METAL SHEET PILING

Abstract: A metal sheet pile includes a wall section having a central flange flanked by outwardly inclined side walls. The free edges of the side walls include longitudinally extending interlocks each having a cavity filled with a sealant. The sealant present in one or each cavity has a flowable consistency and the open side of the cavity is closed by a member which is progressively displaced by the interlock of a neighbouring sheet pile on driving that neighbouring pile. An end plate is positioned to close the lower open end of the cavity.

Description: METAL SHEET PILING This invention relates to metal sheet piling. More especially, but not exclusively, the invention relates to steel sheet piling. Steel sheet piles are used in general and marine engineering as permanent structures inter alia for retaining walls, basements, underground car parks, pumping stations, bridge abutments, containment barriers and marine structures. These are only examples of such structures. Conventional sheet piles include those known as Larssen or LX sheet piles which are of generally "U" shape and includes a wall section comprising a pan defined by a central flange flanked by outwardly inclined side walls along the free edges of which are formed interlocks. These interlocks (also known as clutches) normally extend over the entire height of the pile and typically comprise a locking toe of generally triangular cross- section which stands proud of a lip which extends along each side edge of the pile, the lip lying generally normal to the adjoining pile surface. The space between the toe and the lip defines an elongate cavity for receiving the locking toe of an adjoining pile. The lip defines the bottom wall of this recess. Other known sheet piles include Frodingham piles which are of generally "Z" profile and typically comprise a wall section including an inclined central web flanked by outwardly extending flanges along the free edges of which are formed interlocks. Conventionally sheet piling structures are produced by sequentially driving a plurality of piles to produce the barrier required, the interlocks of neighbouring piles being connected one to the other during the driving process. In cases where water-tightness is required, methods of enclosing sealant n the interlocks may be adopted. For ease of understanding, this conventional driving process will be described with reference to Figures 1 and 2. Figure 1 shows a grounded sheet pile 1 before the driving of a neighbouring pile 2 (see Figure 2). The piles 1, 2 have interlocks 3, 4 (only one for each pile being shown) along each of their side edges. As will be seen, the cavity 5 defined between the toe 6 and lip 7 of interlock 3 is closed by an angled metal strip 8 which extends over the entire height of the pile 1 and is welded to the pile at the junction between the interlock and the adjoining pile wall. The cavity is filled with a sealant 9. Only one interlock of each pile carries an angled strip 8. For assembly of the pile 2, the interlock 4 is positioned immediately above the interlock 3 and the strip 8 flexed to allow entry of the interlock 4 into the space defined between the interlock 3 and the strip 8. The pile 2 is then driven downwardly to the position shown in Figure 2, the so formed joint being sealed by the presence of the sealant 9 and the angled strip 8. Our co-pending Application 9927867.3 discloses an improved sheet pile which includes a wall section comprising a central flange flanked by outwardly inclined side walls along the free edges of which are longitudinally extending interlocks, and at least one additional longitudinal interlock secured to the wall section of the sheet pile and extending generally parallel to the interlocks secured to the edges of the side walls of the pile. All of the sheet piles discussed above include an angled metal strip which extends over the entire height of the pile and is welded to the pile at the junction between the interlock and the adjoining piling wall. The presence of this angled metal strip increases production times and piling costs. The present invention sets out to provide a metal sheet pile which enjoys the benefits of the piles discussed above but which does away with the need for an angled metal strip in certain circumstances. According to the present invention in one aspect, there is provided a The sealant may have hydrophilic properties. The closure member may comprise a solid length of relatively hard sealant; alternatively, the closure member may comprise a spring clip. The invention will now be described by way of example only with reference to the accompany diagrammatic drawings in which:- Figure 3 illustrates an end view of a first embodiment of sheet pile in accordance with the invention; Figure 4 is an end view to an enlarged scale of one interlock of the sheet pile illustrated in Figure 3; and Figure 5 is an end view of an interlock of a second embodiment of a -sheet pile in accordance with the invention. As will be seen from Figure 3, the sheet pile comprises a wall section including a pan defined by a central flange 10 flanked by outwardly inclined side walls 11 along the free edges of which are longitudinally extending interlocks 12. Each interlock is shaped to define a cavity 14. The sheet pile is preferably produced from steel. However, other suitable metallic and/or non-metallic materials may be employed. As will be seen from Figure 4, the cavity 14 is filled before grounding with a relatively soft sealant 15 having a flowable consistency, the side of the cavity being closed by a wall or layer of relatively hard sealant 16. The sealant 15 may have hydrophilic properties. The end of the cavity which will be positioned at the base of the pile when grounded is closed by a metal end plate welded or otherwise secured to the underside of the interlock, and the outer open end of the cavity is closed by a layer of hardened sealant or a removable end plate. In the embodiment of Figure 5, the hardened sealant 16 is replaced by a spring clip 17. Other similar closure members may be employed. When grounded, the presence of the hard sealant 16 or alternative closure member prevents soil particles entering the cavity and displacing the flowable sealant and the metal end plate prevents displacement of the relatively soft sealant during driving of the pile. The hard sealant 16 protects the flowable sealant 15, if hydrophilic, from absorbing moisture before the pile is driven into the ground. On driving of a neighbouring pile, the hardened sealant 16 or spring clip 17 is progressively removed through contact with the lower surface of the respective interlock of the neighbouring pile. This progressive removal ensures that a significant amount of sealant is retained within the cavity during driving. Thus, the end plate and collapsible hardened sealant or spring clip ensures that sufficient soft sealant remains within the cavity when the adjoining sheet pile is driven to complete the required interlock and seal connection. It will be appreciated that the foregoing is merely exemplary of metal sheet piling in accordance with the invention and that modifications can readily be made thereto without departing from the true scope of the invention.

Claims: CLAIMS 1. A metal sheet pile which includes a wall section comprising a central flange flanked by outwardly inclined side walls along the free edges of which are longitudinally extending interlocks each including a cavity at least one of which is filled with a sealant, the sealant present in one or each cavity having a flowable consistency with the open side of the cavity being closed by a member which is progressively displaced by the interlock of a neighbouring sheet pile on driving that neighbouring pile, and an end plate positioned to close the lower open end of the cavity. 2. A pile as claimed in claim 1 wherein the sealant has hydrophilic properties. 3. A pile as claimed in claim 1 or claim 2 wherein the closure member comprises a solid length of relatively hard sealant. 4. A pile as claimed in claim 1 or claim 2 wherein the closure member comprises a spring clip. 5. A metal sheet pile substantially as herein described with reference to Figures 3 and 4 of the accompanying drawings.

Inventors: WHITE GRAHAM ROBERT, WHITE, GRAHAM, ROBERT
Applicants: CORUS UK LTD, WHITE GRAHAM ROBERT, CORUS UK LIMITED, WHITE, GRAHAM, ROBERT
Application year: 2001
Main classification: E02D5
IPC codes: E02D5