US20140208687A1 - Freeform pool - Google Patents

Abstract

A swimming pool consisting of a plurality of panels that withstands water pressure in both a concave and convex configuration to create any freeform shape or size. Each panel consists of an adhered wall of skinning of metal or plastic over expanded polystyrene or expanded urethane foam. The density of the foam is adjusted as necessary to increase the strength of the wall based on static loading of water when swimming pool is assembled as a whole and fully filled with water.

Description

CROSS-REFERENCE TO RELATED APPLICATION
• The present application relates to and claims priority to U.S. Provisional Application Ser. No. 61/756,722, filed Jan. 25, 2013.
BACKGROUND OF THE INVENTION
• The present invention relates to swimming pools, and more particularly free form swimming pools.
• Free form swimming pools require particular structural detail to account for the stress imparted to the curved walls when the pool is filled with water. Without appropriate bracing, convex walls will shift, buckle and ultimately fail due to the distribution of the static loading.
SUMMARY OF THE INVENTION
• A swimming pool consisting of a plurality of panels that withstands water pressure in both a concave and convex configuration to create any freeform shape or size. Each panel consists of an adhered wall of skinning of metal or plastic over expanded polystyrene or expanded urethane foam. The density of the foam is adjusted as necessary to increase the strength of the wall based on static loading of water when swimming pool is assembled as a whole and fully filled with water. Panels with water pressure in the convex direction have adjusters attached at the bottom to allow for vertical movement during installation and horizontal tabs (anchor plate) locking into a concrete foundation as the pool is assembled. The swimming pool can be installed fully above ground, semi-in-ground or fully in-ground.
• According to one aspect, an embodiment of the present invention comprises a section of a swimming pool wall comprising: a panel, having a first and a second surface a top and a bottom and at least one anchor extending radially outward from at least one surface of the panel, and dimensioned to, when in use, lock the panel into a concrete foundation.
• According to another aspect, a section comprising at least one adjuster extending downward from the bottom of the panel, adapted to permit vertical movement during the panel's installation.
• According to another aspect a section comprising at least one a-frame support attached to the panel.
• According to another aspect, the A-frame support comprises a post, having a top and a bottom, attached to and extending along the second surface of the panel; a crossmember, extending radially outward from second surface of the panel and attached to the bottom of the post, wherein the crossmember locks into the concrete foundation when in use; a leg, having a first end a second end, wherein the first end is attached to the post and the second end is attached to the crossmember.
• According to another aspect, the anchor is a tab.
• According to another aspect, the anchor is a plate.
• According to another aspect, the panel comprises a skinning over a foam interior.
• According to another aspect, the panel is bowed.
• According to another aspect the curve of the panel is bowed outward, relative to the interior of the pool when in use.
• According to another aspect, the anchor extends radially outward from the bottom of the panel.
BRIEF DESCRIPTION OF THE DRAWINGS
• FIG. 1 is a perspective view/photograph of a swimming pool including a plurality of panels in accordance with an embodiment of the present invention;
• FIG. 2 is a rear perspective view of a pool panel of the pool assembly of FIG. 1 in accordance with an embodiment of the present invention;
• FIG. 3 is a front perspective of a pool panel of the pool assembly of FIG. 1 in accordance with an embodiment of the present invention;
• FIG. 4A is a diagram/perspective view of a pool assembly including a plurality of panels in accordance with an embodiment of the present invention;
• FIG. 4B is a diagram/perspective view of A-frame supports of the pool assembly of FIG. 4A in accordance with an embodiment of the present invention;
• FIG. 4C is a diagram/illustration of a panel joint of the pool assembly of FIG. 4A in accordance with an embodiment of the present invention;
• FIG. 5 is a diagram/illustration of loads and boundary conditions of a pool assembly in accordance with an embodiment of the present invention;
• FIG. 6 is a deflection plot illustration of a pool assembly from a front perspective in accordance with an embodiment of the present invention;
• FIG. 7 is a deflection plot illustration of a pool assembly from a rear perspective in accordance with an embodiment of the present invention;
• FIG. 8 is a von Mises stress plot illustration of a pool assembly in accordance with an embodiment of the present invention;
• FIG. 9 is a von Mises stress plot illustration of a polystyrene foam layer of a pool assembly in accordance with an embodiment of the present invention;
• FIG. 10A is a von Mises stress plot illustration of aluminum panels of a pool assembly in accordance with an embodiment of the present invention;
• FIG. 10B is a magnified view of a “cutout” aluminum panel portion as shown in FIG. 10A in accordance with an embodiment of the present invention;
• FIG. 11 is a von Mises stress plot illustration of aluminum panels of a pool assembly in accordance with an embodiment of the present invention;
• FIG. 12A is a von Mises stress plot illustration of aluminum splines of a pool assembly in accordance with an embodiment of the present invention;
• FIG. 12B is a magnified view of a “cutout” aluminum spline as shown in FIG. 12A in accordance with an embodiment of the present invention;
• FIG. 12C a magnified view of the aluminum spline as shown in FIG. 12B in accordance with an embodiment of the present invention;
• FIG. 13A is a von Mises stress plot illustration of aluminum splines of a pool assembly in accordance with an embodiment of the present invention;
• FIG. 13B is a magnified view of a “cutout” aluminum spline as shown in FIG. 13A in accordance with an embodiment of the present invention;
• FIG. 14A is a von Mises stress Plot illustration of aluminum supports of a pool assembly in accordance with an embodiment of the present invention;
• FIG. 14B is a magnified view of a “cutout” aluminum support as shown in FIG. 14A in accordance with an embodiment of the present invention;
• FIG. 15 is a von Mises stress plot illustration of a polystyrene foam layer of a pool assembly in accordance with an embodiment of the present invention;
• FIG. 16 is a von Mises stress plot illustration of a pool assembly in accordance with an embodiment of the present invention.
DETAILED DESCRIPTION
• Referring to the drawings wherein like reference numerals refer to like parts throughout, there is seen in FIG. 1 a swimming pool 10 comprising a plurality of panels 12, most of which are either concave or convex. Each panel comprises a wall of skinning 14 of plastic or metal formed over expanded polystyrene or expanded urethane foam 16. The density of the foam is selected to increase the strength of the wall based on the static load conditions of water when the pool is fully assembled (thus, dependant on overall size volume of the pool). Those panels 12 with water pressure being asserted in the convex direction have adjusters 18 attached at their bottom to permit vertical movement during installation, horizontal tabs 20 (or an anchor plate) locking into a concrete foundation as the pool is assembled, and A-frame supports 22. Pool 10 can be a fully above ground pool, a partially above ground pool, or an entirely in-ground pool.
• FIG. 4A shows a diagram of the assembled swimming pool, including pool wall panels. FIG. 4B shows a diagram of the A-frame support, and FIG. 4C shows a diagram of the panel joint when in use.
• FIGS. 4-16 show a structural analysis of a free-form 18′×32′ pool constructed from an embodiment of the present invention, to demonstrate the structural integrity of such a pool. To summarize the results, the maximum deflection in the assembly is 0.057″, and the maximum stress is 8,259 psi, which occurs at the aluminum sheet metal. The maximum stress is still well below the tensile yield strength of the pool. The resulting factor of safety for the aluminum A-frame supports is 3.03, the aluminum spline is 3.78, and the polystyrene foam is 20. These figures demonstrate that the embodiment of the invention is safe under the fully filled water condition.
• The following assumptions were made in the analysis: (1) linear material properties of aluminum and polystyrene are assumed for the purpose of the analysis; (2) 18′×32′ Lagoon Swimming Pool is considered filled with water; and (3) liquid specific gravity is assumed to be equal to water density. All units are English units. Material properties were simulated with the properties shown in Table 1:

• 	TABLE 1
  		Young's	Poisson's	Tensile Yield
  	Material	Modulus (psi)	Ratio	Strength (psi)
  	Aluminum	10E+6	0.33	21029.73
  	Polystyrene	5.221E+5	0.34	6671.7-8702.3

• FIG. 5 shows the loads and boundary conditions of the interior surface of the pool. The graph demonstrates that the liquid column applied on the floor was simulated to be 1.8 psi, and a variable pressure was simulated on the pool faces, ranging from 0.1044 to 1.4232 psi.
• FIGS. 6 and 7 are deflection plots of the pool from opposite sides. Both deflection plots demonstrate that the maximum deflection is 0.057 inches at the apex of the pool wall's convex curves.
• FIGS. 8-16 show von-Mises stress plots (in psi) of various components of the structure of the pool assembly. FIG. 9, shows the stress of the polystyrene layer is 328 psi. Assuming a tensile yield strength of 6671.7 psi results in a factor of safety of 20 for the polystyrene layer per the equation shown in Table 2 below.

• TABLE 2
  $\mathrm{SAFTEY}\mathrm{FACTOR}=\frac{\mathrm{YIELD}\mathrm{STRENGTH}}{\mathrm{WORKING}\mathrm{STRESS}}=\frac{6671.7}{328}=20$

• FIGS. 10A-B shows the stress of a concave aluminum panel is 8259 psi. Assuming the tensile yield strength is 21029.73 results in a factor of 2.55 for the concave aluminum panel per the equation shown in Table 3 below.

• TABLE 3
  $\mathrm{SAFTEY}\mathrm{FACTOR}=\frac{\mathrm{YIELD}\mathrm{STRENGTH}}{\mathrm{WORKING}\mathrm{STRESS}}=\frac{21029.73}{8259}=2.55$

• Similarly, FIG. 11 shows the stress of a convex aluminum panel is 5697 psi, resulting in a factor of safety of 3.69. FIGS. 12A-C and 13A-B show the maximum stresses of an aluminum spline are 5556 psi and 4509 psi at the highest points, yielding a stress factor 3.78 at the spline per the equation shown in Table 4 below.

• TABLE 4
  $\mathrm{SAFTEY}\mathrm{FACTOR}=\frac{\mathrm{YIELD}\mathrm{STRENGTH}}{\mathrm{WORKING}\mathrm{STRESS}}=\frac{21029.73}{5556}=3.78$

• FIGS. 14A-B show the stress of the aluminum A-frame supports are 6929 psi and 3981 at the highest points, resulting in a safety factor of 3.03 per the equation shown in Table 5 below.

• TABLE 5
  $\mathrm{SAFTEY}\mathrm{FACTOR}=\frac{\mathrm{YIELD}\mathrm{STRENGTH}}{\mathrm{WORKING}\mathrm{STRESS}}=\frac{21029.73}{6929}=3.03$

• FIG. 15 shows a von Mises stress plot, for all stresses on the polystyrene foam layer rising above 6672 psi, demonstrating that a no point does the stress rise above 6672. Similarly, FIG. 16 shows a von Mises stress plot, for all stresses on the pool assembly rising above 21029, demonstrating that no stresses rise above 21029 psi.

Claims (10)

What is claimed is:

1. A section of a swimming pool wall, comprising:

a panel, having a first and a second surface, a top and a bottom; and

at least one anchor extending radially outward from at least one surface of the panel, and dimensioned to, when in use, lock the panel into a concrete foundation.

2. The section of claim 1, further comprising:

at least one adjuster extending downward from the bottom of the panel, adapted to permit vertical movement during the panel's installation;

3. The section of claim 1, further comprising:

at least one a-frame support attached to the panel.

4. The section of claim 3, wherein the a-frame support comprises:

a post, having a top and a bottom, attached to and extending along the second surface of the panel;

a crossmember, extending radially outward from second surface of the panel and attached to the bottom of the post, wherein the crossmember locks into the concrete foundation when in use;

a leg, having a first end a second end, wherein the first end is attached to the post and the second end is attached to the crossmember.

5. The section of claim 1, wherein the anchor is a tab.

6. The section of claim 1, wherein the anchor is a plate.

7. The section of claim 1, wherein the panel comprises a skinning over a foam interior.

8. The section of claim 1, wherein the panel is bowed.

9. The section of claim 8, wherein the curve of the panel is bowed outward, relative to the interior of the pool when in use.

10. The section of claim 1, wherein the anchor extends radially outward from the bottom of the panel.

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