Patent Application
20190168096
This invention relates generally to golf course sand bunkers and more particularly to stabilized golf course sand bunkers making use of barrier liners and methods of stabilizing and lining golf course sand bunkers.
As is known golf course sand traps or bunkers are pits filled with sand and surrounded by turf. Such bunkers typically contain approximately 4-6 inches of sand on the bottom of the pit, tapering to a thickness of 2 inches on the sides. Normal usage and the weather tend to cause the sand to slide down of the bunker, particularly if the sidewalls are relatively steep. This action may result in mixing of the sand with subsurface materials. One technique frequently used to prevent the mixing of the sand with substrate materials is to use a geotextile fabric blanket or mat as a bunker liner. In particular, a geotextile blanket or mat is laid in the pit forming the bunker and is stapled to the sidewalls about the perimeter of the pit. The edges of the blanket typically extend under the turf at the perimeter of the bunker.
While the use of such fabrics may impede mixing of the bunker sand with the substrate material and may facilitate drainage, the use of such geotextile blankets is not without its own problems. For example, the installation of such blankets or mats is somewhat expensive and requires a great deal of hand labor to install since they are typically laid in sections and anchored in place with numerous staples. Moreover, the fabric making up such blankets or mats is relatively smooth and when in place does not deter sand from sliding down the bunker's sidewall, particularly when subjected to heavy traffic and/or rainfall. That action may expose the blanket or mat, rendering the bunker unsightly. Even if not exposed, the portions of the blanket or mat located close to where the turf grass meets the edge of the bunker and where the layer of bunker sand is the thinnest, are susceptible to being pulled up and damaged during routine maintenance of the bunker. For example, the exposed portions of the blanket or mat may be snagged during manual or power raking of the bunker sand or on edging of the surrounding turf grass.
Other techniques have been used in the prior art to stabilize the sand within a bunker, such as the use of a layer of gravel or some other particulate material to line the pit forming the bunker, and with an adhesive or some other material sprayed onto the particulate material. See for example, U.S. Pat. No. 8,529,159 (Lemons).
Other prior art systems for lining a golf bunker are found in U.S. Pat. No. 4,960,345 (Hurley et al.); U.S. Pat. No. 5,746,546 (Hubbs et al.): U.S. Pat. No. 5,848,856 (Bohnhoff); U.S. Pat. No. 6,467,991 (Joyce et al.); U.S. Pat. No. 6,863,477 (Jenkins et al.); U.S. Pat. No. 7,207,747 (England); U.S. Pat. No. 7,344,340 (Carlson et al.); U.S. Pat. No. 7,699,562 (Clark); and U.S. 2004/0156679 (Jenkins).
As of the present time no prior art system exists for low cost installation and long term usage in a bunker to maintain the stability of the sand in the bunker, while enabling the safe and easy edging of the turf grass at the border of the bunker, yet which enables water to effectively drain from the bunker, and which is sufficiently flexible to readily absorb impact without damage. The subject invention addresses that need.
One aspect of this invention is a stabilized golf course bunker having a desired configuration. The bunker is configured to be covered with sand and comprises soil, a surrounding landscape and a barrier liner. The soil and surrounding landscape is in the desired configuration of the bunker having turf, an opening, a top edge, a keyway surrounding the opening at the top edge, an interior surface including sides and a floor formed by compacted soil, and a hinge point located between the key way and the sides. The sides have a downward sloping grade immediately adjacent the hinge point. The key way extends at an acute angle to the grade of the sides. The turf is located above the key way and extends to the hinge point. The barrier liner is formed by a curable semi-solid barrier material applied on the floor, the sides and up and over the top edge for a predetermined distance on the key way and under a portion of the turf surrounding the opening of the bunker. The barrier liner has a thickness at the key way which is greater than a thickness of the barrier liner at the sides. The barrier liner is configured to cure and thereafter be covered with bunker sand to complete the bunker, whereupon the barrier liner enables water to percolate therethrough to reduce water accumulation in the bunker and is sufficiently flexible to dampen or absorb impact when a golf ball hits the bunker.
In accordance with one preferred aspect of the stabilized golf course bunker of this invention the curable semi-solid barrier material comprises a mixture of a dry binding agent, lightweight aggregate and water.
In accordance with another preferred aspect of the stabilized golf course bunker of this invention the barrier liner includes an outer surface at the sides and floor and wherein the barrier liner additionally comprises a thin layer of finishing sand fixedly secured to the outer surface of the barrier liner at the sides and floor.
In accordance with another preferred aspect of the stabilized golf course bunker of this invention bunker sand is disposed over the thin layer of finishing sand.
In accordance with another preferred aspect of the stabilized golf course bunker of this invention the predetermined distance is approximately 4 to 6 inches.
In accordance with another preferred aspect of the stabilized golf course bunker of this invention the thickness of the barrier liner at the key way is in a range of ¾ to 1 inch.
In accordance with another preferred aspect of the stabilized golf course bunker of this invention the thickness of the barrier liner at the sides is in a range of ⅝ to ¾ inch.
In accordance with another preferred aspect of the stabilized golf course bunker of this invention the barrier liner additionally comprising an opening at the floor in fluid communication with a drain pipe.
In accordance with another preferred aspect of the stabilized golf course bunker of this invention the drain pipe is disposed in gravel.
Another aspect of this invention is method of stabilizing and lining a golf course bunker to be covered with sand. The method entails preparing soil of the golf course by forming the soil and surrounding landscape into a desired configuration of a bunker having an opening, a top edge, a lip surrounding the opening, a floor, sides and turf surrounding the opening. The sides have a downward sloping grade. The top edge and the lip surrounding the opening are graded to form a key way surrounding the opening. The key way has a grade extending outward and downward from the opening at an acute angle to the grade of said sides to form a hinge point therebetween. The key way extends underneath a portion of the turf surrounding the opening. The soil is compacted to produce a compacted soil surface. A barrier liner for the bunker is formed by applying a curable semi-solid barrier material on the compacted soil surface of the floor, on the sides, up and over the hinge point, and on the key way. The curable semi-solid material on the key way extends under a portion of the turf surrounding the opening for a predetermined distance outside the hinge point. The barrier liner has a thickness at the key way which is greater than a thickness of the barrier liner at the sides. The barrier liner is allowed to cure, whereupon the cured barrier liner is configured to be covered with sand and which when cured allows water to percolate therethrough to reduce water accumulation in the bunker and is sufficiently flexible to dampen or absorb impact when a golf ball hits the bunker.
In accordance with one preferred aspect of the method of this invention, the barrier liner is cured for 24 hours.
In accordance with another preferred aspect of the method of this invention the curable semi-solid barrier material comprises a mixture of a binding agent, lightweight aggregate and water.
In accordance with another preferred aspect of the method of this invention the thickness of the barrier liner at the key way is in the range of ¾ to 1 inch.
In accordance with another preferred aspect of the method of this invention the thickness of the barrier liner at the sides is in the range of ⅝ to ¾ inch.
In accordance with another preferred aspect of the method of this invention the barrier material is applied by hand.
In accordance with another preferred aspect of the method of this invention the barrier liner includes an outer surface and wherein the method additionally comprises fixedly securing a layer of finishing sand onto the outer surface of the barrier liner to form a finished outer surface for the barrier liner.
In accordance with another preferred aspect of the method of this invention the method additionally comprises applying bunker sand over the finished outer surface.
Referring now to the various figures of the drawing wherein like reference characters refer to like parts, there is shown in
The precursor material that is used to make the barrier liner 22 is set forth in detail in Table 1 and basically comprises a mixture of a dry binding agent, lightweight aggregate, and water. The resulting precursor material mixture is semi-solid so that it can be readily applied by hand or by machine application, e.g., spray application, and the allowed to cure.
The soil 24 is prepared by forming and compacting the soil and landscape in the configuration and contours of the pit 26 that is desired to stabilize the soil. In particular, as shown clearly in
A drainage trench 26D, having a chamfered or beveled entryway 26E is located at the bottom of the pit. A perforated 4″ diameter ADS perforated drain pipe 36 is disposed within the trench and surrounded by ⅜″ pea gravel 38. The drain pipe 36 serves to drain water, e.g., rain water, from the completed bunker by virtue of the barrier liner directing that water to the drain pipe, as will be described later.
Following the stabilization of the soil 42, as described above, the barrier liner precursor material is mixed to form a curable semi-solid mixture which is then applied by hand or by machine over the surface of the floor, 26A, sidewalls 26B, up and over the hinge point 26 and for a predetermined distance, e.g., 4 inches over the compacted soil at the key way 30. The curable semi-solid material is preferably applied in a thickness range of ⅝ to ¾ inch over the floor, sidewalls and hinge point. The curable semi-solid material that is applied over the key way 30 to form a flanged anchoring portion 22A is thicker, e.g., ¾ to 1 inch, than the thickness of the curable semi-solid material on the floor, sidewalls and hinge point. No curable semi-solid precursor material is applied over the trench holding the drain pipe in the pea gravel, so that there will be a passageway or opening 22B in the floor of the barrier liner communicating with pea gravel the trench 26D. Since the drain pipe is perforated its interior will be in fluid communication with the interstices between the particles of gravel 38
A layer of clean, dry bunker sand is then spread out or sprinkled over the surface of the curable semi-solid material of the barrier liner and then lightly hand troweled to bind the sand to the surface of the curable semi-solid material. Thus, when the curable semi-solid material cures the layer of clean, dry bunker sand is fixedly secured to the outer surface of the barrier liner. This provides a faux “sandy” appearance on the surface of the barrier liner. The semi-solid precursor material with the dry bunker sand thereon is allowed to cure for at least 24 hours, whereupon it becomes a solid self-supporting body, which as mentioned earlier is porous and somewhat flexible.
Regular bunker sand 28 is then applied over the barrier liner 22 and spread out. Then additional soil 32 is filled over the anchoring portion and key way 30 and that additional soil is compacted. Turf grass 34 is then placed over the compacted additional soil 32 so that the inner edge 34A of the turf grass 34 is located immediately adjacent the hinge point 26C, thereby completing the bunker.
As should be appreciated by those skilled in the art, the configuration of the cured barrier liner with the anchoring portion 22A located under the additional soil 34 and the turf grass 34 and with the acute, e.g., 45 degree, angle of the key way at the hinge point allows the hardened barrier liner 22 to anchor and reinforce the opening of the bunker. This action has the effect of reducing any chipping of the bunker by maintenance equipment and precluding the turf grass 34 from growing over the lip of the bunker and into the bunker. In addition, the sand finish on the barrier liner serves to help hold the bunker sand 28 in place. Moreover, in the event that the bunker sand 28 on the sloping sides slides downward, such as could occur in a bunker with steep sloped sides in a heavy rainstorm, the sand of the barrier liner will provide the appearance as if the bunker sand was still in place, thereby maintaining the aesthetics of the bunker until the bunker sand can be replaced on the sloping sides.
As should also be appreciated by those skilled in the art, with the barrier liner 22 in place, water entering the bunker 20 will drain from the bunker by virtue of the water being directed downward by the sloping sides of the barrier liner to the floor of the barrier liner and out through the opening or passageway 22B into the gravel 38 and from there into the drain pipe 36. In addition, some of the water within the bunker will percolate through the porous barrier liner into the underlying soil. Those combined actions result in a bunker that is very efficient in draining water from it.
The curable semi-solid material for forming the barrier liner can take various forms. The specifications for one preferred embodiment are set forth in Table 1 immediately below.
The ranges for the “practical amount” in the above table represents various expected weather conditions, with the midrange being for normal or typical weather conditions, with lesser amounts to be used in less adverse conditions, and greater amounts to be used in more adverse conditions. Moreover, the above formula provides what is believed to be the best and longest lasting composition. The binding agent serves as a filler and provides some flexibility for the barrier liner after it has cured. The aggregate type has been found to have the best size and bulk density to allow for the most desirable amount of hardness and pliability. The overall mixture when cured allows water to percolate through the barrier liner, making it well suited for long term use, while being sufficiently flexible to readily absorb ball impacts and other physical stresses. In addition, the portion of the barrier liner forming the hinge point will be resistant to damage during maintenance or edging of the turf grass at the bunker.
The binding agent is available from CTS Cement Manufacturing Corporation, 11065 Knott Ave, Suite A, Cypress, Calif. under the product identifier “Rapid Set Cement All”, Product codes: 120010055; 120012000; 120013000; 120020010; 120020025; and 120040055.
One type of pumice aggregate that can be used is that produced by Hess Pumice of Idaho which is amorphous aluminum silicate with a chemical analysis of silicon dioxide 76.2%, aluminum oxide 13.5%, ferric oxide 1.1%, sodium oxide 1.6%, potassium oxide 1.8%, calcium oxide 0.8%, magnesium oxide 0.05%, moisture, less than 1%.
It must be pointed out at this juncture that the precursor materials and method of forming the bunker 20 as described above are merely exemplary. Thus, other precursor materials and methods can be used to form a bunker in accordance with this invention. For example, before the curable semi-solid precursor material to form the barrier liner is applied, and after the soil of the bunker has been compacted a liquid adhesive polymer can be applied to bind the surface of the soil. An alternative curable semi-solid material can then be applied as described above to form the barrier liner 20. After the alternative semi-solid precursor barrier material is allowed to cure for at least 24 hours, another application of adhesive can be sprayed on to the prepared surface and a layer of clean, dry bunker sand applied to form the faux appearance. That alternative semi-solid material precursor material used to make the alternative barrier liner can be like that set forth in Table 2 below.
The ranges for the “practical amount” in the above table represents various expected weather conditions, with the midrange being for normal or typical weather conditions, with lesser amounts to be used in less adverse conditions, and greater amounts to be used in more adverse conditions. The plastic cement serves as a filler and provides flexibility of the barrier liner. The aggregate type provides good size and bulk density to allow for a desired amount of hardness and pliability. The overall precursor mixture, like that of the precursor material of Table 1, when cured allows water to percolate through the barrier liner.
The Dry Powdered adhesive which serves as a formulated soil stabilizer is available from Soil Tech, 6420 S. Cameron Drive, Suite 207, Las Vegas, Nev. and has the following characteristics:
(702)873-2023
Euclid Chemical, 19215 Redwood Road, Cleveland, Ohio, sells one type of a PSI Fiberstrand F, fibrillated polypropylene micro-fiber suitable for use in the present invention with the following characteristics: PSI FIBERSTRAND F is a fibrillated polypropylene micro-fiber to concrete reinforcement that complies with ASTM C 1116, Standard Specification for Fiber Reinforced Concrete and Shotcrete, and is specifically designed to help mitigate the formation of plastic shrinkage cracking in concrete. Typically used at a dosage rate of 1.5 lbs/yd3 (0.9 kg/m3), PSI FIBERSTRAND F micro-fibers have been shown to greatly reduce plastic shrinkage cracking when compared to plain concrete, PSI FIBERSTRAND F micro-fibers also comply with applicable portions of the International Code Council (ICC) Acceptance Criteria AC32 for synthetic fibers:
The plastic cement is available from Paragon Building Products, Inc., 2895 Hamner Avenue, Norco, Calif. 92860 and has the following characteristics:
The aggregate set forth in Table 2 is a pumice aggregate produced by Hess Pumice of Idaho and is amorphous aluminum silicate with a chemical analysis of silicon dioxide 76.2%, aluminum oxide 13.5%, ferric oxide 1.1%, sodium oxide 1.6%, potassium oxide 1.8%, calcium oxide 0.8%, magnesium oxide 0.05%, moisture, less than 1%.
Without further elaboration the foregoing will so fully illustrate our invention that others may, by applying current or future knowledge, adopt the same for use under various conditions of service.
This application is a continuation of application Ser. No. 15/723,621, filed on Oct. 3, 2017, entitled Golf Course Sand Bunker with Liner and Method of Making the Same, which in turn is a Continuation-In-Part of our prior application Ser. No. 14/989,315, filed on Jan. 6, 2016, entitled Golf Bunker Liner, which applications are assigned to the same assignee as this invention, and whose disclosures are incorporated by reference herein.
| Number | Date | Country | |
|---|---|---|---|
| Parent | 15723621 | Oct 2017 | US |
| Child | 16267769 | US |
| Number | Date | Country | |
|---|---|---|---|
| Parent | 14989315 | Jan 2016 | US |
| Child | 15723621 | US |
