OBJECT OF THE INVENTION
[0001] The present invention can be included in the technical field of solar energy utilisation.
More specifically, the object of the invention relates to a device and a method for
anchoring a support structure for solar collectors to the ground.
BACKGROUND OF THE INVENTION
[0002] In the field of construction, so-called piles are known, used as construction elements
used for anchoring structures, allowing loads to be transferred to a resistant soil
layer when they are located at a depth such that conventional foundation footings
or slabs are rendered technically or economically unfeasible.
[0003] In this connection, British Patent
GB2360809 relates to a pile and an installation method, disclosing a pile that comprises a
rod having at least one helix acting as a screw thread to facilitate the penetration
of the rod into the ground, where the helix has a plough-shaped load flank for compressing
the ground radially outwards during penetration of the rod. The pile introduction
process comprises the incorporation of a bonding agent around the rod during introduction
for insertion into a vacuum created by the plough-shaped assembly.
[0004] Likewise, British Patent
GB2397327 relates to a pile comprising at least two portions axially aligned telescopically
in order to fix the effective pile length and comprises fixing means for allowing
one of the sections to be fixed to another section in a plurality of positions to
selectively determine the total length of the pile.
[0005] Specifically, in the field of solar energy, the use of foundation piles for anchoring
photovoltaic solar panel structures to the ground is known.
[0006] However, the application of the piles to solar concentration structures, for example,
of the PTC type (parabolic trough collectors) has drawbacks due to, among other reasons,
the high stresses to which the foundations of thermal collectors are subject with
respect to photovoltaic collectors. Additionally, fixation using plies entails accuracy
requirements that are not within reach of all the systems used.
[0007] The problem posed consists of defining means for fixing solar collector structures
to foundation piles allowing execution of the fixation in a simple and highly accurate
manner.
DESCRIPTION OF THE INVENTION
[0008] The present invention describes, according to a first aspect, a device for laying
the foundations of a support structure for solar collectors comprising:
- at least one pile having a first end adapted for insertion into the ground and a second
end projecting from the ground; and
- joining means for joining the pile to the structure.
[0009] According to a first embodiment of the invention, the joining means for joining the
pile to the structure comprise a bolt, attached to the pile by a lower end of the
bolt (threaded or not threaded) and attachable to the structure by a threaded upper
end opposite the lower end. The lower end of the bolt is, according to this first
embodiment, housed and fixed in a body inserted in the second end of the pile (the
end projecting from the ground) and fixed to said pile. Preferably, the body is made
of hardenable material susceptible of, by drying and/or setting, hardening and adhering
to the pile and bolt, such as, for example, cement, concrete or mortar.
[0010] A second aspect of the invention relates to a method for anchoring a support structure
for solar collectors to the ground, using the device of the invention, which comprises
the following steps:
- introduction of the first end of the pile in the ground, leaving the second end above
the ground; and
- fixation of the structure to the outer end of the pile.
[0011] When the joining means comprise a bolt, the method can include the additional step
of fixing the bolt to the pile.
[0012] Therefore, the bolt can be fixed to the pile following the steps below:
- defining, on the second end of the pile, a receptacle open at least partially;
- disposing and holding the lower end of the bolt in place in the interior of the receptacle,
preferably using templates or topographic control;
- pouring the hardenable material into the interior of said receptacle through the second
opening; and
- allowing the hardenable material to harden.
[0013] Alternatively, it is possible to pour the hardenable material first and, subsequently,
before said material hardens, insert the lower end of the bolt in said hardenable
material.
[0014] Preferably, defining a receptacle on the second end of the pile comprises forcibly
introducing, to a certain depth, a first watertight elastic plug, preferably of polystyrene
foam, having dimensions slightly larger than the cross-section of the second end of
the pile, said receptacle being composed of the first plug and by the inner surface
of the second end of the pile, above the first plug.
[0015] Optionally, the step that involves defining the receptacle may include an additional
stage of forcibly introducing to a second depth, less than the first depth, a second
watertight elastic plug, preferably of polystyrene foam, having dimensions slightly
larger than the cross-section of the second end of the pile, said second plug having
a first opening for inserting the bolt and a second opening for pouring the hardenable
material. The location of the first opening can be established preferably using templates
or topographic control.
[0016] In accordance with a second preferred embodiment, the joining means comprise, alternatively
to the bolt, a plug disposed tightly around the exterior of the second end of the
pile, said plug having first fixing means for fixing the pile to the structure. Preferably,
the fixing means comprise a metal bracket having a first side for fixation to the
plug and a second side for fixation to the structure. The second side can also be
fixed to the structure using bolts or other types of fasteners.
[0017] According to a third preferred embodiment, the joining means comprise, in addition
to a bolt:
- a first plate fixed to the upper part of the second end of the pile having a plurality
of first slots; and
- a second plate disposed overlying the first plate, having a first bore and second
slots (in plan), the directrix of which cuts the directrix of the first slots, and
at least partially overlapping the first slots, in order to enable the fixation of
the first plate and the second plate in relatively variable positions by means of
second fixing means insertable through the first slots and second slots;
where the bolt crosses the first bore and is fixed to the second plate.
[0018] Preferably, the first slots and the second slots comprise:
- first and second straight slots, the guides of which are straight line segments, preferably
in directions extending from the external contour towards the interior of the plates;
and
- first and second circumferential slots, the directrixes of which are circumference
segments, preferably with respect to the centres of the plates;
where each first slot is overlapped by a second circumferential slot and each first
circumferential slot is overlapped by a second radial slot.
[0019] Therefore, the fixation of the bolt comprises the following steps:
- fixing the first plate to the pile;
- introducing the lower end of the bolt in the first bolt and fixing said bolt to the
second plate;
- superimposing the second plate to the first plate, aligning at least partially the
first slots with the second slots; and
- screwing the first plate to the second plate by introducing the second fixing means
through the slots.
[0020] In a manner compatible with any of the embodiments described, the joining means may
additionally comprise a joining element, preferably a profile, having a flat face,
wherein said flat face comprises bores to facilitate the fixation of the piles to
the structure, said flat face being adapted for the structure to rest on said flat
face.
[0021] Optionally, the method explained comprises the additional step of determining the
location of the pile with respect to the ground prior to the introduction of said
pile in the ground, as well as determining the location, if using bolts, of the bolt
with respect to the pile prior to fixing the bolt to the pile. The location of the
bolt and/or pile shall be determined preferably using one of the following techniques:
- topographic determination and control; and
- use of templates having marks indicating the relative locations of the piles and/or
the bolts.
[0022] The present invention allows anchoring of a support structure for solar collectors
to the ground in a fast, accurate and cost-effective manner, simply and cleanly, without
need for passage of trucks, cement mixers, etc.
DESCRIPTION OF THE DRAWINGS
[0023] In order to complement the description being made and with the object of helping
to better understand the characteristics of the invention, in accordance with a preferred
embodiment thereof, said description is accompanied, as an integral part thereof,
by a set of drawings where, in an illustrative and non-limiting manner, the following
has been represented:
Figure 1 shows a sectional view of the device in accordance with the first preferred
embodiment.
Figure 2 shows a view of the device in accordance with the second preferred embodiment.
Figure 3a shows a perspective view of the first plate in accordance with the third
preferred embodiment.
Figure 3b shows a perspective view of the second plate of the third preferred embodiment.
Figure 3c shows a perspective view of the first plate and the second plate joined
together in accordance with the third preferred embodiment.
Figure 3d shows a side view of the joint between the first plate and the second plate.
Figure 4a shows a view of an example of a joint between the pile and the structure
by means of a profile.
Figure 4b shows a detailed view of the joint by means of a profile of figure 4a.
PREFERRED EMBODIMENTS OF THE INVENTION
[0024] As can be observed in figures 1, 2, 3a, 3b, 3c, 3d, 4a and 4b, the device for anchoring
a support structure (2) for solar collectors to the ground (1), in accordance with
the invention, comprises: at least one pile (3) having a first end (4) adapted for
insertion into the ground (1) and a second end (5) projecting from the ground (1);
and joining means for joining the pile (3) to the structure (2). Likewise, the method
for anchoring a support structure (2) for solar collectors to the ground (1) using
the device of the invention and which comprises the following steps: introduction
of the first end (4) of the pile (3) in the ground (1), leaving the second end (5)
above the ground (1); and fixation of the structure (2) to the bolt (7).
[0025] According to a first embodiment of the invention, as illustrated in figure 1, the
joining means for joining the pile (3) to the structure (2) comprise a bolt (7) attached
to the pile (3) by a lower end (8) (threaded or not threaded) and attachable to the
structure (2) by an upper end (9) threaded opposite the lower end (8).
[0026] Continuing with the first embodiment, the method comprises the previous step of fixing
the bolt to the pile. To this end, the lower end (8) of the bolt (7) is housed in
a body (10), formed by mortar, inserted in the second end (5) of the pile (3) and
fixed to said pile (3).
[0027] Therefore, the bolt (7) can be fixed to the pile (3) by forcibly and consecutively
introducing, prior to the bolt (7), through the second end (5) of the pile (3), a
first watertight plug (13) and a second watertight plug (14), preferably of polystyrene
foam, having dimensions slightly larger than those of the cross-section of the second
end (5) of the pile (3), defining a receptacle (not shown) between the two plugs.
Next, a second opening (12) and a first opening (not shown) are made in the second
plug (14) and the mortar is poured into the receptacle through the second opening
(12), allowing said mortar to harden. The location of the first opening is determined
preferably using a template or topographic control. Next, the lower end (8) of the
bolt (7) is housed inside said first opening.
[0028] In accordance with a second preferred embodiment, as shown in figure 2, the joining
means comprise, alternatively to the bolt (7), a plug (30) disposed, preferably in
a tight-fitting manner, around the exterior of the second end (5) of the pile (3),
said plug (30) having first joining means in the manner of a metal bracket (31) having
a first side (32) for fixation to the plug (30) and a second side (33) having a bore
for fixation directly to the structure (2). Additionally, the first fixing means may
comprise a second bracket (34) comprising a lower bored side (35) resting on the second
side (33) and an upper side (36) whereon the structure (2) rests. There is no reason
why the first bracket (31) or second bracket (32) cannot be fixed to the structure
(2) by means of bolts (7).
[0029] According to a third preferred embodiment, as can be observed in figures 3a, 3b,
3c and 3d, the joining means comprise, in addition to the bolt (7):
- a first plate (18), preferably circular, fixed to the upper part of the second end
(5) of the pile (3), having a plurality of first slots (20, 21), as shown in figure
3a;
- a second plate (24), preferably circular (see figure 3b), disposed on the first plate
(18) (see figures 3c and 3d), having a first bore (not shown) and second slots (22,
23); and
- second fixing means (26), preferably screws (see figure 3c), insertable through the
first slots (20, 21) and second slots (22, 23) for fixing the first plate (18) to
the second plate (24), wherein the bolt (7) passes through the first bore of the second
plate (24) and is fixed to the second plate (24).
[0030] In the third embodiment, the first slots (20, 21) and the second slots (22, 23) comprise:
- straight slots (20, 22), the directrixes of which are straight line segments extending
in radial directions with respect to the centres of the plates (18, 24); and
- circumferential slots (21, 23), the directrixes of which are concentric circumference
segments with respect to the centres of the plates (18, 24);
wherein each first straight slot (20) is overlapped by a second circumferential slot
(23) and each first circumferential slot (21) is overlapped by a second straight slot
(22).
[0031] In accordance with the third embodiment, the fixation of the bolt (7) to the pile
(3) comprises the steps of: fixing the first plate (18) to the pile (3); introducing
the lower end (8) of the bolt (7) in the first bore of the second plate (24) and fixing
said bolt (7) to said second plate (24); superimposing the second plate (24) on the
first plate (18), aligning at least partially the first slots (20, 21) with the second
slots (22, 23); and screwing the first plate (18) to the second plate (24) by introducing
the second fixing means (26) through the slots (20, 21, 22, 23).
[0032] In a manner compatible with any of the embodiments described, as can be observed
in figures 4a and 4b, the joining means additionally comprise a joining element, preferably
a profile (15), having a flat face (29), wherein said flat face (29) comprises second
bores (not shown) for facilitating the joint between the piles and the structure;
likewise, the flat face (29) is adapted so that the structure (2) rests on said flat
face (29). In particular, in the case of use of bolts (7), the second bores serve
to house and fix the bolts (7) of two adjacent piles (3).
[0033] The method explained comprises the additional step of determining the location of
the pile (3) with respect to the ground (1) prior to introducing said pile (3) in
the ground (1), as well as determining, when a bolt (7) is used, the location of said
bolt (7) with respect to the pile (3) prior to fixing the bolt (7) to the pile (3).
The location of the bolt (7) and/or pile (3) can be determined preferably using at
least one of the following techniques: topographic determination and control; and
use of templates (not shown) having marks indicating the relative locations of the
piles (3) and/or the bolts (7).
1. A device for anchoring a support structure (2) for solar collectors to the ground
(1), comprising:
- at least one pile (3) having a first end (4) adapted for insertion into the ground
(1) and a second end (5) projecting from the ground (1); and
- joining means for joining the pile (3) to the structure (2),
characterised in that the joining means comprise a bolt (7) attached to the pile (3) by a lower end (8)
and attachable to the structure (2) by a threaded upper end (9) opposite the lower
end (8).
2. A device for anchoring a support structure (2) for solar collectors to the ground
(1), comprising:
- at least one pile (3) having a first end (4) adapted for insertion into the ground
(1) and a second end (5) above the ground (1); and
- joining means for joining the pile (3) to the structure (2),
characterised in that the joining means comprise a plug (30) disposed on the exterior of the second end
(5) of the pile (3), said plug (30) having first fixing means for fixing said plug
(30) to the pile (3) and to the structure (2).
3. A device for anchoring a support structure (2) for solar collectors to the ground
(1), according to claim 2, characterised in that the first fixing means comprise a metal bracket (31) having a first side (32) for
fixation to the plug (30) and a second side (33) for fixation to the structure (2).
4. A device for anchoring a support structure (2) for solar collectors to the ground
(1), according to claim 3, characterised in that the first fixing means additionally comprise a second bracket (34) comprising a lower
bored side (35) resting on the second side (33) and an upper side (36) whereon the
structure (2) rests.
5. A device for anchoring a support structure (2) for solar collectors to the ground
(1), according to any one of claims 3 or 4, characterised in that it additionally comprises bolts (7) for fixing the first bracket (31) or the second
bracket (32) to the structure (2).
6. A device for anchoring a support structure (2) for solar collectors to the ground
(1), according to claim 1, characterised in that the lower end (8) of the bolt (7) is housed and fixed in a body (10) inserted in
the second end (5) of the pile (3) and fixed to said pile (3).
7. A device for anchoring a support structure (2) for solar collectors to the ground
(1), according to claim 6, characterised in that the body (10) is made of a material susceptible of, by drying and/or setting, hardening
and adhering to the pile (3) and to the bolt (7).
8. A device for anchoring a support structure (2) for solar collectors to the ground
(1), according to claim 7,
characterised in that the body (10) is made at least of a material selected from among:
- cement;
- concrete; and
- mortar.
9. A device for anchoring a support structure (2) for solar collectors to the ground
(1), according to claim 1,
characterised in that the joining means additionally comprise:
- a first plate (18) fixed to the upper part of the second end (5) of the pile (3),
having a plurality of first slots (20, 21); and
- a second plate (24) disposed overlying the first plate (18), having a first bore,
as well as second slots (22, 23), the directrix of which cuts the directrix of the
first slots (20, 21), and at least partially overlapping the first slots (20, 21)
to allow fixation of the first plate (18) and the second plate (24) in relatively
variable positions by means of second fixing means (26), insertable through the first
slots (20, 21) and the second slots (22, 23);
wherein the bolt (7) passes through the first bore of the second plate (24) and is
fixed to the second plate (24).
10. A device for anchoring a support structure (2) for solar collectors to the ground
(1), according to claim 9, characterised in that the plates (18, 24) are circular.
11. A device for anchoring a support structure (2) for solar collectors to the ground
(1), according to claim 9,
characterised in that the first slots (20, 21) and the second slots (22, 23) comprise:
- straight lines (20, 22), the directrixes of which are straight line segments; and
- circumferential slots (21, 23), the directrixes of which are concentric circumference
segments;
where each first straight slot (20) is overlapped by a second circumferential slot
(23) and each first circumferential slot (21) is overlapped by a second straight slot
(22).
12. A device for anchoring a support structure (2) for solar collectors to the ground
(1), according to claim 11, characterised in that the directrixes of the straight slots (20, 22) extend from the external contour toward
the interior of the plates (18, 24).
13. A device for anchoring a support structure (2) for solar collectors to the ground
(1), according to claims 10 and 11, characterised in that the directrixes of the straight slots (20, 22) extend in radial directions with respect
to the centres of the plates (18, 24) and the directrixes of the circumferential slots
(21, 23) are concentric with respect to said centres.
14. A device for anchoring a support structure (2) for solar collectors to the ground
(1), according to any one of claims 1 or 2, characterised in that the joining means additionally comprise a joining element having a flat face (29),
wherein said flat face (29) comprises second bores for fixing the piles (3) to the
structure (2).
15. A device for anchoring a support structure (2) for solar collectors to the ground
(1), according to any one of claims 14, characterised in that the second bores are adapted for housing and fixing the bolts (7) of two adjacent
piles (3).
16. A device for anchoring a support structure (2) for solar collectors to the ground
(1), according to claim 14, characterised in that the joining element is a profile (15).
17. A method for anchoring a support structure (2) for solar collectors to the ground
(1) using the device described in any one of the preceding claims,
characterised in that it comprises the following steps:
- introduction in the ground (1) of the first end (4) of the pile (3), leaving the
second end (5) above the ground (1); and
- fixation of the bolt (7) to the pile (3) or to the plug (30).
18. A method for anchoring a support structure (2) for solar collectors to the ground
(1), according to claim 17,
characterised in that the fixation of the bolt (7) to the pile (3) comprises the following steps:
- defining a receptacle at least partially open on the second end of the pile (3);
- disposing and holding in place the lower end (8) of the bolt (7) in the interior
of the receptacle;
- pouring the hardenable material into the interior of said receptacle; and
- allowing the hardenable material to harden.
19. A method for anchoring a support structure (2) for solar collectors to the ground
(1), according to claim 18, characterised in that the hardenable material is poured prior to disposing the lower end (8) of the bolt
(7).
20. A method for anchoring a support structure (2) for solar collectors to the ground
(1), according to any one of claims 18 or 19, characterised in that defining a receptacle comprises forcibly introducing to a first depth a first watertight
elastic plug (13) having dimensions slightly larger than the cross-section of the
second end (5) of the pile (3).
21. A method for anchoring a support structure (2) for solar collectors to the ground
(1), according to claim 20, characterised in that it comprises the additional step of forcibly introducing to a second depth, less
than the first depth, a second watertight elastic plug (14) having dimensions slightly
larger than the cross-section of the second end (5) of the pile (3).
22. A method for anchoring a support structure (2) for solar collectors to the ground
(1), according to any one of claims 20 or 21, characterised in that the first plug (13) and the second plug (14) are made of polystyrene foam.
23. A method for anchoring a support structure (2) for solar collectors to the ground
(1), according to claim 17,
characterised in that the fixation of the bolt (7) to the pile (3) comprises the following steps:
- fixing the first plate (18) to the second end (5) of the pile (3);
- introducing the lower end (8) of the bolt (7) in the first bore of the second plate
(24) and fixing said bolt (7) to said second plate (24);
- superimposing the second plate (24) to the first plate (18), aligning at least partially
the first slots (20, 21) with the second slots (22, 23); and
- fixing the first plate (18) to the second plate (24) by introducing the fixing means
(26) through the slots (20, 21, 22, 23).
24. A method for anchoring a support structure (2) for solar collectors to the ground
(1), according to claim 17, characterised in that it comprises the additional step of determining the location of the pile (3) with
respect to the ground (1) prior to introducing said pile (3) in the ground.
25. A method for anchoring a support structure (2) for solar collectors to the ground
(1), according to claim 17, characterised in that it comprises the additional step of determining the location of the bolt (7) with
respect to the pile (3), prior to fixing the bolt (7) to the pile (3).
26. A method for anchoring a support structure (2) for solar collectors to the ground
(1), according to any one of claims 24 or 25,
characterised in that the location of the bolt (7) and/or of the pile (3) is determined using at least
one of the following techniques:
- topographic determination and control; and
- use of templates having marks indicating the relative locations of the piles (3)
and/or the bolts (7).