Abstract:
An improved tree stabilization system with a perimeter anchor system of a plurality of individual ground anchor assemblies configured adjacent to the tree or shrub to be supported and a related stabilization method. The tree stabilization system is particularly well suited for use in securing mature trees and stands of trees. As it is adjustable, it may be used for long term stability rather than simply during initial root development. The tree stabilization system includes a retention system that is attached to the perimeter anchor system and runs over the root system and pins the root system to the ground at certain important locations. The ground anchor assemblies are inserted into the ground so that the top end to which the retention system is attached is at or under ground level. The tree stabilization system may include a configuration for anchoring an entire stand of trees and may include a feature for adjusting the tension of the retention system to allow the appropriate amount of downward pressure as conditions change.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     1. Field of the Invention  
         [0002]     The present invention relates to stabilizing trees and shrubs. More particularly, the present invention relates to an apparatus and method for anchoring the root systems of trees and shrubs to the ground to assist them in remaining upright. Still more particularly, the present invention relates to a system of retention structures above the root system at or just below ground level to retain the root systems.  
         [0003]     2. Description of the Prior Art  
         [0004]     It is common for trees to encounter stability problems due to a variety of conditions. For the purposes of the description of the present invention, the word tree includes trees, woody shrubs, and plants. Even the healthiest of trees can tilt or fall over completely due to conditions such as excess moisture in the ground, high winds, the unexpected application of force by an object such as a collision by a car or another tree falling. In such situations, it is often the lack of adequate support from the root system that leads to a tree uprooting and tilting or falling.  
         [0005]     The situations in which the need to stabilize trees arises may be endless. For instance, mature trees located close to houses or other valuable property could be stabilized to prevent the trees from falling and causing significant property damage. Perhaps an especially desirable tree should be preserved. Trees may be located to shelter a structure such as a house from extreme weather conditions such as high prevailing winds, in which case, such sheltering trees could be stabilized in a way that maximizes their resistance to such winds.  
         [0006]     Conventional devices focus on stabilizing newly planted trees and shrubs, and generally consist of two or more stakes driven into the ground adjacent to the trunk of the tree or shrub. The stakes are attached to wires or cables that connect the stakes to the trunk. The connection to the trunk consists of wrapping the wire around the circumference of the trunk and inserting padding to protect the trunk. The trunk receives support from the wires because the lateral movement of the trunk is inhibited.  
         [0007]     There are several limitations associated with such conventional devices. One limitation is that the devices support the trunk, but not the root system. It is, however, the root system that most often is the weakest link. Some studies indicate that trees and shrubs fall more often because of failure of a significant root. Another limitation is that the stakes and wires are located above ground level. They are therefore unsightly and can detract from the appearance of the tree or shrub. They are also dangerous to pedestrians, children, landscaping equipment and other activities. The exposure increases susceptibility to intentional or accidental damage. For instance, stakes may become loose from regular bumping by a lawnmower or trimmer. The wire connection can also damage the tree trunk. Friction can wear away bark and/or the trunk can grow big enough to become constricted by the wire. A further undesired limitation is that such devices cannot support large trees and are not permanent in nature.  
         [0008]     U.S. Pat. No. 6,625,926, Mancini, titled Tree and Shrub Stabilizing Apparatus and Method for Stabilizing a Tree or Shrub, shows an apparatus and method for stabilizing newly planted trees and shrubs. Mancini shows a plurality of stakes attached to a plurality of straps. The stakes are driven into the ground in an arrangement around the hole into which a tree is being planted. The straps contact the root ball and provide support with downward pressure. The invention is designed to provide temporary support to newly planted trees and, in the preferred embodiment, teaches the use of biodegradable straps. This invention, however, does not address the problem of permanently securing trees or securing mature trees that have been planted for some time. The invention thus lacks a means for permanently securing a tree that has a mature root system rather than a root ball. It also lacks a means of adjusting the tension of the straps after installation. Such adjustment capability is critical for long term stabilization because conditions change over time and varying amounts of pressure are needed. Changing conditions include soil erosion, changes in moisture levels, wind loading due to neighboring trees being removed or blown down, and root system growth and shifting. The Mancini device also cannot be used to secure an entire stand of trees.  
         [0009]     Therefore, what is needed is a system for permanently stabilizing both large and small trees by anchoring the root system to the ground. The system must be adaptable for use with a variety of root systems and landscaping conditions ranging from loose, sandy soil to solid rock. The system must be capable of being installed at or just below the surface of the ground. The means for supporting the root system should be adjustable to allow appropriate pressure as required by changing conditions. The system must be capable of being positioned around a single tree or a stand of trees to stabilize the entire stand.  
       SUMMARY OF THE INVENTION  
       [0010]     It is an object of the present invention to provide artificial support for the root systems of trees or shrubs. It is also an object of the present invention to provide such support with an anchor perimeter fixed in the ground. The ground may consist of soil or rock or both. The anchor perimeter includes a plurality of individual ground anchors attached to a retaining system running above the root system but at or just below the ground surfaces. It is also an object of the invention to provide a means for adjusting the tension of the retaining system to ensure the proper amount of support is provided to the root system as conditions change. It is also an object of the invention to provide support to stands of trees and shrubs.  
         [0011]     These and other objects are achieved by the present invention, which is a tree stabilization system and related method. The stabilization system includes a perimeter anchor system and a retention system. The perimeter anchor system is affixable in the underlying soil or rock. The perimeter anchor system includes a plurality of ground anchor assemblies, each terminated at the top thereof by a fixing component positioned at or below the surface of the ground. One or more retention means such as a retaining cable or cables is/are attached to the ground anchor assemblies at the fixing component, preferably but not necessarily, with adjustment means to tighten the retention means when desired. The retaining cables may be detachably connected to the fixing component such as by a bolt or other such detachable connecting means. An eyebolt or other looped structure may also be affixed to the fixing component to optionally retain a means for connecting the ground anchor assemblies to the trunk such as a guy wire. A load distribution means to distribute the downward pressure laterally from the cable across a wider lateral area to the root system, and to minimize root damage over time, may be included. The stabilization system can be positioned around a single tree or a stand of trees to stabilize the entire stand.  
         [0012]     The present invention is a stabilization system suitable for retaining the roots of trees in place under sporadic high load conditions, such as severe wind gusts. The stabilization system is positioned about the tree or set of trees, preferably just at or below the ground surface. That positioning ensures that the most significant roots of the tree are retained by the retention system without impeding traffic about the tree or trees. The adjustability of the retention system ensures that the stabilizing load may be maintained at a constant over a long period of time with minimal root damage. These and other advantages of the invention will become apparent upon review of the following detailed description, the accompanying drawings and the appended claims. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0013]      FIG. 1  is a side view of the stabilization system positioned about a single tree.  
         [0014]      FIG. 2  is an overhead view of the stabilization system as shown in  FIG. 1 .  
         [0015]      FIG. 3 , comprising  FIGS. 3A-3D , provides side views of four different embodiments of the ground anchor assembly of the perimeter anchor system of the present invention.  
         [0016]      FIG. 4 , comprising  FIGS. 4A-4C , provides side views of three versions of the first embodiment of the ground anchor assembly of  FIG. 3A .  
         [0017]      FIG. 5  is a detailed side view of the fourth embodiment of the ground anchor assembly of  FIG. 3D .  
         [0018]      FIG. 6  is a detailed side view of an embodiment of the perimeter anchor system and the retention system of the present invention.  
         [0019]      FIG. 7  is a side view of an adjustable retainer of the retention system.  
         [0020]      FIG. 8 . is a side view of a first embodiment of the adjustable retainer.  
         [0021]      FIG. 9  is a side view of a second embodiment of the adjustable retainer.  
         [0022]      FIG. 10  is atop view of a first embodiment of the stabilization system to stabilize a stand of trees.  
         [0023]      FIG. 11  is a top view of a second embodiment of the stabilization system to stabilize a stand of trees.  
         [0024]      FIG. 12  is a top view of a third embodiment of the stabilization system to stabilize a stand of trees.  
         [0025]      FIG. 13  is a top view of a fourth embodiment of the stabilization system with an alternative arrangement for a stand of trees.  
         [0026]      FIG. 14  is a top view of an optional retention load distribution device of the present invention.  
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0027]     As illustrated in  FIGS. 1 and 2 , the present invention is a tree stabilization system  10  position about a tree  100  to be stabilized. The stabilization system  10  includes a perimeter anchor system  12  and a retention system  14 . The perimeter anchor system  12  is installed in the ground around the tree  100  proximate to the tree trunk  110  at or just below the ground surface  120 . The retention system  14  is removably affixed to the perimeter anchor system  12  about the roots of the tree  100  and in contact with those roots through application of downward pressure developed by the perimeter anchor system  12 . The perimeter anchor system  12  includes a plurality of ground anchor assemblies  16 , arranged in a configuration most advantageous for given conditions of the underlying ground and the area around the tree  100 .  FIG. 1  shows a configuration of four ground anchor assemblies  16  arranged in a square around a single tree, but other configurations are possible. The ground anchor assemblies  16  are suitable for installation in a variety of ground conditions ranging from solid rock to loose soil. Each of the ground anchor assemblies  16  includes a top end  18  and a bottom end  20 , and is designed to be installed so that their uppermost portions are at or just below ground level  120 . The top ends  18  of the ground anchor assemblies  16  include a means for attaching and fixing in position the retention system  14  to the perimeter anchor system  12 .  
         [0028]     As illustrated in  FIGS. 3-7 , the ground anchor assemblies  16  each includes an anchor body  22 , a top end  24  to which the retention system  14  is attached, and a bottom end  26  that is configured and arranged to ensure that the ground anchor assembly  16  remains affixed in the underlying substrate, whether that substrate is loose soil, clay, ledge, bedrock, or coral rock. The top end  24  includes a top plate assembly  28  for removably fixing the retention system  14  in place about the tree roots. The top plate assembly  28  preferably includes top plate  30  and a base plate  32 . The top plate assembly  28  includes means for retaining the retention system  14  thereto. The retention system  14  is preferably a set of one or more cables  34  attached to the ground anchor assemblies  16  at the top plate assembly  28 . The retention system  14  is attached to the ground anchor assemblies  16  in a manner that allows the retention system  14  to run above important parts of the root system, at or just below ground level  120 . The cables  32  can be made of steel, stainless steel, Kevlar™, or any other material suitable for attaching to the ground anchor assemblies  16  and of sufficient strength to maintain the roots in place under varying loads. The retention system  14  is installed with tension necessary to provide the proper amount of support for the root system.  
         [0029]     The ground anchor assemblies  16 , including the body  22 , the top end  24 , and the bottom end  26 , are preferably made from steel, but any relatively strong rigid material is acceptable. The bottom end  26  is configured and designed to ensure that it may be inserted into the ground and affixed in place once there. A standard stake would not be sufficient for the purpose of the present invention as such a component would likely loosen over time and cause slack in the stabilization system  10  that could not be taken up without considerable adjustment thereof. Such a requirement would not be conducive to an effective stabilization of a tree or set of trees over a period of years. Nevertheless, the bottom end  26  may be tapered, pointed, or threaded. It may also have a cutting end for boring into the ground. Alternatively, the bottom end can be a straight pipe or bar with or without threads. However, it also includes means for securing in the ground. A hole may be predrilled in the ground to facilitate installation of the ground anchor assembly  16 .  
         [0030]     In a first embodiment of the ground anchor assembly  16  shown in  FIG. 3A , a first bottom end  36  includes a threaded anchor pin. The threaded anchor pin  36  can be installed into the ground with or without a predrilled hole by rotating the anchor pin  36  in the direction (usually clockwise) causing the threads to draw the pin  36  downward. The top end  24  includes a sliding cap that causes the pin body  22  to move upwardly when the cap is moved upwardly. The top plate assembly  28  is connected to the anchor pin  36  by way of the anchor body  22  using conventional attachment means, such as threading, bolting, or pinning together. In a second embodiment of the ground anchor assembly  16  shown in  FIG. 3B , a second bottom end  38  includes an expandable retention assembly  40  attached to the anchor body  22 . The expandable retention assembly  40  includes one or more retention structures rotatably attached to the anchor body  22  so that as the ground anchor assembly  16  is positioned in the ground and preferably in soft soil, the retention structures of the assembly  40  dig into the ground and become affixed in place. The expansion of the retention structures, when in position, increase resistance to upward movement of the ground anchor assembly  16 .  
         [0031]     With reference to  FIG. 3C , a third embodiment of the ground anchor assembly  16  is shown. The third embodiment includes a third bottom end  42  formed as a bit to facilitate installation of the ground anchor assembly  16  into the ground. The bit can be any type that is suitable for boring into soil or rock. The top plate assembly  28  of this embodiment is optionally removable to allow easier attachment and maintenance of the retention system  14 . Any of the many known means for detachably attaching are acceptable, including threads, bolts, or pins.  
         [0032]      FIGS. 3D and 5  show a fourth embodiment of the ground anchor assembly  16  with a fourth bottom end  44  and including one or more cartridges  46  or some other means for retaining therein a liquid phase material  48  with the ability to harden, such as resin or concrete. Alternatively, the liquefied material  48  may be displaced through the end of the body  22 , which in that instance would be a hollowed body, using pump or injection means applied to the top of the body  22  without an internal cartridge. After first inserting the ground anchor assembly  16  into a hole, an injection means  50  is activated to inject the liquid phase material  48  into the surrounding soil through one or more openings  52  in the bottom end  44 , which injected liquid phase material  48  hardens to form a more secure anchoring platform  54 . In one example, a plunger  50  is placed in the hollow portion of the bottom end  44  of the ground anchor assembly  16  as the means to force the liquid phase material  44  through the openings  52 . In operation, the bottom end  44  is installed in the ground and the plunger  50  is pushed downward to compress the cartridge  46  containing the liquid phase material  48 . The resulting pressure forces the liquid phase material  48  out of the opening(s)  52  in the bottom end  44  of the ground anchor assembly  16  and into the surrounding soil where the liquid phase material  44  hardens.  
         [0033]     In the arrangement of the ground anchor assembly of  FIG. 5 , the top plate assembly  28  may include a cover plate  54  with a bolt  56 , which is screwed into the top plate  30  and retains the retention system  14  therein. The cartridges  46  may be stackable or all a single assembly and of variable volume for use dependent upon the ground within which the ground assembly  16  is retained. For example, more material  48  is required for sandy soils. The cartridges  46  preferably include a gasket  58  to prevent the material  48  from passing into the interior of the hollow anchor body  22 . Further, the openings  52  may be smooth, rough for better adhesion, or even include retention structures such as those shown in  FIG. 3B . It is to be noted that for this arrangement, it may be necessary to use a drive rod (not shown) to force the ground anchor assembly  16  into the ground and to force the material  48  through the openings  52 . A hydraulic hammer may also be used for either purpose.  
         [0034]      FIGS. 4A-4C  show variants of the first ground anchor assembly of  FIG. 3A  particularly suited for installation in rock. As shown in  FIG. 4A , with a short distance between the ground level  120  and the underlying bedrock  130 , a short anchor body  60  or short ledge pin may be joined to the top plate assembly  28  that is hollow or solid, with a bedrock plate  62  affixed at a point on the short anchor body  60  at the surface of the bedrock  130 . The short anchor body  60  may be hammered or screwed into rock. As shown in  FIG. 4B , with an intermediate distance between the ground level  120  and the underlying bedrock  130 , a small anchor body  64  or small ledge pin may be joined to the top plate assembly  28  that is hollow or solid, with the bedrock plate  62  affixed at a point on the small anchor body  64  at the surface of the bedrock  130 . The small anchor body  64  may be threaded and may be hammered or screwed into rock. As shown in  FIG. 4C , with a long distance between the ground level  120  and the underlying bedrock  130 , a long anchor body assembly  66  includes an intermediate anchor rod  70  and a bottom anchor rod  72  adjustably joined together with a coupling tube  74  that allows for modification of the complete length of the long anchor body assembly  66 . The intermediate anchor rod  70  may be joined to the top plate assembly  28  that is hollow or solid. The bedrock plate  62  is affixed at a point on the coupling tube  74  at the surface of the bedrock  130 . The anchor rods  70  and  72  may be male threaded and the coupling tube  74  female threaded. Washers or flare heads  76  ensure that the top plate assembly  28 , and anchor rods  70  and  72  remain set in the desired positions. The assembly of  FIG. 4C  allows for substantial adjustment of the length of the ground anchor assembly  16 . Specifically, rotation of the top plate assembly  28  draws the bottom anchor rod upward.  
         [0035]      FIG. 6  shows a variation of the ground anchor assembly  16  of  FIG. 3A  having a bottom end  37  that includes means for adjusting  78  the length of the ground anchor assembly  16 . The bottom end  37  includes an opening  80  at its top portion. A modified anchor body  82  is positionable in the opening  80 . Openings  84  in the sides of the body  82  are positioned at various places along the length of the body  82  to allow for adjustment of the overall length of the ground anchor assembly  16 . In particular, a selected opening of the openings  84  may be aligned with the opening  80  of the bottom end  37  and a pin is inserted into the aligned openings to secure them together and fix the length of the ground anchor assembly  16 . Cut-ins may be applied to the outer surface of the top portion of the bottom end  37  to allow for wrench placement and movement. Rotation of the bottom end  37  draws the bottom end  37  upwardly toward the top section  28 . It is to be noted that additional intermediate anchor bodies of similar arrangement may be combined to increase the total length if necessary. Alternatively, selected components may be reduced in length as necessary in the field by cutting the top portion or the anchor body lengths down. It is to be noted in regard to the system of  FIG. 6  that fitting  86  shown may be employed on one or more ground anchor assemblies  16  as shown. In particular, the fitting  86  may be an eyebolt, ring, or other looped structure installed at the top plate assembly  28 . The fitting  86  may be screwed or bolted into the top plate  30  and the cable  34  passed therethrough. The fitting  86  may also be used to secure a guy wire about the trunk of the tree  100  if desired.  
         [0036]      FIG. 7  shows an embodiment of the retention system  14  having an optional adjustment means  88  for adjusting the tension on the cable  34 . In this embodiment, the cable  34  is retained in position to the two ground anchor assemblies  16  shown between the bottom plates  32  and the top plates  30 . The adjustment means  88  is positioned on or around the cable  34  intermediate between the two ground anchor assemblies  16  and arranged to enable loosening or tightening of the cable as required by the condition of the ground, the assemblies, the tree or any combination thereof. It is to be noted that the cable  34  may be a single cable or it may include a plurality of cables, including, for example, an arrangement in which two cables are affixed to the adjustment means  88  at opposite ends thereof and either drawn toward, or pushed away from, one another.  
         [0037]      FIG. 8  shows a side view of a first embodiment of the adjustment means  88  with an adjustment assembly  90  that includes a threaded rod  92 . One end of the threaded rod  92  is screwed into the hollow portion of a connecting structure  94  suitable for connecting to a ground anchor assembly  16 . The second end of the threaded rod  92  is screwed into a rotatable adjusting structure  96 . Rotating the rotatable adjusting structure  96  in one direction decreases the length of the retention system  14  (and thus the tension of the retention system) by drawing the threaded rod  92  further into the rotatable adjusting structure  96  opening. Rotating the rotatable adjusting structure  96  in the other direction has the opposite effect. The end of the rotatable adjusting structure  96  opposite from the end connected to the threaded rod  92  is connected to the cable  34 , which, in turn, is suitable for connecting to a ground anchor assembly  16  as previously described.  
         [0038]      FIG. 9  shows a second embodiment of the adjustment means  88  that includes an adjustment nut  98 . The adjustment nut  98  is connected to a threaded rod  92 . One end of the threaded rod  92  is insertable into a coupling assembly  100  threaded at both ends thereof. The other end of the threaded rod  92  is connectable to a second coupling assembly  102  affixable to a ground anchor assembly  16 . The other end of the coupling assembly  100  is affixed to the cable  34  in a non-adjusting manner. The cable  34  is, in turn, connectable to the ground anchor assembly  16 . The second embodiment of  FIG. 9  is distinct from the first embodiment of  FIG. 8  in that the cabling of  FIG. 8  is adjustable in both directions from by way of the threaded rod  92 , whereas the second end of the coupling assembly  100  fixes the cable attached thereto without adjustment capability. Rotating the adjustment nut  98  changes the distance between the two coupling assemblies  100  and  102 . Rotating the adjustment nut  98  in one direction decreases the distance between the two coupling assemblies  100  and  102  and thus increases the tension of the retention system. Rotating the adjustment nut  98  in the other direction has the opposite effect.  
         [0039]      FIG. 10  shows the stabilization system of the present invention configured to stabilize a stand of trees  200 . The perimeter anchor system  12  surrounds the stand of trees  200  and portions of the retention system  14  are run between several of the trees in the stand to increase the support.  FIG. 11  shows yet another configuration to stabilize a large stand of trees  210 . An outer portion of the perimeter anchor system  12  surrounds the outermost boundary of the stand  210 . An inner portion of the anchor system  12  runs parallel to the outer portion, running along the inside edge of the outermost trees in the stand  210 . At various points, portions of the retention system  14  are run between the outer and inner portions of the perimeter anchor system  12 . Each portion of the perimeter anchor system  12  includes ground anchor assemblies  250 .  FIG. 12  shows yet another example of supporting a stand of trees  220 . The stabilization system  10  is arranged in a line parallel to the line of trees to be stabilized. The stabilization system  10  is placed on the side of the stand  220  that encounters the prevailing wind.  
         [0040]     In another embodiment of the stabilization system of the present invention for a stand of trees shown in  FIG. 13 , a series of triangulation combinations is established. A portion of the trees located generally about the perimeter of the stand are employed as anchor trees, designated in the drawing as trees “X,” while other trees of the stand to be stabilized are designated in the drawing as trees “O.” Above-surface retention lines  300  shown as solid lines are placed about and interconnect both types of trees. A perimeter anchor system including ground anchor assemblies  302  and anchor lines  304  located at or below the ground surface is established about the tree stand. However, as can be seen from the drawing, a portion of the anchor lines  304  extend into the tree stand to the root systems of certain ones of the anchor trees X. The retention lines  300 , the ground anchor assemblies  302 , and the anchor lines  304  are joined and arranged such that each tree of the stand is connected to at least two other trees of the stand or to at least one other tree and one or more ground anchor assemblies. This arrangement is distinct from the system of  FIG. 11  in that the additional retention lines  300  are employed to create the triangular support arrangement without using anchor assemblies  302  about every tree of the stand. The ground anchor assemblies  302  and anchor lines  304  may be of any of the types previously described herein. The retention lines  300  and the anchor lines  304  may be of fabricated of the same material.  
         [0041]      FIG. 14  shows an optional load distribution device  106  for distributing the downward pressure from the retention system  14  across a larger horizontal area than is provided by the cable  34  alone. The load distribution device  106  is preferably a strip, plate, or sheet wider than the cable  34  and is preferably fabricated of a material that can withstand the environment it will be in and also of sufficient strength to enable load distribution without causing root damage. The load distribution device  106  is therefore preferably a rubber or plastic pad or mat. The use of the device  106  ensures downward pressure from the retention system  14  is distributed across a wider horizontal area of the root system without causing root damage. Its position may be adjusted over time as required.  
         [0042]     While the present invention has been described with particular reference to certain embodiments of the stabilization system, it is to be understood that it includes all reasonable equivalents thereof as defined by the following appended claims.