Stamping machine and method

Abstract

A pile driver assembly for driving a pile, preferably offshore, into the ground and a method of driving a pile into the ground using the pile driver assembly are disclosed. The assembly includes a casing defining a chamber configured to contain a fluid, the chamber including a channel extending at least partially therethrough. The assembly further includes a positioning element configured to position the casing on or on the pile, at least a portion of the positioning element being positioned between the chamber and the pile, the positioning element including a guide element configured to extend at least partially through the channel of the chamber. The assembly further includes actuation means, wherein actuation of the actuation means displaces the chamber relative to the positioning element away from the pile, and the actuation means is configured to release the chamber to displace toward the pile so as to apply a force to the positioning element by the chamber, thereby controllably driving the pile into the ground.

Description

Technical Field

[0001] The present invention relates to a pile driver, and more specifically, to a pile driver suitable for driving operations in the offshore area. The present invention also relates to a method for driving a pile downward into the ground.

Background Art

[0002] To drive a pile into the offshore ground, it generally involves dropping a ram or hammer from a certain height onto the upper part of the pile via a strike plate. To apply the downward impact force of the hammer to a wider surface area at the upper part of the pile and protect the upper part of the pile from damage, generally, a wooden impact liner is arranged between the lower side of the strike plate or anvil and the upper part of the pile (see DE8900692U1). To better protect the strike plate and the upper part of the pile, the use of a pressure gas spring connected to the strike plate has also been proposed (see DE8900692U1). To protect the hammer and the upper part of the pile from damage caused by the direct impact of the hammer on the pile, the use of a pressure chamber filled with liquid above the strike plate to provide liquid resistance and a confined gas cushion between the hammer and the upper part of the pile has also been proposed (see GB1576966A). For this purpose, the use of a stack of spring disks or a hydraulic block to provide a cushion between the hammer and the strike plate above the pile has also been proposed (see US2184745A and US3498391A). The use of a stack of oil and gas buffers above the hammer to soften the impact of the hammer on the anvil at the upper part of the pile is also described in the so-called HYDROBLOK impact hammer developed by Hollandsche Beton Groep. The use of a water column above the hammer to provide a downward driving force to the hammer has also been proposed (see WO2018 / 030896, WO2013 / 112049, and WO2015 / 009144).

[0003] However, the designs of known pile drivers have not been very suitable for driving large-diameter piles into the offshore seabed. Conventional pile drivers have limitations on the impact force that their hammers can apply to the top of the pile. For larger piles (usually having a diameter exceeding 6 meters), it has been necessary to disperse the impact force provided by the hammers of conventional pile drivers over a much wider area. That is, the force of the conventional hammer needs to be dispersed from the center of the pile where the hammer strikes the anvil to the edge of this very large-diameter pile. This requires a very large anvil between the hammer and the pile.

SUMMARY OF THE INVENTION

[0004] According to a first aspect of the present invention, there is provided a pile driver assembly for driving a pile into the ground, preferably offshore, the assembly comprising a casing defining a chamber configured to contain a fluid, and a positioning element configured to position the casing on or above the pile, at least a part of the positioning element being positioned between the chamber and the pile, and actuating means, wherein actuation of the actuating means displaces the chamber relative to the positioning element such that the chamber moves away from the pile, and the actuating means is configured to release the chamber to displace it towards the pile and apply a force to the positioning member by the chamber to controllably drive the pile into the ground.

[0005] Such a configuration provides a pile driving machine assembly for efficiently driving piles, particularly larger piles (usually having a diameter exceeding 6 meters) into the ground. In contrast to known hammer configurations, in this configuration, there is no hammer enclosed within a casing and actively driven into the pile. Instead, the release of a fluid, such as water, from a distance away from the pile is utilized to drive the pile into the ground. This configuration allows for the use of a much larger mass chamber (especially when filled with fluid), and rather than a driving hammer, the "pushing force" is imparted to the pile by the chamber. Such a configuration is more delicate and less noisy than a configuration using a hammer. Compared to known configurations, there is a two-fold noise reduction. First, the peak noise level of each strike is reduced, and further, due to the large mass of the chamber, the impact required by the pile driving machine is reduced, and thus the cumulative noise (number of strikes × peak noise per strike) is decreased.

[0006] Furthermore, the use of positioning elements for positioning the casing relative to the pile allows for fine alignment between the casing and the pile (no intermediate elements such as an anvil are required). Next, the force applied by the casing can be directly applied to the pile by the positioning elements without the need to be dispersed via an anvil. Both of these factors help to avoid unnecessary stresses on the pile or the pile driving machine assembly resulting from misalignment between the two. Additionally, compared to prior art assemblies and / or devices, since there is no actual impact between components (e.g., a metal hammer against a metal anvil), the operation results in a low-noise pile driving operation.

[0007] Preferably, the actuating means is disposed intermediate at least a portion of the chamber and the positioning elements. Positioning the actuating means in this way (i.e., in the space between the chamber and a portion of the positioning elements) assists in lifting the entire chamber / casing (i.e., the actuating means pushes the chamber upward from below the chamber to lift the chamber), and thus allows for driving the pile into the ground using a larger chamber / casing of greater mass.

[0008] Preferably, this assembly further includes cushioning means for controllably cushioning the force applied to the pile by the chamber when the pile is driven into the ground. The use of the cushioning means makes it possible to apply the higher impact energy level from the high-mass casing / chamber more gently. By making the effect of each impact on the pile last longer, the peak force and the vibration of the pile are reduced, thereby also reducing the noise in water and air. Therefore, in such a configuration, the need for noise reduction measures (e.g., noise reduction bubble curtains) during pile driving operations is reduced. The more gentle application of the impact force also reduces the driving fatigue of the secondary steel parts of the pile driver (when used) and helps to generate a more uniform load on the pile, thereby reducing the stress variation and installation fatigue of the pile.

[0009] Preferably, the cushioning means is integral with the actuating means. That is, the actuating means includes the cushioning means. This reduces the need for additional components and makes the construction and maintenance of this assembly easier. Further, by combining the cushioning means with the actuating means, the cushioning means can also be disposed intermediate at least a part of the chamber and the positioning element without restricting space. Positioning the cushioning means in the space between the chamber and at least a part of the positioning element allows for easy access for maintenance and other types of activities.

[0010] Preferably, the actuating means includes at least one actuator. Preferably, the actuating means includes a central movable element having an extended position and a retracted position.

[0011] Preferably, upon actuation of the actuating means, the central movable element moves from the retracted position to the extended position, and the actuating means is configured to cushion the force applied to the positioning member by the chamber when the central movable element moves from the extended position to the retracted position.

[0012] Preferably, the actuating means includes a fluid chamber configured to contain a fluid, and an increase in the amount of fluid in the fluid chamber causes the central movable element to move from the retracted position towards the extended position.

[0013] Suitably, the actuating means further includes an additional fluid chamber fluidly connected to the first fluid chamber, and the central movable element moves between an extended position and a retracted position in response to the fluid pressure in these fluid chambers.

[0014] Suitably, these fluid chambers are fluidly connected by a valve element. Thereby, the pressure difference between the chambers can be easily controlled. As a result, this assembly can be preset to be in a pre-loaded state. Thereby, a strong impact of the casing on the pile can be avoided, and thus the noise is significantly reduced.

[0015] Suitably, the actuating means includes a buffer chamber configured to contain a buffer fluid, and as the central movable element moves from the extended position to the retracted position, the volume of the buffer chamber decreases.

[0016] Suitably, the actuating means includes adjustment means configured to adjust the internal buffer characteristics of the actuating means. Suitably, the adjustment means is configured to control the amount of buffer fluid in the buffer chamber. This helps to control the volume and pressure of the buffer fluid in the buffer chamber, and thus helps to control the buffer characteristics of the actuating means. By being able to adjust these characteristics, in this configuration, the damping means can be used in a sophisticated manner during pile driving operations, and the buffer effect is adjusted in real time on-site according to the details of the work.

[0017] Suitably, at least a part of the positioning element (positioned between the chamber and the pile) is a plate element configured to cover the upper surface of the pile. The configuration of the casing and the positioning element appropriately distributes the force applied to the pile over the entire circumference of the pile, so that the pile driving operation is performed in an energy-efficient manner.

[0018] Suitably, the positioning element further includes a sleeve element releasably connected to the upper part of the pile. The sleeve element helps to maintain the relative position / orientation between the pile and the positioning element, and thus provides a firm and stable system.

[0019] Suitably, the casing includes a sleeve portion at its end, and the sleeve portion is configured to surround the sleeve element of the positioning element to provide alignment between the positioning element and the casing. Thereby, a secure sleeve assembly (including the sleeve element of the positioning element and the sleeve portion of the casing) is provided, which can provide stability to this assembly during the pile driving operation. Further, this configuration enables fine adjustment of this assembly during the pile driving operation. In other words, the sleeve element of the positioning element and the sleeve portion of the casing provide an overlapping portion of the casing and the positioning element. Thereby, relative lateral displacement / rotation between the casing and the pile can be minimized, and thus the stability of the pile driving machine assembly with respect to the pile can be improved.

[0020] Suitably, the chamber has a channel extending at least partially therethrough. When the channel extends through the entire chamber, particularly when it extends axially through the chamber, a path for deploying a tool (such as a drill or a water jet, etc.) is provided therethrough. When the axial channel is positioned coaxially with the axis of the hollow pile, the tool can access and operate on the soil directly below the pile, and can reduce the resistance of the soil plug.

[0021] Suitably, the positioning element includes a guide element configured to extend at least partially through the channel. Suitably, the guide element is configured to extend further through the channel when the chamber moves towards the pile. In other words, the guide element and the channel provide an overlapping portion of the casing and the positioning element. Thereby, relative lateral displacement / rotation between the casing and the pile can be minimized, and thus the stability of the pile driving machine assembly with respect to the pile can be ensured.

[0022] Suitably, the chamber is filled with fluid via a conduit provided in the wall of the casing, and the wall has a valve for controlling the flow of the fluid. Thus, the chamber of this assembly can be filled in-situ, and this assembly can be transported to the work site in an empty state. Next, depending on the application, the chamber can be filled to a desired level (i.e., a level appropriate for the desired conditions for driving the pile into the ground).

[0023] According to a second aspect of the present invention, there is provided a pile driving machine assembly for driving a pile into the ground, preferably offshore, the assembly comprising a casing defining a chamber configured to contain a fluid, the chamber including a channel extending at least partially therethrough, and positioning means configured to position the casing on or above the pile, at least a part of the positioning means being positioned between the chamber and the pile, the positioning means including a guide element configured to extend at least partially through the channel of the chamber, actuating means, actuation of the actuating means displaces the chamber relative to the positioning means such that the chamber moves away from the pile, the actuating means is configured to release the chamber to displace towards the pile and apply a force to the positioning member by the chamber to controllably drive the pile into the ground.

[0024] This configuration provides the same advantages as described above for the first aspect of the present invention. Further, the interaction between the guide element and the channel improves the stability of the pile driving machine assembly with respect to the pile.

[0025] Suitable features of the second aspect of the present invention described below, where applicable, have the same advantages as the corresponding features of the first aspect of the present invention.

[0026] Suitably, the actuating means includes at least one actuator.

[0027] Preferably, this assembly further includes cushioning means for controllably cushioning the force applied to the pile by the chamber when the pile is driven into the ground. Preferably, the cushioning means includes at least one cushioning element. Preferably, the cushioning means is disposed intermediate the chamber and the positioning element.

[0028] Preferably, the cushioning means includes a central movable element having an extended position and a retracted position. Preferably, the cushioning means is configured to cushion the downward force applied to the positioning member by the chamber when the central movable element moves from the extended position to the retracted position.

[0029] Preferably, the cushioning means includes a cushioning chamber configured to contain a cushioning fluid, and the volume of the cushioning chamber decreases as the central movable element moves from the extended position to the retracted position.

[0030] Preferably, the cushioning means includes adjustment means configured to adjust the internal cushioning characteristics of the cushioning means. Preferably, the adjustment means is configured to control the amount of cushioning fluid in the cushioning chamber. By being able to adjust these characteristics, in this configuration, the damping means can be used delicately during pile driving operations, while the cushioning effect can be adjusted in real time on-site according to the details of the work.

[0031] Preferably, the actuating means is disposed intermediate the chamber and at least a portion of the positioning element.

[0032] Preferably, the actuating means is disposed at the distal end of the chamber away from the cushioning means. In other words, the cushioning means is disposed proximal to the first side of the chamber, and the actuating means is disposed proximal to the opposite second side of the chamber. Preferably, the actuating means is coupled to the end of the guide element. By positioning the actuating means in this way, easy access to the actuating means is enabled, and more space is provided between the chamber and the plate element (for example, for a larger cushioning means).

[0033] Suitably, the actuating means includes a clamp configured to releasably clamp the chamber.

[0034] Suitably, at least a part of the positioning element is a plate element configured to cover the upper surface of the pile. Suitably, the positioning element further includes a sleeve element releasably connected to the upper part of the pile.

[0035] Suitably, the guide element is configured to extend further through the channel when the chamber moves towards the pile.

[0036] Suitably, the chamber is filled with fluid via a conduit provided in the wall of a casing having a valve for controlling the flow of fluid.

[0037] According to a third aspect of the present invention, there is provided a method of driving a pile into the ground, preferably offshore, providing a pile to be driven into the ground; providing a pile driving machine assembly according to the first or second aspect of the present invention coaxially on or in the pile; actuating the actuating means so that the chamber moves away from the pile; further actuating the actuating means to release the chamber so that the chamber is displaced towards the pile and applies a force to the positioning member, and controllably driving the pile into the ground.

[0038] The proposed method provides a simple and safe way of driving piles into the ground, resulting in maximum stability and a balanced weight distribution throughout the pile driving operation.

[0039] Suitably, the method further includes controllably cushioning the force applied to the pile by the chamber when the pile is controllably driven into the ground. The steps of the method serve to enable the assembly to perform the pile driving operation with a minimum of underwater noise generation and thus a minimum of underwater noise propagation.

[0040] Suitably, the method further includes the step of operating the actuating means and further operating the actuating means until the pile is driven into the ground at a pre-set position.

[0041] Suitably, the method further includes the step of substantially filling the chamber with fluid. Suitably, the fluid is water from an offshore location.

[0042] As used herein, terms such as "upper", "lower", "upward", and "downward" are to be understood to refer to the orientation of the pile driver assembly or its components relative to the pile, particularly when positioned on a vertically extending pile. It will be understood that prior to assembly / positioning of the pile driver assembly, or in positions of the assembly in non-vertical orientations subsequent thereto, those terms may be adjusted accordingly.

[0043] As used herein, the "extended" and "retracted" positions of a component are to be understood as relative terms. That is, in the extended position, the component has an increased length (i.e., an extended length) compared to the retracted position of the component. When referring to a component having a piston or piston rod arrangement (or the like), in the extended position, the rod extends further from the respective component compared to the retracted position of the component.

[0044] As used herein, it is to be understood that the "amount of fluid" refers to an amount of fluid without limitation as to volume and pressure. For example, the "amount of fluid" received within a chamber can be a specific number of moles of fluid. Generally, this amount corresponds to the volume at a given pressure. It will be understood that the volume and pressure of the fluid within the chamber in which it is received depend on the volume of the chamber at any given instant (the volume can be variable).

[0045] As used herein, it should be understood that "buffering fluid" refers to a fluid suitable for use in a buffer / damper. Generally, as used herein, "buffering fluid" refers particularly to a gas, and the gaseous state enables its compression to assist in buffering / damping.

[0046] Here, embodiments are described by way of example only with reference to the accompanying drawings, which include the following.

Brief Description of the Drawings

[0047]

Figure 1

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DETAILED DESCRIPTION OF THE INVENTION

[0048] FIGS. 1 to 5 show an example of a pile driver assembly 10 for driving a pile 12 into the ground. The pile driver assembly 10 includes a casing 14 that defines a chamber 32. That is, the casing 14 includes an internal volume (i.e., the chamber 32) defined by an outer wall 30. In this example, the casing 14 is substantially cylindrical (i.e., the outer wall 30 of the casing 14 is substantially cylindrical). The cylindrical shape of the casing facilitates the transportation of the assembly. Further, the cylindrical shape enables good load transfer of the pressure accumulated within the casing. Due to the internal pressure during impact, hoop stress is generated in the wall of the casing. However, in other examples, casings of different shapes can be used.

[0049] Chamber 32 is configured to contain a fluid, such as water. In other words, the chamber provides a generally enclosed space configured to contain and maintain a volume of fluid therein. The walls of the casing 14 include a valve coupled to a fluid source / reservoir (e.g., via a pipe or conduit) to enable filling the chamber 32 before or during use. In this way, the assembly can be transported to the work site with an empty chamber. Next, the chamber 32 is filled to the desired level in place (before lifting the chamber 32 or while lifted and waiting for release). It will be understood that the "desired level" is pre-determined to generate a predetermined impact energy for driving the pile into the ground. The water used to fill the chamber 32 can be water pumped from an offshore location, such as seawater.

[0050] In this example, chamber 32 has a volume capable of holding from about 1000 to 5000 tons of water. A chamber 32 of this volume is generally suitable for driving monopiles with a diameter of about 6 to 15 meters into the ground. When chamber 32 is filled with water, the total mass of the casing 14 (including the water therein) may be at least 8 times (appropriately about 8 to 12 times) greater than the mass of a typical driving hammer used in pile driving operations. For example, the mass of a large hydraulic impact hammer can be about 200 to 270 tons, while the total mass of the casing 14 containing water therein can be about 2700 tons.

[0051] The pile driving machine assembly 10 further includes positioning elements configured to position the casing 14 on or over the pile 12. The positioning elements include a portion positioned between the chamber 32 and the pile 12. In this example, this portion is a plate element 38 configured to cover the upper surface of the pile 12. The plate element 38 can be of any suitable shape corresponding to the cross-sectional shape of the pile 12. For example, the plate element 38 can be circular (corresponding to a cylindrical pile). In the illustrated example, the plate element 38 has an annular profile corresponding to the cylindrical / tubular pile 12.

[0052] In this example, the positioning element further includes a sleeve element 20 releasably connected to the upper part of the pile 12. In other words, the sleeve element 20 is configured to surround the upper part of the pile 12. In this example, the sleeve element 20 has a cylindrical / tubular contour to correspond to the cylindrical / tubular pile 12.

[0053] In this example, the plate element 38 is provided at the end (specifically, the axial end) of the sleeve element 20. The plate element 38 can be positioned on the cylindrical wall of the sleeve element 20, or attached or joined to the upper surface of the sleeve element 20 at or near its outer edge. In this way, when positioned on the pile 12, the plate element 38 is configured such that the sleeve element 20 projects downward therefrom and is located on the upper surface of the pile 12. In some examples, the sleeve element 20 and the plate element 38 can be formed as a single integral component, or the plate element 38 can be coupled to the sleeve element 20, for example, by welding or an adhesive.

[0054] In this example, the positioning element is at least partially provided at the end of the casing 14. That is, the positioning element is at least partially positioned or coupled adjacent to the end of the casing 14, particularly the lower end of the casing when the assembly is positioned on the pile 12. In this example, both the plate element 38 and the sleeve element 20 are positioned at the lower end of the casing 14. This close arrangement allows for fine adjustment of the assembly during pile driving operations.

[0055] In this example, the casing 14 includes a sleeve portion 16 at its end. The sleeve portion 16 is configured to at least partially surround the sleeve element 20 of the positioning element to provide alignment between the positioning element and the casing 14. In other words, the sleeve portion 16 of the casing 14 extends over and is configured to at least partially overlap the sleeve element 20 of the positioning element. In this way, during the pile driving operation (when the casing 14 moves relative to the positioning element), the sleeve portion 16 ensures that the casing remains axially aligned with the pile. Thereby, the arrangement remains stable during the pile driving operation. The sleeve portion 16 may have a length determined to ensure at least some overlap with the sleeve element 20 at each stage of the piling operation, regardless of the axial separation between the chamber 32 and the pile 12.

[0056] The pile driving machine assembly 10 further includes actuating means. In this example, the actuating means includes at least one actuator 44, or a plurality of actuators 44 in the illustrated example, such as hydraulic or pneumatic actuators.

[0057] In this example, the actuator 44 is disposed intermediate (i.e., between) the chamber 32 and the plate element 38. In other words, a space (or separation region) is provided between the lower part of the chamber 32 and the plate element 38 in which the actuator 44 is disposed.

[0058] In use, the pile driving machine assembly 10 is positioned on a pile 12 that is driven into the ground. The pile 12 is on land or offshore. Generally, the pile 12 extends substantially vertically from the ground, although the pile 12 may deviate from the vertical arrangement.

[0059] The pile driving machine assembly 10 is positioned on the pile 12 in a coaxial arrangement. That is, when positioned on the pile 12, the casing 14 is configured to extend from the pile 12 along the longitudinal axis of the pile 12. For example, in the case of a vertical pile, the axis of the chamber (e.g., the longitudinal axis of a substantially cylindrical chamber) extends perpendicular to the axis of the pile 12.

[0060] In some examples, chamber 32 may have a channel extending therethrough. The channel may be, for example, an axial channel extending along a longitudinal axis that extends substantially perpendicular to chamber 32. The channel can provide a path for deploying a tool (such as a drill or a water jet, etc.) therethrough. If the axial channel is positioned substantially coaxially with the axis of the hollow pile, the tool can access and work on the soil directly below the pile and reduce the resistance of the soil plug.

[0061] In this example, actuator 44 is positioned on plate element 38 at a position corresponding to the wall of the pile. In other words, actuator 44 is aligned with the axially extending wall of the pile. For example, in the illustrated pile driving machine assembly, actuator 44 is positioned on the circumference / periphery of annular plate element 38 so as to correspond to the circumference of cylindrical pile 12. In this way, during the pile driving operation, the force applied by the casing / chamber acts directly on the pile (via the actuator), minimizing the stress on the pile.

[0062] Any suitable number of actuators 44 can be used depending on the specifications of actuator 44 and the mass to be lifted. In this example, actuator 44 is positioned around the entire circumference of plate element 38 (corresponding to the wall of pile 12) to ensure uniform lifting of casing 14. However, in other examples, fewer actuators 44 can be used, equally spaced around the periphery.

[0063] Following the positioning of pile driving machine assembly 10 on pile 12, actuator 44 is actuated to move chamber 32 away from pile 12. In other words, the actuation of the actuation means displaces chamber 32 relative to the positioning element such that chamber 32 moves away from pile 12. The entire chamber separates upwardly from the pile.

[0064] The actuation of the actuator 44 can be provided in any suitable manner (corresponding to the type of actuator 44 being used), for example, the actuation can be provided hydraulically or pneumatically depending on the type of actuator 44 being used. The chamber 32 can be displaced until it reaches a predetermined distance from the pile (e.g., corresponding to a position of the chamber 32 having a predetermined position / impact energy suitable for driving the pile into the ground).

[0065] Next, the actuator 44 is further actuated to release the chamber 32 such that the chamber 32 is displaced towards the pile 12. That is, in this example, the chamber 32 is released to fall downward towards the pile 12. When releasing the chamber, the actuator 44 enables the chamber to fall towards the pile 12 as a result of gravity only (i.e., without additional driving force).

[0066] The chamber 32 can be released by at least partially retracting the actuator 44, for example, by at least partially removing the operating pressure (i.e., hydraulic or pneumatic pressure) within each actuator 44 such that the chamber 32 is not supported. In other examples, the positioning element or the actuating means can include locking means configured to lock the chamber 32 at a predetermined height. When locked, the actuating means may be retracted before the chamber is "unlocked" and released.

[0067] Following the release, the chamber falls and applies a force (specifically a downward force) to the positioning member. In this example, the force is applied to the positioning member via the actuator 44. In some examples, following complete retraction of the actuator 44, the chamber 32 falls (through the space where the actuator 44 is present) and impacts the actuator 44. Alternatively, the chamber 32 falls when the actuator is retracted and impacts the actuator 44 when the actuator is completely retracted. The force of the impact is transmitted from the actuator 44 to the plate element 38 and then via the plate element 38 to the pile 12.

[0068] The above configuration is advantageous in that rather than a smaller hammer being driven into the pile 12 to impact it, a larger mass (in this example, a large water chamber) drops onto the pile 12. Thus, the force from the large mass "pushes" the pile into the ground, resulting in less noise and lower stress on the pile compared to assemblies that utilize the impact of the ram of a hammer. In a conventional hammer configuration, an actuator is used to drive the hammer towards a central pile via an anvil, and the anvil disperses the force onto the pile. For larger piles, a larger anvil is required to disperse the applied force. In the above configuration, since the force is transmitted to the pile via the actuator and positioning elements, eliminating the need for an anvil, it is better suited for larger piles.

[0069] In this example, the casing 14 includes an impact surface 46 configured to collide with the actuator 44 following the release of the chamber. In this example, the impact surface 46 is an annular surface corresponding to the positioning of the actuator 44. Thus, the force applied by the casing 14 is concentrated on the actuator 44, resulting in a more efficient transfer of energy to the actuator (and subsequently the pile).

[0070] In this example, the assembly 10 further includes cushioning means for controllably cushioning the force applied to the pile 12 by the chamber 32 when the pile is being driven into the ground. The provision of the cushioning means serves to control the force applied by the casing / chamber to the pile 12 when driving the pile into the ground. Thereby, the peak force can be controlled (e.g., reduced to reduce underwater noise) by cushioning the applied force over a longer period. Any suitable cushioning means can be used, for example, the cushioning means may include at least one cushioning element.

[0071] An example of the buffer element 100 is shown in FIG. 6. The buffer element 100 can be positioned at any suitable location. For example, the buffer element 100 can be adjacent to the actuator 44 (e.g., radially inside or outside the actuator 44), or can be disposed between actuators 44 that are spaced apart from each other. When the chamber 32 is released, the actuator 44 retracts beyond the upper end of the buffer element 100, and the chamber 32 collides with the buffer element 100 rather than the actuator 44. In the same manner as described above for the actuator 44, the buffer element 100 can be disposed at a position corresponding to the wall of the pile in order to efficiently transmit force.

[0072] The buffer element 100 includes a central movable element, in this example a piston and rod arrangement 102. In this example, the buffer element 100 has a piston with a diameter from about 500 mm to 1200 mm and a rod with a diameter from about 200 mm to 700 mm, but buffer elements of any suitable dimensions can be used according to the required damping characteristics.

[0073] The piston and rod arrangement 102 has an extended position and a retracted position, and the buffer element 100 is configured to buffer the downward force applied to the positioning member by the chamber 32 when the piston and rod arrangement 102 moves from the extended position to the retracted position. In this example, the buffer element 100 includes a buffer chamber 104 configured to contain a buffer fluid (e.g., a gas such as nitrogen). When the piston and rod arrangement 102 moves from the extended position to the retracted position, the volume of the buffer chamber 104 decreases and the fluid therein is compressed. This acts to decelerate the piston (and ultimately stop it), and thus also decelerates the chamber 32 that is driving the piston and rod arrangement 102 towards the retracted position.

[0074] The damping characteristics of the buffer element 100 can be set before use (or adjusted between impacts) according to the required level of attenuation / damping. For example, the amount of fluid in the buffer chamber 104 can be set to optimize the impact signature (i.e., force - time, dF / dt, response) on the pile. In other words, the damping characteristics can be optimized to reduce the resulting noise / pile vibration while still providing the required driving performance. For example, the peak force applied after damping needs to reduce the peak force and thereby reduce vibration and noise. However, the peak force applied after damping still needs to be sufficient to overcome the static soil resistance (which is typically in the range of several hundred meganewtons).

[0075] The selection of the damping characteristics of each buffer element can depend on the impact energy of the chamber 32 and / or the number of buffer elements 100 used, and / or the size of the pile 12 driven into the ground and / or the preferred number of "drops" of the chamber 32 required to drive the pile 12 into the ground and / or the expected static soil resistance.

[0076] In this example, the buffer element 100 includes a further buffer chamber 106 configured to contain a buffer fluid. The buffer chambers 104, 106 are separated (and sealed from each other) by a piston. The amount of fluid in each buffer chamber 104, 106 (and thus the relative pressure between them) can be controlled to control the damping characteristics of the buffer element 100. In other words, each buffer element 100 has an equilibrium state (i.e., a state where the piston is stationary as a result of opposing forces acting on the piston canceling each other out). The amount of fluid in each buffer chamber 104, 106 can be pre - tensioned in the buffer element 100 and thus can be set to prevent a strong impact of the chamber 32 on the pile.

[0077] The buffer element 100 may include adjustment means configured to adjust the internal buffer characteristics of the buffer element 100. For example, the buffer element 100 may control one or more valves configured to control the amount of fluid or the pressure of at least one of the fluids in the buffer chambers 104, 106.

[0078] As an example, in the equilibrium state, the buffer chambers 104, 106 of the buffer element 100 have an initial pressure ranging from about 60 bar to 140 bar. The peak pressure in the buffer chamber 104 can reach a peak pressure ranging from about 100 bar to about 600 bar during the buffering of the force applied by the chamber to the pile.

[0079] The equilibrium state of the buffer element 100 at the initial stage of the pile driving operation may include the weight of the chamber (with or without water therein). That is, the buffer chambers 104, 106 of each buffer element 100 may be pressurized until the pressure in the buffer chambers 104, 106 causes the weight of the chamber to be supported by the buffer element 100 (i.e., until the chamber 32 is slightly lifted by the buffer element 100). When the actuating means is actuated, the actuator 44 receives the weight of the chamber 32 from the buffer element 100. By doing so, the piston of each buffer element finds a new equilibrium position.

[0080] The impact of the chamber 32 on the piston and rod arrangement 102 can compress the fluid within the buffer chamber 104 (of each buffer element 100) until the pressure therein is greater than the weight of the chamber. In this situation, the chamber can "bounce". That is, when the piston reaches the retracted position, the piston begins to move at least partially towards the extended position. Next, the buffer fluid within the further buffer chamber 106 is compressed to decelerate the upward movement of the piston. In some examples, the actuator 44 can be actuated (to initiate another stroke) to further lift the chamber 32 when the chamber 32 is at the top of its bounce. By doing so, the energy input required to then return the chamber from the semi-extended position to its raised position is reduced. In other words, the spring effect is provided by the buffer chambers 104, 106 of each buffer element 100, such that when the casing is controllably released, the pile is driven into the ground and, due to the elasticity of the buffer means, better distribution of the downward force is enabled while significantly reducing the noise in the water.

[0081] In the examples shown in FIGS. 1 to 5, rather than including buffer elements 100 separate from the actuator 44, the buffer means is integral with the actuating means. That is, each actuator 44 also functions to buffer the force applied to the pile 12 by the chamber 32 when the pile is driven into the ground. Thus, when referring to the examples shown in FIGS. 1 to 5, the terms "actuating means" and "buffer means" can generally be used interchangeably.

[0082] FIG. 7 shows a cross-section of the actuator 44 (with an integrated buffer function) of this example. The actuator 44 includes a central movable element, namely a piston 48, having an extended position and a retracted position. The actuator 44 includes a fluid chamber (or fluid volume) 58 configured to contain a fluid, such as a suitable hydraulic fluid, for example, oil. In use, an increase in the amount of oil within the fluid chamber 58 moves the central movable element 48 from the retracted position towards the extended position (i.e., actuates the actuator 44).

[0083] In this example, the piston 48 is elongated and at least partially received within the actuator housing 54. The piston 48 is movable within the actuator housing 54, but is prevented from separating from the actuator housing 54 by the engagement between the flange portion 62 of the piston 48 and the lip portion 50 of the actuator housing 54.

[0084] In this example, the fluid chamber 58 is defined by a hollow space that extends axially within the piston 48. The fluid chamber 58 is configured to receive a conduit / channel 59 that fluidly couples the fluid chamber 58 to a fluid source / reservoir. In this example, the conduit 59 extends upward from a position proximate to the base of the actuator 44, and the conduit 59 is substantially coaxial with the hollow space of the fluid chamber 58. With the piston 48 in the retracted position, the conduit 59 is configured to substantially fill the fluid chamber 58.

[0085] When oil is supplied to the fluid chamber 58 via the conduit 59, the pressure within the fluid chamber 58 increases. This causes the piston 48 to move relative to the conduit 59. Specifically, the piston 48 slides axially along the conduit 59, thereby increasing the volume of the fluid chamber 58.

[0086] In this example, the actuator 44 includes a valve 70 configured to control the flow into and out of the fluid chamber 58. The valve 70 is fluidly coupled to the fluid chamber 58 via the conduit 59.

[0087] In this example, the actuator 44 further includes an additional fluid chamber 60 configured to contain a fluid, such as a hydraulic fluid like oil. In this example, the additional fluid chamber 60 is defined between the outer surface of the piston 48 and the inner surface of the actuator housing 54. The space between the piston 48 and the inner surface of the actuator housing 54 corresponds to the fluid chamber 60.

[0088] In this example, the actuator 44 includes a valve 72 configured to control the flow entering and exiting the fluid chamber 60. Although not shown in FIG. 7, in some examples, an additional fluid chamber 60 is fluidly connected to the first fluid chamber 58. That is, valves 70 and 72 can be connected by conduits or pipes. In such examples, the fluid chamber 60 serves to store fluid from the first chamber 58 when the piston 48 is in a retracted state (i.e., before or during operation). In other words, when both valves 70 and 72 are open (and fluid chambers 58 and 60 are fluidly connected by valves 70, 72), oil can pass between fluid chambers 58 and 60 when the piston extends / retracts. In some examples, the maximum volume of fluid chamber 58 (achieved when piston 48 is in its most extended position) is substantially equal to the maximum volume of fluid chamber 60 (achieved when piston 48 is in its most retracted position).

[0089] Generally (e.g., in a situation where valve 74 is open), the central movable element moves between an extended position and a retracted position in response to the fluid pressure in the fluid chamber. That is, if the pressure of the oil in fluid chamber 58 is higher than the pressure of the fluid in fluid chamber 60 (e.g., by the chamber 32 colliding with the piston 48), the piston 48 moves from the extended position to the retracted position (to reach equilibrium). As the piston moves, the fluid in chamber 58 is pushed into fluid chamber 60.

[0090] The amount of oil in each fluid chamber 58, 60 can be determined to provide a particular equilibrium position of the piston 48 depending on the mass of the casing 32 and the force expected to be applied to the pile 12. For example, the equilibrium position can be matched to a relatively extended position of the piston 48, thereby preventing a strong (and thus large) impact of the casing 32 against the pile 12.

[0091] Actuator 44 is configured to cushion the downward force applied to the positioning member by chamber 32 when piston 48 moves from the extended position to the retracted position. In other words, actuator 44 is configured such that the chamber is decelerated when piston 48 of each actuator 44 moves from the extended position to the retracted position.

[0092] In this example, actuator 44 includes a buffer chamber 68 configured to contain a buffer fluid, such as a gas like nitrogen. In this example, buffer chamber 68 is defined between the outer surface of conduit 59 and the inner surface of actuator housing 54. In particular, actuator housing 54 is separated into buffer chamber 68 and fluid chamber 60 by flange portion 62 of piston 48.

[0093] The volume of buffer chamber 68 decreases as piston 48 moves from the extended position to the retracted position. In particular, the volume of buffer chamber 68 decreases as piston 48 slides on conduit 59 towards the base of actuator 44.

[0094] The buffering effect of actuator 44 is provided by the buffer fluid within buffer chamber 68. More specifically, when piston 48 moves from the extended position to the retracted position, the decrease in the volume of buffer chamber 68 causes piston 48 to compress the gas within buffer chamber 68. The resistance provided by the compression of the gas within buffer chamber 68 acts to decelerate (and ultimately stop) piston 48 (and similarly, the passage of oil from fluid chamber 58 to fluid chamber 60). Thus, chamber 32, which is driving piston 48 towards its retracted position, is also decelerated and ultimately stopped.

[0095] In this example, the actuator 44 includes adjustment means configured to adjust the internal damping characteristics of the actuating means. In particular, the actuator 44 includes a valve 74 configured to control the amount of gas in the damping chamber (however, in FIG. 7, the valve 74 is not shown as being fluidly connected to the damping chamber 68). By doing so, the pressure in the damping chamber 68 of each actuator 44 for a given load can be controlled. Thus, the deceleration of the piston / chamber, and the resulting force-time response, are also controlled.

[0096] In use, when using the actuator 44 as shown in FIG. 7, pressurized oil (e.g., pumped from a reservoir) can be supplied to the valve 70 of each actuator 44. Similarly, pressurized nitrogen can be supplied to the valve 74 of each actuator 44. Next, the valve 70 is opened and fluid is provided to the fluid chamber 58, thereby actuating the piston 48 to lift the casing 14. A typical hydraulic pressure range can be from about 200 to 420 bar.

[0097] As described above, the operation of the actuator 44 acts to lift the chamber 32 / casing 14. At this point, the valve 72 can be opened and the piston 48 can be moved to its extended position without the need to compress a fixed amount of oil in the chamber 60. Thus, when the piston moves to its extended position, the oil in the second chamber 60 is squeezed out by the flange portion 62 of the piston (in other words, the flange portion 62 advances towards the lip portion 50 of the actuator 44).

[0098] At this time, valve 74 can also be opened. First, thereby, piston 48 can move to its extended position without being restricted by expanding a certain amount of gas in chamber 68 (which can lead to a suction force due to decompression). Further, this enables a predetermined amount of buffer fluid to be provided to buffer chamber 68. As a result of the increase in the volume of buffer chamber 68, gas can be allowed to flow in or be sucked in. The typical peak pressure in buffer chamber 68 can be from about 200 to 800 bar.

[0099] When actuator 44 reaches its intended extended position, then the valves 70, 72, 74 of each actuator are closed. When a relatively incompressible hydraulic liquid is used in fluid chamber 58, closing the valves in this way acts to lock the pistons in place.

[0100] Next, valves 70 and 72 of each actuator 44 can be opened, and as a result, fluid can flow from the first chamber 58 of each actuator 44 to the second chamber 60. Thereby, the weight of the casing 14 and the liquid therein can be biased to move piston 48 downward. When piston 48 is pushed downward, piston 48 propels oil from the first chamber 58 to the second chamber 60 via the second valve 72. At the same time, piston 48 (or more specifically its flange portion 62) compresses the gas in chamber 68. The resulting increase in gas pressure in buffer chamber 68 decelerates and ultimately stops the downward movement of piston 48, thereby stopping the downward movement of casing 14.

[0101] The force acting to push down the piston 48 is transmitted to the pile 12 via the compressed gas. The compression of the gas acts to change the force-time response. The duration of the application of the force to the pile 12 is extended such that the peak force decreases. In a similar manner as described above for the buffer element 100 of FIG. 6, during the compression of the gas, the pressure in the buffer chamber 68 rises until the pressurized gas in the buffer chamber 68 applies an upward force to each piston 48, exceeding the weight of the casing 14. Thus, the piston 14 and the chamber 32 are biased upward. Due to this bounce / rebound, oil is pushed out from the second chamber 60 of each actuator 44 and flows back into the first chamber 58.

[0102] In some examples, during this rebound, the second valve 72 of each actuator 44 is preferably switched from the open position to the check valve position. This allows the oil to flow back from the second chamber 60 of each actuator 44 to the first chamber 58 while the casing moves upward, but blocks the flow of oil in the opposite direction. As a result, when the casing 14 begins to accelerate downward again, the hydraulic pressure rises in the first chamber 58 within each actuator. This suppresses further movement of the casing 14. Thus, the pile driver assembly 10 is ready for the next stroke. In other words, the actuator 44 can lock in the (semi)-extended position. That is, at the top of the "bounce". By doing so, the energy input required to then return the chamber 32 from the semi-extended position to its raised position is reduced.

[0103] Next, the actuator 44 is repeatedly actuated until the pile 12 is driven into the ground at a preset position.

[0104] FIGS. 8 to 14 show another example of a pile driver assembly 110. This example includes features that generally correspond to the features of the previous example, and such features are labeled in the same way. For the sake of brevity, the same features as in the previous example will not usually be described again.

[0105] According to the previous example, the pile driver assembly 110 includes cushioning means for controllably cushioning the force applied to the pile 12 by the chamber 32 when the pile 12 is driven into the ground. In this example, the cushioning means includes a plurality of cushioning elements 100 of the type shown in FIG. 6. In this example, the cushioning means is separate from (i.e., not integral with) the actuating means. In other words, the pile driver assembly 110 includes an actuator 144 separate from the cushioning element 100. However, in a variant of this example, the pile driver assembly 110 may include an actuator 44 that also provides a cushioning function as shown in FIG. 7.

[0106] As best shown in FIGS. 8 and 9, the cushioning element 100 and the actuator 144 are disposed intermediate (i.e., between) the chamber and the positioning element. In this example, the cushioning element 100 is positioned on the plate element 38 at a location corresponding to the wall of the pile. The actuator 144 is positioned radially inward of the cushioning element 100.

[0107] In this example, the chamber includes a channel 200 that extends axially through the chamber in part. In this example, the channel 200 extends through the lower part of the chamber 32. That is, the casing 14 includes a recessed channel 200 on its outer surface, particularly on its lower surface. In other words, the channel extends upward (towards the inside of the chamber 32) from the lower surface or base of the casing and extends through at least a part of the chamber 32.

[0108] In this example, the positioning element includes a guide element 220. In this example, the guide element 220 is a cylindrical or columnar structure.

[0109] In this example, the guide element 220 extends through the plate element 38. That is, the guide element 220 extends from the first side of the plate element 38 to the second side of the plate element 38. In other examples, the guide element 220 can extend from only one side of the plate element 38. For example, the guide element 220 can extend from the upper surface of the plate element 38.

[0110] The guide element 220 can be integrally formed with the plate element 38 and can be fixed to the plate element 38, for example, by welding.

[0111] The guide element 220 is configured to extend at least partially through the channel 200 of the chamber 32. In other words, the guide element 220 is configured to fit or engage with the channel 200, and the channel 200 is configured to receive the guide element 220.

[0112] Figures 10 through 14 show a pile driver assembly 110 that performs a pile driving operation. Figure 10 shows the pile driver assembly 110 in an initial rest position. The actuator 144 is retracted, and the buffer element 100 does not contain gas within its buffer chamber. Figure 11 shows the pile driver assembly 110 in a standby position. That is, the buffer chamber of the buffer element 100 is at least partially filled with gas so as to lift the chamber slightly from its rest position. At this stage, the system is ready for lifting. Figures 12 through 14 show the pile driver assembly during the lifting operation. In particular, Figures 12 through 14 show the pile driver assembly with the actuator 144 being gradually extended and lifting the chamber to the raised position.

[0113] During the lift / lower operation, the chamber 32 moves relative to the positioning element. Accordingly, the guide element 220 moves relative to the channel 200. That is, in this example, the guide element 220 is configured to extend further through the channel 200 as the chamber 32 moves towards the pile. Similarly, the guide element 220 is configured to partially retract from the channel 200 as the chamber 32 moves away from the pile.

[0114] In this example, the guide element 220 is configured such that a portion of the guide element 220 remains within the channel 200 during all lifting / release operations (i.e., the guide element 220 is configured to only partially retract). Specifically, the guide element 220 is sized to be longer than the maximum displacement of the chamber 32 from the plate element 38.

[0115] Providing the guide element 220 and the channel 200 that interact in this way is advantageous in helping to maintain alignment between the casing 14 / chamber 32 and the positioning element (and thus, further, the pile 12). In particular, the guide element has a fixed position and orientation relative to the pile. By configuring the assembly such that the channel engages the guide element during lifting and release of the casing / chamber, the casing / chamber remains aligned with the pile and can thus provide a more consistently concentrated force to the pile.

[0116] In this example, the interaction of the guide element 220 / channel 200 is used instead of a sleeve assembly (i.e., the sleeve element of the positioning element and the sleeve portion of the casing surrounding the sleeve element) to provide consistent alignment. However, in some examples, the assembly may include both a guide element / channel and a sleeve assembly.

[0117] The guide element 220 can extend completely through the chamber 32 to provide additional guidance and support to the chamber 32. Further, the channel 200 / guide element 220 can be of any suitable shape. For example, both the channel 200 and the guide element 220 can have a square, rectangular, or I-shaped cross-section. In some examples, the cross-section of the guide element substantially matches the cross-section of the channel to provide a tight fit and thus improve stability.

[0118] Figures 15 through 17 illustrate another example of the pile driver assembly 210. This example includes features that generally correspond to those of the previous example, and such features are identically labeled. For the sake of brevity, features similar to those of the previous example will not normally be described again.

[0119] In a manner similar to the previous example, the chamber 14 includes a channel 200 that extends axially through the chamber 32. However, in this example, the channel 200 extends over the entire length of the chamber 32. In other words, the channel 200 extends between the lower and upper surfaces of the chamber 32.

[0120] In a manner similar to the previous example, the positioning element includes a guide element 220 configured to extend at least partially through the channel of the chamber. However, in this example, the guide element 220 extends through the entire channel 200. That is, the guide element extends from the plate element 38, enters the channel on the first side of the chamber 32, passes through the channel 200, and emerges on the opposite side of the chamber 32.

[0121] In this example, the guide element 220 is tubular such that a passage through the channel 200 is provided. Thus, in the same manner as described above, the guide element / channel provides a path through which a tool (e.g., a drill, or a water jet, etc.) can be deployed.

[0122] In this example, the actuator 144 is disposed at one end of the chamber 32 distal to the buffer element 100. In other words, the buffer element 100 is disposed intermediate the chamber (specifically its lower end) and the plate element 38 of the positioning element, and the actuator 144 is disposed adjacent the upper end of the chamber 32.

[0123] Actuator 144 is coupled to one end of guide element 220. Specifically, guide element 220 has a lower end coupled or integrally formed with plate element 38 and an upper end configured to extend from channel 200 above chamber 32. Actuator 144 is coupled to the upper end of the guide element.

[0124] Actuator 144 can be coupled to guide element 220 in any suitable manner. For example, the upper end of guide element 220 can include a radially outwardly extending flange. Actuator 144 can be coupled to the flange of guide element 220. In other examples, actuator 144 can be coupled to guide element 220 by a collar member or connection member attached to the upper end of guide element 220.

[0125] Actuator 144 couples guide element 220 to chamber 32. That is, actuator 144 is coupled to both guide element 220 and chamber 32. In other words, in this example, guide element 220 functions as a stationary lifting point. In this example, each actuator 144 includes a clamp 96 configured to releasably clamp chamber 32.

[0126] FIG. 15 shows the pile driver assembly 220 in an initial position. In this example, buffer element 100 is pressurized to support the weight of chamber 32. Actuator 144 is in an extended position and is coupled to the upper surface of casing 32 via clamp 96. In other examples, buffer element 100 can be pressurized only after the weight of the chamber is received by actuator 144.

[0127] Next, the actuator 144 is actuated such that the chamber 32 moves away from the pile. The actuator 144 can utilize the piston / piston rod type described above, but it will be understood that it is used in an "inverted arrangement". In this inverted arrangement, upon actuation of the actuating means, the piston moves from the extended position to the retracted position. When the actuator retracts, the chamber 32 is pulled upward toward the upper end of the guide element 220. The actuator is retracted until the chamber reaches a predetermined height above the pile / positioning element.

[0128] Next, the actuating means is further actuated to release the chamber such that the chamber is displaced toward the pile. In this example, the actuator further actuates by releasing the clamp to effectively drop the chamber. However, in other examples, the actuator can be further actuated by removing the pressurized fluid used to initially actuate the actuator (i.e., drive the chamber upward).

[0129] Next, the actuator can be actuated in the opposite direction to extend the central movable element of the actuator back to the initial position of FIG. 15 and repeat the pile driving operation.

[0130] In any of the foregoing examples, the positioning element remains stationary above the pile (i.e., the positioning element functions as a static lifting point and there is no movement between the positioning element and the pile during operation). As such, the pile is closed (e.g., with a flow arrestor) to allow a restricted outflow of water or air from within the pile. The restricted outflow can function as a brake to prevent the pile from freely falling when passing through very soft soil (thereby reducing the impact load on the crane when the pile falls). Such a flow arrestor can be placed inside the hammer or separately inside the pile. This is all possible with the low acceleration levels achieved by using a large mass as the hammer and the static positioning of the positioning element.

[0131] It will be apparent to those skilled in the art that the features described in connection with any of the above embodiments are interchangeably applicable between different embodiments. The above embodiments are examples for explaining various features of the present invention.

[0132] Throughout the description and claims of this specification, the terms "comprise" and "contain" and their variants mean "include but are not limited to", and are not intended to (nor do they) exclude other parts, additives, components, integers, or steps. Throughout the description and claims of this specification, unless the context requires otherwise, the singular form includes the plural form. In particular, when an indefinite article is used, unless the context requires otherwise, this specification should be understood to contemplate not only the singular but also the plural.

[0133] Features, integers, characteristics, compounds, chemical moieties or groups described in connection with a particular aspect, embodiment, or example of the present invention are to be understood as applicable to any other aspect, embodiment, or example described herein, unless incompatible therewith. All features (including any accompanying claims, abstract, and drawings) disclosed herein, and / or all steps of any method or process so disclosed, may be combined in any combination, except combinations where at least some of such features and / or steps are mutually exclusive. The present invention is not limited to the details of any of the foregoing embodiments. The present invention extends to any novel one, or any novel combination, of the features disclosed herein (including any accompanying claims, abstract, and drawings), or to any novel one, or any novel combination, of the steps of any method or process so disclosed.

Claims

Claim 1 A pile driving machine assembly for driving a pile, preferably into the seabed floor, comprising: An outer casing including an outer wall and an internal space configured to contain a fluid, the internal space including a channel extending at least partially therethrough, and the outer casing; A positioning element configured to position the outer casing on or above the pile, at least a part of the positioning element being positioned between the outer casing and the pile, the positioning element including a guide element configured to extend at least partially through the channel of the internal space and engage with the channel of the internal space; Actuating means; Including; Actuation of the actuating means displaces the outer casing relative to the positioning element such that the outer casing moves away from the pile; The actuating means is configured to release the outer casing to move towards the pile and apply a force to the positioning element by the outer casing to controllably drive the pile into the ground; The guide element is configured to further extend through the channel when the outer casing moves towards the pile. A pile driving machine assembly. Claim 2 The assembly according to claim 1, wherein the actuating means includes at least one actuator. Claim 3 The assembly according to claim 1 or 2, further comprising damping means for controllably damping the force applied to the pile by the outer casing when the pile is driven into the ground. Claim 4 The assembly according to claim 3, wherein the damping means is disposed intermediate the outer casing and the positioning element. Claim 5 The assembly according to claim 3 or 4, wherein the damping means includes at least one damping element. Claim 6 The assembly according to any one of claims 3 to 5, wherein the damping means includes a central movable element having an extended position and a retracted position. Claim 7 The assembly according to claim 6, wherein the damping means is configured to damp a downward force applied to the positioning element by the outer casing when the central movable element moves from the extended position to the retracted position. Claim 8 The buffer means includes a buffer chamber configured to contain a buffer fluid, and the volume of the buffer chamber decreases as the central movable element moves from the extended position to the retracted position, the assembly according to claim 6 or 7.

9. The buffer means includes adjustment means configured to adjust the internal buffer characteristics of the buffer means, the assembly according to any one of claims 3 to 8.

10. The adjustment means is configured to control the amount of buffer fluid in the buffer chamber, the assembly according to claim 9 when dependent on claim 8.

11. The actuating means is arranged intermediate at least a part of the outer casing and the positioning element, the assembly according to any one of claims 1 to 10.

12. The actuating means is arranged at one end of the outer casing distal from the buffer means, the assembly according to any one of claims 3 to 11.

13. The actuating means is coupled to one end of the guide element, the assembly according to claim 12.

14. The actuating means includes a clamp configured to releasably clamp the outer casing, the assembly according to claim 12 or 13.

15. At least a part of the positioning element is a plate element configured to cover the upper surface of the pile, the assembly according to any one of claims 1 to 14.

16. The positioning element further includes a sleeve element releasably connected to the upper part of the pile, the assembly according to claim 15.

17. The outer casing is filled with fluid via a conduit provided in the wall of the outer casing having a valve for controlling the flow of fluid, the assembly according to any one of claims 1 to 16.

18. A method of driving a pile, preferably into the offshore seabed, comprising: providing a pile to be driven into the ground; providing a pile driving machine assembly according to any one of claims 1 to 17 coaxially on or in the pile; operating the actuating means so that the outer casing moves away from the pile; further operating the actuating means to release the outer casing such that the outer casing is displaced towards the pile and applies a force to the positioning element to controllably drive the pile into the ground. A method of driving a pile into the ground, including

19. The method of driving a pile into the ground according to claim 18, further comprising the step of controllably buffering the force applied to the pile by the outer casing when the pile is controllably driven into the ground.

20. The method of driving a pile into the ground according to claim 18 or 19, further comprising the step of operating the actuating means and further operating the actuating means until the pile is driven into the ground at a pre-set position.

21. The method of driving a pile into the ground according to claim 20, further comprising the step of substantially filling the outer casing with a fluid.

22. The method of driving a pile into the ground according to claim 21, wherein the fluid is water from the offshore location.

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