 can be prevented from being locally deformed so as to fit into the gap between the pair of top plates 46 on the top surface of the filling structure 18. Therefore, it can prevent that excessive tension | tensile_strength arises locally on the water-impervious sheet 20, and can prevent effectively that the water-impervious sheet 20 is damaged.

  The outer surface of the filling structure 18 does not necessarily need to cover the entire outer surface with the pressure receiving panel 110, and only the lower region of the outer surface where the earth pressure increases may be covered with the pressure receiving panel 110. good.

  Even when a filling block or auxiliary block having no window portion is used, an opening is formed in the side plate of the filling block or auxiliary block so that the locking claw 124 can be inserted, and the opening is locked through this opening. The pressure receiving panel 110 may be attached to the filling block or the auxiliary block by inserting the claw 124 into the filling block or the auxiliary block and locking the side plate of the filling block or the auxiliary block with the locking claw 124.

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 a perspective view which shows the structure of the filling block used for the rainwater storage tank shown by FIG. FIG. 4 is a plan view and a side view of the filling block shown in FIG. 3. It is a perspective view which shows the structure of the auxiliary | assistant block used for the rainwater storage tank shown by FIG. It is a perspective view which shows the structure of the 1st step | paragraph of the filling structure used for the rainwater storage tank shown by FIG. It is a perspective view which shows the structure of the part comprised by the filling block in the 1st step | paragraph and the 2nd step | paragraph of the filling structure used for the rainwater storage tank shown by FIG. It is a perspective view which shows the structure of the 1st step | paragraph and the 2nd step | paragraph of the filling structure used for the rainwater storage tank shown by FIG. It is a perspective view which shows the structure of the 1st step | paragraph-the 3rd step | paragraph of the filling structure used for the rainwater storage tank shown by FIG. It is a side view from the 1st step to the 3rd step in the filling structure shown in FIG. It is a top view which shows the structure of the filling structure used for the rainwater storage tank shown by FIG. It is a perspective view which shows the state which attached the pressure receiving panel as an optional member to the filling structure used for the rainwater storage tank shown by FIG. It is a perspective view which shows the surface side and back surface side of the pressure receiving panel shown by FIG. It is a top view which shows typically the state which is supporting the earth pressure by the pressure receiving panel shown by FIG. It is sectional drawing which shows the state which has attracted and collect | recovered the earth and sand accumulated in the rainwater storage penetration tank which concerns on embodiment of this invention with a vacuum hose.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Rainwater storage tank 16 Water-blocking protective layer 18 Filling structure 20 Water-blocking sheet 40 Filling block 42 Auxiliary block 44 Side plate (filling block)
46 Top plate (filling block)
70 Window (filling block)
72 Window (filling block)
74 Window (filling block)
90 Side plate (auxiliary block)
92 Top plate (auxiliary block)
96 Window (auxiliary block)
110 pressure receiving panel 112 pressure receiving surface 114 mounting surface 116 first reinforcing rib 118 second reinforcing rib 124 locking claw

Claims (6)

A cylindrical side plate having one end opened along the height direction, and a top plate that integrally closes the other end of the side plate, and a filling block having a window opening to the side plate;
A water shielding sheet laid so as to cover the inner surface of the concave water storage pit formed on the ground;
A plurality of the filling blocks are arranged along a row direction and a column direction orthogonal to the height direction, and are stacked along the height direction, and are formed in the water storage pit via the water shielding sheet. A filling structure disposed in
It can be attached to the side plate forming the outer side surface of the filling structure, and when attached to the side plate, the window portion on the outer side surface of the filling structure and an area between a pair of adjacent window portions are outside. A plate-shaped pressure receiving panel covering from
The rainwater storage tank characterized by having.   The pressure-receiving panel can be attached to the top plate forming the top surface of the filling structure, and when attached to the top plate, covers the space between the pair of adjacent top plates on the top surface of the filling structure from above. The rainwater storage tank according to claim 1.   The rainwater according to claim 1 or 2, wherein the pressure-receiving panel has a flat pressure-receiving surface on a surface opposite to an inner mounting surface facing the outer surface or top surface of the filling structure. Reservoir.   The locking claw that is inserted into the inside of the side plate through the window portion and that locks the peripheral edge portion of the window portion in the side plate is integrally formed on the mounting surface. Rainwater storage tank.   5. A reinforcing rib that integrally contacts the side plate from the outside and supports the pressure receiving surface so as to extend in a substantially vertical direction is integrally formed on the mounting surface. Rainwater storage tank. A concave gap extending along the arrangement direction of the filling blocks is formed on the top surface of the filling structure, and a convex shape extending along the arrangement direction of the filling blocks is formed on the mounting surface. Forming reinforcing ribs,
The rainwater storage tank according to any one of claims 3 to 5, wherein the reinforcing rib is inserted into the gap to position the pressure receiving panel at a predetermined mounting position on a top surface of the filling structure. .

Images