Patent Application
20110280670
The present invention relates generally to the field of subsurface barrier walls and/or flood walls, and more particularly to a sheet piling system and an active gripping system and method of installation of a sheet piling system.
Barrier walls and flood walls can be formed from a plurality of elongated, vertically-oriented piles driven completely into the earth, or to a depth sufficient to support the piles in an upright orientation above the earth. In some cases, the piles are in the form of extruded structural sheet piles and are formed with male and female opposed edges so that similar sheet piles can be locked together at their adjacent side edges to form a continuous barrier or “cutoff” wall for blocking migration of subsurface fluids and/or surface fluids. Such barrier walls may also be utilized for seawalls, dikes, retaining walls, and other applications.
Sheet piles can be formed of various materials, including without limitation, polyvinyl chloride (PVC), high-density polyethylene (HDPE), or other plastics, fiberglass, composite, aluminum, steel or other metals, ceramics, and/or other materials. The most commonly used sheet piles typically have a Z-shape, Box-shape, or other corrugated cross-sectional profile to provide a measure of structural rigidity. Flat shaped sheet pile profiles are occasionally used in shallow driving depths or low lateral load applications. Regardless of their material and/or profile, however, sheet pilings are subject to buckling deformation during installation and/or from lateral loading. This buckling deformation typically increases exponentially as the length of the pilings increase.
A mandrel system can be utilized for installation of sheet piles when the depth the pile is to be driven and/or the hardness of the soil or other substrate through which the pile is to be driven exceed the structural ability of the piling to resist deformation. U.S. Pat. No. 7,056,066 and U.S. patent application Ser. No. 12/778,545, both incorporated herein by reference, disclose various apparatus and methods for installing sheet piles into a soil formation. Many known mandrel systems and installation methods, however, are limited by the passive attachment of the piling to the mandrel. For example, in deeper installations, the skin friction generated by the soil contacting the sheet piling can be greater than the passive gripping forces applied as the mandrel is driven into the soil. This limitation of the current systems and methods restricts the length of pile that can be installed and/or mandates the use of a much heavier pile than necessary.
Accordingly, it can be seen that needs exist for improved sheet piling systems and improved installation methods and apparatus for sheet piling systems. It is to the provision of systems, methods and apparatus meeting these and other needs that the present invention is primarily directed.
In example embodiments, the present invention provides improved sheet pile configurations and improved installation methods and apparatus, providing more effective installation and improved efficiencies. Example forms of the invention provide an active gripping mechanism for engagement with an installation mandrel along one or both sides of the sheet pile. Example forms of the invention also provide an improved mandrel configuration to reduce damage to the lower or leading edge of the sheet piles during installation and to resist detachment of the male and female interlocks of adjacent sheet piles. Example forms of the invention also provide a sheet pile having a profile allowing engagement by the mandrel along both sides on the same face of the sheet pile, and allowing expansion between adjacent sheet piles to maintain the interlock integrity.
In one aspect, the present invention relates to a method of installing a sheet pile. The method includes actively gripping a portion of a sheet pile by actuating an active gripping member of an installation mandrel, driving the mandrel with the sheet pile carried thereon into the ground to an installation depth, releasing the active gripping member, and withdrawing the mandrel to leave the sheet pile in place in the ground.
In another aspect, the invention relates to a system for installing a sheet pile, the system including a mandrel having at least one active gripping member for engaging and releasing the sheet pile.
In still another aspect, the invention relates to a method of installing a sheet pile. The method includes providing a sheet pile having first and second sides and first and second ends, mounting the sheet pile onto a mandrel and engaging the sheet pile to the mandrel along at least a portion of the first side, driving one of the first and second ends into the ground, and releasing the sheet pile from the mandrel and withdrawing the mandrel from the ground leaving the sheet pile in place.
In another aspect, the invention relates to a method of installing a plurality of sheet piles to form an assembly. The method includes installing a first sheet pile at least partially into the ground using a mandrel, the first sheet pile having a first locking profile. The method further includes installing a second sheet pile at least partially into the ground using the mandrel, the second sheet pile having a second locking profile. The method further includes engaging the second locking profile with the first locking profile while maintaining at least a portion of the first and second locking profiles within a channel of the mandrel.
In yet another aspect, the invention relates to a sheet pile having a first side and a second side, the first side having a first locking profile and the second side having a second locking profile, and further including a gripping flange extending from the second locking profile.
These and other aspects, features and advantages of the invention will be understood with reference to the drawing figures and detailed description herein, and will be realized by means of the various elements and combinations particularly pointed out in the appended claims. It is to be understood that both the foregoing general description and the following brief description of the drawings and detailed description of the invention are exemplary and explanatory of preferred embodiments of the invention, and are not restrictive of the invention, as claimed.
The present invention may be understood more readily by reference to the following detailed description of the invention taken in connection with the accompanying drawing figures, which form a part of this disclosure. It is to be understood that this invention is not limited to the specific devices, methods, conditions or parameters described and/or shown herein, and that the terminology used herein is for the purpose of describing particular embodiments by way of example only and is not intended to be limiting of the claimed invention. Any and all patents and other publications identified in this specification are incorporated by reference as though fully set forth herein.
Also, as used in the specification including the appended claims, the singular forms “a,” “an,” and “the” include the plural, and reference to a particular numerical value includes at least that particular value, unless the context clearly dictates otherwise. Ranges may be expressed herein as from “about” or “approximately” one particular value and/or to “about” or “approximately” another particular value. When such a range is expressed, another embodiment includes from the one particular value and/or to the other particular value. Similarly, when values are expressed as approximations, by use of the antecedent “about,” it will be understood that the particular value forms another embodiment.
With reference now to the drawing figures, wherein like reference numbers represent corresponding parts throughout the several views,
The mandrel 14 comprises an elongate beam of steel, iron or other structural material having sufficient rigidity to be driven into the soil or other substrate to the desired depth of installation of the sheet piles. The mandrel has a lower or leading end 20 that is driven into the substrate, and an opposite upper end 22 that generates or receives the driving or motive force, for example applied vibrationally, hydraulically or by impact. The edge of the leading end 20 of the mandrel is optionally sharp or rounded for improved penetration. The mandrel 14 has first and second lateral sides 24, 26, and inner and outer faces 28, 30 extending between the leading end 20 and the upper end 22.
The mandrel 14 comprises one or more retention members for gripping the sheet pile 12 and holding the sheet pile in place as the mandrel and attached sheet pile are driven into the substrate. For example one or more upper retention members 40 (two are depicted, 40a, 40b) hold the top end of the sheet pile 12 at or adjacent the upper end 22 of the mandrel, one or more lower retention members 42 hold the bottom end of the sheet pile at or adjacent the leading end 20 of the mandrel, and one or more side retention members 44 hold side edges of the sheet pile along first and second lateral sides 24, 26 of the mandrel.
At least one of the retention members comprises an active gripping retention member. For example, in the depicted embodiment the side retention members 44 comprise active gripping retention members that are engaged and disengaged by application of external force via a shaft 50 actuated by a hydraulic motor and gearbox 52, or by other external actuation means such as for example pneumatic drive means, solenoids or other electromagnetic drive means, and/or motors or other electrical drive means. By contrast, the upper retention members 40 and the lower retention members 42 comprise passive retention members such as hinged clips actuated by contact with the substrate, clamps, resilient arms or lips, or other retention features not engaged or disengaged by application of external force.
Advantageously, application of one or more retention members, whether active or passive, along one or both lateral sides 24, 26 of the mandrel allows application of a gripping force that may be increased with increasing length of the sheet pile (since a longer sheet pile has longer lateral sides, and thus more contact surface for engagement by the retention members). Forces such as skin friction on the surface of the sheet pile as it is driven through the substrate that tend to separate a sheet pile from the mandrel typically increase with increasing drive depths. Accordingly, side retention members may enable deeper drive depths than previously considered feasible, as the gripping force holding the sheet pile to the mandrel can likewise be increased in proportion to the drive depth.
In use, the system 10 enables an installation method for sequential placement of sheet piles in a connected array to form a barrier wall or other structure extending a depth into the soil or other substrate. A sheet pile 12 is mounted with the corresponding profiles aligned along the length of the mandrel 14. The retention members are engaged to secure the sheet pile 12 in place on the mandrel 14. Active gripping retention members such as the side retention members 44 are engaged by actuation of the hydraulic motor which drives the shaft 50 through gearbox 52 to close the side retention members onto the side profile of the sheet pile 12. The active gripping force of the side retention members onto the sheet pile 12 against the mandrel 14 can be controlled by appropriate selection and operation of the hydraulic motor or other actuation mechanism. The mandrel is then raised into a vertical orientation over the installation site, using a crane and/or other equipment, and the mandrel and affixed sheet pile are driven into the substrate to the desired depth. The active gripping retention members are released by reverse actuation of the hydraulic motor or other actuation mechanism. The mandrel is then withdrawn leaving the sheet pile in place. Passive retention members, if present, typically release in response to the movement of the mandrel upon withdrawal. Sequential sheet piles are then installed in similar fashion, with the male and female engagement profiles of adjacent sheet pile members interengaged, to form the barrier wall or other structure.
With reference to
The second locking profile 128 of the sheet pile 112 extends transversely and forward from a connecting panel 130, which in turn extends rearward from the main body panel 120, as seen best with reference to
A gripping flange 140 extends rearward from the distal edge of the connecting panel 130, defining a J-shaped channel having an opening directed forward and away from the main body panel 120. The provision of a gripping flange separate from the first and second locking profiles 126, 128 allows engagement with the mandrel 114 along both lateral sides of the sheet pile 112 from the direction of its rearward face, without interfering with the engagement of the locking profiles during installation.
As seen best with reference to
The mandrel 114 comprises first and second channels 180, 182 extending along its length on opposite sides thereof for housing the active gripping retention members and shafts, and for shielding the first and second locking profiles 126, 128 from damage by the substrate during installation of the sheet piles. As seen with reference to
One or more passive engagement members 200 are pivotally mounted toward the lower end of the mandrel 114, actuated by contact with the substrate as the mandrel is driven into the ground, to engage the sheet pile 112 against the mandrel and to protect the leading edge of the sheet pile from damage by the substrate during installation. The pivot axis of the passive engagement members 200 is spaced a distance d from the lower or leading edge of the mandrel 114, so that the leading edge of the mandrel bears the brunt of the impact with the substrate upon installation, rather than the leading edge of the sheet pile 112.
In use, the system 110 enables an improved method of installation of sheet piles to form a barrier wall or other structure. A sheet pile 112 is mounted onto the mandrel 114, and engaged by actuation of active gripping members 160, 162 along the length of both sides of the sheet pile. The mandrel is raised vertically into place above the installation site, and is driven into the ground to the desired depth, carrying the sheet pile into place. The active gripping members are then actuated to release the sheet pile, and the mandrel is withdrawn leaving the sheet pile in place. Subsequent sheet piles are sequentially driven into place in like manner, with the second locking profiles 128 of the sheet pile being driven into place on the mandrel being slid into engagement onto the first locking profiles 126 of the adjacent, previously placed sheet pile.
On each subsequent drive of the mandrel, the second channel 182 follows an existing path through the substrate that was cut by the first channel 180 on the previous drive of the mandrel. Thus, the second locking profiles of the sheet pile being installed (which are enclosed in the second channel 182 of the mandrel) are better maintained in alignment with the first locking profiles of the previously installed sheet pile (which were enclosed in the first channel 180 of the mandrel on the previous drive). Also, because the rigid second channel 182 of the mandrel surrounds the second locking profiles of the sheet pile being installed and the first locking profiles of the previously installed sheet on both sides (see
And even in the event of some degree of misalignment of the sheet piles during installation, the accordion-like expansion provided by the above-described sheet pile profile (see
By actively gripping the sheet pile along both sides, the system of the present invention does not rely on the rigidity of the sheet pile to resist buckling of the sheet pile or peeling of the sheet pile away from the mandrel during installation. Accordingly, the corrugated cross-sectional profile typical of previously known sheet piles, necessary for the rigidity required by prior installation systems and methods, is not needed in the present system and method. As such, a relatively flat sheet pile profile can be utilized regardless of the depth of placement. Indeed, because the system and method of the present invention can grip the sheet pile from the sides, along all or substantially all of the length of the sheet pile, the gripping force applied by the mandrel on the sheet pile can increase with the length of the longer sheet piles used in deeper installations.
Since the system and method of the present invention do not rely on the rigidity of the sheet pile itself to resist buckling and peeling away from the mandrel during installation, a thinner material thickness can be utilized for the sheet piles. This, combined with the elimination of the need for a corrugated sheet pile profile, can considerably reduce the quantity of material used to form the sheet piles, thereby reducing manufacturing costs and conserving resources. Wider sheet piles can also be used with the system and method of the present invention than was possible with previously known systems and methods, thereby reducing the number of drives required for a structure of given length, and consequently reducing installation time and expense. Wider sheet piles also result in fewer seams, thereby reducing the potential for fluid migration through the seams of a barrier.
While the invention has been described with reference to preferred and example embodiments, it will be understood by those skilled in the art that a variety of modifications, additions and deletions are within the scope of the invention, as defined by the following claims.
This application claims the benefit of U.S. Provisional Patent Application Ser. No. 61/333,379, filed May 11, 2010, the entirety of which is hereby incorporated herein by reference for all purposes.
| Number | Date | Country | |
|---|---|---|---|
| 61333379 | May 2010 | US |
