APPARATUS AND METHOD FOR SECURING AN UNDERGROUND CONSTRUCTION ELEMENT ON AN UNDERGROUND CONSTRUCTION MACHINE

Description

CROSS REFERENCE TO RELATED APPLICATIONS

Applicant claims priority under 35 U.S.C. § 119 of European Application No. 24184744.1 filed Jun. 26, 2024, the disclosure of which is incorporated by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates to an apparatus for securing an underground construction element on an underground construction machine, in particular a pile element on a pile-driving apparatus. The invention furthermore relates to an underground construction method.

2. Description of the Related Art

Vibrators or pile drivers, which are displaceably arranged on a guide frame or a leader, are used for introducing underground construction elements, such as, for example, piling sections, sheet pile elements or trench sheets. Furthermore, arrangements are also known in which vibrators or pile drivers are suspended on a cable, a hawser or a chain, or also attached directly to the boom of an excavator or a crane. The underground construction element to be introduced is held, in this regard, by clamping tongs that are connected to the vibrator or the pile driver, and is fixed in place between the jaws of the clamping tongs. In DE 3 602 609 A1, an apparatus for securing the underground construction element is described, in which the underground construction element is secured by means of a sling chain, which is passed through a passage hole or a safety eye in an upper end region of the underground construction element. The sling chain is attached to the pile-driving or vibrating device with one end. The other, loose end is attached to the pile-driving or vibrating device after having been passed through the passage hole or the safety eye. By means of the sling chain, the underground construction element is at first loosely connected to the pile-driving or vibrating device.

The pile-driving or vibrating device can now be moved upward along the leader, wherein the underground construction element is pulled upward by the sling chain, which simultaneously serves as a securing chain. Afterward, the pile-driving or vibrating device can be moved downward along the leader until the upper end of the underground construction element is situated between the jaws of the clamping tongs, where the underground construction element can be clamped in place in the clamping tongs by means of closing the jaws. The underground construction element fixed in place in the clamping tongs in this manner can then be pile-driven or driven into the ground by means of the pile-driving or vibrating device.

If an underground construction element is supposed to be pulled out of the ground using the pile-driving or vibrating device, the sling chain must be passed, once again, accordingly, through the passage hole or the safety eye of the underground construction element with its free end, and subsequently attached to the pile-driving or vibrating device with the free end, so as to secure the underground construction element on the device. Subsequently, the upper end of the underground construction element can once again be clamped between the jaws of the clamping tongs and pulled out of the ground by means of the pile-driving or vibrating device.

In this regard, the sling chain serves to lay the underground construction element down onto the ground. Furthermore, the sling chain functions, to a limited extent, as security in the event of failure of the clamping tongs or of the underground construction element being torn out, so as to prevent uncontrolled falling of the underground construction element after it has been released from the hold in the clamping tongs.

The use of a sling chain or securing chain to secure a pile element that is to be driven into the ground using a pile-driving apparatus is furthermore described in U.S. Pat. No. 5,332,047 as well as in EP 3 708 714 A1.

The previously known sling chain serves for additionally securing the position of the underground construction element. Furthermore, it connects the underground construction element to the pile-driving or vibrating device so as to set the element upright, lift it up, and set it down. Underground construction elements such as, for example, sheet piles can have a length of more than 20 m and a weight of up to 7 metric tons in practice. In the event of failure of the clamping tongs, but also, in particular, in the event of disadvantageous lifting or set-down procedures, it can happen that the sling chain fails, with the result of uncontrolled toppling of the underground construction element. Another cause for failure of the sling chain can be slippage of a fastening toggle of the sling chain out of the underground construction element passage provided for this purpose, tearing of the chain, or also tearing down or tearing out of an upper part of the underground construction element, with damage to the underground construction element passage and loosening of the security chain from the underground construction element. If the connection by means of the sling chain fails, uncontrolled toppling of the underground construction element is critical, above all since life-threatening danger exists for the rigger and the driver, who are in the immediate danger zone.

SUMMARY OF THE INVENTION

This is where the invention wishes to provide a remedy. The invention is based on the task of making available an apparatus for securing an underground construction element on an underground construction machine, in particular a pile element on a pile-driving apparatus, by means of which apparatus the risk of an underground construction element, in particular a pile, toppling in an uncontrolled manner is counteracted. This task is accomplished by means of an apparatus having the characteristics according to one aspect of the invention.

With the invention, an apparatus for securing an underground construction element on an underground construction machine, in particular a pile element on a pile-driving apparatus is made available, by means of which apparatus the risk of an underground construction element, in particular a pile toppling in an uncontrolled manner is counteracted. A securing device is provided, which device is preferably formed by a securing chain and is connected, with a first end, to the underground construction element, and the second end of which is affixed, by way of an energy absorber, to the underground construction machine, wherein the length of the securing device is selected in such a manner that the device forms a loop when the lifting tackle is intact. As a result, uncontrolled toppling of the underground construction element is counteracted even in the event of failure of the lifting tackle. By means of the loop that is formed, it is guaranteed that the securing device is free of a load when the lifting tackle is intact. By means of the energy absorber, the result is achieved, in the event of a failure of the lifting tackle, that the drop energy of the underground construction element is absorbed and conducted away, and thereby the forces that act on the securing device are reduced. The discharge of the energy takes place by means of the energy absorber, in particular by means of conversion of the kinetic drop energy to friction energy, deformation energy and/or heat energy. In the case of a pile-driving or vibrating device that can be displaced on a leader, the energy absorber is attached to the pile-driving or vibrating device or to a component firmly connected to this device, for example to the leader carriage, by way of the securing device connected to the absorber.

The securing device is preferably configured as a flexible securing element, for example in the form of a chain, a cable or a band.

A basic idea of the present invention lies in providing a securing device, independent of the sling chain that has been established in the state of the art and also functions as a securing chain, which device intervenes in the event of failure of the lifting tackle, in particular of the sling chain, and is configured in such a manner that it can absorb the kinetic energy that results from the falling (toppling) movement of the underground construction element as completely as possible. This task is taken on by the energy absorber connected to the securing device.

In a further development of the invention, the energy absorber is formed by a crash absorber (also called a “crash buffer”). These crash absorbers or crash buffers are buffers in which the conversion of kinetic energy to deformation energy takes place, which conversion is accompanied by an irreversible deformation of the buffer, at least in certain regions. Such crash absorbers, which make a great reduction in energy possible, are known in the most varied embodiments and are described, for example, in DE 4317738 A1.

Energy absorbers can also comprise conical elements as a spring having a friction buffer. Potential (spring) energy can be stored in a spring. In order to not allow any long-lasting oscillating movement to occur under stress, the spring is combined with a strong buffer. In this regard, a friction buffer is advantageous, because such a buffer works approximately independent of speed and therefore can make a great reaction force available even at a low speed. In the case of a conical element, a ring that is shaped conically outward engages into a larger ring that is shaped conically inward.

When these rings are pulled into one another, the kinematic energy that occurs is converted to heat energy and spring energy by means of expansion of the rings. To increase the amount of energy that can be absorbed and the brake path, multiple pairs of rings can be arranged axially one behind the other. Furthermore, energy absorbers can also be configured as pure friction buffers.

In an embodiment of the invention, the energy absorber is designed for tension stress. In this way, deflection to the securing device of the kinematic energy to be absorbed is not necessary.

In a further embodiment of the invention, the securing device can also be configured as a cable having an integrated energy absorber. In this regard, the cable has buffering elements, for example elastomer elements, which absorb energy, such as they are known, for example, from shipping/navigation. Also, the cable itself can have buffering properties. A further possible embodiment is core/mantle cables, similar to dynamic cables (for example in accordance with DIN EN 892-2023-07) or semi-static cables (for example in accordance with DIN EN 1891-1998-06), as they are also known from fall protection.

In a further development of the invention, the energy absorber is connected to a draw piece, which is displaceable in a guide, preferably a linear guide arranged on the construction machine, and has a second connection device, wherein the securing device has a second connection part on its first end, which part can be releasably connected to the second connection device. In this way, an energy absorber unit having a guided draw piece is formed, which unit guarantees a defined direction of the force introduction into the energy absorber. This energy absorber unit is attached to the pile-driving or vibrating device or—in the case of a pile-driving or vibrating device that can be displaced on a leader—to a component firmly connected to it, for example to the leader carriage connected to it, by way of which the pile-driving or vibrating device can be displaced along the leader. By way of the second connection device, the securing device can be connected, if needed, to the pile-driving or vibrating device, by way of the energy absorber unit. Also, wear-related replacement of the securing device is easily made possible in this way.

In an embodiment of the invention, the securing device is passed through a passage that is arranged on the underground construction element for this purpose, and has a stop plate at its first end, the width of which plate is greater than the width of the passage against which the stop plate lies, wherein the stop plate preferably covers the passage completely. In this way, easy connection of the securing device to the underground construction element is made possible by means of passing it through the passage of the element and subsequently connecting it to the energy absorber, wherein the stop plate preferably lies against the underground construction element so as to cover the passage completely.

In a further embodiment of the invention, a clamping element is arranged on the stop plate, which element can be attached in the passage of an underground construction element by means of clamping. In this way, fixation of the stop plate in the passage of an underground construction element is made possible even when there is no load on the securing device. For example, the clamping element can be formed by an elastomer plug or by at least two clamping tongues that extend in the direction of the securing device.

The invention furthermore also comprises an underground construction machine for driving in and/or pulling out a pile element, into or out of the ground, in which machine an apparatus according to one of the aforementioned types is arranged. Preferably, clamping tongs for holding a pile element in a clamped manner are provided.

In a further development of the invention, the underground construction machine is a pile-driving apparatus that has a pile-driving mechanism that can be moved along a leader by way of a carriage, wherein an energy absorber is arranged on the pile-driving mechanism or the carriage, which absorber has a second connection device to which the second connection part of the second flexible securing element is releasably connected. In this way, a second securing element can be connected to the pile-driving or vibrating device, if needed, by way of the energy absorber unit. Also, wear-related replacement of the second securing element is easily made possible in this way.

In an embodiment of the invention, the energy absorber is connected to a draw piece that can be displaced in a linear guide arranged on the construction machine, wherein the second connection device is arranged on the draw piece. In this way, an energy absorber unit having a guided draw piece is formed, which piece guarantees a defined direction of force introduction into the energy absorber by way of the linear guide. The securing device can easily be connected to the draw piece, when needed, by way of the connection device.

It is advantageous if multiple energy absorbers and multiple securing devices are provided. Multiple energy absorbers and multiple securing devices are helpful, in particular, if multiple underground construction elements must be accommodated. For example, pile-driving of double profiles is a usual application.

The invention is furthermore based on the task of making available an underground construction method, in particular using an apparatus of the type indicated above, in which method the risk of uncontrolled toppling of an underground construction element, in particular of a pile is counteracted. This task is accomplished by an underground construction method having the characteristics according to another aspect of the invention.

With the invention, an underground construction method is made available, in particular a method using an apparatus of the type indicated above, in which method the risk of uncontrolled toppling of an underground construction element, in particular of a pile, is counteracted. Because the securing device, preferably a securing chain, is connected to the underground construction element with its first end and affixed to the construction machine with its second end, by way of an energy absorber, wherein the length of the securing device is selected in such a manner that this device forms a loop when the lifting tackle is intact, uncontrolled toppling of the underground construction element is counteracted even in the event of failure of the lifting tackle, for example of a sling chain. By means of the loop that is formed, it is guaranteed that the securing device is free of a load when the lifting tackle is intact. By means of the energy absorber, the result is achieved, in the event of a failure of the lifting tackle, that the drop energy of the underground construction element is absorbed and conducted away, and thereby the forces that act on the securing device are reduced.

In a further development of the invention, the energy absorber affixed to the underground construction machine has a draw piece having a second connection device, and the securing device has a second connection part at its second end, wherein the second connection part is releasably connected to the second connection device of the draw piece. In this way, simple affixation of the securing device to the underground construction machine is achieved.

BRIEF DESCRIPTION OF THE DRAWINGS

Other objects and features of the invention will become apparent from the following detailed description considered in connection with the accompanying drawings. It is to be understood, however, that the drawings are designed as an illustration only and not as a definition of the limits of the invention.

In the drawings,

FIG. 1 shows the schematic representation of a pile-driving apparatus having a sling chain and a securing device for an accommodated pile, with the pile during the raising process;

FIG. 2 shows the schematic representation of the pile-driving apparatus from FIG. 1 in the case of failure of the sling chain;

FIG. 3 shows the schematic representation of the pile-driving apparatus from FIG. 1 with the pile in the suspended position (pile element at a slight height);

FIG. 4A shows the schematic representation of the pile-driving apparatus from FIG. 1 in the case of failure of the sling chain, when the pile element is set down onto the ground (securing device free of a load);

FIG. 4B shows the schematic representation of the pile-driving apparatus from FIG. 1 in the case of failure of the sling chain, when the pile element tips over (securing device under load);

FIG. 5 shows the schematic representation of the pile-driving apparatus from FIG. 1 with the pile in the suspended position (pile element at a great height);

FIG. 6 shows the schematic representation of the pile-driving apparatus from FIG. 5 in the case of failure of the sling chain;

FIG. 7 shows the schematic representation of the pile-driving mechanism of the pile-driving apparatus from FIG. 1, with the securing device;

FIG. 8 shows the schematic representation of the pile-driving mechanism of a pile-driving apparatus having a securing device, in a further embodiment;

FIG. 9 shows the schematic representation of the pile-driving mechanism of the pile-driving apparatus from FIG. 3, with the securing device;

FIG. 10 shows the detail representation of the securing device from FIG. 9, with the energy absorber;

FIG. 11A shows the representation of the energy absorber from FIG. 10, in the non-loaded state;

FIG. 11B shows the representation of the energy absorber from FIG. 10, in the partially loaded state;

FIG. 11C shows the representation of the energy absorber from FIG. 10, in the fully loaded state;

FIG. 12A shows the representation of the energy absorber in a further embodiment, in the non-loaded state;

FIG. 12B shows the representation of the energy absorber in a further embodiment, in the fully loaded state;

FIG. 13 shows the representation of an energy absorber in a third embodiment;

FIG. 14A shows the representation of a securing device having an integrated energy absorber, in the non-loaded state; and

FIG. 14B shows the representation of a securing device having an integrated energy absorber, in the fully loaded state.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

The pile-driving apparatus selected as an exemplary embodiment comprises a support frame 1 having a leader 2, on which a work mechanism carriage 3 is arranged so as to be displaced, which carriage holds a pile-driving mechanism 4, on which clamping tongs 5 that can be hydraulically activated are attached, between the jaws 51 (see, e.g. FIG. 7) of which tongs a pile 9, in the present case a sheet pile can be firmly clamped. The pile-driving mechanism 4 is configured in the usual manner in the exemplary embodiment, as a vibrator having imbalance masses that can be driven to rotate, as it is described in EP 2 085 149 A1. For introducing a pile 9 into the clamping tongs 5, extension pieces 52 having introduction flanks that are directed outward at a slant are provided on the jaws 51, which pieces, together, form a V-shaped introduction slot. On their outside, which lies opposite the introduction flank, a coupling insert 54 is arranged on each of the two extension pieces 52.

On a first one of the extension pieces 52, a lifting tackle 6 in the form of a sling chain is attached with its first end. The lifting tackle 6 is provided with a coupling element at its second, free end, in the present case in the form of an insertion plate 61, which can be pushed into the two coupling inserts 54 of the extension pieces 52 and thereby releasably attached with shape fit. In FIG. 7, the insertion plates 61 of the sling chain are accommodated by the coupling insert 54 of the same first extension piece 52 to which they are attached with their first end.

An energy absorber 7 is arranged on the pile-driving mechanism 4, which absorber, in the exemplary embodiment, is oriented parallel to a center longitudinal axis that runs between the jaws 51 of the clamping tongs 5. In the exemplary embodiment, the energy absorber 7 is formed by a crash absorber as it is shown in FIGS. 11A-11C. The crash absorber is structured as an absorber insert 70, having a sleeve part 701 that has a diameter-reduced section 702 and is provided with a fastening tab 703 on its side that lies opposite the diameter-reduced section 702. The sleeve part 701 accommodates a piston 705 that is connected to a piston rod 704, which is guided in the diameter-reduced section 702 and is provided with a connection bore 706 for being connected to the connection chain 71 shown, for example, in FIG. 7. When a tension load is applied to the piston rod 704, the piston 705 is pulled through the diameter-reduced section 702, and thereby this section is plastically deformed, with the conversion of kinetic energy to deformation energy.

The absorber insert 70 of the energy absorber 7 is connected, by way of a connection chain 71, to a draw piece 72 (see FIG. 7), which is linearly guided in a guide 74 attached to the pile-driving mechanism 4, on a common center axis with the energy absorber 7. As is shown in FIG. 10, the connection chain 71 is guided here, to state it precisely. In this way, a complete tension load of the energy absorber 7 is guaranteed. (In a further embodiment, a connection rod 75 can also be provided in place of a connection chain, as is shown in FIG. 8.) The draw piece 72 has a second connection device 73, to which the second connection part 81 of a securing device 8 configured in the form of a securing chain is releasably attached. In the exemplary embodiment, the second connection device 73 is formed by a mushroom-head holder, and the second connection part 81 is a mushroom-head piece attached to the securing device 8, which piece can be inserted into the mushroom-head holder and thereby can be releasably connected to it with shape fit. At its end that faces away from the second connection part 81, a stop plate 82 is attached to the securing device 8, which plate is configured, in the exemplary embodiment, in the form of a circular metal sheet.

The second connection device 73 of the draw piece 72 and the second connection part 81 of the securing device 8 can, of course, also have other embodiments that correspond to one another. Thus, the second connection device 73 of the draw piece 72 can also be configured, for example, in the form of an eye, into which a second connection part 81 of the securing device 8, configured in the form of a hook, preferably a carabiner hook can be hooked. Furthermore, the second connection device 73 of the draw piece 72 and the second connection part 81 of the securing device 8 can also both be configured as eyes or also as a plate provided with a bore, wherein a connection bolt or a connection screw can be passed through the eyes or the bores, for releasable attachment.

To pick up a pile 9 from the ground, first the coupling elements (insertion plates 61) of the lifting tackle 6 are released from the coupling insert 54 of the first extension piece 52 of the clamping tongs 5, passed through a first passage 91 that is present in the pile 9 (see FIG. 9) and releasably connected to the coupling insert 54 of the second extension piece 52. The lifting tackle 6 is now passed through the first passage 91 of the pile 9, and thereby the latter is connected to the pile-driving mechanism 4. Furthermore, the securing device 8, configured as a securing chain in the present case, is passed through a second passage 92 that is provided in the pile 9 for this purpose, with its second connection part 81, until the stop plate 82 lies against the pile 9, covering the second passage 92. Then the securing device 8 is releasably connected to the second connection device 73 of the draw piece 72 with its second connection part 81. It is fundamentally also possible to pass the lifting tackle 6 and the securing device 8 through a common passage of the pile. Because of a risk of reciprocal impairment of lifting tackle 6 and securing device 8, however, this arrangement is not preferred.

Subsequently, the pile-driving mechanism 4 is moved upward by way of the work mechanism carriage 3, along the leader 2, and thereby the pile is raised with its end that faces the lifting tackle 6. The securing device 8, configured as a securing chain, is structured to be so long that it forms a loop (see FIG. 1).

If the lifting tackle 6 fails while the pile 9 is still on the ground with its end that lies opposite the first passage 91, then the pile topples until the securing device 8 has been tensed. The kinetic energy of the falling pile 9 is now transferred to the energy absorber 7, by way of the securing device 8, by way of the linearly guided draw piece 72, which absorber conducts this energy away and converts it to deformation and heat energy, to such an extent that the securing device 8 can absorb the remaining energy. The pile is therefore reliably held by the securing device 8 (see FIG. 2).

If the lifting tackle 6 fails when the pile 9 no longer has any contact with the ground and is suspended at a slight height, perpendicularly, in other words at a distance from the ground that is less than the length of the securing device 8, below the pile-driving mechanism 4 (see FIG. 3), then the pile first drops perpendicularly onto the ground (see FIG. 4A) and then tips over to the side (see FIG. 4B), until the securing device 8 is tensed. In this scenario, a large part of the kinetic drop energy is already absorbed by the ground.

If the lifting tackle 6 fails when the pile 9 no longer has any contact with the ground and is already suspended perpendicularly at a great height, in other words at a distance from the ground that is greater than the length of the securing device, below the pile-driving mechanism 4 (see FIG. 5), then the pile drops down perpendicularly until the securing device 8 is tensed. In this scenario, the entire kinetic drop energy must be absorbed.

In order to cover all three of the scenarios mentioned above, the energy absorber must be dimensioned to absorb the kinetic drop energy that occurs in the last scenario. This kinetic drop energy can reach significant dimensions, depending on the weight of the pile element. It can therefore be practical to limit the maximum lifting height and to dimension the securing device 8 in such a manner that in the event of failure of the lifting tackle 6, the pile 9 that has already been lifted up off the ground first hits the ground perpendicularly before the securing device 8 is tensed. In this way, a large part of the kinetic drop energy is absorbed by the ground, and for this reason the energy absorber can be dimensioned to be correspondingly smaller.

In FIGS. 12A-12B, an absorber insert 70′ is shown in a further embodiment. Here the sleeve part 701′ is configured as a hollow cylinder and accommodates a cup spring assembly 707 through which a piston rod 704′ is passed. The piston rod 704′ is connected, on its end side, to a cylindrical piston 705′, which is guided in the sleeve part 701′ and rests on the cup spring assembly 707. When a tension load is applied to the piston rod 704′, the cup spring assembly 707 is reversibly deformed by the piston 705, with conversion of kinetic energy to deformation energy and friction energy.

In FIG. 13, an absorber insert 70″ is shown in a third embodiment. In this regard, the sleeve part 701″ is once again structured as a hollow cylinder and accommodates a piston rod 704″. The piston rod 704″ is configured to be hollow and has a piston 705″ on its end side, which piston is configured in the form of a circumferential collar. Between the sleeve part 701″ and the piston rod 704″, a friction spring 708 is introduced. When a tension load is applied to the piston rod 704″, friction spring 708 is compressed by the piston 705″ and irreversibly deformed, with the conversion of kinetic energy to deformation energy and friction energy.

In FIG. 14, a securing device 8′ having an integrated energy absorber 70″ is shown. The securing device 8′ is configured as a securing chain, wherein a tension spring 83 is attached between two chain links, in such a manner that in the non-loaded state of the securing chain, a loop is formed. When a tension load is applied to the securing device 8′, the tension spring 83 is stretched so far until the securing chain is stretched out, with the conversion of kinetic energy to deformation energy.

Although only a few embodiments of the present invention have been shown and described, it is to be understood that many changes and modifications may be made thereunto without departing from the spirit and scope of the invention.