VIBRATOR ARRANGEMENT

[0001] The present disclosure relates in general to a filling chimney for a deep vibrator arrangement, a deep vibrator arrangement and a method of operating a deep vibrator arrangement.

[0002] Deep vibrators may be used to produce columns of compacted filling material in soil. During production, the filling material to be compacted may be stored in a silo tube. The filling material stored in the silo tube may be fed into the soil in the vicinity of the deep vibrator where it is compacted by the vibrating deep vibrator. On the one hand, filling and/or refilling the silo tube with filling material may be time- consuming and therefore expensive, and on the other hand it can be a design challenge, since the silo tube is moved during operation. Hence, there is a need for a fast, inexpensive and simple solution.

[0003] A first example relates to a filling chimney configured to be coupled to a silo tube of a deep vibrator arrangement. The filling chimney extends in a longitudinal direction and includes an outer wall surrounding an internal space, an elongated filling opening formed in the outer wall and extending in the longitudinal direction, and a shutter arranged at the filling opening. The shutter is configured to open in response to an external force acting on the shutter from an exterior of the filling chimney so as to allow solid filling material to be fed into the internal space. Further, the shutter is configured to close in response to the external force being released.

[0004] A further example relates to a deep vibrator arrangement which includes a filling chimney according to the first example, a silo tube and a deep vibrator. The silo tube is coupled between the filling chimney and the deep vibrator.

[0005] Yet another example relates to a method of operating a deep vibrator arrangement as outlined above. The method includes arranging the filling beak above a surface, opening the shutter by the filling beak and feeding solid filling material via the filling beak and the filling opening into the filling chimney while the filling chimney coupled to the silo tube and the silo tube coupled to the deep vibrator move into a soil below the surface.

[0006] Embodiments are explained below with reference to the drawings. The drawings serve to illustrate certain principles, so that only aspects necessary for understanding these principles are illustrated. The drawings are not necessarily to scale. In the drawings, identical reference characters denote corresponding elements.

[0007] Figure l is a schematic cross-sectional side view of a deep vibrator arrangement during the production of vibratory compacted material columns in a stage in which a filling beak extends into a filling opening of a filling chimney.

[0008] Figure 2 is a schematic cross-sectional side view of the deep vibrator arrangement of Figure 1 in a stage in which the filling beak is removed from the filling opening.

[0009] Figure 3 is an enlarged section of Figure 1.

[0010] Figure 4 is a horizontal cross-sectional view of the filling chimney in a cross-sectional plane A-A in Figure 2 illustrating the filling opening being closed by a shutter.

[0011] Figure 5 illustrates the filling chimney of Figure 4 with the filling beak extending into the filling opening.

[0012] Figure 6 is a vertical cross-sectional view of the filling beak of Figure 5 in a cross-sectional plane B-B.

[0013] In the following detailed description, reference is made to the accompanying drawings. The drawings form a part of the description and for the purpose of illustration show examples of how the invention may be used and implemented. It is to be understood that the features of the various embodiments described herein may be combined with each other, unless specifically noted otherwise. [0014] Figure 1 schematically illustrates a vertical cross sectional side view of a deep vibrator arrangement 100 during the production of vibratory compacted material columns 16. Figure 3 is an enlarged section of Figure 1.

[0015] Referring to Figures 1 and 3, the deep vibrator arrangement 100 includes, inter alia, a penetration unit 90. The penetration unit 90 includes a deep vibrator 5 which may also be referred to as "vibroflot", a filling chimney 11 and a silo pipe 6 coupled between the deep vibrator 5 and the filling chimney 11. The penetration unit 90 further includes an optional lock tank 7 coupled between the silo pipe 6 and the filling chimney 11 and an optional storage tank 8 coupled between the silo pipe 6 and the filling chimney 11. The lock tank 7 has an upper lock 10 at an upper side facing the filling chimney 11 and a lower lock 9 at a lower side facing the silo tube 6. If the penetration unit 90 includes both the lock tank 7 and the storage tank 8, the lock tank 7 may be coupled between the silo pipe 6 and the storage tank 8 and the storage tank 8 may be coupled between the lock tank 7 and the filling chimney 11. The penetration unit 90 may further include a tremie pipe 15 coupled to the silo pipe 6 and running along the deep vibrator 5.

[0016] As illustrated, the deep vibrator arrangement 100 may further include a crane or a crane-like frame 2 which in the here shown example includes a beam and a roller 3 to which the penetration unit 90 is connected freely suspended via a lifting head 4. Using the lifting head 4, the penetration unit 90 may be moved upwards and downwards. In order to provide the penetration unit 90 with a solid filling material 141, the deep vibrator arrangement 100 may include a hopper 14 containing the solid filling material 141, and a filling beak 13 for feeding the solid filling material 141 through a filling opening 112 of the filling chimney 11 into an internal space 110 of the filling chimney 11.

[0017] The purpose of the deep vibrator arrangement 100 is to produce vibratory compacted material columns 16 in a soil 171. For this purpose, the solid filling material 141 stored in the hopper 14 is fed through the filling opening 112 into the internal space 110 of the filling chimney 11 using the filling beak 13. Once in the internal space 110, the filling material 141 falls down to the storage tank 8 (if provided). After opening the upper lock 10 of the lock tank 7, filling material 141 stored in the storage tank 8 (if provided) or falling down from the filling chimney 11 (if the storage tank 8 is omitted) enters and, because of the closed lower lock 9, remains in the lock tank 7. Subsequently, the upper lock 10 closed and the lower lock 9 is opened so that the filling material 141 situated in the lock tank 7 falls down into the silo pipe 6 from where it enters the tremie pipe 15. At the bottom end of the tremie pipe 15, the filling material 141 leaves the tremie pipe 15 in the vicinity of the deep vibrator 5, where it gets into the soil 171 and is compacted by the vibrating deep vibrator 5. By pulling the penetration unit 90 upwardly and simultaneously releasing and compacting filling material 141, a vibratory compacted material column 16 is formed successively. A single completed vibratory compacted material column 16 is illustrated in Figure 2.

[0018] As can be seen from the process described above, for large maximum depths d91max of a vibratory compacted material column 16 to be produced, the filling process may advantageously use the optional double lock which in the present example consists of the lock tank 7 with the upper lock 10 and the lower lock 9 in order to feed the filling material 141 to the silo pipe 6 in metered quantities. In principle, feeding filling material 141 to the silo pipe 6 in metered quantities could be achieved using a single lock instead of the double lock. However, the double lock allows to always provide excess air pressure in the silo tube 6 to assure that at the bottom end of the tremie pipe 15 there is always a pressure inside the tremie pipe 15 exceeding a pressure in the soil 171 outside and in the vicinity of the tremie pipe 15. For this reason, at any given time only one of the upper lock 10 and the lower lock 9 is open. In the drawings, a compressor and supply lines for providing the pressure are omitted.

[0019] The storage tank 8 serves to store solid filling material 141 within the penetration unit 90, is situated above the upper lock 10, and may have any cross- sectional shape, e.g. round, square, oval, as long as it does not negatively interfere with operational requirements of the penetration unit 90 such as easy laydown and sufficient clearance to any mast or boom of the crane or crane-like frame 2.

[0020] In the present example, the size of the storage tank 8 and the lock tank 7 are drawn the same size, but this is not necessary as long as the storage volume above the upper lock 10 (e.g. the storage volume of the storage tank 8) is at least as large as the volume of the lock tank 7. Note that the storage tank 8 is not necessary in cases where the filling chimney 11 itself has enough volume to fill the lock tank 7.

[0021] In the illustrated example, the soil 171 is below water 172. For that reason, the crane or crane-like frame 2, the hopper 14 and the filling beak 13 are installed on a barge 1 floating on the water 172. Of course, vibratory compacted material columns 16 may also installed into a soil 171 without water 172 covering the soil 171. In such a case, the barge 1 may be omitted and, instead, the crane or crane-like frame 2 and, optionally in each case, the hopper 14 and the filling beak 13 may be installed in an immobile manner on the soil 171 or, in a mobile manner, on a vehicle like a crane truck.

[0022] In the examples illustrated in Figures 1 and 2, the lock tank 7 has a larger diameter than the silo tube 6. In this case, if there is no water, that is, if the soil 171 forms the surface 170 on which the hopper 14 and filling beak 13 are located, the lock tank 7 cannot enter the soil 171 (because it is wider than the silo tube 6). In this case, the lock tank 7 is either omitted so that the filling chimney 11 is used to feed material directly into the silo tube 6, or the lock tank 7, the optional storage tank 8 and, optionally, the filling chimney 11 are designed to have essentially the same cross sectional shape as the silo tube 6.

[0023] Figure 1 illustrates a phase of vibratory compacted material column installation shortly after the bottom end 91 of the penetration unit 90 has penetrated to a maximum depth d91max below the surface 170 and after a lowermost section 161 of the vibratory compacted material column to be produced has been completed. Prior to producing the lowermost section 161, a solid filling material 141, e.g. gravel or sand, forming the vibratory compacted material column 16 (or at least the lowermost section 161 thereof) needs to be filled into the penetration unit 90. The related filling process may start after the penetration unit 90 has intersected the surface 170 (i.e. after the penetration unit 90 has penetrated into the water 172 and/or into the soil 171) and prior to or after the bottom end 91 has reached the maximum depth d91max. [0024] Next, a filling process of solid filling material 141 through a filling opening 112 of the filling chimney 11 into an internal space 110 of the filling chimney 11 will be described with additional reference to Figures 4 to 6. Figure 4 is a horizontal cross- sectional view of the filling chimney 11 in a cross-sectional plane A-A in Figure 2 illustrating the filling opening 112 being closed by a shutter 12, Figure 5 illustrates the filling chimney 111 of Figure 4 with the filling beak 13 extending into the filling opening 112, and Figure 6 is a vertical cross-sectional view of the filling beak 13 of Figure 5 in a cross-sectional plane B-B.

[0025] The filling chimney 11 is a silo tube of any shape and extends in a longitudinal direction z. Without being restricted to, the filling chimney 11 of the present examples is shown to have a round or substantially round cross-section. The filling chimney 11 includes an outer (e.g. lateral) wall 111 which surrounds an internal space 110. An elongated filling opening 112 (e.g. a side opening) is formed in the outer wall 111 and extends in the longitudinal direction z. A shutter 12, which is arranged at the filling opening 112, is configured to open in response to an external force F acting on the shutter 12 from an exterior of the filling chimney 11 (Figure 5) so as to allow solid filling material 141 to be fed into the internal space 110. Further, the filling opening 112 is configured to close in response to the external force F being released (Figure 4). In the closed state, the shutter 12 covers the filling opening 112.

[0026] For instance, the shutter 12 may be is configured to be elastically deformed when the external force F is applied. According to one example, the shutter 12 may include a flexible material, e.g. rubber or a rubber-like material. Optionally, the flexible material may be reinforced. For instance, the shutter 12 may be a reinforced rubber sheet.

[0027] The shutter 12 mainly serves to keep filling material 141 that has been filled into the filling chimney 11 inside the filling chimney 11. According to one example, the shutter 12 is further implemented in such a way that, in a closed state, it prevents water or soil from entering the filling chimney 11. According to one example, the external force the shutter 12 can withstand without opening, that is, the external force F required to open the shutter 12 may be at least as large as the force generated by the water pressure at seabed. This would prevent water from entering the filling chimney 11 when such filling chimney 11 is not filled with solid filling material 14 and when the penetration unit 90 has been lowered such that the lock tank 7 or the shutter 12 is close to the level of the seabed (which is the surface of the soil). According to one example, the shutter 12 is configured to withstand an external pressure of between 0.5 bar and 2 bar without opening.

[0028] However, this is not a necessary requirement for the equipment to function, as entry of such water into the filling chimney 11 is not per se detrimental for the overall function of the material transport as herein described. According to one example, the penetration unit 90 is operated in such a way that the filling chimney 11 never enters soil 171 but always stays clearly above the seabed. In this case, no specific closing force of the shutter 12 may be required as long as it closes again after the filling beak 13 is removed from the shutter 12, so as to prevent filling material 141 from leaving the filling chimney 11 via the shutter 12 through the filling opening 112.

[0029] In cases in which the penetration unit 90 is operated only in soil 171, that is, in cases in which there is no water above the soil 171 surface and in which the chimney 11 (and the lock tank 7, if there is one) is configured to enter the soil 171, then there should be a pressure acted by the shutter 12 upon such soil 171 that is larger than the soil pressure upon the shutter 12 to prevent the filling chimney 11 from getting contaminated by intruding soil when such filling chimney 11 is not filled with filling material 141. This pressure acted by the shutter 12 against the filling opening 112 (more precisely: against the inner surface of the outer wall 111) may then present the technical limit for the depth to which the filling chimney 11 can enter soil.

[0030] As illustrated in Figures 4 and 5, the shutter 12 may be mounted to an inside of the outer wall 111. For instance, on one side the shutter 12 may be fixed to the filling chimney 11, e.g. by a clamp 19, while the opposite side 20 of the shutter 12 is freely resting on the inside of the filling chimney 11.

[0031] If filling material 141 needs to be filled in the filling chimney 11, the filling beak 13 receives filling material 141 from the hopper 14 which itself is periodically filled for example by a conveyor belt not shown here. The filling beak 13 enters into the filling chimney 11, e.g. by for example rotating around a horizontal axis 130 shown in Figure 3, and/or by being laterally moved (parallel to the direction x in Figure 3) closer towards the filling chimney 11. As a tip 131 of the filling beak 13 comes closer to the filling chimney 11, it displaces shutter 12, which rotates sideways as shown in Figure 5. As soon as in this way the filling opening 112 has been opened, the hopper 14 releases filling material 141 to the filling beak 13 and filling material 141 flows via the filling beak 13 into the filling chimney 11 and falls from there by gravity to the optional storage tank 8 as already described above.

[0032] Since the filling opening 112 is longish and extends in the longitudinal direction, filling material 141 can be filled into the filling chimney 11 even if the penetration unit 90 is moving downwards or upwards an even if a major part of the penetration unit 90 is below the surface 170. This allows for only locally opening the filling opening 112 during operation at the actual position of the tip 131 of the filling beak 13 relative to the filling opening 112. For instance, in the longitudinal direction z the filling opening 112 may have a length 1112 which is at least 30%, of a length 111 the filling chimney 11 has in the longitudinal direction z, c.f. Figure 3. Furthermore, the filling opening 112, accordion to one example, may have in a transverse direction y perpendicular to the longitudinal direction z a width wl 12 of between 10 cm

(centimeters) and 50 cm, in particular between 20 cm and 50 cm.

[0033] With the present invention, the filling chimney 11 in the top section of a penetration unit 90 (which may include, inter alia, a double lock 7, 9, 10) serves the purpose to fill continuously a filling material 141 like gravel or sand into the upper part of the penetration unit 30 without having to stop the up/down motion of the penetration unit during the filling process. The filling chimney 11 of the penetration unit may be shaped in a way that an over depth continuous longish filling opening 112 is provided with a shutter 12, e.g. a (optionally reinforced) rubber sheet, that is on the one hand strong enough to keep the filling material 141 inside the filling chimney 11 and on the other hand flexible enough to allow the localized entry of the (tip 131 of the) filling beak 13 via which the filling material can be funneled into the filling chimney 11. The shape of the filling beak 13 may be optimized so that lateral movements of the penetration unit 90 and some rotation around its axis can be overcome by either a tolerance of the filling beak 13 to move with the penetration unit or by having several hinges to adapt to such motions.

[0034] As a special variant illustrated in Figures 1 to 3, the filling beak 13 has the capacity to rotate around an axis 130 that runs substantially perpendicular to the vertical direction, thereby allowing the tip 131 of the filling beak 13 to enter and exit the filling chimney 11. Additionally or alternatively there may be the possibility of the filling beak 13 to move sideways, e.g. parallel to a substantially horizontal direction x, closer and further from the filling chimney 11 in cases in which the rope holding the suspended penetration unit 90 does not stay perfectly vertical and hence makes make such movement necessary. Such lateral movement is easy to accomplish, in particular when the hopper 14 fills into a long enough catch basin 132 of the filling beak 13 opposite the tip 131.

[0035] The arrangement and method described above have the following advantages:

1. The penetration unit can already on its way down to depth be filled with filling material 141 as soon as the filling beak 13 is on the same level as the lower end of the filling opening 112.

2. The filling process may take place from devices mounted to the floor of a barge 1 without need for any skip buckets or filling material pumping hoses that would have to reach the top of the penetration unit 90 right under the lifting head 4 as this is the case in conventional arrangements. Not to have to reach with filling material 141 to the top of the crane 2 has in particular on offshore projects many advantages such as: a. The penetration unit 90 can be built lighter in weight. b. The“handover” of the filling material 114 is easier on deck as the penetration unit 90 is not moving as much relative to the barge 1 as it does on its upper end. Such movement, if it exceeds certain limits, has in the past stopped the works on barges. This invention will stretch this limit further. c. Most importantly, the filling process is much faster since there is no driving time of the bucket up and down the mast.

3. The filling chimney 11 can be per meter possibly much lighter than the corresponding silo tubes on conventional double lock penetration units that have the double lock on top. Saving weight may result in lower weight cranes needed to suspend the penetration unit 90. This advantage becomes more important the deeper the body of water in which the works are done.

4. For very deep water there could be a disassembly point at the lower end of the filling chimney 11 that would allow to separate the penetration unit 90 in two pieces at this point when it has to be brought back on deck.

5. For very deep water 172 one could envision the lock tank 7 and the two locks 9, 10 to be of the same diameter as the silo tube 6, using the locks inside silo tubes as in conventional arrangements. Then it could be envisioned that the filling chimney 11 would become part of the penetration unit 90 that enters the soil 171 as described above. As long as the filling chimney 11 is filled sufficiently high with filling material 141 and water, the shutter 12 should not bulge outward into the soil 171, nor inward.