CN111663633A

CN111663633A - Rainwater storage and infiltration facility

Info

Publication number: CN111663633A
Application number: CN201910175865.4A
Authority: CN
Inventors: 结城和久
Original assignee: Tensho Electric Industries Co Ltd
Current assignee: Tensho Electric Industries Co Ltd
Priority date: 2019-03-08
Filing date: 2019-03-08
Publication date: 2020-09-15

Abstract

Problem in order to maintain the strength of the rainwater storage/infiltration facility even by reducing the number of unit members used per unit area, the void space ratio of the rainwater storage space is increased, and a plurality of inspection ports penetrating in the vertical direction are formed, thereby facilitating the inspection work of the rainwater storage/infiltration facility. The solution cell element (A) comprises a square flat plate (31) of given thickness and hollow legs (32, 33) in the shape of truncated cones, which lead to contact surfaces (34) formed at the four corners and on the flat plate (31). The contact face (34) is provided with an engaging convex portion 321 and an engaging concave portion (331) for interconnecting with the other unit members A. The engaging convex portion (321) of one unit member (A) and the engaging concave portion (331) of the other unit member (A) are placed to face each other to form a pair of unit members, and a given number of pairs of unit members are assembled in horizontal and vertical directions to construct a rainwater storage/infiltration facility. Since the contact surface (34) has a step thereon, the load can be supported by the steps of both lateral sides of the contact surface. The problems are solved: the strength of the rainwater storage/infiltration facility is maintained with the number of unit members used per unit area reduced to increase the void space ratio of the rainwater storage space, and a plurality of inspection ports penetrating in a vertical direction are formed to facilitate the inspection work of the rainwater storage/infiltration facility.

Description

Rainwater storage and infiltration facility

Technical Field

The present invention relates to a rainwater storage/infiltration facility which provides a rainwater storage space by placing a plurality of unit members in both horizontal and vertical directions under the ground. More particularly, the invention relates to a rainwater storage/infiltration installation making it possible: the number of unit members used per unit space is reduced, thereby allowing an increase in void space ratio of the rainwater storage space, and a plurality of inspection ports penetrating from the bottom to the ground in the vertical direction are constructed to facilitate inspection of the rainwater storage/infiltration facility.

Background

The rainwater storage/infiltration facility is placed underground in public facilities such as roads, parks, parking lots, and the like, and is constructed by stacking a plurality of unit members molded with plastics or the like in horizontal and vertical directions. The periphery of the unit member is covered with a water permeable sheet and a waterproof sheet, and rainwater is stored in the internal void space of the rainwater storage/infiltration facility. Various structural configurations have been developed for use as structural members that support loads in a vertical direction. For this type of rainwater storage/infiltration facility, a facility having a rainwater storage space with a larger void space ratio is preferable because it can store a larger capacity of rainwater. Further, since soil, sand particles, and the like accumulate in the facility during long-term use, a rainwater storage/infiltration facility in which internal inspection of the facility and removal of soil and sand particles in the facility are easy is desired.

In the rainwater storage/infiltration facilities described in detail in patent citation 1 and patent citation 2, unit members constituting the facilities are placed in intimate contact in both horizontal and vertical directions, and the unit members are connected to each other with fitting members. Therefore, the weight per unit volume increases, and the void space ratio of the rainwater storage space decreases, which makes it difficult to reduce the material cost.

In the rainwater storage/infiltration facility described in detail in patent citation 3, the unit members are placed at a distance from each other, and the corners of four adjacent unit members are connected by means of the linking members. Further, since the ceiling portions of the four adjacent unit members are covered with the ceiling material, the weight of the unit space is reduced, and by forming the inspection hole penetrating into the ground in the vertical direction, the inspection work for the rainwater storage/lower facility becomes easy. However, the rainwater storage/infiltration facility of patent citation 3 has drawbacks, one of which is that a connecting member for connecting adjacent unit members is required, which increases the number of required parts, and the other of which is that it is difficult to make the capacity of the rainwater storage space larger because it is difficult to stack the unit members further above the ceiling material.

Prior Art

Patent citation

Patent citation 1: japanese patent laid-open publication No. Hei-10-252108

Patent citation 2: japanese patent laid-open publication No. 2002-309658

Patent citation 3: japanese patent laid-open publication No. 2010-48010

Disclosure of Invention

Technical problem to be solved by the invention

The present invention is achieved in the background art as described above, and the present invention achieves the following objects.

The present invention aims at: increasing a void space ratio of the rainwater storage space by reducing the number of unit members required for the unit space; and rainwater storage/infiltration facilities with high strength for providing connection between the unit members.

It is another object of the present invention to provide a rainwater storage/infiltration facility as follows: by making it possible to form inspection ports that penetrate in the vertical direction at many or arbitrary positions, inspection work of the rainwater storage/infiltration facility is facilitated.

Means for solving the problems

The present invention adopts the following composition in order to solve the above problems.

Namely, the rainwater storage/infiltration facility according to the present invention 1;

the construction is carried out by assembling and placing a plurality of unit members in both horizontal and vertical directions under the ground to form a rainwater storage space,

the unit member is characterized by comprising:

a square or rectangular flat plate having a given thickness,

connection portions formed on four corners of one side surface of the flat plate, the connection portions being provided with contact surfaces adapted to be connected to the connection portions on the four corners of the flat plate of the other unit member, an

Hollow legs each having a cylindrical shape, formed integrally with the flat plate at four corners thereof, protruding to the other side surface of the flat plate, and leading to the one side surface.

The rainwater storage/infiltration facility according to claim 2 is characterized in that, in the invention 1, the contact surface is a rectangular pit bottom surface, each rectangular pit bottom surface is formed to be thin in thickness so as to halve the thickness of the flat plate, and each rectangular pit bottom surface extends from the one side surface to the other side surface; and are two side faces adapted to be brought into contact with any lateral side face in the four corner portions of the flat plate of the other unit member.

The rainwater storage/infiltration facility according to the invention 3 is characterized in that in the invention 2, the connecting portion is provided with an engaging portion and an engaged portion for engaging with the connecting portion of the other unit member, distal end portions of the legs located at diagonal positions of the flat plate are formed into convex and concave portions adapted to be connected to the legs of the other unit member, and the legs are formed in a circular or truncated cone shape, the diameter of the legs being gradually reduced from the one side face to the other side face.

The rainwater storage/infiltration facility according to the invention 4 is characterized in that, in the invention 3, the convex parts and the concave parts of the legs are respectively connected to constitute a pair of unit members, the engaging parts, the engaged parts and the contact surfaces of the pair of unit members and the other pair of unit members are respectively engaged to assemble the unit members, and then, they are placed underground in both horizontal and vertical directions so as to establish a rainwater storage space.

The rainwater storage/infiltration facility according to the invention 5 is characterized in that, in the invention 4, it is buried in the earth covering laid over the upper side of the unit member group at the top section, and a hollow structure is provided which connects the upper part of the inspection port formed between the flat plates of the adjacent unit members located at the top section and the ground surface so that the inspection camera can be inserted into the inspection port.

The rainwater storage/infiltration facility according to the invention 6 is characterized in that, in the invention 4, the inspection manhole is provided by: the unit members are removed in a vertical direction, thereby forming a cylindrical space extending from an upper side of the unit members positioned at the top section to the ground, and an inspection manhole is provided.

According to one aspect of the present application, there is provided a rainwater storage/infiltration facility for creating a space for storing rainwater, constructed by assembling a plurality of unit members in both horizontal and vertical directions and placing the assembled unit members under the ground, characterized in that,

the unit member includes:

a square or rectangular flat plate having a given thickness,

connection portions formed on four corners of one side surface of the flat plate, the connection portions being provided with contact surfaces adapted to be connected to the four corners of the flat plate of the other unit member, an

And hollow cylindrical legs integrally formed with the flat plate at four corners of the flat plate, the hollow cylindrical legs protruding toward the other side surface of the flat plate and leading to the one lateral side surface.

Optionally, the contact surface is rectangular dimple bottom surfaces, each rectangular dimple bottom surface being formed thin in thickness to halve the thickness of the flat plate and each rectangular dimple bottom surface extending from the one side surface to the other side surface; and are two side faces adapted to be in contact with any of the four corner portions of the flat plate of the other unit member.

Optionally, the connecting portion is provided with an engaging portion and an engaged portion for engaging with the connecting portion of the other unit member,

the end portions of the legs located at diagonal positions of the flat plate include protruding convex portions and protruding concave portions for connection with the legs of other unit members, an

The legs are formed in a circular or truncated cone shape, and the diameter of the legs is made to gradually decrease in a direction from the one side surface toward the other side surface.

Alternatively, the convex and concave portions of the legs are connected to configure a pair of unit members, the engaging portions, the engaged portions and the contact surfaces of the pair of unit members and the other pair of unit members are engaged and alternately assembled in the horizontal direction and the vertical direction, and then the assembled unit members are placed under the ground to construct the rainwater storage space.

Optionally, an inspection port is embedded in the casing laid over the group of top section unit members and formed between the sides of the flat plates of adjacent top section unit members, the top of the inspection port being connected to the earth's surface, an

A hollow structure is provided to the facility, and an inspection camera is insertable into the hollow structure through an inspection port.

Alternatively, the inspection manhole connected to the ground is provided by: the unit members are removed in the vertical direction to form a cylindrical space extending from the top surface of the top section unit member group up to the ground.

Advantageous effects of the invention

With the rainwater storage/infiltration facility according to the present invention, since the number of unit members required for a unit space can be reduced and the rainwater storage capacity is increased by the improvement of the void space ratio of the rainwater storage space, the manufacturing cost is reduced. Further, since the joining surfaces of the connecting portions that connect two pairs of unit members are joined by three joining surfaces, the joining strength becomes so high that the connection of the unit members and other unit members is established. Further, since it is possible to form a plurality of inspection ports passing in the vertical direction at arbitrary positions, facility inspection work can be facilitated.

Drawings

FIG. 1: fig. 1 is a perspective view of the entire rainwater storage/infiltration facility according to the present invention.

FIG. 2: fig. 2 is a perspective view showing a unit member group for shielding a first stage of the rainwater storage/infiltration facility group shown in fig. 1 and a cover member of a void space below the unit member group.

FIG. 3: fig. 3 is a perspective view showing a unit member group at a second stage of the rainwater storage/infiltration facility shown in fig. 1, and a lateral side cover member for shielding a side void space of the unit member group.

FIG. 4: fig. 4 is a perspective view showing the following configuration: and stacking a second section of unit component group on the first section of unit component group, joining the two unit component groups, and connecting the first section of unit component group and the second section of unit component group along the horizontal direction and the vertical direction.

FIG. 5: fig. 5 is a perspective view showing a third stage unit member group of the rainwater storage/infiltration facility shown in fig. 1.

FIG. 6: fig. 6 is a perspective view showing a cover member for shielding a void space at an upper side of the rainwater storage/infiltration facility shown in fig. 1.

FIG. 7: fig. 7 is a perspective view showing a cover member for covering an inspection port of the rainwater storage/infiltration facility shown in fig. 1.

FIG. 8: fig. 8 shows a unit member a constituting the rainwater storage/infiltration facility shown in fig. 1, fig. 8(a) is a front view of the unit member a, fig. 8(b) is a side view of the unit member a shown in fig. 8(a), and fig. 8(c) is a sectional view of the unit member a shown in fig. 8(a) taken along line a-a.

FIG. 9: fig. 9 shows a unit member B constituting the rainwater storage/infiltration facility shown in fig. 1, fig. 9(a) is a front view of the unit member B, fig. 9(B) is a right side view of the unit member B shown in fig. 9(a), and fig. 9(c) is a sectional view of the unit member B shown in fig. 9(a) taken along line B-B.

FIG. 10: fig. 10 shows unit members C1, C2, both constituting the rainwater storage/infiltration facility shown in fig. 1, fig. 10(a) is a front view of the unit member C1, fig. 10(b) is a right side view of the unit member C1 shown in fig. 10(a), fig. 10(C) is a sectional view of the unit member C1 shown in fig. 10(a) taken along line C-C, fig. 10(D) is a front view of the unit member C2, fig. 10(e) is a right side view of the unit member C2 shown in fig. 10(D), and fig. 10(f) is a sectional view of the unit member C2 shown in fig. 10(D) taken along line D-D.

FIG. 11: fig. 11 shows a cover member a constituting the cover member shown in fig. 6, fig. 11(a) is a front view of the cover member a, fig. 11(b) is a right side view of the cover member a shown in fig. 11(a), and fig. 11(c) is a sectional view of the cover member a shown in fig. 11(a) taken along a line E-E.

FIG. 12: fig. 12 shows a cover member B constituting the cover member shown in fig. 6, fig. 12(a) is a front view of the cover member B, fig. 12(B) is a right side view of the cover member B shown in fig. 12(a), and fig. 12(c) is a sectional view of the cover member B shown in fig. 12(a) taken along a line F-F.

FIG. 13: fig. 13 shows a cover member C constituting the cover member shown in fig. 6, fig. 13(a) is a front view of the cover member C, fig. 13(b) is a right side view of the cover member C shown in fig. 13(a), and fig. 13(C) is a sectional view of the cover member C shown in fig. 13(a) taken along line G-G.

FIG. 14: fig. 14 shows a cover member D for covering the inspection port shown in fig. 7, fig. 14(a) is a front view of the cover member D, fig. 14(b) is a right side view of the cover member D shown in fig. 14(a), and fig. 14(c) is a sectional view of the cover member D shown in fig. 14(a) taken along a line H-H.

FIG. 15: fig. 15 shows a lateral side cover member a, fig. 15(a) is a front view, fig. 15(b) is a right side view of the lateral side cover member a shown in fig. 15(a), and fig. 15(c) is a plan view of the lateral side cover member a shown in fig. 15 (a).

FIG. 16: fig. 16 shows a lateral side cover member B, fig. 16(a) is a front view, fig. 16(B) is a right side view of the lateral side cover member B shown in fig. 16(a), and fig. 16(c) is a plan view of the lateral side cover member B shown in fig. 16 (a).

FIG. 17: figure 17 is a longitudinal cross-sectional view of an inspection port buried in casing laid over a rain storage/infiltration facility and dedicated for use with an inspection camera.

FIG. 18: fig. 18 is an example of setting an inspection port as an inspection manhole to a rainwater storage/infiltration facility, fig. 18(a) is a plan view of a top section of the rainwater storage/infiltration facility taken along line a-a shown in fig. 18(b), and fig. 18(b) is a longitudinal sectional view of the periphery of the inspection port for the inspection manhole.

Detailed Description

Now, an embodiment for carrying out the present invention will be described below with reference to the accompanying drawings. FIG. 1 is a perspective view of the entire rainwater storage/infiltration facility of the present invention; fig. 2 is a perspective view showing a cover member for shielding a first stage of a unit member group of the rainwater storage/infiltration facility and a void space below the unit member group. FIG. 3 is a perspective view showing a second stage unit member group of the rainwater storage/infiltration facility shown in FIG. 1; fig. 4 is a perspective view showing the following configuration: stacking a second segment unit member group on the first segment unit member group to join them and connecting the first segment unit member group and the second segment unit member group in both horizontal and vertical directions. Fig. 5 is a perspective view showing a third stage unit member group of the rainwater storage/infiltration facility shown in fig. 1. As shown in fig. 1 to 5, the rainwater storage/infiltration facility 1 shown in fig. 1 is assembled and placed in a space formed by digging in the ground, and a first stage unit member group 11 shown in fig. 2, a second stage unit member group 12 shown in fig. 3, and a third stage unit member group 13 shown in fig. 5 are stacked and joined in order to construct the first, second, and third stage unit member groups by being connected to each other in both horizontal and vertical directions.

Unit component A

Each of the first stage unit cell group 11, the second stage unit cell group 12, and the third stage unit cell group 13 includes a unit cell a21 shown in fig. 8, a unit cell B22 shown in fig. 9, and a unit cell C123 and a unit cell C224 shown in fig. 10. The unit member a21, the unit member B22, the unit member C123, and the unit member C224 are all molded with a synthetic resin (e.g., polypropylene). As shown in fig. 8, a square flat plate portion 31 and four hollow

cylindrical legs

32, 33 are integrally formed to a unit member a 21. The

legs

32, 33 are integrally formed to four corners of the flat plate 31 at equal intervals, protrude toward one side 311 of the flat plate 31, and open to the other side 312 of the flat plate 31. Each of the

legs

32, 33 is formed in a truncated conical shape, the diameter of which gradually decreases as the leg protrudes from the side 311.

Legs

32, 32 are formed on one diagonal of plane 31 and

legs

33, 33 are formed on the other diagonal.

An engaging convex portion 321 is formed on each of the protruding ends of the

legs

32, 32 in a truncated cone shape, and an engaging concave portion 331 is formed on each of the protruding ends of the

other legs

33, 33 in a truncated cone shape capable of engaging with the engaging convex portion 321. Eight through holes 39 having a small diameter are formed in each of the protruding ends of the

legs

32, 33 so that water entering the hollow cylindrical portions of the

legs

32, 33 can leak out of the

legs

32, 33. The protruding ends of the

legs

32, 33 of the unit member a21 are stacked on the protruding ends of the

legs

32, 33 of the other unit member a21 in the vertical direction, thereby constructing the unit member a of the two-step structure. Thereafter, by engaging the engaging protrusions 321 on the ends of the

legs

32, 32 with the engaging recesses 331 of the legs 33, a pair of unit members a21, 21 stacked up and down can be connected in the vertical direction. The connection of the engagement concave portion 321 and the engagement convex portion 331 is advantageously achieved by a large-area taper junction (instead of the conventional pin connection) because the bending strength can be enhanced.

A contact face 34 having a side length of L1 is formed on each of the four corners of the flat plate 31 at the other side face 312 of the unit member a21, the contact face 34 being formed in the form of a square depression. It is noted that the recess is provided with two lateral sides. The contact surfaces 34 are formed on four corners of the flat plate 31 at equal intervals along four sides thereof, and the contact surfaces 34 are recessed by half the thickness H of the flat plate 31 on the side surface 311. When the two lateral sides are in contact with the contact faces 34 of the other unit members a, these lateral sides are in contact with the corresponding lateral sides at the corners of the other unit members a and operate to receive a load applied from the lateral direction. That is, since the contact surface 34 is recessed from the other side surface 312, even if dynamic pressure from the side surface caused when rainwater flows in or static pressure due to soil pressure is applied, the mechanical strength of the rainwater storage/infiltration facility assembled by the unit members a being connected is enhanced. This is because: by means of the cooperation of the two lateral sides of the rectangular contact surface 34, a pressure force from the lateral direction is received. Two engaging portions 35 and two engaged portions 36 are formed on the contact face 34. The engaging portion 35 is a convex portion: it projects from the contact face 34 to the other side face 312 of the flat plate 31, and the engaged portion 36 is a recess portion: it opens onto the contact surface 34. The two engaging portions 35 and the two engaged portions 36 are arranged on the same circumference concentric with the

legs

32, 33 at angular intervals of 90 degrees. The engaging portion 35 and the engaged portion 36 are formed to face each other on the same oblique line.

As shown in fig. 8, the length of one side of the square flat plate 31 is 2L1+ L2. From the description of the unit member a, it is understood that the unit member a has a symmetrical structure in which the central axis is a line extending perpendicular to the plane of the flat plate 31. With the assembly of a pair of unit members a, the engaging convex portions 321 on the protruding ends of the

legs

32, 32 of the unit member a are inserted into the engaging concave portions 331 of the protruding ends of the

legs

33, 33 of the other unit member a. The basic structure of the rainwater storage/infiltration facility according to the present invention is to assemble a pair of unit members a obtained by alternately assembling two unit members a in horizontal and vertical directions. The pair of unit members a is square or rectangular in outer shape. In summary, the rainwater storage/infiltration facility of the present invention is constructed by stacking unit members in both horizontal and vertical directions in a square or rectangular shape while maintaining void spaces between the unit members. Note that, for a rainwater storage/infiltration facility of small size, a structure in which the placement of the unit members does not provide a void space may be applicable.

Unit component B

The main difference between the unit member B22 shown in fig. 9 and the unit member a21 described above is that: on the unit member B22, only two

legs

32, 33 are formed. That is, the unit member B22 is integrally formed with the rectangular flat plate 37 and the two

hollow legs

32, 33. When the main unit member a is assembled to construct a box-shaped rainwater storage/infiltration facility, a discontinuity (void) is inevitably formed at the corner of the unit member a. The unit member B serves to prevent the occurrence of such discontinuity formation. The

legs

32, 33 are integrally formed on two corners of the plate 37, projecting toward one side 371 of the plate 37 and opening out to the other side 372 of the plate 37. Each of the

legs

32, 33 is formed in the form of a truncated cone, and the inside of the leg is a cavity, which gradually decreases in diameter toward the side 371, with constant thickness. The

legs

32, 33 of the unit member B are the same shape as the

legs

32, 33 of the unit member a21 except for the end portions.

An engaging convex portion 321 is formed on the projecting end of the leg 32, and an engaging concave portion 331 engageable with the engaging convex portion 321 is formed on the projecting end of the other leg 33. Eight through holes 39 are formed on the protruding ends of the

respective legs

32, 33 so that water flows out of the

legs

32, 33, the through holes 39 having a narrow diameter. The protruding ends of the

legs

32, 33 of the unit member B22 are disposed upward in the vertical direction, and the protruding ends of the

legs

32, 33 of the other unit member B22 are disposed downward in the vertical direction, thereby building a unit member stacked in two stages. Then, by engaging the engaging convex portion 321 of the leg 32 with the engaging concave portion 331 of the leg 33, the pair of upper and lower unit members B22, 22 can be connected in the vertical direction. A square contact face 34 having a respective side length L1 is formed on each of the two corners at the other side 372 of the flat plate 37 of the unit member B22. The contact surface 34 is formed to be recessed toward the lateral side 371 by half the thickness H of the flat plate 37 (see fig. 9 (b)).

Two engaging portions 35 and two engaged portions 36 are formed on the contact face 34. The engaging portion 35 is a convex portion: it projects from the contact face 34 to the other side 372 of the flat plate 37, the engaged portion 36 being a recess: it opens onto the contact surface 34. The two engaging portions and the two engaged portions 36 are arranged at intervals of 90 degrees on the same circumference concentric with the

legs

32, 33. The engaging portion 35 and the engaged portion 36 are formed to face each other on the same oblique line. As shown in fig. 9, the length of the long side of the rectangular flat plate 37 is 2L1+ L2, and the length of the short side is L1. That is, the sides of the square flat plate 31 of the cell member a21 and the long sides of the flat plate 37 of the cell member B22 are formed with the same length.

Unit component C1 and unit component C2

The unit members C123 and C224 shown in fig. 10 are mainly different from the unit member B22 in that: on each of the unit member C123 and the unit member C224, one

leg

32 or 33 is formed. That is, a square flat plate 38 having a side length of L1 is provided to each of the unit member C123 and the unit member C224. When the main unit member is used to construct the box-shaped rainwater storage/infiltration facility, a break between the unit members will inevitably occur. Like cell member B, cell member C1 and cell member C2 are used to fill in this discontinuity (void) in the corner. The unit member C123 is integrally formed with the hollow leg 32.

Legs

32, 33 are formed integrally with plate 38, and

legs

32, 33 project toward one side 381 of plate 38 and open to the other side 382. Each of the

legs

32, 33 is formed in a truncated conical shape, the diameter of which gradually decreases toward the side surface 381. An engaging convex portion 321 is formed on the protruding end of the leg 32, and an engaging concave portion 331 engageable with the engaging convex portion 321 is formed on the protruding end of the leg 33. Each of the protruding ends of the

legs

32, 33 is provided with eight through holes 39 so that water inside the

legs

32, 33 can flow out, the through holes 39 having a small diameter.

The protruding end of the leg 32 of the unit member C123 is placed to the upper side in the vertical direction, and the protruding end of the leg 33 of the unit member C224 is placed to the lower side in the vertical direction, so that the unit member C1 and the unit member C2 are stacked in two stages in the vertical direction. Thereafter, the unit member C123 and the unit member C224 can be connected in both the horizontal and vertical directions by engaging the engaging convex portion 321 of the leg 32 with the engaging concave portion 331 of the leg 33. A square contact face 34 having a side length of L1 is formed on the other side 382 of the flat plate 38 of each of the unit member C123 and the unit member C224. The contact surface 34 is formed with a thickness of H/2, which is the same as the thickness of the contact surface 34 of the unit member a21 or the unit member B22. Two engaging portions 35 and two engaged portions 36 are formed on the contact face 34. The engaging portion 35 is a convex portion protruding from the contact surface 34 toward the other side surface 382 of the flat plate 38, and the engaged portion 36 is a concave portion leading to the contact surface 34. The two engaging portions 35 and the two engaged portions 36 are arranged on the same circumference concentric with the

legs

32, 33 at angular intervals of 90 degrees. The engaging portion 35 and the engaged portion 36 are formed to face each other on the same oblique line. Since the

legs

32 and 33 of the unit members a21, B22, C123, and C224 are formed in the form of hollow truncated cones, they can be compactly stacked during transportation, which leads to a reduction in transportation cost.

Now, a sequence of assembling the unit cell a, the unit cell B, the unit cell C1, and the unit cell C2 to construct the box-shaped rainwater storage/infiltration facility will be described below.

First stage unit member group 11

The first stage unit member group 11 shown in fig. 2 is constructed by placing nine two-stage stacked unit members a21 in a grid pattern on a horizontal plane equidistantly in three rows and three columns. The distance between the edges of the flat plates 31 of the adjacent two-piece stacked unit members a21 is set to L2. Further, three two-stage stacked unit members B22 are disposed equidistantly and in parallel to rows and columns on the far side of the two-stage stacked unit member a21 shown in fig. 2. The distance between the unit member B22 and the adjacent unit member a21 is also set to L2. Likewise, the distance between two adjacent sides of the flat plate 37 is also set to L2. Further, one two-piece unit component C123 or one two-piece unit component C224 is placed at the intersection of the rows (horizontal and vertical rows) of the three two-piece unit components B22. The distance between the edge of the flat plate 38 of the two-piece unit member C123 or unit member C224 and the edge of the flat plate 37 of the two-piece unit member B22 is also set to L2. That is, with respect to the first-stage unit member group 11, all of the two-stage unit member a21, the unit member B22, the unit member C123, and the unit member C224 are placed at the same distance L2 and are placed in a grid pattern.

Cover member A

As shown in fig. 2, the cover member a serves to close the bottom of the rainwater storage/infiltration facility. Fig. 11 shows the details, and the void space in the bottom side of the first stage unit member group 11 is closed by installing the cover member a shown in fig. 11, the cover member B shown in fig. 12, and the cover member C shown in fig. 13. As shown in fig. 11, the square flat plate 61 is provided to the cover member a 51. One lateral side 611 of the flat plate 61 is formed straight, and a square contact surface 64 having a side length L1 is formed to each of the four corners on the other side 612. The contact surfaces 64 are formed equidistantly on the four corners of the flat plate 61, and are each recessed by half the thickness H of the flat plate 61 in the direction of the side surface 611. The thickness H of the flat plate 61 is the same as the thickness H of the flat plate 31 of the unit member a shown in fig. 8. Two engaging portions 65 and two engaged portions 66 are formed on each of these contact faces 64. The engaging portion 65 is a convex portion protruding from the contact surface 64 toward the other side surface 612 of the flat plate 61, and the engaged portion 66 is a concave portion leading to the contact surface 64. The shapes of the two engaging parts 65 and the two engaged parts 66 are the same as those of the engaging part 35 and the engaged part 36 of the unit member a shown in fig. 8, respectively, and the two engaging parts 65 and the two engaged parts 66 are formed at the same positions as those of the engaging part 35 and the engaged part 36 of the unit member a. As shown in fig. 11, the side length of the square flat plate 61 is 2L1+ L2, which is the same as the side length of the flat plate 31 of the unit member a shown in fig. 8.

Cover member B

As shown in fig. 2, the cover member B is adapted to close (fix) the end of the rainwater storage/infiltration facility bottom. Fig. 12 shows details of the cover configuration, and a rectangular flat plate portion 67 is provided to the cover member B52. One lateral side 671 of the flat plate portion 67 of the cover member B52 is formed straight, and a square contact face 64 having a side length of L1 is formed to each of two corners on the other lateral side. The contact face 64 is formed recessed toward the one lateral side 671 by half the thickness H of the flat plate 67. Two engaging portions 65 and two engaged portions 66 are formed on the contact face 64. The engaging portion 65 is a convex portion protruding from the contact surface 64 toward the other lateral side 672 of the flat plate 67, and the engaged portion 66 is a concave portion leading to the contact surface 64. The shapes of the two engaging parts 65 and the two engaged parts 66 are the same as those of the engaging part 35 and the engaged part 36 of the unit member shown in fig. 9, and the two engaging parts 65 and the two engaged parts 66 are formed at the same positions as those of the engaging part 35 and the engaged part 36 of the unit member B. As shown in fig. 12, the length of the long side of the rectangular flat plate portion 67 is L1. That is, the length of the long side and the short side of flat plate portion 67 is designed to be the same as the length of the long side and the short side of unit member B22.

Cover member C

As shown in fig. 2, the cover member C is used to close the corner of the rainwater storage/infiltration facility bottom. As shown in fig. 13, the cover member C53 is provided with a square flat plate 68 having a side length of L1. One lateral side 681 of the flat plate 68 of the cover member C53 is formed straight, and the square contact face 64 having the side length L1 is formed on the other lateral side 682 of the flat plate 68. The thickness of the contact face 64 is set to H/2, which is the same as the thickness of the contact faces 64 of the cover members a51 and B52. Two engaging portions 65 and two engaged portions 66 are formed on the contact face 64. The engaging portion 65 is a convex portion that protrudes from the contact surface 64 toward the other lateral side 682 of the flat plate 68, and the engaged portion 66 is a concave portion that leads to the contact surface 64. The two engaging parts 65 and the two engaged parts 66 are identical in shape to the engaging parts 65 and the engaged parts 66 of the unit member C shown in fig. 10, and are formed in the same positions as those of the engaging parts 35 and the engaged parts 36 of the unit member C.

As described above, the cover member C53 is placed on the contact face 34 at the front side corner of the unit member a21 at the front side corner shown in fig. 2. Then, the engaging portion 65 and the engaged portion 66 of the cover member C53 are engaged with the engaging portion 35 and the engaged portion 36 of the unit member a21, thereby fixing the cover member C53 to the contact face 34 of the unit member a 21. Thus, the opening of the

leg

32 or 33 placed in the front side corner of the unit member a21 is closed. Further, the cover member B52 is placed on the contact faces 34, 34 on the front sides of the unit members a21 and B22 placed in the front row and the front row of fig. 2. After that, the engaging portions 65 and the engaged portions 66 of the cover member B52 are engaged with the engaging portions 35 and the engaged portions 36 of the unit members a21 and B22, thereby fixing the cover member B52 to the contact faces 34, 34 of the unit members a21 and B22.

Thus, the openings of the

legs

32 or 33 placed in the front sides of the unit members a21 and B22 are closed. In addition, the cover member a51 is placed on the adjacent four contact faces 34, 34 of the unit member a21, the unit member B22, the unit member C123, and the unit member C224 other than the above-mentioned ones. Then, the engaging portions 35 and the engaged portions 36 of the unit members a21, B22, C123, and C224 are engaged with the engaging portions 65 and the engaged portions of the cover member a51, thereby fixing the cover member a51 to the contact faces 34, 34 of the unit members a21, B22, C123, and C224. Thus, the openings of the adjacent four

legs

32, 33 of the unit members a21, B22, C123, and C224 are closed.

Second-stage unit member group 12

The second-stage unit member group 12 shown in fig. 3 is constructed by placing nine sets of two-stage unit members a21 in a grid pattern on a horizontal plane equidistantly in three rows and three columns. The distance between the adjacent flat plates 31 of the two-piece unit member a21 is set to L2. In addition, the three sets of two-piece unit members B22 are respectively placed in front of the two-piece unit member a21 shown in fig. 3 at equal distances and are placed in parallel to the front row and the front row of the two-piece unit member a 21. The distance between the two-piece unit member B22 and the adjacent two-piece unit member a21 is also set to L2. Likewise, the distance between the side of the flat plate 37 of the two-stage unit member B22 and the other side of the adjacent flat plate 37 is also set to L2. Further, one two-piece unit component C123 and one two-piece unit component C224 are placed on the intersections of the rows and columns of three two-piece unit components B22. Similarly, the distance between the edge of the flat plate 38 of the two-piece unit component C123 or the two-piece unit component C224 and the edge of the flat plate 37 of the two-piece unit component B22 is also set to L2. That is, the first-stage unit member group 11 and the second-stage unit member group 12 differ in that: the two-piece unit component B22, the two-piece unit component C123, and the two-piece unit component C224 are placed in parallel to both the front row of the two-piece unit component a21 and the front row of the two-piece unit component a 21.

Lateral side cover member A

As shown in fig. 3, the lateral side cover member a is adapted to close the lateral side of the rainwater storage/infiltration facility. By installing the lateral side cover member a 55 shown in fig. 15 and the lateral side cover member B shown in fig. 16, the void space on the lateral side of the second-stage unit member group 12 of the rainwater storage/infiltration facility is closed. As shown in fig. 15, the lateral side cover member a 55 is provided with a rectangular flat plate 81. One lateral side 811 of the flat plate 81 is formed straight, and the contact surface 813 is formed on the upper side (the upper side of (a) and (b) in fig. 15) of the other lateral side 812, the contact surface 813 projecting beyond the other lateral side 812. On the contact surface 813, two engaging portions 82 are formed on both ends in the left-right direction shown in fig. 15, respectively. The engaging portion 82 is a projection projecting from the contact surface 813 and is engageable with the lateral side surface 371 of the flat plate 37 of the unit member B. Two contact protrusions 83A and two other contact protrusions 83B are formed on the lower position of the other lateral side 812 (lower position in (a) and (B) in fig. 15), both protruding from the other lateral side 812. The

contact protrusions

83A and 83B can contact the outer circumferences of the truncated cone-shaped

legs

32, 33 of any of the unit member a, the unit member B, the unit member C1, and the unit member C2. The contact protrusions 83A, 83A having a smaller degree of protrusion can contact the larger outer circumferences of the

legs

32, 33. While the

contact protrusions

83B, 83B having a larger protrusion degree can contact the smaller outer circumferences of the

legs

32, 33.

A contact face 84A inclined at 45 degrees is formed on an end face 814 of the flat plate 81 (upper portions of (a) and (b) in fig. 15). The inclined contact surface 84A faces the lateral side surface 811. In addition, a contact face 84B inclined at 45 degrees is formed in the contact face 84 of the other end face 815 of the flat plate 81 (lower portions of (a) and (B) in fig. 15). The angled contact face 84B faces the other lateral side 812. Two

engagement grooves

841B, 842B and two

engagement projections

843B, 844B are formed on the inclined contact surface 84B. Each of the

engagement grooves

841B, 842B is a rectangular groove formed by scraping the inclined contact surface 84B. Each of the

engagement protrusions

843B, 844B is a rectangular protrusion protruding from the inclined contact surface 84B toward the other lateral side 812, and is formed on the same plane as the other lateral side 812. The engaging

protrusions

843B, 844B are provided with engaging

portions

845B, 846B, the shapes of the engaging

portions

845B, 846B being the same. The engaging

portions

845B, 846B are formed to protrude from the other lateral side 812.

Two

engagement projections

841A, 842A and two

engagement grooves

843A, 844A are formed on the inclined contact face 84A. Each of the

engagement projections

841A, 842A is a rectangular projection projecting from the inclined contact face 84A toward the lateral side 811, and is formed on the same plane on which the lateral side 811 is formed. Each of the

engagement grooves

843A, 844A is a rectangular groove formed by scraping the inclined contact surface 84A. Rectangular engaging

holes

845A, 846A are formed in the bottoms of the

engaging grooves

843A, 844A, respectively. The engagement holes 845A, 846A open to the contact surface 813. As shown in fig. 3, six lateral side cover members a are attached side by side in order from the front corner to the lateral side at the front right side of the second-stage unit member group 12. The length L5 of the short side (vertical side shown in fig. 15) of the lateral side cover member a is set to L1+ L2+ L4. L4 is the length in the short side direction of the inclined contact surfaces 84A, 84B of the lateral side cover member a. Since the height of the vertically stacked two-stage unit member B22 is set to H1, the length L6 of the long side (the side in the vertical direction shown in fig. 15 (a)) of the lateral side cover member a is denoted by H1-H. H is the thickness of the flat plate 37 of the unit member B22.

As shown in fig. 3, the inclined contact face 84B of the lateral side cover member a located at the rear in one row and column is placed on the inclined contact face 84A of the lateral side cover member a located at the closest side. Accordingly, the

engagement grooves

841B, 842B of the lateral side cover member a positioned at the rear in one row and column are engaged with the

engagement projections

841A, 842A of the lateral side cover member a positioned at the closest side. In addition, the

engagement projections

843B, 844B of the lateral side cover member a located at the rear in one row and column are engaged with the

engagement grooves

843A, 844A of the lateral side cover member a located at the closest side. Meanwhile, the engaging

portions

845B, 846B of the lateral side cover member a positioned at the rear in one row and column are engaged with the engaging

holes

845A, 846A of the lateral side cover member a positioned at the closest side, whereby the lateral side cover member a positioned at the closest side is connected with the lateral side cover member a positioned at the rear in one row and column. All six lateral side cover members a are attached to the lateral sides of the second-stage unit member group 12 on the front and right sides in accordance with the same procedure.

Next, as shown in fig. 3, a lateral side cover member a turned upside down is attached to a corner portion of the lateral side of the second-stage unit member group 12 on the left front side. The

contact projections

83A, 83B of the lateral side cover member a turned upside down are in contact with the outer circumferences of the truncated cone-shaped

legs

32, 33 of the unit member C1 and the unit member C2. In addition, the engaging

portions

82, 82 of the lateral side cover member a turned upside down are engaged with the other

lateral sides

312, 312 of the flat plate 31 of the first stage unit member a and the third stage unit member a. Thereafter, the inclined contact faces 84B of the lateral side cover member a turned upside down are stacked on the inclined contact faces 84B of the lateral side cover member a located on the corner of the right front lateral side shown in fig. 3. Thereafter, the

engagement projections

843B, 844B of the side cover member a turned upside down are engaged with the

engagement grooves

841B, 842B of the side cover member a located at the corner of the right front side of the cover member a. At the same time, the

engagement grooves

841B, 842B of the lateral side cover member a, which are turned upside down, are engaged with the

engagement projections

843B, 844B of the lateral side cover member a, which are located on the corner portion of the right front side. Therefore, the lateral side cover member a positioned on the corner portion of the right front side is connected to the lateral side cover member a turned upside down. Although not shown, the void space in the left anterior lateral side is closed by: five pieces of the upside-down lateral side cover members a are attached to the left front lateral side of the second-stage unit member group 12, continuing to the upside-down lateral side cover members a on the corner portion among the left front lateral side.

Lateral side cover member B

As shown in fig. 3, the lateral side cover members B are adapted to close the corners of the rainwater storage/infiltration facility. Since six lateral side cover members a are attached to the right front side of the second-stage unit member group 12, a void space of length L1 still exists in the corner on the rear side of the right front side of the second-stage unit member group 12. Therefore, by mounting the lateral side cover member B shown in fig. 16, the void space is shielded. As shown in fig. 16, a rectangular flat plate 85 is formed in the lateral side cover member B56. The side 851 and the other side 852 of the flat plate 85 are formed flat. On the other lateral side 852, two contact protrusions 83A and two contact protrusions 83B are formed on the vertically intermediate portion shown in fig. 16(a) and 16(B), both the two contact protrusions 83A and the two contact protrusions 83B protruding from the other lateral side 852. The contact protrusion 83A and the contact protrusion 83B have the same shape and the same function as the contact protrusion 83A and the contact protrusion 83B.

An inclined contact surface 86A having an angle of 45 degrees is formed on one end surface 854 of the flat plate 85 (upper side of (a) and (b) in fig. 16). The inclination of the inclined contact face 86A is opposite to the inclination direction of the inclined contact face 84A of the lateral side cover member a, and the inclination of the inclined contact face 86A faces the other lateral side 852. In addition, an inclined contact face 86B having an angle of 45 degrees is formed on the other end face 855 of the flat plate 85 (lower sides of (a) and (B) in fig. 16). The angled contact surface 86B also faces the other lateral side 852. The inclined contact surface 86A and the inclined contact surface 86B are formed symmetrically to each other in the vertical direction in fig. 16 (a). That is, two

engagement grooves

861B, 862B and two

engagement projections

863B, 864B are formed on the inclined contact face 86B. Each of the

engagement grooves

861B, 862B is a rectangular groove formed by scraping the inclined contact face 86B. Also, each of the engaging

protrusions

863B, 864B is a rectangular protrusion protruding toward the other lateral side 852, and is formed on the same plane on which the other lateral side 852 is formed. Engaging

portions

865B, 866B are formed on the engaging

protrusions

863B, 864B, respectively, and both are formed in the same shape. The engaging

portions

865B, 866B are formed to protrude from the other lateral side 852.

Similar to the inclined contact face 86B, two engagement grooves 861A, 862A and two engagement projections 863A, 864A are also formed on the inclined contact face 86A. Each of the engagement grooves 861A, 862A is a rectangular groove formed by cutting the inclined contact face 86A. Each of the engaging protrusions 863A, 864A is a rectangular protrusion protruding from the inclined contact face 86A toward the other lateral side 852, and is formed on the same plane on which the other lateral side 852 is formed.

Engaging portions

865A, 866A are formed on the engaging protrusions 863A, 864A, respectively, both of the engaging

portions

865A, 866A having the same shape. The engaging

portions

865A, 866A are formed to protrude from the other lateral side 852. The length L7 of the short side (side in the vertical direction of (B) in fig. 16) of the lateral side cover member B is set to L1+ L4+ L4. L4 is the length in the short side direction of the inclined contact surface 86A or the inclined contact surface 86B of the lateral side cover member B. The length L6 of the long side (side in the left-right direction in fig. 16 (a)) of lateral side cover member B is the same as the length of the long side of lateral side cover member a, and is set to H1-H (subtracting H from H1).

The inclined contact face 86B of the lateral side cover member B is stacked on the inclined contact face 84A of the lateral side cover member a located on the far side shown in fig. 3. Thus,

engagement grooves

861B, 862B of lateral side cover member B are engaged with

engagement projections

841A, 842A, respectively, of lateral side cover member a. The

engagement projections

863B and 864B of the lateral side cover member B are engaged with the

engagement grooves

843A and 844A of the lateral side cover member a, respectively. Meanwhile, the engaging

portions

865B, 866B of the lateral side cover member B are engaged with the engaging

holes

845A, 846A of the lateral side cover member a, respectively, thereby connecting the lateral side cover member a with the lateral side cover member B.

Next, as shown in fig. 3, a lateral side cover member B turned upside down is mounted on the corner portion near the lateral side at the far right side of the second-stage unit member group 12. The

contact projections

83A, 83B of the lateral side cover member B turned upside down are in contact with the outer circumferences of the

cylindrical legs

32, 33 of the unit member B. Thereafter, the inclined contact face 86A of the lateral side cover member B turned upside down is stacked on the inclined contact face 86A of the lateral side cover member B located on the corner portion of the rear side of the right front lateral side shown in fig. 3. Then, the engagement projections 863A, 864A of the vertically-reversed lateral side cover member B are engaged with the engagement grooves 861A, 862A of the lateral side cover member B located at the rear corner of the right front lateral side. In addition, the engagement grooves 861A, 862A of the vertically inverted lateral side cover member B are engaged with the engagement projections 863A, 864A of the lateral side cover member B located at the rear corner of the right front lateral side. Therefore, the lateral side cover member B positioned on the rear corner of the right front lateral side is connected to the lateral side cover member B turned upside down. Although not shown, the void space formed on the right distal side is blocked by: five pieces of the vertically turned lateral side cover members a are mounted to the right far lateral side of the second-stage unit member group 12, continuing to the vertically turned lateral side cover member B.

According to the procedure as described above, the void space formed at the periphery of the lateral side of the unit member group can be blocked with both of the lateral side cover member a and the lateral side cover member B. As described above, first, the lateral side of the cell member group is shielded by the plurality of lateral side cover members a, and by installing one lateral side cover member B, a portion of the corner where the void space of length L1 remains is shielded. In addition, by installing one lateral side cover member B turned upside down or one lateral side cover member a turned upside down, a portion on a corner portion of the lateral side adjacent to the side to be first shielded is shielded.

Connection of the second stage unit member group 12 to the first stage unit member group 11

As shown in fig. 4, the second-stage unit member group 12 is connected to the first-stage unit member group 11. As shown in fig. 4, the unit cell a of the second-stage unit cell group 12 is placed shifted to the rear side of the row and column by a distance of L1+ L2 with respect to the unit cell a of the first-stage unit cell group 11. Therefore, the contact surfaces 34 of the unit members a of the second-stage unit member group 12 are brought into contact against the contact surfaces 34 of the adjacent four unit members a of the first-stage unit member group 11. Thus, the two engaging portions 35 and the two engaged portions 36 of the first stage unit member a and the second stage unit member a are engaged (connected) with each other, respectively, thereby connecting the first stage unit member a and the second stage unit member a in both the horizontal and vertical directions. The contact surface 34 is formed recessed toward the lateral side 311 by a length of half the thickness H of the flat plate 31. Therefore, the flat plates 31 of the first stage unit member group 11 and the second stage unit member group 12 are aligned on the same plane by contacting the contact surfaces 34 connecting the first stage unit member group 11 and the second stage unit member group 12. Therefore, the shear area of the connection portion becomes larger, and the strength of the connection portion is enhanced, particularly the strength against a load from the horizontal direction will be improved.

Similarly, the unit cell B of the second-stage unit cell group 12 is placed shifted by the length of L1+ L2 in the row and column directions with respect to the unit cell a of the first-stage unit cell group 11. Therefore, the contact surfaces 34 of the unit members B of the second-stage unit member group 12 are in contact with the contact surfaces 34 of the two adjacent unit members a of the first-stage unit member group 11 in a bridging manner. Accordingly, the two engaging portions 35 and the two engaged portions 36 of the first stage unit member a and the second stage unit member B are connected, respectively, thereby connecting the first stage unit member a and the second stage unit member B in the horizontal and vertical directions. Further, the unit members C1, C2 of the second-stage unit member group 12 are placed on the corners of the front side of the unit member a of the first-stage unit member group 11. Therefore, the contact surfaces 38 of the unit members C1, C2 of the second-stage unit member group 12 are in contact with the contact surfaces 34 on the corners of the unit member a of the first-stage unit member group 11. Thus, the two engaging parts 35 and the two engaged parts 36 of the second stage unit members C1, C2 engage with each other the first stage unit member a, thereby connecting the first stage unit member a to the second stage unit members C1, C2 in the horizontal and vertical directions. Accordingly, the second stage unit member group 12 and the first stage unit member group 11 are connected in both the horizontal and vertical directions. Thereafter, the inspection port 4 is formed, and the inspection port 4 is square in a plan view, passing through in a vertical direction. The inspection port 4 is formed between the lateral sides of the flat plates 31 of the adjacent unit members a 21. Each of the inspection ports 4 is formed in a square form with a side length of L2, and nine inspection ports are formed equidistantly.

Connection of the third stage unit member group 13 to the second stage unit member group 12

The third-stage unit cell member group 13 shown in fig. 5 is connected to the second-stage unit cell member group 12 shown in fig. 4. Since the structure of the third stage unit cell group 13 shown in fig. 5 is the same as that of the first stage unit cell group 11 shown in fig. 2, a detailed description of the third stage unit cell group is skipped. The unit cell a of the third stage unit cell group 13 is placed shifted by the length of L1+ L2 to the front side of both the row and the column with respect to the unit cell a of the second stage unit cell group 12. Therefore, the contact surface 34 of the unit cell a on the front-side corner of the third stage unit cell group 13 is in contact with the contact surfaces 38 of the unit cells C1, C2 of the second stage unit cell group 12, the contact surfaces 34, 34 of the two unit cells B adjacent to the unit cells C1, C2, and the contact surface 34 of one unit cell a adjacent to the unit cells C1, C2. Thus, the unit members a located on the front-side corner portions of the third section are joined to the second-section unit member group 12 and connected to each other in both the horizontal and vertical directions.

The contact face 34 of the unit cell a in the front side row and column of the third-stage unit cell group 13 is in contact with the contact faces 34, 34 of the unit cell B on the front side row and column of the second-stage unit cell group 12 and the contact faces 34, 34 of one unit cell a adjacent to the unit cell B. Thus, the unit members a in the front row and column of the third-stage unit member group 13 are engaged with the second-stage unit member group 12, and the unit members a are connected in both the horizontal and vertical directions. In addition, the remaining unit members a of the third unit member group 13 are in contact with the contact surfaces 34 of the four unit members a adjacent to the second unit member group 11 in a bridging manner. Therefore, the remaining unit cell a of the third stage is engaged with the second unit cell group 12, and the remaining unit cell a of the third stage is connected in both horizontal and vertical directions.

Cell member B, cell member C1, and cell member C2, which are distal to the third segment cell member group 13, are in contact with the contact faces 34, 34 of cell member a in the row and column distal to the second segment cell member group 12. Thus, cell member C1 and cell member C2, which are distal to the third stage cell member group 13, are connected to the second stage cell member group 12 in both the horizontal and vertical directions. Thus, as shown in fig. 1, the first-stage unit member group 11, the second-stage unit member group 12, and the third unit member group 13 are stacked and joined in both the horizontal and vertical directions, thereby constituting the rainwater storage/infiltration facility 1. Thereafter, the inspection port 4 is formed to the level of the flat plate 31 of the unit member a21 located below the third stage unit member group 13, the shape of the inspection port 4 in plan view being square, passing through in the vertical direction.

As described above, the rainwater storage/infiltration facility 1 according to the embodiment of the present invention is configured in such a manner that: the unit members a21, B22, C123 and C224 are placed such that the distance between the respective adjacent lateral side faces of the

flat plates

31, 37 and 38 of the unit members a21, B22, C123 and C224 is set to L2. Therefore, the number of unit members used per unit volume can be reduced, so that the manufacturing cost is reduced, and the void space ratio of the rainwater storage space is improved, which makes the rainwater storage capacity larger. Further, since the formation of a plurality of inspection ports penetrating in the vertical direction becomes practicable, inspection work of the rainwater storage/infiltration facility will become easier. In addition, since a fitting member for connecting the unit members is not required, the manufacturing cost is further reduced. With the rainwater storage/infiltration facility according to the embodiment of the present invention, the load applied from the vertical direction can be appropriately supported by the alignment of the legs of the stacked unit members on the same vertical line. In addition, with another alignment in the horizontal line of the legs of the unit members placed in the horizontal plane, the load from the horizontal direction is also appropriately supported.

Fig. 6 is a perspective view of a cover member adapted to be mounted on the third-stage unit member group 13 of the rainwater storage/infiltration facility 1 shown in fig. 1 for shielding a void space above the rainwater storage/infiltration facility 1 to prevent soil and sand particles from invading the facility. As shown in fig. 6, by installing the cover member a shown in fig. 11, the cover member B shown in fig. 12 and the cover member C shown in fig. 13, the void space of the upper side of the rainwater storage/infiltration facility 1 of the present invention 1 is shielded, and the shielding of the bottom side of the rainwater storage/infiltration facility 1 shown in fig. 2 by the cover members. As shown in fig. 6, the cover member C53 is stacked on the contact face 34 on the corner on the front side of the unit member a21 placed on the corner on the front in fig. 6. After that, the engaging portion 35 and the engaged portion 36 of the unit member a21 are engaged with the engaging portion 65 and the engaged portion 66 of the cover member C53 to fix the cover member 53 to the contact face 34 of the unit member a 21. Thus, the openings of the

legs

32 or 33 placed on the corners of the front of the unit member a21 are closed. Further, the cover member B52 is stacked on the contact faces 34, 34 on the front sides of the unit members a21 and B22 placed in the front row and column in fig. 6. After that, the engaging portions 65 and the engaged portions 66 of the cover member B52 are engaged with the engaging portions 35 and the engaged portions 36 of the unit members a21 and B22 to fix the cover member B52 to the contact faces 34, 34 of the unit members a21 and B22.

Therefore, the openings of the

legs

32 or 33 placed in the front sides of the unit members a21 and B22 are shielded. Further, the cover member a51 is placed on the adjacent four contact faces 34, 34 of the unit member a21, the unit member B22, the unit member C123, and the unit member C224, respectively. After that, the engaging portions 65 and the engaged portions 66 of the cover member a51 are engaged with the engaging portions 35 and the engaged portions 36 of the unit members a21, B22, C123, and C224 to fix the cover member a51 to the contact faces 34, 34 of the unit members a21, B22, C123, and C224. Therefore, the openings of the adjacent four

legs

32, 33 of the unit members a21, B22, C123, and C224 are blocked.

Cover member D

Fig. 7 is a perspective view of a cover member D adapted to be mounted on the third-stage unit member group 13 of the rainwater storage/infiltration facility 1 shown in fig. 1, which shields the inspection port 4 of the rainwater storage/infiltration facility 1 from the intrusion of soil and sand particles into the facility. As explained with reference to fig. 6, by installing the cover member a, the cover member B and the cover member C, the void space of the upper side of the rainwater storage/infiltration facility 1 of the present invention is shielded, but shielding of the inspection port 4 is made with a different cover member D. The cover member a, the cover member B, the cover member C, and the cover member D are made of any type of synthetic resin. As shown in fig. 14, the lid member D54 is formed in a square box shape having a side length of L2 and a thickness of H, which is the same as the thickness of the flat plate 31 of the unit member a shown in fig. 8. The length of the side of the cover member D54 is formed at the same length as the length L2 of the side of the square inspection port 4. The bottom plate 71 is integrally formed on one lateral side of the cover member D54, and the other lateral side of the cover member D54 is open. Flange portions 72 having a width L3 are formed on four sides of the lid member D54.

As shown in fig. 7, after the bottom plate 71 of the cover member D54 is placed thereon, the cover member D54 is pushed into the inspection port 4 of the third-stage unit member group 13 of the rainwater storage/infiltration facility 1 to mount the cover member D54 to the inspection port 4. Thereafter, the inspection port 4 of the rainwater storage/infiltration facility 1 is shielded, and the occurrence of soil and sand intrusion into the facility is completely prevented. In this way, by completely blocking the void space of the rainwater storage/infiltration facility 1 and covering the top of the illustrated facility 1 with soil and sand, the occurrence of soil and sand intrusion into the rainwater storage/infiltration facility 1 can be prevented, and the land in which the rainwater storage/infiltration facility 1 is buried can be utilized. Note that, when it is necessary to inspect the rainwater storage/infiltration facility 1, the inspection should be completed by removing the cover member D54 from the rainwater storage/infiltration facility 1.

Inspection port

As described above, the rainwater storage/infiltration facility 1 according to the present invention is provided with the penetration hole penetrating from the top section to the bottom section by its structure without implementing special configuration and design changes. Fig. 17 is a longitudinal cross-sectional view of an inspection port for use with an inspection camera, the inspection port being embedded in casing laid over a rain storage/infiltration facility. As shown in fig. 17, when covering earth 73 such as soil, sand, and crushed stone on the upper side of the rainwater storage/infiltration facility 1, a hollow cylindrical structure (for example, a pipe made of vinyl chloride or the like) connecting the top of the inspection port 4 of the third-stage unit member group 13 and the ground is buried without mounting a cover member D54 to the inspection port 4. A cover 75 is removably attached to the upper portion of the hollow cylindrical structure 74. A plurality of hollow cylindrical structures 74 are mounted at desired locations of the inspection port 4. When it is necessary to inspect the rainwater storage/infiltration facility 1, the cover 75 is removed, and an inspection camera is inserted into the inspection port 4 through the cylindrical structure 74 so as to perform the inspection. In this way, no work is required to remove and backfill the casing 73 around the inspection port 4.

Although the inspection port 4 is for use with an inspection camera, there are cases where a worker needs to enter the rainwater storage/infiltration facility 1 for repair work, sediment removal operation, and the like. Fig. 18 shows an embodiment in which the rainwater storage/infiltration facility is provided with an inspection manhole, fig. 18(a) is a plan view of a top section of the rainwater storage/infiltration facility taken along line a-a shown in fig. 18(b), and fig. 18(b) is a longitudinal sectional view of the periphery of the inspection manhole. The inspection manhole 80 is a square tubular space formed in the rainwater storage/infiltration facility 1 in the vertical direction. The size of the opening of the inspection manhole 80 is a dimension: the inspection worker can enter into the interior of the rainwater storage/infiltration facility. The inspection manhole 80 is a trumpet-shaped space formed by removing some of the unit members a of the rainwater storage/infiltration facility 1 placed in the vertical direction.

In the embodiment shown in fig. 18(a), ten unit members a are placed in a rectangular pattern around the outer circumference of the inspection manhole 80 provided on the top section of the rainwater storage/infiltration facility 1. In this embodiment, two unit members B are also placed (upper and lower positions in fig. 18 (a)). The cell member B, which is a small number, is fixed by the cell member a, but mechanical strength is weak due to the formation of the inspection manhole 80. For this reason, as shown in fig. 18(B), the unit member B is fixed with a reinforcing member 81 made of a rectangular corner member or the like, the reinforcing member 81 matching the shape of the inspection manhole 80. Further, a square plate-shaped concrete floor 82 is placed on the top section of the rainwater storage/infiltration facility 1, and it is also on the outer circumference of the inspection manhole 80. A circular hole 83 is formed in the center portion of the concrete floor 82. A circular adjusting ring 85 for adjusting the horizontal height position of the cast iron cover 87 is disposed in the casing 84 on the concrete floor 82. A cast iron cover 87 and a support frame 86 for supporting the cast iron cover are placed on the adjustment ring 85. When it is necessary to inspect or maintain the interior of the rainwater storage/infiltration facility 1, a worker may open the cast iron cover 87 into the facility. The inspection manhole 80 according to the embodiment is formed in a structure in which: it extends from the top section to the bottom section without the need for special constructional and design changes to the stormwater storage/infiltration facility 1.

OTHER EMBODIMENTS

Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments. For example, the rainwater storage/infiltration facility 1 according to the embodiment of the present invention is constructed by stacking a set of unit building groups into three sections, however, a facility constructed with more than one section may be applicable. When there is no conditional requirement on the height of the facility or there is any structural limitation on the height of the facility to be installed, a structure constructed by placing the unit members a, B, C, a cover member a, etc. on a plane without coupling the legs to each other may be applicable. Note that, as the lower ends of the legs in this case, a cover member (not shown) connected to the terminal concave and convex portions is used. In addition, although the legs in the embodiment of the present invention are formed in the form of a truncated cone, the sectional shape of the legs is not limited to a circle, and any arbitrary shape may be applicable, such as a square cone shape and a hexagonal cone shape. Since deformation due to creep occurs during long-term use of the rainwater storage/infiltration facility, it is necessary to check long-term performance against continuously acting loads, the guidelines of which are prescribed by the relevant organization. Accordingly, a check of the long-term performance against continuously acting loads is carried out. In this respect, the inspection of the load in both the vertical and horizontal directions is performed.

Although the thickness of the leg is constant in the above-described embodiment (see fig. 8, 9), when the creep caused by the load in the horizontal direction exceeds the degree specified in the guideline, the strength may be enhanced by increasing the diameter of the leg or by attaching a rib to some portion. This improvement in material strength can be applied not only to the legs but also to other parts, if desired. The flat plate 31 shown in fig. 8 is formed in a square form in a schematic plan view, and it is not limited to the square form, and other shapes are also applicable, such as a rectangular form and a combination of the square form and the rectangular form.

Claims

1. A rainwater storage/infiltration facility for creating a space for storing rainwater, constructed by assembling a plurality of unit members in both horizontal and vertical directions and placing the assembled unit members under the ground, characterized in that,

the unit member includes:

a square or rectangular flat plate having a given thickness,

2. Rainwater storage/infiltration installation according to claim 1,

the contact surface is a rectangular dimple bottom surface, each rectangular dimple bottom surface being formed thin in thickness to halve the thickness of the flat plate and each rectangular dimple bottom surface extending from the one side surface to the other side surface; and are two side faces adapted to be in contact with any lateral side face in the four corner portions of the flat plate of the other unit member.

3. Rainwater storage/infiltration installation according to claim 2,

the connecting portion is provided with an engaging portion and an engaged portion for engaging with the connecting portion of the other unit member,

4. Rainwater storage/infiltration installation according to claim 3,

the convex and concave portions of the legs are connected to configure a pair of unit members, the engaging portions, the engaged portions and the contact surfaces of the pair of unit members and the other pair of unit members are engaged and alternately assembled in the horizontal direction and the vertical direction, and then, the assembled unit members are placed under the ground to construct a rainwater storage space.

5. Rainwater storage/infiltration installation according to claim 4,

an inspection port is buried in the casing laid over the group of top section unit members and formed between the side surfaces of the flat plates of the adjacent top section unit members, the top of the inspection port being connected to the ground surface, an

6. A stormwater storage/infiltration facility as claimed in claim 4, characterized in that the inspection manhole connected to the ground is provided by: the unit members are removed in the vertical direction to form a cylindrical space extending from the top surface of the top section unit member group up to the ground.