TECHNICAL FIELD
[0001] The present invention relates to the production of hydraulic works aimed at reducing
the risk of flooding. Embodiments described herein relate to modular blocks for producing
underground basins for temporarily storing rainwater or river water.
BACKGROUND ART
[0002] In recent years, with extreme climate change, a number of natural disasters which
have caused increasingly frequent and harmful severe flooding have occurred. By examining
the statistics of the flood events that have occurred starting from 1900 to the present
day, as published by Wikipedia, it is possible to note particularly significant and
troubling values.
[0003] Firstly, the index of occurrence of the flood event, obtained by dividing the number
of these events occurring over a ten-year period by the total in the same ten years,
increases in value over time, reaching substantial numbers (more than double) in the
last twenty-five years and have more than quadrupled in the last five years. These
phenomena require an adaptation of the hydraulic network to reduce the risk of floods
and limit their damages.
[0004] There are no easy solutions to this adaptation, above all for reasons linked to the
high costs to be sustained and to the high environmental impacts, which the various
approaches to the problem can cause. Some solutions possible with ordinary techniques
are difficult to put in place. For example, building a new hydraulic network or even
simply expanding the existing network has very high costs and above all is limited
by highly urbanized and developed territories, where the availability of land that
is undeveloped or without restrictions is very limited. Added to these factors are
also serious problems of impact on the landscape.
[0005] Alternatively, extensive "reservoir" areas, can be produced, with basins in which
to temporarily store rainwater or river water, so as to reduce the flow rate during
periods of heavy rainfall. The water temporarily stored is subsequently drained away
slowly once the rains decrease or cease. The identification, along the path of a river
course, of large areas in which the excess waters of the water course can be temporarily
stored and retained while waiting for the flood wave to pass, is a concrete alternative,
with relatively low costs. Some important limits to this solution are that there can
be no buildings in these areas, and also that is it not easily achievable in populated
areas, where the need is often greater, as it is in these areas that rivers overflow
their banks more frequently, due to the inadequacy of their hydraulic cross section.
[0006] Therefore, there is the need to find new solutions to the aforesaid problems.
SUMMARY
[0007] According to one aspect, there is provided a block made of plastic material, preferably
recycled plastic, for filling underground storage basins for rainwater or river water.
The block comprises a first plurality of hollow truncated-pyramid shaped bodies, extending
from a first side of a median plane of the block, and a second plurality of hollow
truncated-pyramid shaped bodies, extending from a second side of the median plane.
Each truncated-pyramid shaped body has a larger base on the median plane and a smaller
base at a distance from the median plane. The hollow truncated-pyramid shaped bodies
are configured and arranged so that identical blocks can be mutually superimposed
in two distinct positions, i.e.: in a position with minimum overall dimensions, in
which truncated-pyramid shaped bodies of one block are inserted into truncated-pyramid
shaped bodies of a superimposed block; and in a second position with maximum overall
dimensions, in which truncated-pyramid shaped bodies of two superimposed blocks rest
on one another at the respective smaller bases.
[0008] The truncated-pyramid shaped bodies have on the respective walls, and in particular
on the wall defining the smaller base, openings to place the inner volumes of the
pyramid shaped bodies of mutually superimposed blocks in fluid communication in the
position with maximum overall dimensions.
[0009] By placing several modular blocks of this type horizontally side by side with one
another side, to form a respective layer, and superimposing several layers on one
another, arranged so that modular blocks of adjacent layers are arranged in the position
with maximum overall dimensions, it is possible to obtain filling volumes of underground
basins, containing a very high percentage of empty space, for example up to around
90%, which can be filled with rainwater and/or river water. The structure resulting
from superimposing the layers of modular blocks also allows the basin to be covered
with a layer of material suitable to reconstruct on top of the surface occupied by
the basin, an area that can be used, for example, for agricultural or other purposes.
[0010] It is thus possible to produce, rapidly and with minimum costs, underground, or subterranean,
basins, of large size, which represent watersheds for storing excess water that can
be removed from a river or other water course, reducing its flow rate and consequently
preventing flooding. In combination or alternatively, rainwater, i.e., storm water,
can be stored in the basin. The basin is filled and emptied easily due to the structure
of the modular blocks. The mechanical compression strength of the layers of superimposed
modular blocks allows the surface above the basin to be used efficiently. This can
thus be produced without sacrificing useful surface, for example to create green areas,
car parks, cultivable areas, roads or other infrastructures.
[0011] According to a further aspect, a system for temporarily storing rainwater or river
water is described, comprising: an underground basin for temporarily storing rainwater
or river water; and at least one hydraulic connection for conveying water into the
basin. The storage volume is filled with a plurality of modular blocks of the type
defined above, and a covering resting on the filling blocks is formed above the volume
of the basin, to form a usable area.
[0012] Further advantageous features and embodiments of the modular block and of the basin
filled with the modular blocks are defined in the appended claims, which form an integral
part of the present description.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] The invention will be better understood by following the description and the accompanying
drawings, which illustrate a non-limiting example of embodiment of the invention.
More in particular, in the drawing:
Fig. 1 shows an axonometric view of a modular block in an embodiment;
Fig.2 shows a plan view of the modular block of Fig. 1;
Fig.3 shows a section according to the line III-III of Fig.2;
Fig.4 shows an axonometric view of superimposed blocks;
Fig. 5 shows a cross section of modular superimposed blocks;
Fig.6 shows an enlargement of the detail VI of Fig.5;
Fig.7 shows a section of a portion of a basin filled with layers of modular blocks;
and
Fig. 8 shows a schematic view of a basin associated with a water course.
DETAILED DESCRIPTION
[0014] A modular block for storage basins for temporarily storing or collecting river water
or rainwater is represented in an axonometric view in Fig.1 and in a plan view in
Fig.2. The block 1 is preferably made of molded plastic material. Advantageously,
the plastic material can be recycled plastic material.
[0015] The modular block 1 comprises a first series or plurality of hollow truncated-pyramid
shaped bodies 3A, which extends from a median plane with the trace M (see section
of Fig.3) on one side of this median plane. On the opposite side of the median plane
M a second series or plurality of hollow truncated-pyramid shaped bodies 3B extends.
The hollow truncated-pyramid shaped bodies 3A, 3B have a quadrangular, and more precisely
square, cross section. The truncated-pyramid shaped bodies are arranged in a checkerboard
pattern, i.e., alternated. In substance, by observing the block 1 from above (Fig.2),
25 truncated-pyramid shaped bodies 3A are arranged on one side thereof, in rows alternately
of three and four truncated-pyramid shaped bodies. The cavities that define the inner
volume of the same number of truncated-pyramid shaped bodies 3B that protrude from
the opposite side of the median plane M are inserted between them.
[0016] The total number of truncated-pyramid shaped bodies 3A, 3B is by way of example and
it must be understood that modular blocks 1 of different sizes, with a different number
of hollow truncated-pyramid shaped bodies, could also be produced.
[0017] Each hollow truncated-pyramid shaped body 3A, 3B has a larger base lying on the median
plane M, and in practice consisting of the opening of the hollow compartment defined
inside the hollow truncated-pyramid shaped body 3A, 3B. Moreover, each truncated-pyramid
shaped body 3A, 3B has a smaller base, a distance from the median plane M, defined
by a closing wall of the hollow truncated-pyramid shaped body 3A, 3B. The smaller
bases of the truncated-pyramid shaped bodies 3A, 3B are indicated with 5. Lateral
walls 7 defining the sides of each hollow truncated-pyramid shaped body 3A, 3B extend
from the larger bases to the smaller bases.
[0018] In practice, as can be easily understood from the axonometric view of Fig. 1 and
from the section of Fig.3, each block 1 consists mainly of a layer of shaped plastic
material, which forms the lateral walls 7 and the smaller bases 5 of each truncated-pyramid
shaped body. The thickness of the lateral walls 7 and of the smaller bases 5 of the
hollow bodies 3A, 3B can be approximately constant, for example in the order of 5
mm.
[0019] The shape and alternated arrangement of the truncated-pyramid shaped bodies 3A, 3B
is such as to allow superimposing of blocks 1 in a position with minimum overall dimensions,
inserting the truncated-pyramid shaped bodies 3A of one block into the cavities defining
the truncated-pyramid shaped bodies of a block above or below. In this way, the blocks
1 interpenetrate allowing a large number of blocks 1 to be stored and transported
in a small volume.
[0020] Alternatively, the blocks 1 can be superimposed in the layout shown in the axonometric
view of Fig.4 and in the sections of Figs. 5 and 6, with the truncated-pyramid shaped
bodies 3A of one block placed opposite the truncated-pyramid shaped bodies 3B of a
block above or below, arranging truncated-pyramid shaped bodies 3A, 3B in mutual opposition,
resting on one another at the respective smaller bases 5. In this layout, a structure
formed by layers of mutually superimposed blocks 1 occupies a very large and mostly
empty volume due to the large empty space inside each hollow truncated-pyramid shaped
body 3A, 3B.
[0021] To stack the modular blocks 1 in the position with maximum overall dimensions, with
the smaller bases 5 opposite each other, the modular block 1 comprises mutual interlocking
elements, associated with the smaller bases 5 of the single truncated-pyramid shaped
bodies 3A, 3B.
[0022] In the illustrated embodiment, male and female elements are provided on each smaller
base 5 of the truncated-pyramid shaped bodies 3A, 3B, destined to engage with one
another when two blocks 1 are mounted superimposed in the position with maximum overall
dimensions.
[0023] More in particular, in the illustrated embodiment each smaller base 5 of the hollow
truncated-pyramid shaped bodies 3A, 3B comprises a pair of female elements 9 and a
pair of male elements 11. These elements are arranged close to the four corners of
the smaller base 5 of quadrangular shape. More specifically, the two female elements
9 are arranged closed to two corners along a first diagonal of the smaller base 5
and the male elements 11 are arranged close to the other two corners along the second
diagonal of the smaller base 5.
[0024] As can be seen in particular in the enlarged section of Fig.6, the female element
9 is a through opening, which passes through the whole of the thickness of the smaller
base 5. The male element 11 consists of a protrusion extending from the smaller base
5 outward. The male element 11 is apertured in 11A and can have a beveled outer edge
11B to facilitate insertion into the corresponding opening 9.
[0025] As can be easily understood from Figs. 5 and 6, when two blocks 1 are superimposed
on one another with the male elements 11 inserted into the female elements 9, the
two blocks 1 are stabilized relative to one another and cannot slide laterally. Moreover,
the apertures 11A formed in the male elements 11 form passages that place the inner
volumes of the single truncated-pyramid shaped bodies 3A, 3B in mutual fluid communication,
for purposes that will be clarified below.
[0026] In some embodiments, reinforcing walls 15 can be provided inside the hollow truncated-pyramid
shaped bodies 3A, 3B. As can be seen in particular in Figs.2 and 5, each wall 15 extends
from the inner surface of the smaller base 5 toward the hollow inner volume of the
respective truncated-pyramid shaped body.
[0027] In the illustrated embodiment, inside each hollow truncated-pyramid shaped body 3A,
3B there are four walls 15, each of which surrounds one of the openings 9 or one of
the passages 11A of the male elements 11.
[0028] The walls 15 form ribs that increase the crush resistance of the single hollow truncated-pyramid
shaped bodies 3A, 3B.
[0029] Possible methods of use of the above described modular blocks 1 are illustrated in
particular in Figs. 7 and 8.
[0030] As is evident from the description above, with the modular blocks 1 it is possible
to form layers of blocks, each comprising a plurality of coplanar blocks. In turn,
the layers can be superimposed on one another so that the modular blocks 1 of each
layer are arranged in a position with maximum overall dimensions with the modular
blocks 1 of the adjacent layers, arranged with the smaller bases 5 of the single hollow
truncated-pyramid shaped bodies resting on one another and with the male and female
elements 9, 11 interlocked with one another.
[0031] By arranging layers of modular blocks 1 superimposed in this manner it is possible
to occupy large volumes, a small part of which will be filled by the plastic forming
the modular blocks 1 while the majority will be formed of the cavities of the hollow
truncated-pyramid shaped bodies 3A, 3B. Advantageously, the thickness of the walls
5, 7 that define the single hollow truncated-pyramid shaped bodies 3A, 3B, and the
elements 11 and the reinforcing walls or ribs 15 can be such that the total volume
of plastic is around 1/10 of the total volume occupied by the layers of superimposed
modular blocks 1 in the layout with maximum overall dimensions.
[0032] The modular blocks 1 can thus be used as filling material of an underground, or subterranean,
basin I, as shown schematically in Fig.7. The underground basin I is filled with layers
of superimposed modular blocks 1, which rest on a base B forming the bottom of the
basin. A covering, which can for example be formed of a layer S1 of soil, which forms
a useful surface S, is created above the layers of modular blocks 1. As a function
of the type of material used to create the covering S1, the useful surface S can have
different uses. In the example of Fig.7, the layer S1 formed of soil can form a cultivable
area, destined for grazing land, a wooded area, or a public park.
[0033] In other embodiments, the underground basin I can be closed at the top with a material
intended to form an area useful for other purposes, for example a car park.
[0034] The truncated-pyramid shaped structure of the hollow bodies 3A, 3B and the reinforcing
walls or ribs 15 give the structure formed by the layers of modular blocks 1 high
crush resistance, such that the covering S1 can be formed of even a very thick layer.
[0035] If useful or necessary, the layer S1 can be composite, and have a lower substrate
S2 in contact with the top layer of modular blocks 1. The substrate S2 can, for example,
be created with a material suitable to prevent soil from penetrating the basin filled
with the modular blocks 1 below. Similar solutions can be used on the bottom of the
basin I, with a substrate S3.
[0036] Due to the fact that around 90% of the volume of the underground basin I is empty,
it has the capacity to store a large amount of water, for example rainwater or river
water, diverted from a water course as will be better described below with reference
to Fig.8.
[0037] The openings 9 and 11A place the single inner volumes of the truncated-pyramid shaped
bodies 3A, 3B in fluid communication, so that the water can easily fill the whole
of the hollow volume of the hollow truncated-pyramid shaped bodies 3A, 3B.
[0038] In some embodiments, not shown, a faster flow of water can be obtained by also producing
openings in the lateral walls 7 defining the sides of the hollow truncated-pyramid
shaped bodies 3A, 3B.
[0039] Fig.8 schematically shows the arrangement of an underground basin I, associated with
a water course F. The underground basin I can be connected to the water course F by
means of one or more hydraulic connections 21, 23. Apparatus to regulate the flow
of water into and out of the underground basin I can be arranged along the hydraulic
connections 21 and 23. In the illustrated embodiment, two hydraulic connections are
provided, connected to the water course F in two points, one upstream and the other
downstream, respectively. In the event of a flood, water can be diverted from the
water course F toward the underground basin I by means of the hydraulic line 21, to
reduce the flow rate downstream, and reduce or prevent the risk of flooding. After
the flood wave has passed by, the water temporarily stored in the basin I can be drained
away gradually by means of the second hydraulic connection 23 back into the water
course F. Suitable bulkheads can be provided in 25 and 27 to regulate water flow.
[0040] In some embodiments, water lifting stations can be provided at the inlet and/or outlet.
The use of these lifting stations can be provided as a function of the height at which
the entry and exit points of the hydraulic lines are located relative to the basin.
For example, a lifting station can be provided on the outflow hydraulic line 23.
[0041] Although two distinct hydraulic lines 21, 23 are provided in Fig.8, it would also
be possible to provide a single hydraulic line, both for conveying the water into
the basin I, and for outflow therefrom. In this case, it is more probable that a water
lifting station will be required to empty the basin.
[0042] It would also be possible for the basin to be connected to more than two hydraulic
lines, for example connected to more than one water course or connected in several
points of the same water course, according to specific needs and to the morphology
of the territory.
[0043] From the above description, it is clear that the modular block has a particular shape
that allows total reversibility. In other words, each load bearing surface is similar
to the opposite one. This result is obtained by mutually intersecting no. 50 hollow
truncated-pyramid shaped bodies 3A, 3B (25 on each side of the median plane M). Each
modular block 1 has an extremely compact load-bearing structure, capable of distributing
the static load. With suitably dimensioning of the modular blocks 1 it is possible
to achieve, for example, tensile strengths in the order of 15 tons per square meter
without deformations of the modular blocks 1.
[0044] With modules of 1.2 m per side and heights of 0.35 m and wall thicknesses of around
5mm it is possible to obtain basin volumes of around 0.5 m
3 for each block 1. Due to the extremely rapid assembling of the modular blocks 1 side
by side with, and superimposed on, one another in a layout with maximum overall dimensions,
it is possible to fill large underground basins in a very short time, with a structure
that is substantially 90% empty and hence able to collect large amounts of water and
at the same time provide a usable covering surface. The tapered shape of the truncated-pyramid
shaped bodies and their alternated arrangement allow the modular blocks 1 to be stacked
in a layout with minimum overall dimensions in which the pitch between superimposed
blocks can be around 80 mm, for instance.
[0045] With the aforesaid dimensions, each modular block can have a weight in the order
of 30-35 kg, which makes the block very easy to handle.
[0046] The filling structure of the underground basin formed by the superimposed layers
of modular blocks 1 has a high draining capacity due to the fact that the whole structure
is in suitable mutual communication, with wide passages both on the surfaces resting
on the ground and on the load-bearing surfaces. The draining capacity can be increased
by providing slots or openings (not shown) on the lateral walls 7 of the truncated
pyramid shaped bodies 3A, 3B. These slots or openings can be obtained via the mold
during the injection molding step. These features facilitate the inflow/outflow of
rainwater or flood water in the event of flooding of the river courses.
[0047] In summary and in conclusion, the described modular block 1 allows a plurality of
advantages to be obtained, including:
- low cost of the raw material used (otherwise unusable plastic waste);
- easy, rapid and inexpensive production, due to the use of multiple cavity molding
systems;
- high load-bearing capacity, lightness and draining capacity;
- stackable to reduce transport costs, up to around 20 times less relative to the transport
costs of conventional stone materials;
- ease of handling, rapid and flexible use.
1. A block made of plastic material (1) for filling underground basins (I) for storing
rainwater or river water; said block (1) comprising: a first plurality of hollow truncated-pyramid
shaped bodies (3A), extending from a first side of a median plane (M) of the block;
a second plurality of hollow truncated-pyramid shaped bodies (3B), extending from
a second side of the median plane;
- wherein each truncated-pyramid shaped body (3A, 3B) has a larger base on the median
plane and a smaller base (5) at a distance from the median plane (M);
- wherein the hollow truncated-pyramid shaped bodies (3A, 3B) are configured and arranged
so that identical blocks can be mutually superimposed:

in a first position with minimum overall dimensions, wherein truncated-pyramid shaped
bodies (3A, 3B) of a block (1) are inserted into truncated-pyramid shaped bodies (3A,
3B) of a superimposed block (1);

in a second position with maximum overall dimensions, wherein truncated-pyramid shaped
bodies (3A, 3B) of two superimposed blocks rest on one another at the respective smaller
bases (5);
- and wherein the truncated-pyramid shaped bodies (3A, 3B) have on the respective
walls (5, 7) through openings (9, 11A) to place the inner volumes of the truncated-pyramid
shaped bodies (3A, 3B) of mutually superimposed blocks (1) in fluid communication
in the position with maximum overall dimensions.
2. The block (1) of claim 1, wherein the truncated-pyramid shaped bodies (3A, 3B) have
a quadrangular, and in particular square, cross section.
3. The block (1) of claim 2, wherein the truncated-pyramid shaped bodies (3A, 3B) are
distributed in a checkerboard pattern, so that the truncated-pyramid shaped bodies
(3A, 3B) protruding from one side of the median plane (M) are arranged alternately
with cavities defined by the truncated-pyramid shaped bodies (3B, 3A) protruding from
the opposite side of the median plane (M).
4. The block (1) of one or more of the preceding claims, wherein each truncated-pyramid
shaped body (3A, 3B) has openings (9, 11A) on the respective smaller base (5).
5. The block (1) of one or more of the preceding claims, wherein each truncated-pyramid
shaped body (3A, 3B) has on the smaller base (5) mutual interlocking elements (9,
11), configured so as to mutually couple when two blocks (1) are superimposed in a
position with maximum overall dimensions.
6. The block (1) of claim 5, wherein the interlocking elements (9; 11) configure openings
(9; 11A) that place the inner volume of truncated-pyramid shaped bodies (3A, 3B) superimposed
and coupled by means of said interlocking elements (9; 11) in fluid communication.
7. The block of one or more of the preceding claims, wherein each truncated-pyramid shaped
body (3A, 3B) comprises, on the wall defining the smaller base (5), a pair of through
openings (9) and a pair of apertured protrusions (11), arranged so that, when truncated-pyramid
shaped bodies (3A, 3B) are superimposed in a position with maximum overall dimensions
of the respective blocks, the pervious protrusions (11) of one block are inserted
into the through openings (9) of the superimposed block (1).
8. The block (1) of claim 7, wherein each smaller base (5) of the truncated-pyramid shaped
bodies (3A, 3B) is provided with two through openings (9), close to the two diagonally
opposite corners of the smaller base (5) and two pervious protrusions (11), close
to the other two diagonally opposite corners, said smaller base (5) having a quadrangular,
and in particular square, shape.
9. The block (1) of one or more of the preceding claims, wherein the truncated-pyramid
shaped bodies (3A, 3B) have through openings on respective lateral walls (7) extending
from the larger base to the smaller base (5).
10. The block (1) of one or more of the preceding claims, wherein reinforcing walls (15),
preferably orthogonal to the respective smaller base (5), are provided inside each
truncated-pyramid shaped body (3A, 3B).
11. The block (1) of claim 10, wherein the reinforcing walls (15) surround openings (9;
11A) formed in the smaller base (5) of the respective truncated-pyramid shaped body
(3A, 3B).
12. The block (1) of one or more of the preceding claims, wherein the plastic material
defining said block (1) is distributed so that, in the position with maximum overall
dimensions, no more than 15%, preferably no more than 12% of a total volume of superimposed
blocks is occupied by the plastic material forming the blocks.
13. A system for temporarily storing river water or rainwater, comprising: an underground
basin (I) for temporarily storing river water or rainwater; and at least one hydraulic
connection (21; 23) for conveying water into the basin; wherein the basin is filled
at least partially with a plurality of blocks (1) according to one or more of the
preceding claims, on which a covering (S1, S2) resting on the filling blocks (1) is
formed, said covering forming a usable area.
14. The system of claim 13, wherein the usable area is a cultivable area, a covering comprising
a layer of soil being formed on said blocks.
15. The system of claim 13 or 14, comprising at least one of the following features: a
second hydraulic connection (23; 21) for the outflow of water from the basin; a lifting
station of the water from the basin; a bulkhead (25, 27) on at least one of said hydraulic
connections.