Abstract:
A retention basin includes interlocking concrete vertical wall segments engaged with adjacent segments. Each segment has a vertical wall and a top edge that defines a lifting bore that is complimentary in shape to a removable lifting bolt that is configured to provide a lifting attachment point for a lifting cable and an internal bore in alignment with the internal bore of an adjacent segment. A pin is disposed in the internal bores to maintain the segments in alignment. An eyebolt includes an eye portion disposed around the pin. A plate is bolted to the eyebolt and against the vertical walls of two adjacent segments to maintain the two segments in a spatial relationship. An earth anchor is buried in the soil to provide lateral support to the segments. A post-installation attachment is affixed to the lifting bore of at least one segment.

Description:
CROSS-REFERENCE TO RELATED APPLICATION(S) 
     This application is a continuation-in-part of, and claims the benefit of, U.S. patent application Ser. No. 13/447,733, filed Apr. 16, 2012, which is a continuation of U.S. patent application Ser. No. 12/622,832, filed Nov. 20, 2009, which issued on Apr. 17, 2012 as U.S. Pat. No. 8,157,991 the entirety of each of which is hereby incorporated herein by reference. This application also claims the benefit of U.S. Provisional Patent Application Ser. No. 61/674,327, filed on Apr. 16, 2012, the entirety of which is hereby incorporated herein by reference. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to utility systems and, more specifically, to a prefabricated segmented system for building bio-retention system enclosures. 
     2. Description of the Prior Art 
     Storm water runoff places a substantial economic burden on public water treatment facilities. As open land comes under development and is paved over, storm water that would otherwise be absorbed by soil flows into local storm sewer systems. Such water often suspends solids and other pollutants as it flows over paved surfaces. Once in the storm sewer system, the water flows to a water treatment facility where it must be treated to remove the solids and pollutants. Not only is such water treatment expensive, but so is the cost of infrastructure improvements necessary to convey the storm water. 
     Local bio-retention basins are increasingly used to catch storm water and allow it to settle solids locally before transfer to a storm sewer system. Many such basins also allow storm water to be infiltrated into the surrounding soil, thereby reducing the demands placed on the local storm sewer system. 
     A bio-retention system can be configured as a rain garden. A rain garden is a garden that diverts storm water for storm water filtration and groundwater recharge. Typically, a rain garden includes an area that retains storm water that would otherwise flow into the storm sewer system. Rain gardens mitigate the effects of runoff in urban areas by allowing storm water to seep into the water table, thereby filtering the water by the surface soil and preventing flow of the storm water into the storm sewer system. Also, some rain gardens use storm water to grow aesthetically pleasing plants, thereby making urban areas more attractive. Use of rain gardens in medians and next to sidewalks that would otherwise be paved over results in less stress on the municipality&#39;s drainage systems, improved groundwater quality and a more pleasing urban environment. 
     Most bio-retention basins include a surrounding curb or retaining wall used to form an enclosure that keeps water local to the basin. Water inlets are included to allow water to flow into the basin and water outlets are provided to allow overflow to exit the basin. 
     Unfortunately, in an urban environment, construction of bio-retention basins can be difficult to construct and expensive. One method of constructing such a basin includes setting concrete forms in the configuration of the basin, placing concrete in the forms, allowing the concrete to cure, removing the forms and then placing gravel and soil in the basin. This method is costly, labor intensive and may be difficult to perform in a limited urban environment. 
     Another method includes pre-casting an entire unitary retention system designed to fit into a specific site. The unitary system is then transported to the site on a truck and then installed. Such a unitary system can be bulky and costly to transport. This method may also be difficult to use in limited urban environments and it is inflexible because once installed, it cannot be easily modified. 
     Therefore, there is a need for a segmental bio-retention enclosure system that is prefabricated, easily transported, inexpensive and that can be arranged in various layouts to accommodate given site conditions. 
     SUMMARY OF THE INVENTION 
     The disadvantages of the prior art are overcome by the present invention which, in one aspect, is a bio-retention basin enclosure system that includes a plurality of prefabricated vertical wall segments and a baffle unit. Each of the plurality of wall segments includes a horizontal top end that defines a notch, an opposite horizontal and substantially flat bottom end, a first vertical edge, a second opposite vertical edge, a front vertical surface and an opposite back vertical surface. Each of the first vertical edge and the second vertical edge defines at least one cylindrical bore configured to receive a connecting dowel therein. The baffle unit is configured to be coupled to at least one of the plurality of prefabricated vertical wall segments and to be held in alignment therewith by at least one connecting dowel. The baffle unit includes a water velocity reduction member that is configured to reduce a velocity of water flowing into the baffle unit. At least one connecting dowel has dimensions complimentary to the bore defined by the plurality of prefabricated vertical wall segments and the bore defined by the baffle unit so as to be configured to hold the baffle unit in alignment with at least one of the plurality of prefabricated vertical wall segments. 
     In another aspect, the invention is a system for constructing bio-retention basin enclosures system that includes a plurality of prefabricated vertical wall segments, at least one prefabricated baffle segment, a planar grate segment, and at least two prefabricated baffle vertical wall members. Each of the plurality of wall segments includes a horizontal top end that defines a notch, an opposite horizontal bottom end, a first vertical edge, a second opposite vertical edge, a front vertical surface and an opposite second vertical surface. Each of the first vertical edge and the second vertical edge defines at least one cylindrical bore configured to receive a connecting dowel therein. The at least one prefabricated baffle segment includes a vertical edge surface, defining a plurality of cylindrical bores, each of which is configured to receive a connecting dowel therein, and a planar member from which a plurality of protrusions extend upwardly therefrom so that the baffle segment is configured to reduce water flow velocity. The planar grate segment defines a plurality of holes passing there through. The at least two prefabricated baffle vertical wall members each have a planar vertical surface that defines a plurality of cylindrical bores disposed so that at least one of the cylindrical bores defined by the vertical edge surface of the prefabricated concrete baffle segment is configured to be placed in alignment therewith. The two baffle vertical wall members are configured to support the prefabricated concrete baffle segment and the planar grate segment so as to form a baffle unit. 
     In another aspect, the invention is a retention basin enclosure that includes a plurality of prefabricated concrete vertical wall segments, a baffle unit and at least one steel connecting dowel. Each of the plurality of wall segments includes a horizontal top end that defines a notch, an opposite horizontal bottom end, a first vertical edge, a second opposite vertical edge, a front vertical surface and an opposite second vertical surface, each of the first vertical edge and the second vertical edge defining at least one cylindrical bore. The at least one prefabricated concrete baffle segment includes a vertical edge surface that defines a plurality of cylindrical bores and a horizontal planar member from which a plurality of protrusions extend upwardly therefrom so that the baffle segment is configured to reduce water flow velocity. A planar grate segment defines a plurality of holes passing there through. At least two prefabricated concrete baffle vertical wall members each have a planar vertical surface that defines a plurality of cylindrical bores disposed so that at least one of the cylindrical bores defined by the vertical edge surface of the prefabricated concrete baffle segment is configured to be placed in alignment with at least one of the cylindrical bores defined by the planar vertical surface. At least one steel connecting dowel has a first portion of which that is disposed in the bore defined by a selected one of the plurality of prefabricated concrete vertical wall segments and a second portion of which that is disposed in the bore defined by one of the vertical edge surface of the baffle unit so as to couple the at least one of the plurality of prefabricated vertical wall segments to the baffle unit. 
     In another aspect, the invention is a retention basin for making an enclosure in soil that includes a plurality of interlocking concrete vertical wall segments. Each segment is engaged with an adjacent segment so as to form an enclosed basin. Each segment has a vertical wall and a top edge that defines a lifting bore that is complimentary in shape to a removable lifting bolt that is configured to provide a lifting attachment point for a lifting cable. Each segment includes an internal bore configured to be in linear alignment with the internal bore of the adjacent segment. A metal pin is disposed in the internal bores of two adjacent segments and is configured to maintain the two adjacent segments in alignment. An elongated eyebolt includes an eye portion disposed around the metal pin. A plate is bolted to the elongated eyebolt and driven against the vertical walls of two adjacent segments and is secured to the eyebolt with a nut. The nut is torqued so as to apply a predetermined tension to the eyebolt and a predetermined force to the plate so that the plate and the metal pin maintain the two segments in a substantially fixed spatial relationship. An earth anchor has a first end attached to the eyebolt and a second end, spaced apart from the first end, that includes an anchoring shape that is buried in the soil so as to provide lateral support to the two segments bolted to the plate. A post-installation attachment is affixed to the lifting bore of at least one segment. 
     In another aspect, the invention is a retention basin segment pair that includes a first concrete wall segment having a first side edge. The first side edge includes a first vertical edge portion having a bottom, a step edge portion extending laterally from the bottom of the first vertical edge portion and having a distal end, and a second vertical edge portion extending downwardly from the distal end of the step edge portion. The step edge portion defines a first internal bore. A second concrete wall segment has a second side edge that is complimentary in shape to the first side edge of the first concrete wall segment. The second side edge includes a first vertical edge portion having a bottom, a step edge portion extending laterally from the bottom of the first vertical edge portion and having a distal end, and a second vertical edge portion extending downwardly from the distal end of the step edge portion. The step edge portion defines a second internal bore. The second concrete wall segment is disposed next to the first concrete wall segment so that the first internal bore is in alignment with the second internal bore. A metal pin is disposed in both the first internal bore and the second internal bore. An elongated bolt is secured to the metal pin. A plate is bolted to the elongated bolt and is driven against both the first concrete segment and the second concrete segment and is secured to the eyebolt with a nut. The nut is torqued so as to apply a predetermined tension to the eyebolt and a predetermined force to the plate so that the plate and the metal pin maintain the first concrete segment in a substantially fixed spatial relationship with the second concrete segment. An earth anchor has a first end attached to the eyebolt and a second end, spaced apart from the first end, that includes an anchoring shape that is configured to be buried in soil so as to provide lateral support to the first concrete segment and to the second concrete segment. 
     In yet another aspect, the invention is a method of constructing a retention basin, in which a first concrete wall segment is placed into an excavation. The first concrete wall segment has a first side edge, the first side edge including a first vertical edge portion having a bottom, a step edge portion extending laterally from the bottom of the first vertical edge portion and having a distal end, and a second vertical edge portion extending downwardly from the distal end of the step edge portion, the step edge portion defining a first internal bore. A second concrete wall segment is placed into the excavation. The second concrete wall segment has a second side edge that is complimentary in shape to the first side edge of the first concrete wall segment. The second side edge includes a first vertical edge portion having a bottom, a step edge portion extending laterally from the bottom of the first vertical edge portion and having a distal end, and a second vertical edge portion extending downwardly from the distal end of the step edge portion. The step edge portion defines a second internal bore. The second concrete wall segment is disposed next to the first concrete wall segment so that the first internal bore is in alignment with the second internal bore. A metal pin is placed in both the first internal bore and the second internal bore so as to hold the first concrete wall segment in alignment with the second concrete wall segment. An elongated bolt is secured to the metal pin. A plate is passed around a portion of the elongated bolt and the plate is driven against both the first concrete segment and the second concrete segment. The plate is then secured to the eyebolt with a nut. The nut is torqued sufficiently so as to apply a predetermined tension to the eyebolt and a predetermined force to the plate so that the plate and the metal pin maintain the first concrete segment in a substantially fixed spatial relationship with the second concrete segment. An earth anchor is driven into soil to provide lateral support to the first concrete segment and to the second concrete segment. The earth anchor has a first end attached to the eyebolt and a second end, spaced apart from the first end. The second end includes an anchoring shape that is driven into the soil. 
     These and other aspects of the invention will become apparent from the following description of the preferred embodiments taken in conjunction with the following drawings. As would be obvious to one skilled in the art, many variations and modifications of the invention may be effected without departing from the spirit and scope of the novel concepts of the disclosure. 
    
    
     
       BRIEF DESCRIPTION OF THE FIGURES OF THE DRAWINGS 
         FIGS. 1-5  are schematic diagrams of different modular components of a retention basin system. 
         FIGS. 6A-6C  are top plan views showing the coupling of a first segment and a second segment. 
         FIGS. 7A and 7B  are schematic diagrams of an inflow baffle unit constructed from components shown in  FIGS. 3-5 . 
         FIG. 8  is an elevational view of one configuration for a retention basin wall using modular components shown in  FIGS. 1 and 5 . 
         FIGS. 9A-9C  are top plan views of different configurations of retention basins that can be constructed using the modular components shown in  FIGS. 1-5 . 
         FIG. 10  is a drawing of one embodiment employed in a rain garden. 
         FIGS. 11A-11B  are schematic drawings of a T-shaped segment. 
         FIGS. 12A-12B  are schematic drawings of an S-shaped segment. 
         FIGS. 13A-13B  are schematic drawings of an inverted T-shaped segment. 
         FIGS. 14A-14B  are schematic drawings of a wall constructed with T-shaped and S-shaped segments. 
         FIGS. 15A-15B  are schematic drawings of a curved S-shaped segment. 
         FIGS. 16A-16B  are schematic drawings of a curved inverted T-shaped segment. 
         FIG. 17  is a schematic drawing of a semicircular basin. 
         FIG. 18A  is a schematic drawing of two basin segments and an anchoring device. 
         FIG. 18B  is a schematic cross sectional drawing of the drawing shown in  FIG. 18A , taken along line  18 B- 18 B. 
         FIG. 18C  is a schematic cross sectional drawing of a portion of the drawing shown in FIG.  18 Bm taken along line  18 C- 18 C. 
         FIG. 18D  is a schematic diagram of an anchoring shape. 
         FIG. 19A  is a schematic drawing of two basin segments during installation. 
         FIG. 19B  is a schematic drawing of the two basin segments shown in  FIG. 19A  after installation. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     A preferred embodiment of the invention is now described in detail. Referring to the drawings, like numbers indicate like parts throughout the views. Unless otherwise specifically indicated in the disclosure that follows, the drawings are not necessarily drawn to scale. As used in the description herein and throughout the claims, the following terms take the meanings explicitly associated herein, unless the context clearly dictates otherwise: the meaning of “a,” “an,” and “the” includes plural reference, the meaning of “in” includes “in” and “on.” 
     As shown in  FIGS. 1-5 , one embodiment employs a kit of modular segments that are typically constructed from precast concrete. The segments may be put together to form the structure of an enclosure for a retention basin (which, in one representative embodiment can include a rain garden). For example,  FIG. 1  shows a main wall segment  100  having a top end  102  a bottom end  104 , two side ends  106 , a front vertical surface  114  and an opposite back vertical surface  115 . Typically, the top end  102  has a rectangular notch  110  formed therein for allowing storm water to drain into or out of the retention basin. The notch  110  includes a substantially flat bottom surface  116  and two vertical surfaces  118 . When the bottom surface  116  is placed at ground level, the notch  110  provides a drain for water flowing into or out of the basin. 
     The ends  106  of the segments  100  include a mechanism to maintain the segments in alignment. For example, bores  112  (which could be cylindrical or, as those of skill in the construction art would readily recognize, of another shape such as prismatic) are be formed therein to receive connecting dowels. When aesthetics require a top surface without a notch  110 , the segment may be inverted so that the bottom end  104  is on top and the notch  110  is buried. A shortened segment  200  is shown in  FIG. 2 . This segment  200  may be used to allow different geometric configurations that would not be possible using only the main segment  100 . As will be readily appreciated by those of skill in the construction arts, the specific dimensions of the segments and the materials from which they are constructed can vary depending on the specific application. 
     A drain grate segment  300  is shown in  FIG. 3 . This segment  300  is used to allow storm water to drain into the retention basin while allowing people to walk on the grate. The drain grate segment  300  includes a plurality of holes  310  passing therethrough. Typically, this segment  300  is used with a water baffle segment  400  and a vertical wall segment  500  to form a baffle unit. The water baffle segment  400  includes an edge surface  402  that defines several bores  112  and a horizontal surface  410  from which plurality of protrusions  420  extend upwardly therefrom (and possibly indentations). The baffle segment  400  is used to reduce the velocity of incoming water and to disperse the water over a wider area so as to reduce local erosion in the retention basin. 
     As shown in  FIGS. 6A-6C , the segments  100  (and similar segments disclosed above) include bores  112  that allow them to be held in alignment with each other when a dowel  120  (such as a steel rod, a stainless steel rod, or a rod made of another material having a suitable shear strength for the specific application) is placed therein. A corner configuration is shown in  FIGS. 6A-6B , wherein  FIG. 6A  shows the segments  100  prior to coupling and  FIG. 6B  shows the segments  100  after coupling. An end-to-end configuration is shown in  FIG. 6C . 
     An example of a baffle unit  600  constructed from the segments discussed above is shown in  FIG. 7A . Such a structure includes two vertical wall segments  500  that are coupled to a baffle segment  400  with four dowels  120 . A drain grate segment  300  coupled to the vertical wall segments  500  with several metal corner brackets  610  (or other types of fasteners as would be readily appreciated by those of skill in the art). As water drains in through the holes  310  defined by the drain grate segment  310 , it is dispersed by the protrusions  420  extending from the horizontal surface  410  of the baffle segment  400 , there by reducing its velocity and its erosive impact on the contents of the basin. An example of a double-tiered baffle unit  610  is shown in  FIG. 7B . This configuration provides an additional level of baffling to incoming storm water. 
     An example of a retention basin wall  700  is shown in  FIG. 8 . The segments employed in such a wall  700  are placed relative to ground surface  12  so that the notches  110  are at a level where storm water can flow from the surrounding ground surface  12  into the basin through the notches  110  (or out of the basin through the notches  110  when the basin is full). If it is desired not to have an exposed notch  110  on every segment  100 , selected segments  100   a  can be inverted so that their notches  110  face downwardly. 
     Several different configurations of the many different configurations of retention basins made possible with the present invention are shown in  FIGS. 9A-9C . A substantially linear basin enclosure  900  is shown in  FIG. 9A ; a substantially linear basin enclosure  910  including two oppositely-disposed baffle units  610  is shown in  FIG. 9B ; and a cornered basin enclosure  920  is shown in  FIG. 9C . A drawing of a rain garden  150  employing a representative embodiment is shown in  FIG. 10 . 
     As shown in  FIGS. 11A-11B , in one embodiment, a T-shaped segment  1000  is used. The T-shaped segment  1000  includes a top edge  1002  and an opposite bottom edge  1004 . (However, as will be seen in  FIG. 19A , the segment  1000  can be used in an inverted position.) Both the top edge  1002  and the bottom edge  1004  define a lifting bore  1250 . Each segment includes an internal bore  1016  that is used to maintain adjacent segments in linear alignment with each other.  FIGS. 12A-12B  show an S-shaped segment  1020  and  FIGS. 13A-13B  show an alternate T-shaped segment  1030 . 
     As shown in  FIGS. 14A-14B , shows one method of connecting segments to form a wall. In this embodiment, a bottom segment  1000  is placed in a desired location and then pins  1040 , such as a steel dowel, are placed in the internal bores  1016  of the bottom segment  1000   a . The pins  1040  maintain the alignment of the segments  1000 . Top segments  1000   b  and  1020  are then lowered into place so that the pins  1040  fit in their internal bores  1016 . 
     Curved S-shaped segments  1050  are shown in  FIGS. 15A-15B  and  FIGS. 16A-16B  show curved T-shaped segments  1060  (in an inverted position). A basin  1060  that is made from both curved segments  1050  and straight segments  1020  is shown in  FIG. 17 . 
     One method of stabilizing a wall of a bio-retention basin is shown in  FIGS. 18A-C . In this method, each segment  1000  includes a side edge that includes a first vertical edge portion  1248  having a bottom from which a step edge portion  1240  extends laterally to a distal end. A second vertical edge portion  1246  extends downwardly from the distal end of the step edge portion  1240 . The internal bore  1016  opens to the step edge portion  1240 . A lateral groove  1242  may also run across the step edge portion  1240 . The segments  1000  are held in alignment with each other and are stabilized in the soil with an anchoring system  1210 . 
     The anchoring system  1210  includes an elongated eyebolt  1224  that includes an eye portion  1225  that is disposed about the about the metal pin  1040  and that fits in the lateral groove  1242 . A metal plate  1226  is bolted to the eyebolt  1224  with a nut  1228 . Sufficient torque is applied to the nut  1228  so that the eyebolt  1224  applies sufficient tension to the metal pin  1040  and so that the plate  1226  applies sufficient force to the segments  1000  to keep them in a substantially fixed spatial relationship. 
     An earth anchor  1210  is used to provide lateral support to the segments  1000 . The earth anchor  1210  includes a chain  1230  (or a cable) with one end coupled to the eyebolt  1224  (e.g., with a second nut). An anchoring shape  1236  is coupled to the opposite end of the chain  1230 . The anchoring shape  1236  is driven into the soil and provides a surface that resists movement within the soil. As shown in  FIG. 20 , the anchoring shape  1236  can include a rod portion  1280  and a transverse portion  1282  that is hingedly attached to the rod portion  1280 . The transverse portion  1282  is initially in lateral alignment with the rod portion  1280  while the anchoring shape  1236  is driven into the soil and then is in a second position that is aligned transversely relative to the rod portion so as to provide resistance to slippage once the anchoring shape is disposed in soil. Typically, the anchoring shape  1236  is pounded into the soil with a steel rod and then the transverse portion  1282  moves into the second position as a result of soil resistance resulting from backwards movement of the anchoring shape  1236 . Once the anchoring shape  1236  is securely in place, the chain  1230  can be tightened to maintain strain on both the eyebolt  1224  and the anchoring shape  1236 . In one example of an alternative embodiment, an anchoring auger (which is screwed into place rather than pounded) can be used as an anchoring shape. 
     As shown in  FIGS. 19A-19B , segments  1000  can be installed by screwing lifting bolts  1252  into the lifting bores  1250 , attaching cables  16  to the lifting bolts  1252  and lifting the segment  1000  from a truck with a crane  14  and lowering it into an excavation  10 . Once the segments  1000  are installed, the lifting bolts  1252  are removed and the excavation  10  is backfilled to the ground surface  12 . While the lifting bores  1250  can be filled in with a material such as patching cement or silicone, they can be used to anchor post installation attachments  1260 , which can be bolted to the segments  1000  with bolts  1262 . A few examples of post-installation attachments, commonly found in the urban environment, that can be bolted to the segments  1000  include: a bench; a sign; a waste receptacle; a shelter; an enclosure; a streetlight; a traffic light; a bicycle rack; a newspaper vending box; a bollard; a fence; and many other types of attachments. 
     The embodiments disclosed herein have the advantages of being easy to transport, inexpensive and they can be arranged in many different layouts to accommodate the available geometry of a specific site. They also have the advantage of being easily modified to allow for changes in design. 
     The above described embodiments, while including the preferred embodiment and the best mode of the invention known to the inventor at the time of filing, are given as illustrative examples only. It will be readily appreciated that many deviations may be made from the specific embodiments disclosed in this specification without departing from the spirit and scope of the invention. Accordingly, the scope of the invention is to be determined by the claims below rather than being limited to the specifically described embodiments above.