CA2752766A1

CA2752766A1 - Anti-flotation anchor for underground tanks

Info

Publication number: CA2752766A1
Application number: CA 2752766
Authority: CA
Inventors: Richard R. A. Aujesky
Original assignee: Individual
Current assignee: Individual
Priority date: 2011-09-16
Filing date: 2011-09-16
Publication date: 2013-03-16

Description

ANTI-FLOTATION ANCHOR FOR UNDERGROUND TANKS
Field of the Invention The invention relates primarily to an anchor that prevents the unwanted upward movement of a buried tank due to buoyancy forces which are present during high water table conditions.

Background of the Invention A tank buried underground displaces the same volume of earth as the tank itself, effectively creating a void in the earth equivalent to the tank volume. During high water table conditions, especially when the tank is empty, the tank acts as a barrier preventing the groundwater from filling the void. This results in the tank being submerged underwater with buoyancy forces acting upon it. If these buoyancy forces are not counteracted, the tank may float to the surface.

One solution to counteract these buoyancy forces is to construct the tank heavy enough so that the weight of the tank will be sufficient to counteract the buoyancy forces. But this creates a tank that is both heavy and dangerous to install.

Another solution is to create a lighter tank, which is easier and safer to install, and with the aid of tethers, anchor it to a sufficiently heavy mass thusly creating the necessary weight. The mass may be bead rock, or an adequate concrete slab among others.
However, depending on location, bead rock may not be practically available, and a concrete slab represents a costly and time-consuming alternative.

Another solution is to generate the necessary weight by attaching said tethers to readymade curbs. This caries the benefit of being faster to install but due to weight requirements, still represents safety risks.

Our solution is to utilize tethers and hollow bucket-like curbs with tether attachment points with each curb light enough to allow ordinary equipment or perhaps one or two men to place and install, and upon filling the bucket-like curb with backfill material produce the necessary weight to counteract the buoyancy forces.

Brief Description of the Drawings Figure 1: An isometric representation of, from bottom to top, anchor body, hooks.

Figure 2: An isometric section view of, from bottom to top, re-enforcing structure, anchor body, hooks attached to re-enforcing structure.

Figure 3: An isometric representation of anchors in use retaining a cylindrical tank, from bottom to top, anchor body, anchor hook, strap hook ring, strap, underground tank.
Figure 4: An isometric representation of stacked anchors, from bottom to top, anchor body, anchor body, hook.

Description of the Invention Figure 1 shows one embodiment of an anchor having an upward-facing cavity and at least one strap attachment point. The upward facing, and outward flaring cavity perimeter wall (1) together with the base wall (2) define a volume that when filled with material of given density create an anchor having a substantially greater combined

2 weight then the material weight used to manufacture the anchor itself.
Further, the upward and outward flaring walls (1) together with stacking stops (3) allow multiple anchors to stack on top of each other as shown in figure 4, without resting on and damaging the strap hooks (4). As illustrated in figure 2, the upward and outward flaring walls (1) and base wall (2) are manufactured from concrete but may be manufactured using fiber re-enforced concrete, fiber reinforced plastic, plastic, steel et cetera. For added strength, a steel re-bar (5) enforcing system is used to which stainless steel anchor hooks (4) are attached. But the re-enforcing system may be manufactured using other materials such as other metals, meshes, fibers, fiber re-enforced plastic et cetera.
Figure 3 illustrates the anchor(s) installed and retaining a tank (20) by connecting anchors placed on opposite sides of the tank (20) and straps (11) having strap hook rings (10) attached to each end placed over the tank (20). Each strap hook ring (10) end is then hooked onto the anchor hook (4) on opposite sides of the tank (20). By filling each properly-sized anchor with a predetermined amount of material, the tank becomes adequately anchored against flotation forces.

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