Patent Publication Number: US-8523495-B2

Title: Bulkhead anchoring system for waterways

Description:
TECHNICAL FIELD 
     This invention relates generally to bulkhead systems used in waterways, and more specifically concerns a bulkhead anchoring system for use with existing or new bulkheads to prevent the bulkhead and/or bank from collapsing into the waterway. 
     BACKGROUND OF THE INVENTION 
     Bulkheads are generally needed for use against banks which are adjacent to waterways, such as lakes, canals, rivers, etc., to provide a defined raised bank-to-waterway edge and to prevent the banks from collapsing into the waterways. The banks may conventionally be dirt and can include rocks, sand, clay or a combination of those and other is soils. However, the bulkheads themselves often deteriorate, shift and even collapse, due to compressive forces against the bulkhead produced by the banks and/or water seepage. Bulkheads are expensive to maintain and replace. One solution used in the past has been to drive pilings and/or sluice slabs for the bulkheads vertically deep into the below-water-table ground, including to bedrock, to provide a more stable bulkhead system. However, such a solution is expensive and in some cases is still not completely effective. Such systems further lack stability at the waterway bottom, where failure of many bulkhead systems begin. 
     Hence, it is desirable to have a bulkhead system or an ancillary anchoring system which is effective to prevent the bulkhead from moving or collapsing into the waterway, while at the same time is reliable over the long term, and which can be used with existing as well as new bulkheads. It is further desirable that such a system be relatively low in cost compared to existing systems such as vertically deep and/or bedrock anchoring systems. 
     SUMMARY OF THE INVENTION 
     Accordingly, the waterway bulkhead anchoring system comprises: a plurality of slab members, sufficiently heavy and configured so as to remain in place, due to suction action, on a bottom surface of a waterway, the slab members being positioned in combination with and close to or adjacent a waterway bulkhead so as to stabilize the bulkhead and prevent it from collapsing into the waterway. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of a bulkhead anchoring system, for a pre-existing bulkhead. 
         FIG. 2  is a perspective view of an alternative bulkhead anchoring system. 
         FIG. 3  is a perspective view of an anchoring system for a new bulkhead. 
         FIG. 3A  is a top view of an alternative to  FIG. 3  using vertically oriented spanning panels between successive risers. 
         FIG. 4  is a side elevational view of the bulkhead anchoring system of  FIG. 1 . 
         FIG. 5  is a front elevational view of the bulkhead anchoring system of  FIG. 1 . 
         FIG. 6  is a top view of a portion of the bulkhead anchoring system of  FIG. 1 . 
     
    
    
     BEST MODE FOR CARRYING OUT THE INVENTION 
       FIGS. 1 ,  4 ,  5  and  6  show a basic bulkhead anchoring system for a pre-existing bulkhead, referred to generally at  10 . Bulkhead  10  can take various forms, including concrete, wood, metal, or various combinations thereof. Bulkhead  10  is used along various waterways  13 , including rivers, canals, lakes and the like. Bulkhead  10  can be of various sizes, with various heights and lengths, depending upon the particular waterway and the bank configuration. Bulkhead  10  is positioned and designed to restrain a bank behind it which forms the edge of the waterway. Bank  12  comprises various soils and other elements, including dirt, sand, clay, rocks, vegetation and other material, including ground water. Bulkhead  10  may or may not include a bulkhead beam, shown at  14 , which extends along the length of the bulkhead  10 . The bulkhead beam  14  will typically, but not necessarily, be concrete. 
     Bulkhead  10  in  FIG. 1  is continuous along its length. One embodiment of a bulkhead anchoring system, referred to generally at  16 , includes a plurality of concrete slabs  18 - 18 . In the embodiment shown, each slab  18  is approximately 8 ft. by 8 ft. by 12 inches thick. The slabs could, however, be different sizes depending upon the particular application. In the embodiment shown, each slab weighs approximately 10,000 pounds. The slab weight can also vary. Concrete slabs  18  can include rebar if desired for additional strength. The concrete slabs comprise cement, as well as water reducing additives, such as acrylic latex, polycarboxalate polymers, or other water-based polymers. In addition, fly ash can be added to the mix to increase the density and the water intrusion resistance. A 0.40-0.45 water to cement ratio during mixing is preferred. Water intrusion preventing products are widely commercially available. 
     The slabs  18  are positioned on the bottom  19  of the waterway  13  adjacent to the bulkhead  10 . The slabs are embedded in the waterway bottom  19 . The embedded slabs force out all the air and almost all the water beneath them so that in effect they are sealed in the bottom material of the waterway. A partial vacuum is formed due to the weight and pressure of the water when any side pressures are exerted against the slabs. The natural suction of the bottom  19  material under and around slabs  18  holds them securely in place so they will not move under bulkhead forces once they are in place. The bottom material, usually mud and other soils, will typically surround the slab so that the material comprising the bottom  19  of the waterway is in continuous physical contact with the bottom of the slab and the sides thereof due to the weight of concrete slabs  18 . A powerful suction force is produced, sealing slabs  18  to the bottom of the waterway or somewhat above, which more than offsets any force exerted by the bulkhead or the bank behind the bulkhead. The suction action is similar to a thin disc being caught against the drain in a single drain pool. The partial vacuum created in the drain underneath the disc (i.e. the difference in pressure above and below the disc) will prevent the disc from moving sideways, even though the disc may weigh relatively little. Suction provides resistance to horizontal movement. With the present bulkhead anchoring system, there is of course no drain. As a result, a relatively heavy slab which is embedded in the waterway bottom material produces a suction force that resists horizontal forces and collapsing of the bulkhead. The suction force is as important, if not more important, than the weight of the slab per se. 
     Typically, the individual slabs  18  will be separated by a small distance, such as 12 in., although this can vary, in some cases up to 8 feet or even more. Two slabs are typically positioned at the opposing ends of the bulkhead, although this again is not necessary, but may be preferred in typical applications. The slabs  18  provide the basic anchoring function for the anchoring system  16  and creates significant stability, a fulcrum of stability at the approximate plane of the bottom of the waterway  19 . 
     Each slab  18  in the embodiment of  FIG. 1  has a plurality of risers  20 - 20  which extend vertically therefrom. The risers are attached to or are part of the slabs  18 . Slab  18  will typically have two risers  20 , one at each rear corner thereof, although this is not necessary, in some cases a single riser per slab will be sufficient. 
     In the embodiment shown, the vertical risers  20  are 12 in. by 12 in. square, although this can vary depending upon the application, and can include rectangular or circular cross-sectional configurations. Typically, risers  20  will extend to just below the top of the bulkhead  10 . In one example the bulkhead is approximately 8 ft. high. Risers  20  are rigid and made out of concrete, similar to slabs  18  with ½ inch rebar (typically) added for additional strength. However, for fresh water waterways, such as rivers, the risers  20  can be made from galvanized steel. 
     The risers  20  are arranged so that they are in contact with the bulkhead  10  at least at one point but not attached thereto, although, in some cases, the risers could actually be secured to the bulkhead  10 . The risers  20 , anchored to the slabs  18 , have the function of maintaining the bulkhead  10  from moving toward the waterway. 
       FIG. 2  shows an alternative to the riser arrangement of  FIG. 1 . In  FIG. 2 , vertical pilings  21 - 21  are provided as part of or against the bulkhead (not shown). The piling  21  are sunk deeply into the waterway bottom along the bulkhead. The slabs  25 - 25  press against the pilings and act as a fulcrum of support against the pilings. Pilings  21  could be made from wood. Extending across the tops of the pilings  21  could be positioned a beam  22  which is attached to and connects the tops of the pilings  21 , although this is not necessary. The beam  22  will typically be made from concrete, or other materials such as steel or even wood. The beam  22  is arranged to stabilize the tops of individual pilings and maintain them in a specific relationship to each other. 
       FIG. 3  shows a similar arrangement to  FIG. 1 , except the bulkhead is new. The bulkhead and its associated anchoring system are thus typically constructed and installed at the same time. In this arrangement, the new bulkhead  24  comprises a plurality of individual sections  26 - 26 , in combination with risers  27 . Concrete slabs like that shown in  FIG. 1  are referred to at  29 . Bulkhead  24  will be made of conventional bulkhead materials, such as concrete, steel, wood and the like. Bulkhead  24  does not require anchoring pillars to be deeply driven such as down to bedrock. Neither do the vertical sections  26  need to be deeply embedded or sluiced into the waterway bottom. The individual sections  26  can be connected together with risers  27  by an arrangement of plates and bolts shown at  28 . 
     A flush appearance of the bulkhead can be produced by aligning sections  26 - 26  with risers  27 - 27 , as shown in  FIG. 3A . The vertical edges of sections  27  are connected to the vertical edges of the risers by tongue and groove connections shown at  31 , dado-type connections shown at  33 , or dado-type components with a T-shaped riser, hat-shaped bracket and bolt, shown at  35 . Other connecting arrangements can be used. With rebar arranged to protrude from the upper surfaces of sections  26  and risers  27 , a capping beam can be used to connect all the parts together and present a smooth bulkhead appearance. Designs of animals, landscapes, etc. can be carved, molded or embossed into the bulkhead sections facing the waterway. 
     The above-described bulkhead anchoring system results in secure protection against the compressive forces of the bank behind the bulkhead which tend to move a pre-existing or new bulkhead into the adjacent waterway. It accomplishes this desired result by a series of slabs which are maintained in position on the waterway floor by a powerful suction force. This provides the desired stable anchoring function without having to drive pilings or other members deeply down into the waterway bottom or to bedrock. Individual risers, which extend upwardly vertically from the slabs, typically two to a slab, maintain contact with the bulkhead but are not secured thereto. Hence, there can be a moving contact between the risers and the bulkhead, as the bulkhead may shift or settle in position due to action of the bank. The risers, along with the slabs as an anchor, prevent the bulkhead from moving or collapsing into the waterway. This is a relatively low-cost but effective alternative to expensive bedrock or deep anchoring systems. It is fast and convenient to use with existing bulkheads as well as new bulkheads. With use of the present system, any excavation of the bank is minimized. Expense associated with replacement of old bulkheads with removal of material encroaching onto landscaping and house foundations is also minimized. Dock piers can as an option be part of or mounted to or rise above the concrete slabs, either as part of or independent of a bulkhead. 
     Although a preferred embodiment has been disclosed for purposes of illustration, it should be understood that various changes and modifications and substitutions could be made in the preferred embodiment without departing from the spirit of the invention as defined by the claims which follow: