OBJECT OF THE INVENTION
The present invention relates to a stiff pile splice for concrete pilings. The concrete pile comprises
- a square base to which the fastening components consisting of protruding lock rods and opposing lock sockets featuring cavities intended for the insertion of the lock rods;
- connecting means featuring the required crosswise holes and a locator tube for the insertion of the locking pin;
- a locking pin penetrating into a tunnel formed by the tubes and pressing the lock socket and lock rod against each other while pre-tensioning the pile splice and being locked permanently in position as a result of the outer edge of the tube being bent over the locking pin.
In a stiff pile splice, the connecting ends of driven reinforced concrete piles feature box-like or plate-like parts to which the locking means are attached. The locking means consist of protruding pins and sleeves inside the box, both of which have a suitable hole to which an expansion locking pin is driven, and of at least a second flat connecting means placed crosswise relative to the longitudinal direction of the piles extending, at the joint, inside each other in the longitudinal direction of the piles being positioned in opposite positions substantially aligned providing a splicing point where these holes of said connecting means are aligned, and crosswise locking pins extending across the connecting means. The locking means pre-tensions the splice tightly together allowing it to withstand forces acting on it from all directions.
STATE OF THE ART
A number of solutions have been proposed for splicing reinforced concrete piles. A common method of splicing piles is to provide the ends of the piles to be joined together with four longitudinal locator and locking pins with crosswise holes or grooves that are inserted into the corresponding recesses in the opposing pile ends after the piles have been placed on top of each other in order to be spliced. The pile splice is locked in position by driving locking pins or keys from the side through the crosswise holes or grooves positioned at the corresponding positions at the pile ends. This method of joining piles together has, however, proved to be complicated to manufacture and it is difficult to make it fit accurately because of the variations in the dimensions of the base plates. Additionally, a problem with all known pile splices is to how to manage to position the splicing half squarely on top of the pile in connection with casting because they can only be locked to the splice casting chute at two corners provided with protruding male locking means. This type of splices varies very much in detail. However, they exhibit numerous drawbacks. First, the structure of known joints is complicated, expensive to manufacture and unreliable in service. Second, both the lock socket and lock rod must be made of solid steel by machining, which results in considerable wastage of raw material and makes the final product heavy and expensive. Additionally, the lock socket is a closed construction easily penetrated by water which then freezes at sub-zero temperatures, meaning that pile splicing cannot be carried out. The removal of ice is highly complicated in pile-driving conditions. Because the type of pile splices described above have proved to be extremely complicated in practical applications, attempts have also been made to develop a range of connecting means for joining reinforced concrete piles together.
Purpose of the Invention
The purpose of the present invention is to provide a simpler stiff pile splice for use in reinforced concrete piles by eliminating the drawbacks exhibited by known similar splices. More specifically, the invention seeks to provide a stiff pile splice with low cost of materials and labour in production. Another purpose of the invention is to provide a pile splice with a locking system that is not loosened even by a large number of impacts. Still a further objective of the invention is to provide a pile splicing solution to whose locking means reinforcement can be threaded or welded, and to provide a locking joint that can be fixed to the casting chute at all the four corners thanks to parallel crosswise holes extending all the way across the structure.
Characteristics of the Invention
In a concrete pile splice in accordance with the invention,
- the locking means are provided with suitable crosswise locator tube perforation to permit the locking pin being driven into the tube-like tunnel of the locking joint to press the lock rod and lock socket firmly against each other;
- the lock sockets are interconnected with tube-like parts;
- the locking pin is round in cross-section;
- and the locking pin is capable of being driven into the tube-like tunnel from the side.
The purposes of the invention are achieved with a pile splice in which the locking means are provided with a suitable crosswise hole permitting the locking pin being drive home into a tube-like tunnel to enable the splice withstand forces acting on it from all directions. The locking pin is locked in position by bending the wall of the tube-like part over the conical part of the locking pin.
The pile splice in accordance with the invention offers a number of benefits. Thanks to simple construction, substantial savings are achieved in the cost of materials and labour. As a result, a non-loosening locked splice is accomplished even after a large number of impacts. At the same time, this construction prevents the problems caused by water freezing in the lock socket on the pile-driving site when piles are spliced. Additionally, the invention provides a locked splice that does not have to be anchored in the base plate using load-bearing welds.
In one embodiment of the invention,
- the locking pin is round with no shoulders and conical in shape at both ends, so that the cross section is identical with that of the crosswise holes substantially in the lock components;
- the tube-like parts in the splice form a crosswise tunnel in the pile serving as casting formwork and as an access route for the locking pin;
- the crosswise tubes in the splice are positioned in the lock rod in such a way that they pre-tension the splice as a result of the deflection of the locking pin.
The round, shoulderless locking pin may be conical at one end only.
In a second embodiment of the invention
- the first piece to be joined consists of a reinforced concrete pile with the connecting means at its end consisting of a round protrusion (qty 1-8) with a round through-hole such that the other piece to be joined is a rock point with connecting means compatible with the splicing means in terms of cross section;
- the connecting means of the reinforced concrete pile and the rock point are interlocked with a locking pin supported on the connecting means placed eccentrically at the distance required for pre-tensioning.
The locking pin can also be locked later by bending the wall of the protective tube over the pin end to prevent it from being dislodged.
EXAMPLES OF APPLICATIONS
The invention is explained in detail in the figures included in the attached drawings. However, the invention is not intended to be limited to the embodiments illustrated by the examples shown in the figures.
List of Figures
FIG. 1 shows an axonometric view of the ends of two reinforced concrete piles with compatible connecting means
FIG. 2 shows the vertical section of two compatible connecting means
FIG. 3 shows a vertical section of the ends of two joined reinforced concrete piles with compatible connecting means
FIG. 4 shows 1 part in a vertical section of the ends of two joined reinforced concrete piles with compatible connecting means
FIG. 5 shows a lateral view of the vertical section of connecting means between two reinforced concrete piles in accordance with the second embodiment
FIG. 6 shows a vertical section of the connecting means in FIG. 5 interconnected.
FIG. 7 shows a section of one part of the connecting means
FIG. 8 shows a vertical section of the reinforced concrete pile splice in accordance with an embodiment of the invention
FIG. 9 shows a section of one part of the connecting means
FIG. 10 shows a lateral view of one embodiment of the connecting means pin
FIG. 11 shows a lateral view of the section of one embodiment of the connecting means
FIG. 12 shows a section of a reinforced concrete pile at the connecting means.
EXPLANATION OF THE FIGURES
FIG. 1 illustrates a situation in which two reinforced concrete piles 1a and 1b are to be joined together with the pile ends close to each other but still not touching. Piles 1a and 1b are primarily made of concrete 1, in addition to which they contain reinforcement bars that are not shown. Instead, FIG. 1 shows the structure of the connecting means 2a and 2b of the reinforced concrete piles 1a and 1b in more detail. Both splicing halves 2a and 2b comprise an end plate 3a and 3b, respectively, possibly with edges 12a-12b, as well as welded anchoring devices 4a and 4b, lock rods 5a and 5b, lock sockets 7a and 7b, locator tubes 8a-b and 9a-b, and locking pins 10a and 10b.
In FIG. 1, the splicing half 2a of the upper reinforced concrete pile 1a comprises the base plate 3a featuring suitable holes 11a for the insertion of lock rods 5a and lock sockets 7a and forming, together with the partly bent sides 12a, the box-like part 3a. Fixed to the opposite sides (or corners) of the base plate 3a, there are lock sockets 7a aligned with the holes 13a in the base plate 3a, while fixed to the opposite sides (or corners) there are lock rods 5a provided with a crosswise hole 6a in the protruding section. The inner surface of the protruding lock rod 5a extends though the base plate 3a to which a reinforcement bar 4a is welded to provide bonding. The lock rods 7a are interconnected with tube-like parts 8a and 9a. Similarly, a cylindrical lock socket 7b with a crosswise hole 8b to which tube-like parts 8b and 9b are attached is shown in FIG. 1 welded to the splicing half 2b of the lower reinforced concrete pile. Facing the concrete, the cylindrical part 7b has a base to which reinforcement bar 4b has been welded to provide bonding. Lock rods 5b have been attached to the opposite sides (or corners) of the base plate 3b. The reinforcement bars 4b are fixed to the lock rods 5b by welding or with threads.
FIG. 1 shows that the locking means 5a-b and 7a-b can be placed on the same sides or at opposite corners.
FIG. 2 shows a vertical section of the structure of the reinforced concrete piles 1a and 1b at one splice before the piles are joined together. Extending through the base plate 3a, there is attached to the upper pile 1a the lock rod 7a, to which parallel tube-like parts 8a and 9a are attached, placed in hole 23 of the lock socket 7a in such a way that dimension 18a is suitably greater than dimension 18b, thereby providing the necessary pre-tensioning of the splice by the action of the deflection of the locking pin 10a. The figure shows that dimension 15a in the lock socket 7a and the dimension 15b in the lock rod 5b can be machined highly accurately to the required size in order to ensure adequate tightness of the splice. This provides optimum tightness because dimension 15a is a few tenths of a millimetre greater than dimension 15b, forcing the locking pin 10a to deflect when two piles are joined together. Additionally, FIG. 2 shows that the splicing half 2a of the upper pile 1a comprises protective caps 16 and 17 to prevent the ingress of concrete into the locking means during casting. The protective cap 17 features the protrusion 17a, which makes it possible to bend the wall of the tube 8a so as to prevent the locking pin 10a from being dislodged when the pile is driven into the ground.
FIG. 2 shows the relative dimensions of the connecting means indicated by alpha-numeric symbols 15a and 15b and determined from the adjoining surfaces of the piles. These dimensions are of critical importance for the proper in-service performance of the connecting means 7a and 5b. The tube-like parts 8a and 9a form a crosswise tunnel 19a extending across the pile 1a. As a result, casting tools can be used to position the splicing half 2a squarely perpendicular to the longitudinal direction of the pile. Additionally, FIG. 2 shows that the lock rod 5b contains the groove 14 sized to dimension 15b from the centre line of the crosswise hole 6b.
FIG. 3 shows a section of the reinforced concrete piles 1a and 1b joined together with the locking pins 10b in position. The lengths of the locking pins 10b are selected so as to ensure that both can be driven home while preventing the other pin from being dislodged. Additionally, FIG. 3 shows that any variation in the thickness tolerances of the base plates 3a and 3b does not affect the tensioning of the splice. The splice is designed so that the base plate 3a-b only serves as a locator of the connecting means 7a 5b. Additionally, FIG. 3 shows that the lock rod 5b has a conical head 5c in order to facilitate splicing.
FIG. 4 shows a vertical section of the structure of reinforced concrete piles 1a and 1b at one splice when joined together with the locking pin 10b secured by bending the wall 20 of the tube 8a in order to prevent the locking pin 10b from being dislodged. The wall of the tube 8a is hammered into position using a suitable tool in order to provide the barrier 20 by making use of the groove 21 when the pile is spliced. FIG. 4 shows that the lock socket 7a includes the cavity 22 of a size that accepts the lock rod. Additionally, FIG. 4 shows that the lock socket 7a can also be made of a tube with the required crosswise hole for fixing the tubes 8a and 9a.
In the splice between reinforced concrete piles 1a and 1b shown in FIG. 5, the lock rod 5 is positioned in the lock socket 7 of the reinforced concrete pile 1b such that the hole 6 of the lock rod 5 and hole 19a of the crosswise tunnel 9 extending through the lock socket 7 have an eccentric disposition relative to each other.
FIG. 6 shows that when the locking pin 10 of the splicing device shown in FIG. 5 is driven through the holes 19a of the crosswise tunnel 9 extending through the lock socket 7 and the hole 6 of the lock rod 5, the eccentricity of the holes causes the locking pin 10 to cold-form and deflect as shown in FIG. 6. At the same time, the locking pin bent in the splice between the reinforced concrete piles 1a and 1b pre-tensions the joint, making it extremely strong.
FIG. 7 shows the structure of the lock socket 7 of the reinforced concrete pile 1b. The lock socket 7 consists of the sleeve 26 and is attached to the hole 11 in the base plate 3. Preferably, use is made of the piece 24 detached from the plate 3 for making the hole 11 by welding it to serve as a base for the lock socket 7. A notch 26 is provided in the side of the sleeve 25, making it possible to position the sleeve 25 in the hole 11 accurately flush with the base plate 3 surface. This ensures that the holes 27 of the sleeve 25 are positioned with great accuracy to achieve the preferred eccentricity of the holes.
FIG. 8 shows a splicing method for reinforcement bars 4 in which the reinforcement bars are welded from the side with welds 28 to the structures of the connecting means. This ensures a strong bond for the reinforcement bars 4.
In FIG. 9, a notch 26 is provided in the base plate 3 joint to prevent the water contained in concrete from leaking into the splicing structures.
In FIG. 10, a textured surface 29 is provided at the end of the locking pin 10 to further enhance the retention of the locking pin 10.
FIG. 11 shows a structure in which a retaining spring 30 is provided at the edge of the hole 19a of the tunnel 9 extending through the lock socket 7 to further improve the retention of the locking pin 10 in the locked position.
FIG. 12 shows an embodiment in which holes 31 are provided at the edge of the base plate 3 of the reinforced concrete pile for pre-tensioning cables.
Additional Comments
It is obvious to a professional trained in the art that the various embodiments of the invention may vary within the limits defined by the scope of protection provided by the claims.
REFERENCE NUMBERS
1 reinforced concrete pile
2 splicing half
3 base plate
4 reinforcement bar (tie bar)
5 lock rod
5
c lock rod bevel
6 lock rod crosswise hole
7 lock socket
8 outer locate tube
9 locator tube between lock sockets
10 locking pin
10
c locking pin bevel
11 base plate holes for lock rod
12 edge collar
13 base plate holes for lock socket
14 lock rod shoulder
15 centre line of lock rod crosswise hole from shoulder
16 lock socket protective cap
17 protective tube cap
18
a distance between locator tubes in lock socket
18
b lock rod diameter
19 lock rod bevel
19
a tunnel opening for locking pin
20 protective tube locking bend
21 groove in concrete to facilitate tube wall bending
22 lock socket inner cavity
23 diameter of lock socket crosswise hole
24 lock socket base
25 sleeve
26 notch
27 hole
28 weld
29 surface texture
30 retaining spring
Patent Application
20090022545
