The present invention relates to a pile to be driven into the ground, a pile installation jig, a method for installing the pile, and a photovoltaic system using the piles.
The supporting capacity of a pile depends heavily on the type of the ground and the strata composition. Soft ground and weak strata seriously deteriorate the supporting capacity of the pile. In this regard, Patent Literature 1 discloses an attempt to improve the supporting capacity of a pile. First, a pipe and a main shaft inserted therein are driven into the ground. Then, only the pipe is driven further. When underground insertion parts at a leading end of the pipe abut on an inclined portion at a leading end of the main shaft, the underground insertion parts are bent and stuck obliquely downward in the ground.
Patent Literature 2 also discloses an attempt to improve the supporting capacity of a foundation pile. In this case, a foundation pile is driven into the ground first. Next, projecting members are inserted in a vertical space inside the foundation pile and pushed down until their leading ends project from projection holes formed in a side wall of the foundation pile. Thereby, the leading ends of the projecting members are stuck obliquely downward in the ground.
Patent Literature 3 tries to improve the supporting capacity of an anchor by driving an anchor into a supporting foundation, fitting a wedge splitting pipe in the anchor, hitting the wedge splitting pipe, and thereby opening a split wedge at a leading end of the anchor.
Patent Literature 4 also discloses an attempt to improve the supporting capacity of a pile main body. In this case, a pile main body has a pointed member at a leading end thereof and pivotally holds a pair of anti-falloff members at the leading end. When the pile main body is driven into the ground, the pointed member is displaced to open the anti-falloff members in the ground.
Patent Literature 5 tries to improve the supporting capacity of a pile main body in the following manner. When a pile main body is driven into the ground, a pressing member causes flared members on a leading end of the pile main body to be displaced and stuck in the ground.
Patent Literature 6 tries to improve the supporting capacity of a pile in the following manner. When a pile is driven into the ground, a pillar-shaped member causes flared members on a leading end of the pile to be displaced outwardly and stuck in the ground.
[Patent Literature 1] JP H02-24416 A
[Patent Literature 2] JP H11-81306 A
[Patent Literature 3] JP H09-31979 A
[Patent Literature 4] JP H10-131180 A
[Patent Literature 5] JP 2005-9295 A
[Patent Literature 6] JP 2005-61159 A
In Patent Literature 1, the underground insertion parts at the leading end of the pipe, which are stuck obliquely downward in the ground, tend to come off easily. For this reason, this arrangement cannot ensure a significant improvement in the pullout strength of the pipe.
Patent Literature 2 requires a space for guiding the protrusion members inside the foundation pile, which complicates the structure of the foundation pile. Besides, the leading ends of the protrusion members, which are stuck obliquely downward in the ground, tend to come off easily. For this reason, this arrangement cannot ensure a significant improvement in the pullout strength of the foundation pile.
In Patent Literature 3, the anchor is driven into the supporting foundation to open the split wedge at the leading end of the anchor. However, if this structure is applied to a pile driven into the ground, the wedge pushes back sand and dirt around the pile and deteriorates the supporting capacity of the pile.
In Patent Literature 4, an end of each of the anti-falloff members is pivotally held on the pile main body. In this structure, the rigidity and the strength between the anti-falloff members and the pile main body are too low to expect a significant improvement in the supporting capacity of the pile main body.
In Patent Literature 5 and 6, in the state where a plurality of flared members are stuck in the ground, an end of each flared member is held only on the pile main body. In this structure, the rigidity and the strength between the flared members and the pile main body are too low to expect a significant improvement in the supporting capacity of the pile main body.
Additionally, Patent Literature 4 to 6 require complicated structures for the leading end of the foundation pile or the pile main body, and also require a greater number of components.
The present invention has been made in view of these conventional problems, and aims to provide a pile, a pile installation jig, a method for installing the pile, and a photovoltaic system using the piles, in which the pile has a simple structure but still ensures a high pullout strength and a high supporting capacity for a pile main body.
In order to solve the above-mentioned problems, a pile according to the present invention, which is a pile to be buried in the ground, is equipped with: a pile main body composed of a columnar member and including at least one groove which extends in a longitudinal direction of the columnar member and which curves in a direction transverse to the longitudinal direction; and a plate-like member which penetrates the groove.
A pile installation jig, which can be employed to install the pile according the present invention, is equipped with: an elongated portion arranged in a longitudinal direction of the pile main body; and an abutment portion provided closer to an end of the elongated portion than to a center thereof and configured to push the plate-like member.
A method according to the present invention for installing a pile includes the steps of: driving a pile into the ground, wherein the pile includes a pile main body and a plate-like member, the pile main body is composed of a columnar member and includes at least one groove which extends in a longitudinal direction of the columnar member and which curves in a direction transverse to the longitudinal direction, and the plate-like member penetrates the groove; and driving a pile installation jig into the ground to cause displacement of the plate-like member along the groove.
Alternatively, a method according to the present invention for installing a pile includes the steps of: driving a pile and a pile installation jig together into the ground, wherein the pile includes a pile main body and a plate-like member, the pile main body is composed of a columnar member and includes at least one groove which extends in a longitudinal direction of the columnar member and which curves in a direction transverse to the longitudinal direction, and the plate-like member penetrates the groove; and driving the pile installation jig further into the ground to cause displacement of the plate-like member along the groove.
A photovoltaic system according to the present invention is equipped with a rack assembled on a plurality of piles according to the present invention, and a photovoltaic module held on the rack.
The present invention can improve the pullout strength and the supporting capacity of a pile by a simple structure.
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Hereinafter, embodiments of the present invention are described in detail with reference to the attached drawings.
As shown in
The grooves 15a, 15b formed in the corresponding walls 12a, 12b are longitudinally aligned with each other in the pile main body 12, with their curves (the J-shaped curves) oriented in the same direction. In other words, suppose that there is a virtual symmetrical plane which passes an L-shaped corner of the pile main body 12 and a midpoint between the walls 12a, 12b and which extends in the longitudinal direction of the pile main body 12, the grooves 15a, 15b are formed in plane symmetry about the virtual symmetrical plane.
The width W of the grooves 15a, 15b is fixed. The peripheral edges of the grooves 15a, 15b are composed of an arc. In fact, the peripheral edges of the grooves 15a, 15b may be composed of an oval, hyperbola, parabola and other curved lines, or may be composed of a polygonal line containing a series of straight and/or curved lines. Any type of curved line or polygonal line is acceptable as far as it curves generally smoothly. In addition, near the ends of the grooves 15a, 15b in the direction transverse to the longitudinal direction of the pile main body 12, the peripheral edges of the grooves 15a, 15b are oriented in a horizontal direction or an inclined near-horizontal direction.
The plate-like member 13 is a rectangular steel plate. The plate-like member 13 has a greater width than the greatest gap between the grooves 15a, 15b, and a smaller thickness than the width W of the grooves 15a, 15b. The plate-like member 13 penetrates the grooves 15a, 15b in a movable manner along the grooves 15a, 15b, and both sides of the plate-like member 13 project outwardly from the walls 12a, 12b.
The length and the thickness of the pile main body 12 can be suitably set in accordance with the type and the strata composition of the ground into which the pile main body 12 is driven, the depth of the pile main body 12 to be driven in, and other like conditions, namely, in accordance with the conditions of use of the pile 11. The length and the thickness of the plate-like member 13 can be suitably set in accordance with the size of the pile main body 12 and the conditions of use of the pile 11.
As shown in
In this embodiment, the shape of the grooves 25a, 25b in the pile main body 22 is different from that of the grooves 15a, 15b in the pile main body 12 in the first embodiment. The shape of the plate-like member 23 is also different from that of the plate-like member 13 in the first embodiment.
For the purpose of description, the ends of the grooves 25a, 25b in the longitudinal direction of the pile main body 22 are defined as upper ends, whereas the ends of the grooves 25a, 25b in a direction transverse to the longitudinal direction of the pile main body 22 are defined as lower ends. The width W of the grooves 25a, 25b is fixed from the upper ends to starting points of their smooth curves which turn into the direction transverse to the longitudinal direction of the pile main body 22. Then, the width W decreases gradually from midway in the curves to the lower ends of the grooves 25a, 25b. Near the lower ends, the width W of the grooves 25a, 25b is substantially the same as or slightly greater than the thickness of the plate-like member 23.
The plate-like member 23 is made of a rectangular steel plate in which two portions near both ends thereof are bent in the same direction. Hence, the plate-like member 23 has a flat central portion 23a and bent portions 23b. The central portion 23a is longer than the greatest gap between the grooves 25a, 25b. The plate-like member 23 penetrates the grooves 25a, 25b in a movable manner along the grooves 25a, 25b, and both sides of the central portion 23a and the bent portions 23b project outwardly from the walls 22a, 22b.
The length and the thickness of the pile main body 22 are suitably set in accordance with the conditions of use of the pile 21. The length and the thickness of the plate-like member 23 are suitably set in accordance with the size of the pile main body 22 and the conditions of use of the pile 21.
As shown in
In this embodiment, the shape of the grooves 35a, 35b in the pile main body 22 is different from that of the grooves 15a, 15b in the pile main body 12 in the first embodiment. The shape of the plate-like member 33 is also different from that of the plate-like member 13 for the pile main body 12 in the first embodiment.
For the purpose of description, the ends of the grooves 35a, 35b in the longitudinal direction of the pile main body 32 are defined as upper ends, whereas the ends of the grooves 35a, 35b in a direction transverse to the longitudinal direction of the pile main body 32 are defined as lower ends. The width W of the grooves 35a, 35b is substantially the same as or slightly greater than the thickness of the plate-like member 33, from the upper ends of the grooves 35a, 35b to starting points of their smooth curves which turn into the direction transverse to the longitudinal direction of the pile main body 32. Then, the width W of the grooves 35a, 35b increases gradually from midway in the curves into the direction transverse to the longitudinal direction of the pile main body 32. When the width W reaches a predetermined width which is sufficiently wider than the thickness of the plate-like member 33, the predetermined width is maintained to the lower ends of the J-shaped grooves 35a, 35b.
The plate-like member 33 is made of a roughly V-shaped steel plate, and has a rectangular central portion 33a and arms 33b. The plate-like member 33 is longer than the greatest gap between the grooves 35a, 35b. The plate-like member 33 penetrates the grooves 35a, 35b in a movable manner along the grooves 35a, 35b, and both sides of the plate-like member 33 project outwardly from the walls 32a, 32b.
The length and the thickness of the pile main body 32 are suitably set in accordance with the conditions of use of the pile 31. The length and the thickness of the plate-like member 33 are suitably set in accordance with the size of the pile main body 32 and the conditions of use of the pile 31.
Next, the fourth embodiment of the present invention concerns a pile installation jig.
As shown in
Each notch 42 is defined by an upper abutment edge 42a, a side edge 42b, and a lower receiving edge 42c. The abutment edge 42a is slightly curved and inclined upwardly toward the side edge 42b, making an acute angle between the abutment edge 42a and the side edge 42b and providing a retention space 42d therebetween.
The pile installation jig 41 in the fourth embodiment is applicable to any of the piles 11, 21, 31 in the first to third embodiments described above. The length and the thickness of the pile installation jig 41 can be suitably set in accordance with the size and the conditions of use of the pile to which the pile installation jig 41 is applied.
As shown in
A notch 52 is formed each of the arms 51d, 51e, at a side edge near a lower end thereof. However, the shape of each notch 52 is different from that of the notches 42 formed at the side edges near the lower ends of the arms 41d, 41e in the fourth embodiment.
Each notch 52 is defined by an upper abutment edge 52a, a side edge 52b, a lower receiving edge 52c, and an inclined edge 52e which is continuous from the abutment edge 52a to a side edge of the corresponding one of the arms 51d, 51e. The abutment edge 52a is slightly curved and inclined upwardly toward the side edge 52b, making an acute angle between the abutment edge 52a and the side edge 52b and providing a retention space 52d therebetween. As the inclined edge 52e extends toward a head of the pile installation jig 51, the inclined edge 52e is inclined in a direction transverse to a longitudinal direction of the pile installation jig 51 in such a manner as to be more distant from the abutment edge 52a.
The pile installation jig 51 in the fifth embodiment is applicable to any of the piles 11, 21, 31 in the first to third embodiments described above. The length and the thickness of the pile installation jig 51 can be suitably set in accordance with the size and the conditions of use of the pile to which the pile installation jig 51 is applied.
As shown in
In this embodiment, the pile installation jig 61 has no equivalent to the arms 41d, 41e in the fourth embodiment. Instead, the walls 61a, 61b are extended by the length of the arms 41d, 41e in the fourth embodiment. In addition, the shape of the notches 62 formed at the lower ends of the walls 61a, 61b is different from that of the notches 42 formed at the side edges near the lower ends of the arms 41d, 41e in the fourth embodiment.
Each notch 62 is defined by an upper abutment edge 62a, a side edge 62b, and an inclined edge 62e which is continuous from the abutment edge 62a to a side edge of the corresponding one of the walls 61a, 61b. The abutment edge 62a is slightly curved and inclined upwardly toward the side edge 62b, making an acute angle between the abutment edge 62a and the side edge 62b and providing a retention space 62d therebetween. As the inclined edge 62e extends toward a head of the pile installation jig 61, the inclined edge 62e is inclined in a direction transverse to a longitudinal direction of the pile installation jig 61 in such a manner as to be more distant from the abutment edge 62a.
In this embodiment, the notches 62 have no equivalent to the receiving edges 42c of the notches 42 in the fourth embodiment and the receiving edges 52c of the notches 52 in the fifth embodiment.
The pile installation jig 61 in the sixth embodiment is applicable to any of the piles 11, 21, 31 in the first to third embodiments described above. The length and the thickness of the pile installation jig 61 can be suitably set in accordance with the size and the conditions of use of the pile to which the pile installation jig 61 is applied.
The following description concerns a method for installing a pile, as the seventh embodiment of the present invention. The installation method in the seventh embodiment of the present invention is a method for burying the pile 11 in the first embodiment (shown in
First, in the state shown in
With the pile 11 and the pile installation jig 41 being combined as shown in
Referring next to
Since the both sides of the plate-like member 13 are fitted in the notches 42 in the arms 41d, 41e of the pile installation jig 41, when the pile installation jig 41 is driven deeper into the ground by the length of the grooves 15a, 15b in the pile main body 12, the abutment edges 42a of the notches 42 in the arms 41d, 41e come into contact with a lateral edge 13a at the both sides of the plate-like member 13, push down the plate-like member 13 from the head 12c side of the pile main body 12, and cause the plate-like member 13 to move along the grooves 15a, 15b. During this process, since the lateral edge 13a at the both sides of the plate-like member 13 is held in the retention spaces 42d of the notches 42 in the arms 41d, 41e, the plate-like member 13 can be pushed down without fail. Then, the plate-like member 13 moves along the grooves 15a, 15b in the direction transverse to the longitudinal direction of the pile main body 12 (in a horizontal direction or an inclined near-horizontal direction) until the plate-like member 13 abuts on the lower terminal ends of the grooves 15a, 15b and stops there. Thereby, the plate-like member 13 is caught and held at transverse portions in the grooves 15a, 15b where the grooves 15a, 15b extend in the direction transverse to the longitudinal direction, i.e. near the lower terminal ends of the grooves 15a, 15b.
Later, as shown in
In the state shown in
By setting a suitable angle between the surface of the plate-like member 13 and a horizontal plane, a further enhancement of the pullout strength can be expected in the pile main body 12. When the angle is 0 degree, i.e. when the surface of the plate-like member 13 is horizontal, the pullout strength will be greatest. Hence, in any of the embodiments, the surface of the plate-like member 13 is described and illustrated as being substantially horizontal. However, it is not essential to make the surface of the plate-like member 13 horizontal or substantially horizontal. In consideration of the installation depth of the pile main body 12, the geological condition at the installation site, and other conditions, the angle between the surface of the plate-like member 13 and the horizontal plane may be suitably changed along with the length, the width, the thickness, and other requirements of plate-like member 13.
In this context, the term “substantially horizontal” assumes that the angle between the surface of the plate-like member 13 and the horizontal plane is 20 degrees or less. This is suitable for improvement in the pullout strength of the pile main body 12, and is also stable for the installation method in which the plate-like member 13 is subjected to a force from above and thereby caused to move along the grooves 15a, 15b.
Additionally, the pile installation method in the seventh embodiment of the present invention is also applicable when burying the pile 21 in the second embodiment (shown in
First, as shown in
With the pile 21 and the pile installation jig 51 being combined as shown in
Referring next to
Later, as shown in
In this case, the plate-like member 23 penetrates the grooves 25a, 25b in pile main body 22, with the bent portions 23b being bent upwardly. At the step of driving the pile main body 22 into the ground, the bent portions 23b of the plate-like member 23 face underground resistance, so that the plate-like member 23 can turn by itself and move smoothly along the J-shaped grooves 25a, 25b.
Further, since the bent portions 23b of the plate-like member 23 project outwardly from the walls 22a, 22b of the pile main body 22, even if the plate-like member 23 is laterally displaced during the step of driving the pile main body 22 into the ground, either one of the bent portions 23b of the plate-like member 23 abuts on one of the walls 22a, 22b of the pile main body 22. Eventually, it is possible to prevent the plate-like member 23 from coming out of the grooves 25a, 25b in the pile main body 22.
At the lower terminal ends of the grooves 25a, 25b in the pile main body 22, the width W of the grooves 25a, 25b is substantially the same or slightly greater than the thickness of the plate-like member 23. Owing to this configuration, when the plate-like member 23 abuts on the lower terminal ends of the grooves 25a, 25b and stops there, the plate-like member 23 is caught without play near the lower terminal ends of the grooves 25a, 25b. Further, the plate-like member 23 is fixed securely by holding sand and dirt on an inner side of the flat central portion 23a and the bent portions 23b. Namely, this arrangement can prevent vertical displacement of the plate-like member 23 relative to the pile main body 22 with more certainty, and can securely fix the plate-like member 23 by sand and dirt. Eventually, this arrangement can further improve the pullout strength and the supporting capacity of the pile main body 22.
The following description concerns a method for installing a pile, as the eighth embodiment of the present invention. The pile installation method in the eighth embodiment of the present invention is a method for burying the pile 31 in the third embodiment (shown in
First, in the state shown in
Next, the pile installation jig 61 is driven into the ground as shown in
Referring next to
Later, as shown in
In this embodiment, the width W of the grooves 35a, 35b is set to be substantially the same or slightly greater than the thickness of the plate-like member 33, from the upper starting ends of the grooves 35a, 35b to starting points of their smooth curves which turn into the direction transverse to the longitudinal direction of the pile main body 22. Owing to this configuration, when the plate-like member 33 is pushed down by the abutment edges 62a of the walls 61a, 61b of the pile installation jig 61, the grooves 35a, 35b can guide the plate-like member 33 downwardly while preventing the plate-like member 33 from wobbling. Besides, while the plate-like member 33 is moving in the ground, it is possible to reduce the underground resistance against the plate-like member 33 and to enable quick displacement of the plate-like member 33 along the grooves 35a, 35b. Moreover, the V-shaped plate-like member 33 projects outwardly in a substantially orthogonal relationship to the walls 32a, 32b of the pile main body 32. The outwardly projecting ends of the plate-like member 33 are long enough to hold a large amount of sand and dirt for securely fixing the plate-like member 33. As a result, the plate-like member 33 serves to improve the pullout strength and the supporting capacity of the pile main body 32 to a greater extent.
The next description concerns other embodiments of the present invention. As shown in
As shown in
In addition to the pair of grooves 82c, 82d, a second pair of grooves 82e, 82f may be formed near the leading ends of the walls 82a, 82b as shown in
As shown in
A pile installation jig for installing these piles 71, 81, 91 is preferably equipped with two abutment portions which abut on both ends of the plate-like members 73, 83, 93 from a head side of the pile main bodies 72, 82, 92 and which push down the plate-like members 73, 83, 93.
In the embodiment shown in
Additionally, the piles in the above embodiments and the plate-like members in the above modified examples may be combined or modified as required. For example, regarding the width of each groove in the pile main body, the width at both the upper starting end and the lower terminal end of the groove may be set substantially the same as or slightly greater than the thickness of the plate-like member, and the width at the curve of the groove may be set sufficiently greater than the thickness of the plate-like member. The pile main body may be a quadrangular or cylindrical member, instead of a hollow member, and the quadrangular or cylindrical pile main body may be provided with a single groove through which a plate-like member is arranged to penetrate. Furthermore, after the pile installation jig is employed to move the plate-like member along the groove(s) in the pile main body, the pile installation jig may not be pulled out of the ground but may be left in the ground as a reinforcing member for the pile main body.
Now, turning to the twelfth embodiment of the present invention, description is made of an example of a photovoltaic system using the piles according to the present invention.
A photovoltaic system 111 is intended to realize, for example, an industrial power plant. The piles 81 in the tenth embodiment as shown in
In
In the photovoltaic system of this embodiment as shown in
The rack 113 includes columns 121 which are provided in a standing manner along extensions of the corresponding piles 81, joint units 122 which connect the columns 121 fixedly on the upper ends of the piles 81, braces 123 which span the columns 121 adjacent in the north-south direction and which serve as reinforcing members, braces 124 which span the columns 121 adjacent in the east-west direction and which serve as reinforcing members, vertical frames 125 which span upper ends of the adjacent north-south columns 121, and four horizontal frames 126 which extend in the east-west direction and which is arranged on and held by the vertical frames 125 aligned in the east-west direction.
In the thus configured rack, a plurality of photovoltaic modules 112 are mounted in a row between the two adjacent horizontal frames 126. As a whole, a plurality of photovoltaic modules 112 are mounted in three rows on the four horizontal frames 126.
As shown in
Next, the joint member 134 is mounted on a top wall 131b of the L-shaped attachment 131, and fixed thereon with use of a set of a bolt 135, a nut 136, and a spacer 137.
Further, the joint member 134 is inserted into the column 121. A bolt 138 is inserted through holes in the column 121 and in the joint member 134, and a nut is tightly screwed on an end of the bolt 138. In this manner, the column 121 is fixedly connected on the upper end of the pile 81.
Hereinbefore, the preferable embodiments and modified examples of the present invention have been described with reference to the accompanying drawing. However, it goes without saying that the present invention should not be limited by these embodiments and examples. It is apparent that those having ordinary skill in the art can conceive of a variety of alternative examples or modified examples within the scope of the claims, and such examples are naturally understood to be within the technological scope of the present invention.
For example, regarding the pile(s) in the above-mentioned embodiment(s), the pile (the pile 11) is intended to be buried in the ground. The pile has a columnar pile main body (the pile main body 12), at least one groove (the groove 15a), and a plate-like member (the plate-like member 13) inserted through the groove. The groove extends longitudinally downward as seen in the state where the pile main body is buried, and curves in a direction transverse to the longitudinal direction of the pile main body.
In this pile, the pile main body is driven into the ground, with the plate-like member inserted through the groove in the pile main body. In this state, when the plate-like member is pushed down by means of a jig or the like, the plate-like member moves along the groove under the ground. As mentioned above, the groove extends longitudinally downward as seen in the state where the pile main body is buried, and curves in the direction transverse to the longitudinal direction of the pile main body. Hence, the plate-like member moving along the groove is caught and held at a transverse portion where the groove extends in the direction transverse to the longitudinal direction. In this state, displacement of the plate-like member in a pullout direction (a longitudinally upward direction) of the pile main body is inhibited by the transverse portion where the groove extends in the direction transverse to the longitudinal direction of the pile main body, and the plate-like member is fixed by sand and dirt. Eventually, it is possible to improve the pullout strength and the supporting capacity of the pile main body.
Regarding the pile(s) of the above-mentioned embodiment(s), the groove is composed of a plurality of grooves. Such grooves (the grooves 15a, 15b) formed in the pile main body are longitudinally aligned, with their curves oriented in the same direction.
In the pile(s) of the above-mentioned embodiment(s), the groove is composed of a plurality of grooves. Suppose that there is a virtual symmetrical plane which passes between the grooves and which extends in the longitudinal direction of the pile main body, the grooves are formed in plane symmetry about the virtual symmetrical plane.
In this case, the pile main body is driven into the ground, with the plate-like member penetrating the plurality of grooves in the pile main body. When the plate-like member is pushed down, the plate-like member moves along the grooves until the plate-like member is caught and held at transverse portions where the grooves extend in the direction transverse to the longitudinal direction of the grooves. Since more than one part of the plate-like member is caught and held in the grooves, the plate-like member is held more securely, and the pullout strength and the supporting capacity of the pile main body can be improved to a greater extent.
Further, in the pile(s) of the above-mentioned embodiment(s), the pile main body has a plurality of walls (the walls 12a, 12b) which extend in the longitudinal direction of the pile main body. The grooves are formed in the corresponding walls.
For example, the pile main body made of an L-shaped steel has two walls, whereas the pile main body made of an H-shaped steel has three walls. Each of these walls is provided with a groove.
Furthermore, in the pile(s) of the above-mentioned embodiment(s), the width of each groove varies from one part of the groove to the other.
For example, in the case where the width of each groove is reduced at the transverse portion where the groove extends in the direction transverse to the longitudinal direction of the pile main body, the plate-like member moving along the groove is caught at this narrowed portion without play. This arrangement further improves the supporting capacity of the pile main body.
Still further, in the pile(s) of the above-mentioned embodiment(s), the plate-like member has a wedge-shaped cross section.
The wedge-shaped cross section in the plate-like member serves to reduce the resistance against the plate-like member moving under the ground and to facilitate displacement of the plate-like member along the groove(s).
Turning next to the pile installation jig(s) in the above-mentioned embodiment(s), the pile installation jig (the pile installation jig 41) is employed to install a pile. The pile installation jig has elongated portions (the walls 41a, 41b and the arms 41d, 41e) and abutment portions (abutment edges 42a). The elongated portions are arranged in the longitudinal direction of the pile main body of the pile to be installed. When a longitudinally downward force is applied on the top of the pile installation jig, the abutment portions can abut on a member projecting from the pile main body and can push the projecting member in an inclined direction relative to the longitudinal direction of the pile main body.
In this pile installation jig, the abutment portions abut, from above as seen in the state where the pile main body is buried, on the member projecting from the pile main body. When the pile installation jig is hit deeper into the ground, the abutment portions push down the projecting member.
Regarding the pile installation jig(s) in the above-mentioned embodiment(s), the abutment portions are provided with inclined portions (the inclined edges 52e) which are continuous from the abutment portions. As the inclined portions extend toward the top of the pile main body as seen in the state where the pile main body is buried, the inclined portions are designed to be more distant from the abutment portions in the direction transverse to the longitudinal direction of the pile installation jig. In this case, the projecting member is first pushed down by the abutment portions, and then pushed down obliquely by the inclined portions.
Further regarding the pile installation jig(s) in the above-mentioned embodiment(s), the pile installation jig is equipped with receiving portions (the receiving edges 42c) which are opposed to the abutment portions over the projecting member and which receive the projecting member. In this case, the projecting member is held between the abutment portions and the receiving portions.
Turning next to the pile installation methods in the above-mentioned embodiments, one of the methods includes the step of driving a pile main body into the ground, and the step of driving a pile installation jig into the ground and causing displacement of a plate-like member inserted in at least one groove, wherein the at least one groove extends longitudinally downward as seen in a state where the pile main body is buried, and curves in the direction transverse to the longitudinal direction of the pile main body.
In this pile installation method, the pile main body is driven into the ground first, and the pile installation jig is driven into the ground later, whereby the pile installation jig pushes down the plate-like member and causes displacement of the plate-like member along the grooves.
An alternative pile installation method in the above-mentioned embodiment includes the step of driving a pile main body and a pile installation jig together into the ground, and the step of driving the pile installation jig deeper into the ground than an installation position of the pile main body and causing displacement of a plate-like member inserted in at least one groove, wherein the at least one groove extends longitudinally downward as seen in a state where the pile main body is buried, and curves in the direction transverse to the longitudinal direction of the pile main body.
In this pile installation method, the pile main body and the pile installation jig are driven into the ground at the same time, and the pile installation jig is driven deeper into the ground later, whereby the pile installation jig pushes down the plate-like member and causes displacement of the plate-like member along the groove(s).
The pile installation methods in the above-mentioned embodiments further include the step of pulling the installation jig out of the ground.
The photovoltaic system in the above-mentioned embodiment includes a plurality of piles, a rack assembled on the piles, a plurality of photovoltaic modules held on the rack. Each of the piles has a columnar pile main body, at least one groove formed in the pile main body, which extend(s) longitudinally downward as seen in a state where the pile main body is buried and which curve(s) in the direction transverse to the longitudinal direction of the pile main body, and a plate-like member inserted through the groove(s).
This photovoltaic system also exhibits the operations and effects similar to those achieved in the above embodiments.
Number | Date | Country | Kind |
---|---|---|---|
2013-186304 | Sep 2013 | JP | national |
Filing Document | Filing Date | Country | Kind |
---|---|---|---|
PCT/JP2014/071826 | 8/21/2014 | WO | 00 |