Patent Publication Number: US-9896814-B2

Title: Quay wall with absorption blocks and inter-chamber flow paths

Description:
TECHNICAL FIELD 
     This disclosure relates to the field of quay wall construction. 
     BACKGROUND 
     Walls beside water extending from water floor to berth level are used in ports and harbors as facilities for berthing and cargo handling. These walls are also used in non-berthing areas to provide access to the water, and can serve as sinks for wave energy to calm waters in a vicinity thereof. 
     SUMMARY 
     A quay wall absorption block includes a back wall, a cap, and a half-octagonal columnar wall extending between the back wall and cap. The half-octagonal columnar wall defines a plurality of chamber surfaces and mating surfaces on opposite sides thereof such that the chamber surfaces define portions of a plurality of closed-end octagonal flow chambers on opposite sides thereof when the mating surfaces are in contact with corresponding mating surfaces of other quay wall absorption blocks. The half-octagonal columnar wall also defines a plurality of flow paths that extends therethrough to fluidly connect the plurality of closed-end octagonal flow chambers on opposite sides thereof. 
     A quay wall includes a plurality of absorption blocks stacked to form a honey comb portion. Each of the absorption blocks includes a back wall, a cap, and a half columnar wall extending between the back wall and cap. Each of the half columnar walls defines a plurality of chamber surfaces and mating surfaces on opposite sides thereof such that the chamber surfaces define portions of a plurality of closed-end flow chambers on opposite sides thereof when the mating surfaces are in contact with corresponding mating surfaces of other of the absorption blocks. Each of the half columnar walls also defines a plurality of flow paths that extends therethrough to fluidly connect the plurality of closed-end flow chambers on opposite sides thereof. 
     A quay wall absorption block includes a back wall, a cap, and a half columnar wall extending between the back wall and cap. The half columnar wall defines a plurality of chamber surfaces and mating surfaces on opposite sides thereof such that the chamber surfaces define portions of a plurality of closed-end flow chambers on opposite sides thereof when the mating surfaces are in contact with corresponding mating surfaces of other quay wall absorption blocks. The half columnar wall also defines a plurality of flow paths that extends therethrough to fluidly connect the plurality of closed-end flow chambers on opposite sides of the half columnar wall. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIGS. 1 and 2  are perspective views of an absorption block. 
         FIG. 3  is a front view of the absorption block of  FIGS. 1 and 2 . 
         FIG. 4  is a front view of a quay wall. 
         FIG. 5  is a plot of quay wall wave absorption percentage versus wave period. 
     
    
    
     DETAILED DESCRIPTION 
     Embodiments of the present disclosure are described herein. It is to be understood, however, that the disclosed embodiments are merely examples and other embodiments can take various and alternative forms. The figures are not necessarily to scale; some features could be exaggerated or minimized to show details of particular components. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a representative basis for teaching one skilled in the art to variously employ the present invention. As those of ordinary skill in the art will understand, various features illustrated and described with reference to any one of the figures can be combined with features illustrated in one or more other figures to produce embodiments that are not explicitly illustrated or described. The combinations of features illustrated provide representative embodiments for typical applications. Various combinations and modifications of the features consistent with the teachings of this disclosure, however, could be desired for particular applications or implementations. 
     Referring to  FIGS. 1, 2 and 3 , an absorption block  10  includes a backing wall  12  and a half-octagonal columnar wall  14  extending therefrom. The half-octagonal columnar wall  14  includes a plurality of side walls  16 ,  18 ,  20 ,  22 ,  24  arranged to generally form a half-octagon shape, and a cap  26  parallel with and opposite to the backing wall  12 . Each of the side walls  16 ,  18 ,  20 ,  22 ,  24  extends between the backing wall  12  and cap  26 . 
     As discussed more below, the absorption block  10  may be stacked with other such blocks to form portions of a quay wall that defines a plurality of flow chambers into which water may flow. As such, the side walls  16 ,  18 ,  20 ,  22 ,  24  define chamber surfaces  28 ,  30 ,  32 ,  34 ,  36  respectively. Likewise, the side walls,  16 ,  18 ,  20  define chamber surfaces  38 ,  40 ,  42  respectively. And, the side walls  20 ,  22 ,  24  define chamber surfaces  44 ,  46 ,  48  respectively. Moreover, the cap  26  includes mating surfaces  50 ,  52 ,  54 ,  56 . As the name suggests, the mating surfaces  50   52 ,  54 ,  56  may be mated with other such mating surfaces of other blocks to form a wave-energy-dissipating structure. 
     In one example, the mating surface  52  of a first absorption block may be placed in contact with the mating surface  56  of a second absorption block such that the chamber surfaces  38 ,  40 ,  42  of the first absorption block and the chamber surfaces  44 ,  46 ,  48  of the second absorption block  10  collectively define half of an octagonal flow chamber. To complete the other half of this octagonal flow chamber, the mating surface  58  of a third absorption block may be placed in contact with half of the mating surface  54  of the first absorption block such that the chamber surface  42  of the first absorption block and the chamber surface  36  of the third absorption block are flush with each other, etc. Thus, the chamber surfaces associated with a given half-octagonal columnar wall can partially define a plurality of closed-end flow chambers on opposite sides of the half-octagonal columnar wall as will be apparent with reference to  FIG. 4 . 
     Generally speaking, a length of the half-octagonal columnar wall  14  is greater than a width of the cap  26 . The length, for example, may be about 4 meters and the width may be about 2 meters. Such dimensions, however, will depend upon the target wave lengths and wave spectrum to be absorbed. 
     The examples so far have described absorption blocks that form hexagonal flow chambers. Other forms, however, are also contemplated. Some blocks have may have a half-hexagonal or half-circular columnar wall. Such blocks would thus form hexagonal or circular flow chambers respectively. Other blocks may have a quarter-octagonal, quarter-circular, etc. columnar wall. 
     Referring to  FIG. 4 , a quay wall  60  includes a plurality of absorption blocks  10  stacked to form a honey comb portion  62  defining a number of closed-end flow chambers  64  (as described above). The void space on the face of the honey comb portion  62  can fall within the range of 25% to 50% for example. The honey comb portion  62  is supported on the bottom and sides by solid rectangular blocks  66 , and on top by a cast-in-place ridge  68 . Gravel, dirt, etc. may be positioned behind the quay wall for further support. Other supporting arrangements, of course, are contemplated. 
     As waves approach the quay wall  60 , water carried thereby flows into the flow chambers  64  so as to dissipate the energy therewith over a larger surface area as compared with a flat quay wall, which may reflect some of the wave energy and thus further agitate the waters. The inventors, however, have discovered that chamber-to-chamber differences in pressure may limit the wave-energy-absorbing effectiveness of honey comb portions, and that such differences over time may affect long-term durability of any associated quay wall. The inventors have further discovered that constructing the absorption blocks  10  such that they define inter-chamber flow paths  70  acts to reduce chamber-to-chamber differences in pressure, thereby increasing the wave-energy-absorbing effectiveness of the honey comb portion  62  and the long-term durability of the quay wall  60 . As above, the size of the flow paths  70  will depend upon the materials being used, the type of waters expected, the size of waves, the target wave periods, wave lengths and wave spectrum associated therewith, etc. 
     Referring again to  FIGS. 1, 2 and 3 , each of the mating surfaces  52 ,  56  defines recesses  72 ,  74 , respectively. The recess  72  extends between the mating surface  50  and the chamber surface  38 . The recess  74  extends between the mating surface  58  and the chamber surface  48 . When the absorption blocks  10  are arranged as shown in  FIG. 4 , the recesses  72 ,  74  of adjacent blocks collectively define corresponding flow paths. Each of the side walls  18 ,  22  defines one of the flow paths  70 . The flow path  70  defined in the side wall  18  extends between the chamber surfaces  30 ,  40 . The flow path  70  defined in the side wall  22  extends between the chamber surfaces  34 ,  46 . The side wall  20  defines one of the flow paths  70 . The flow path  70  defined in the side wall  20  extends between the chamber surface  32  and mating surface  54 . 
     The flow paths  70  are rectangular in cross-section. Any suitable cross-sectional shape, however, may be used (e.g., circular, hexagonal, etc.). Moreover, the flow paths defined in the side walls  18 ,  22  are offset or staggered from the flow path  70  defined in the side wall  20  and the recesses  72 ,  74 . This staggered relationship further improves the pressure-equalizing capability associated with the flow paths  70 . In other examples, the flow paths  70  and recesses  72 ,  74  may be aligned, etc. 
     Referring to  FIG. 5 , testing was conducted to confirm the functionality and effectiveness of the wave absorbing quay wall blocks contemplated herein. A model wall was constructed and subjected to waves in a wave tank of different periods while measuring the reflection coefficients of the model. The results showed marked improvement over conventional vertical solid walls, absorbing between 30% to 50% of the wave energy—resulting in reductions in reflected waves. 
     The words used in the specification are words of description rather than limitation, and it is understood that various changes may be made without departing from the spirit and scope of the disclosure. As previously described, the features of various embodiments can be combined to form further embodiments of the invention that may not be explicitly described or illustrated. While various embodiments could have been described as providing advantages or being preferred over other embodiments or prior art implementations with respect to one or more desired characteristics, those of ordinary skill in the art recognize that one or more features or characteristics can be compromised to achieve desired overall system attributes, which depend on the specific application and implementation. These attributes may include, but are not limited to cost, strength, durability, life cycle cost, marketability, appearance, packaging, size, serviceability, weight, manufacturability, ease of assembly, etc. As such, embodiments described as less desirable than other embodiments or prior art implementations with respect to one or more characteristics are not outside the scope of the disclosure and can be desirable for particular applications.