Wet well apparatus with base form and installation method regarding same

A wet well apparatus, and installation method therefore, that includes a cylindrical body extending between a first end and a second end along a body axis defining an interior material holding volume and a base form closing the first end of the cylindrical body to define a base interior volume adjacent the interior material holding volume of the cylindrical body. The base form is configured to receive a flowable fill material in the base interior volume.

BACKGROUND

The present invention relates generally to wet wells for the containment of materials, such as water and/or other compositions therein, e.g., underground wet wells for water or waste.

Various configurations of wet wells are available and have been used in a variety of applications. For example, as shown inFIG. 1, fiberglass wet wells available from Xerxes Corp. (Minneapolis, Minn.) may be used in wastewater applications. Such applications may include the use of an underground fiberglass wastewater tank10, fluidly coupled to an underground wet well20by one or more different components34. For example, such connection components34may include a nozzle32associated with the tank10, a connector38, and a nozzle36associated with the wet well20. Further, as shown inFIG. 1, access to the tank10is provided via sump40, manway42, and cover44. A vent46is also provided for the tank10. Access to the interior of the wet well20is provided at ground surface via a cover structure50and a pump and conduit assembly54is configured for moving compositions out of the wet well20. Such compositions (e.g., water, wastewater, etc.) generally are provided into the wet well20from the tank10.

Yet further, the wet well20includes an anti-flotation flange28. The anti-flotation flange28is a full or partial disk that surrounds the base, and extends a few inches out from the base, beyond the normal “diameter” of ribs26. When properly buried, the flange28engages the surrounding burial material, and resists the tendency of the wet well20to “lift” or “float” under the influence of water, where the water-table or other conditions are such that the hole in which the wet well20is buried becomes filled or partially filled with water.

Wet wells are typically sunk vertically, or in a vertical alignment, into the ground14, and are used to contain water, or other liquids (e.g., waste). For example, the top of the wet well20may be installed level with a black top material16. Wet wells may, for example, be used in waste water facilities (e.g., such as shown inFIG. 1), in fire suppression systems, and/or in other fluid or water recovery systems (e.g., lift station and pump vault applications). A conventional wet well may be made in a variety of diameters and depths, and may be prepared in sections.

Early wet wells were prepared of wood and/or concrete materials. These materials, which typically have to be erected in situ, may present a variety of problems, most particularly involving leakage. Wet wells were subsequently prepared using steel, or steel and concrete. Steel, however, presented problems associated with corrosion. Given the nature of the contained liquids held in wet wells and other storage tanks (e.g., which include industrial wastes, organic wastes or sewage, and/or other various compositions), corrosion and subsequent leakage in such configurations present significant problems.

In comparison, fiberglass reinforced plastic (FRP) is relatively light, can be prepared at the plant and shipped to the site, and is corrosion resistant. It is similarly unlikely to develop leaks. As such, wet wells (e.g., underground wet wells) have been made using FRP to provide watertight and rustproof construction. For example, a FRP wet well may be made on a male mold or mandrel, and once cured, at least preliminarily, removed from the mandrel. The process of manufacturing on a mandrel of this type is typically referred to as a “spray up” process, where fibers and plastic resin are applied over a release agent to the mandrel, which lends the wet well its shape.

To provide a FRP wet well, such as wet well20shown inFIG. 1, with sufficient stiffness and strength to resist applied forces, and to resist deformation or buckling, ribs26as shown inFIG. 1are used. Such ribs26provide the molded product with hoop strength.

In a male molding process, the ribs26are provided by attaching a form to the molded wet well, and then laying fiber up and across the form, providing the connection between the rib and the well in the form of a secondary attachment. Processes for the manufacture of wet wells of this type are not substantially different from the processes of manufacturing underground storage tanks through the same method, such as those shown in U.S. Pat. No. 3,925,132, incorporated herein by reference.

FRP wet wells have also been prepared from plastic resin and chopped fiber that is sprayed onto the interior of a female mold. The resin is preferably applied with a catalyst, as it is sprayed together with the chopped fiber, to create a strong, relatively stiff, water impermeable and corrosion resistant wall. The mold itself includes ribs where necessary, so that they become part of the integral structure. Information on the method of comminuting the glass fibers, as well as application of the fibers and resin to the interior of the female mold, is set forth in U.S. Pat. No. 5,645,231, incorporated herein by reference. After preliminary curing, the female mold halves separate along a longitudinal axis and a full cure commences of the resin impregnating the fibrous body.

Typically in a wet well, pumps and the associated lines and valves are disposed either in the bottom of the wet well itself, or adjacent to the wet well in a separate installation. Particularly, where the pump and associated piping are to be disposed on the bottom of the wet well itself, it is necessary to provide a bottom structure that exhibits very small deflections when forces are applied thereto (e.g., upward forces on the bottom of the wet well, such as a result of water thereunder). Resistance to deflection is important even when no fluid is present in the wet well itself, such as in a situation where water surrounds the outside of the wet well (e.g., in a high-water table environment). Very limited deflection is tolerated, and excessive movement of the bottom in response to applied pressure could disrupt or break the pumps, piping and/or pumping controls, leading to pumping failure and/or leakage.

Various techniques have been used to install wet wells to provide resistance to such deflection. For example, wet wells have been installed on poured concrete structures (e.g., having a planar top surface) to prevent deflection. In other words, concrete structures, made thick enough, have been used in an attempt to provide resistance to applied forces and prevent significant deflection to the bottom of the wet well. However, the presence of cracks, or pores in the concrete, introduce leakage issues and allow fluid access to the bottom of the wet well. As such, concrete structures are not always successful to prevent deflection of the bottom of the wet well.

In other words, water can get between the concrete pad and the bottom of the wet well presenting the same applied pressure and deflection issues as if there were no concrete base provided. While one can resist the tendency of the bottom of the wet well to “float” off the base, by bolting the floor or the wet well to the concrete, the bolt holes provide leakage spots and the bolts represent points of corrosion, creating a variety of issues involving sealants. Further, others have attempted to connect the wet well bottom to the concrete slab using external anchors (e.g., extending from the bottom of the wet well) encompassed by the concrete of the pad when formed.

The concrete or the bottom of the wet well could be coated to provide a seal between the concrete and the wet well bottom in an attempt to resist leakage and fluid from reaching the bottom of the wet well. However, the applied pressures or force may frequently pop off or crack such coatings. Further, attempting to adhere the concrete base to the bottom of the wet well is both time consuming and expensive, and presents the prospect of introducing other poisons or toxins into the environment. In particular, it has proven difficult to provide a complete and lasting seal, between the concrete and the side walls, or bottom, of the wet well.

Still further, the thickness of the FRP bottom can be increased to prevent deflection thereof. For example, FRP laminates have become a preferred material because they combine significant stiffness and strength, and reduce or eliminate leakage, while also reducing the problem of corrosion. However, as the diameter of required wet wells increase, the amount of material necessary to provide FRP wet wells with sufficiently stiff bottoms that can support pumping apparatus and the like also increases, making such a solution cost prohibitive.

SUMMARY

One or more embodiments of the present invention provide wet wells (e.g., FRP wet wells), of variable diameter and height, that are resistant to applied forces, are corrosion resistant, and/or are resistant to leakage. Further, one or more embodiments of the present invention provide wet wells in an environment where the bottom of the wet well is substantially flat to support pumping apparatus, piping, controls and the like, without significant deflection, and/or without issues associated with leakage or corrosion.

One embodiment of a wet well apparatus according to the present invention includes a cylindrical body (e.g., of fiberglass reinforced plastic) extending between a first end and a second end along a body axis defining an interior material holding volume (i.e., wherein the cylindrical body at the first end thereof lies a first distance from the body axis). The wet well apparatus further includes a base form (e.g., an FRP base form) closing the first end of the cylindrical body to define a base interior volume adjacent the interior material holding volume of the cylindrical body. In one embodiment, the based form is configured to receive a flowable fill material (e.g., concrete) in the base interior volume and includes a base bottom (e.g., a base bottom that occupies an area greater than the cross-section area of the first end of the cylindrical body taken orthogonal to the body axis) and one or more base side walls extending from the base bottom (e.g., wherein at least one or more portions of the one or more base side walls of the base form are located a distance farther from the body axis than the first distance).

In one embodiment of the wet well apparatus, the base bottom may be planar. Further, the base form may include one or more upper surface portions extending inward toward the cylindrical body from the one or more base side walls.

In another embodiment, the one or more base side walls may be orthogonal to the base bottom. Further, for example, the one or more upper surface portions extending inward toward the cylindrical body from the one or more base side walls may be parallel to the base bottom.

Further, in another embodiment, the base form may include reinforcement material (e.g., rebar) positioned in the interior of the base form, one or more layers of material (e.g., fiberglass reinforced plastic) located at the first end of the cylindrical body between the base interior volume and the interior material holding volume of the cylindrical body, and/or one or more fill openings defined in the one or more layers of material located at the first end of the cylindrical body. In one or more embodiments, the fill openings are all defined in the one or more layers of material (e.g., fiberglass reinforced plastic) located at the first end of the cylindrical body between the base interior volume and the interior material holding volume of the cylindrical body.

In another embodiment, the base form forms a fluid-tight connection with the cylindrical body. Further, in still another embodiment, the base form may be filled with a flowable fill material (e.g., concrete, such as cement or polymer concrete).

In yet another embodiment, the base form of the wet well apparatus may be filled with a flowable fill material resulting in an upper surface portion of the fill material adjacent the interior material holding volume of the cylindrical body. Further, the upper surface portion of the fill material may be covered with one or more layers of material (e.g., fiberglass reinforced plastic), wherein the one or more layers of material may be secured at the first end of the cylindrical body.

One exemplary embodiment of a method of installing a wet well apparatus in a hole includes positioning a wet well apparatus in the hole. The wet well apparatus may include a cylindrical body (e.g., formed of fiberglass reinforced plastic) extending between a first end and a second end along a body axis to define an interior material holding volume, and a base form closing the first end of the cylindrical body, wherein the base form defines a base interior volume adjacent the interior material holding volume defined by the cylindrical body. The method further includes providing a flowable fill material (e.g., concrete) within the base interior volume defined by the base form (e.g., while the wet well apparatus is in the hole or prior to positioning the wet well apparatus in the hole).

In one embodiment of the method, the cylindrical body of the wet well apparatus at the first end thereof is a first distance from the body axis, and the base form includes a base bottom and one or more base side walls extending from the base bottom. At least one or more portions of the one or more base side walls of the base form are located a distance farther from the body axis than the first distance.

Further, in one or more embodiments of the method, the wet well apparatus may include one or more layers of material (e.g., fiberglass reinforced plastic) located at the first end of the cylindrical body between the base interior volume and the interior material holding volume of the cylindrical body, and one or more fill openings defined in the one or more layers of material located at the first end of the cylindrical body. In such an embodiment, for example, providing the flowable fill material within the base interior volume defined by the base form may include providing flowable fill material within the base interior volume defined by the base form through one or more of the fill openings.

In one or more embodiments of the method, reinforcement material may be positioned in the base interior volume defined by the base form (e.g., prior to positioning the wet well apparatus in the hole or after positioning the wet well apparatus in the hole).

In still another embodiment of the method, providing flowable fill material within the base interior volume defined by the base form results in an upper surface portion of the fill material adjacent the interior material holding volume defined by the cylindrical body. In such an embodiment, the installation method may further include positioning one or more layers of material (e.g., fiberglass reinforced plastic) at the first end of the cylindrical body to cover the upper surface portion of the fill material.

Another exemplary embodiment of a wet well apparatus according to the present invention includes a cylindrical body of fiberglass reinforced plastic extending between a first end and a second end along a body axis defining an interior material holding volume and a base form of fiberglass reinforced plastic forming a fluid-tight connection with the cylindrical body and closing the first end of the cylindrical body to define a base interior volume adjacent the interior material holding volume of the cylindrical body. The base form is configured to receive a flowable fill material in the base interior volume. Further, the base form may include a base bottom (e.g., wherein the base bottom occupies an area greater than the cross-section area of the first end of the cylindrical body taken orthogonal to the body axis) and one or more base side walls extending from the base bottom. Generally, a cross-section area of at least a portion of the base form taken orthogonal to the body axis is greater than a cross-section area at the first end of the cylindrical body taken orthogonal to the body axis.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS

In the following detailed description of illustrative embodiments of the invention, reference is made to the accompanying figures of the drawing which form a part hereof, and in which are shown, by way of illustration, specific embodiments in which the invention may be practiced. It is to be understood that other embodiments may be utilized and structural changes may be made without departing from the scope of the present invention. Unless stated otherwise herein, the figures of the drawing are rendered primarily for clarity and thus may not be drawn to scale.

As used herein, “a,” “an,” “the,” “at least one,” and “one or more” are used interchangeably. The term “and/or” (if used) means one or all of the listed elements or a combination of any two or more of the listed elements.

FIGS. 2A-2Cshow a perspective view, a top view, and a side view, respectively, of one exemplary embodiment of a wet well apparatus100according to the present invention.FIG. 2Dshows an exemplary detail cross-section view of a portion of the wet well apparatus100ofFIGS. 2A-2Cwith a base form130thereof filled with a flowable fill material150, e.g., concrete, according to the present invention.

Wet well apparatus (e.g., a vertically positioned storage tank generally installed upright and having a height greater than its diameter) described herein, such as wet well apparatus100, may be provided of fiberglass reinforced plastic (FRP). However, the wet well apparatus may be formed of other materials such as one or more metals (e.g., steel), one or more polymers (e.g., polyethylene, polyvinyl chloride, polypropylene, polyurethane, and the like), or any other suitable storage tank material.

In one or more embodiments, such wet well apparatus may be produced using either male or female molding techniques. However, any manufacturing methods may be used to provide a wet well apparatus having a base form in accordance with the present invention as would be known to one skilled in the art. The present invention is not limited to any particular manufacturing technique, although certain techniques may have benefits over others. For example, in one embodiment, the wet well apparatus provided herein may be female molded to provide integral ribs (e.g., ribs128of wet well apparatus100), to enhance strength and resist detachment of ribs from walls of the wet well apparatus under application of compressive forces.

The wet well apparatus100generally includes a body (e.g., a FRP cylindrical body110) extending along an axis116from a first end112to a second end114defining an interior material holding volume120. The wet well apparatus100is provided with a base form130used to provide a wet well apparatus100with resistance to deflection, as required, for instance, when pumping or similar apparatus is provided in the wet well apparatus100. For example, the base form130may be filled with a flowable fill material (e.g., such as concrete) to provide resistance to deflection.

The base form130and cylindrical body110of the wet well apparatus100may be manufactured as an integral unit or the components may be produced separately and assembled using suitable materials (e.g., fiberglass lapping materials) as known to one skilled in the art. The base form130and the cylindrical body110form a fluid-tight connection. This fluid-tight connection can be the result of the components being formed integrally, or connected in a fluid-tight manner (e.g., with fiberglass lapping materials and processes). Further, the base form130and cylindrical body110of the wet well apparatus may be installed (e.g., in a hole) as a single unit (e.g., already assembled at the manufacturer), or constructed on site (e.g., below or above grade) after the components are shipped to the installation site.

In one embodiment, a FRP wet well apparatus100of the present invention may be prepared from female-molded plastic resin and chopped fiber, that is sprayed onto the interior of a female mold. The resin may be applied with a catalyst, as it is sprayed together with the chopped fiber, to create a strong, relatively stiff, water impermeable wall.

For example, the mold itself may include structure for forming ribs128(e.g., circumferential ribs) between wall portions126(e.g., circumferential smooth portions) where necessary, so that they become part of an integral wet well structure. Information on the method of comminuting the glass fibers, as well as application of the fibers and resin to the interior of the female mold, is set forth in U.S. Pat. No. 5,645,231, incorporated herein by reference. After preliminary curing, the female mold halves separate along a longitudinal axis and a full cure commences of the resin impregnating the fibrous body. The result is a cylinder body110of the type generally shown inFIG. 2. Such a cylindrical body need not have smooth interior and exterior surfaces, but rather may have features associated therewith, such as the ribs128, flanges at one or more locations, etc.

Although various configurations are possible for the cylindrical body, the cylindrical body110of the wet well apparatus100shown inFIGS. 2A-2Dgenerally includes smooth wall portions126and ribs128. The cylindrical body110shown inFIGS. 2A-2Dlies at a first distance d1from the body axis116. In other words, the inner surface117of the cylindrical body110having a circular cross-section orthogonal to body axis116has a radius d1. In this embodiment, the first end112also lies a first distance d1from the body axis. The ribs128of the cylindrical body110extend a predetermined distance d2farther away from the body axis116than the exterior surface119of the wall portions126as shown inFIG. 2C.

The ribs128of the wet well apparatus110may be formed in various manners. For example, in a male-molded wet well apparatus, the ribs may be attached to the outer surface of the cylindrical body. Female molded FRP wet well apparatus may be produced in the same fashion as female molded underground storage tanks (e.g., such as that shown inFIG. 1). These wet well apparatus feature a monocock or unitary construction where the ribs are integral with the tank. Because, in a female mold process, the ribs are “molded in” to the well form, in either a closed or open design, accurate placement of the ribs is premised on the mold, and can be designed to mold tolerances.

In other words, wet well apparatus100is provided with circumferential ribs128. In one embodiment, such ribs128assist the filled base form130described herein in holding down the tank when installed within a hole. As discussed, if a female molding process is employed as described herein, ribs128are integral with the cylindrical wall portions of the cylindrical body110. Ribs128may be either “open” (not shown), that is, they follow the contour of the rib form itself, or they may be “closed”, providing a layer of FRP over the base of the rib and a smooth interior cylinder as is shown inFIG. 2D.

Unlike most male molded processes, the rib attachment point is eliminated when using a female molding process. In all but the smallest of diameters, female molding substantially reduces waste in manufacturing. A typical female molding process, as applied to underground storage tanks, is set forth in U.S. Pat. No. 5,720,404, incorporated herein by reference. While this reference focuses on a double-walled storage tank, the wet well apparatus of the present invention can be double-walled or single-walled, depending on application and applicable regulation.

Although the cylindrical body110is shown as a cylinder having the same diameter along its entire height, one will recognize that the diameter may change along the height. For example, the diameter may become smaller at the first end112to form a truncated partial dome-shaped end121terminating adjacent the based form130as shown by the optional dashed line configuration inFIG. 2C. In other words, the cylindrical body110of the wet well apparatus100could be configured like a truncated underground storage tank (e.g., a portion of a storage tank with the dome-shaped end cut off).

The cylindrical body110of the wet well apparatus100is terminated at the second end114by flange102. For example, flange102may be used to support a FRP top, a steel top provided with fixtures, a concrete block top, or communicate with a more complicated street box or other access structure. Further, for example, in one or more embodiments, the second end114provides access to the interior material holding volume120(e.g., which may allow concrete to be filled into the base interior volume132(e.g., seeFIG. 2D) defined by the base form130). Yet further, the second end114may be a closed end. Further, generally, for example, the second end114may be at or above the surface of the hole (e.g., hole190as shown inFIG. 2C) in which the wet well apparatus100is installed.

As described herein, the presence of water presents particular concerns with respect to deflection of the walls of the installed wet well apparatus. The walls of the wet well apparatus are typically featureless, other than access ways (e.g., ladders in deep wells, piping access, and the like) alarms and similar appurtenances. For example, such piping access is indicated generally by nozzles127inFIG. 2A. It is frequently the case that one or more pumps, pump-associated piping, control modules, level monitors and the like are associated with the bottom of the tank. To this end, significant deflection of the bottom is to be avoided to ensure that the pump and related apparatus is not damaged, or its operation interrupted.

A stable base with minimal deflection is accomplished according to the present invention with use of base form130which closes the first end112of the cylindrical body110of the wet well apparatus100(e.g., in a fluid-tight manner) and defines a base interior volume132adjacent the interior material holding volume120of the cylindrical body110. As illustrated inFIGS. 2A-2D, the cylindrical body110terminates in the base form130that can be filled with a flowable material150(e.g., concrete as shown inFIG. 2D). As used in this context, the term “adjacent” does not only necessarily refer to the volumes being directly adjacent (e.g., such that air in one is in contact with air in the other), but may refer to the volumes being separated by one or more layers of material, such as in the wet well apparatus shown inFIG. 4.

The base form130is configured to receive a flowable fill material150(e.g., concrete) in the base interior volume132and includes a base bottom140and one or more base side walls144extending from the base bottom140. In one or more embodiments, at least one or more portions of the base side walls144of the base form130are located a distance farther from the body axis116than the first end of the cylindrical body110(e.g., farther than first distance d1). In at least one embodiment all the side walls are located a distance farther from the body axis116than the first end of the cylindrical body110(e.g., the square type base form shown inFIG. 2).

In one embodiment of the wet well apparatus100, the base bottom140may be planar and occupy an area greater than the cross-section of the cylindrical body110at the first end112thereof orthogonal to the body axis116. Further, the base form130may include one or more upper surface portions146extending inward toward the cylindrical body110from the one or more base side walls144.

As shown inFIG. 2A, the base form130takes the form of a box (e.g., the cross-section of the base form130orthogonal to the body axis116is a square) with four base side walls144being orthogonal to the base bottom140. Each of the four base side walls144is located at a distance farther from the body axis116than the first end114of the cylindrical body. Further, the upper surface portion(s)146extending inward toward the cylindrical body110from the four base side walls144are generally parallel to the base bottom140. As shown inFIG. 2D, the distance from the side walls144to the body axis116is at least as great as the distance from the body axis116to the farthest portion of the rib128.

However, the base form130may be configured in various manners. For example, the base form may take the form of a cylinder. For example, the cross-section taken orthogonal to the body axis116may take the form of a circle with the base bottom being a circle (see, for example, the optional dashed line cylindrical configuration147inFIG. 2A). Further, for example, the base form may be any rectangular shape (e.g., a square), or have a cross-section having any polygonal shape (e.g., multi-sided). Further, for example, the base form130may take the form of a truncated cone with the smaller diameter of the truncated cone being adjacent the first end112. Yet further, for example, the base form130may take the faun of a truncated sphere portion (e.g., a truncated dome structure), with the smaller diameter of the truncated sphere being adjacent the first end112. The present invention is not limited to the particular shape of base forms described herein. However, certain base forms may be more advantageous than others. For example, a square box type base form may have certain shipping advantages.

Further, for example, the side walls144as shown inFIG. 2extend orthogonal from the planar base bottom140at the edges thereof. However, such side walls144may extend from other portions of the base bottom140. For example, the side walls may extend orthogonally (e.g., parallel to body axis) at a location inward from such edges leaving an additional flange at the edge. Various locations of the side walls may be suitable.

Yet further, for example, the side walls144do not need to extend orthogonally from the planar base bottom140. However, the sides walls144may extend at different angles relative to the planar base bottom140. For example, the side walls may extend at an angle back to the cylindrical body110forming a tapered box. Various angles for the side walls may be suitable.

As shown inFIG. 2D, the base form130may include reinforcement material152(e.g., rebar) positioned in the base interior volume132of the base form130. Fill material150(e.g., concrete) is flowed into the base form130to provide a non-deflecting bottom140. The fill material may be any suitable material that provides adequate non-deflecting properties. Generally, the fill material is a flowable fill material that is able to flow into various spaces of the base form130(e.g., flow into corners of a box type base form with or without assistance). The present invention is, however, not limited to the use of a particular type of flowable fill material150. For example, various materials such as concrete, e.g., polymer concrete, cement, etc., and flowable materials like concrete may be used. In one or more embodiments, the flowable fill material150may be provided in the base form130at the factory or may be provided in the base form130when the wet well apparatus100is above or below grade at the site of installation.

Also, as shown inFIG. 2D, at least in one embodiment, the base form130is secured to the cylindrical body110by fiberglass lay-up materials (e.g., resulting in overlay160) adhering to an exterior surface172at the first end112of the cylindrical body110and an exterior surface174of the base form130adjacent to the first end112of the cylindrical body110(e.g., an exterior surface174of the upper surface portion146).

Yet further, as shown inFIG. 2D, the flowable fill material may be shaped at the first end112of the cylindrical body110. For example, the flowable fill material may be applied to form an optional taper180from cylindrical body110to an upper planar surface182of the fill material150. For example, a 45 degree angle may be formed to prevent material in interior material holding volume120from gathering in the corners of the wet well apparatus100.

Various mounting apparatus199(see, e.g.,FIG. 2D) may be provided (e.g., mounted, embedded, etc.) at the bottom of the wet well apparatus100. For example, such mounting apparatus199may be fasteners, stud bolts, plates, anchors, openings for mounting items, or any other mounting apparatus used to mount items in the wet well apparatus100. For example, such mounting apparatus may be used to mount controls, pumps, piping, plumbing, or any other apparatus that is used within a wet well. For example, such mounting apparatus199, may be embedded (e.g., fully or partly) in the flowable fill material when it is provided in the base form130(e.g., at the factory or on site). For example, a stainless steel plate with stud bolts may be partly embedded for use in mounting a pump. Still further, for example, such mounting apparatus199may be provided as part of or mounted to the layers of material provided at the first end of the112of the wet well apparatus100between the interior material holding volume120and base interior volume132. For example, although not shown, such mounting apparatus199may be provided as part of layers of material186described with reference toFIG. 3, or may be provided as part of upper surface portions246described with reference toFIG. 4C.

FIG. 3shows an alternate exemplary detail cross-section view of a portion of the wet well apparatus ofFIGS. 2A-2Cwith the base form130thereof filled with a flowable fill material150, e.g., concrete, according to the present invention. As shown therein, the base form130of the wet well apparatus100may be filled with the flowable fill material150resulting in an upper surface portion184of the fill material150adjacent the interior material holding volume120defined by the cylindrical body110. The upper surface portion184of the fill material150may be covered with one or more layers of material186(e.g., one or more FRP layers). For example, at least in one embodiment, the one or more layers of material186may be secured to the interior surface117at the first end112of the cylindrical body110by fiberglass lay-up materials188.

FIGS. 4A-4Bshow a perspective view and a top view, respectively, of another exemplary embodiment of a wet well apparatus200according to the present invention. The wet well apparatus200is substantially similar to the wet well apparatus100, except that wet well apparatus200includes a base form230that can be filled with flowable fill material (e.g., concrete) through one or more fill openings (e.g., fill openings240,242).FIG. 4Cshows an exemplary detail cross-section view of a portion of the wet well apparatus200ofFIGS. 4A-4Bwith the base form230thereof filled with a flowable fill material250, e.g., concrete.

As shown inFIGS. 4A-4C, base faun230closes the first end212of the cylindrical body210of the wet well apparatus200and defines a base interior volume232adjacent the interior material holding volume220defined by the cylindrical body210. The base form230is configured to receive a flowable fill material250(e.g., concrete) in the base interior volume232and includes a base bottom241and one or more base side walls244extending from the base bottom241. Further, the base faun230includes one or more upper surface portions246(e.g., such surface portions extending inward toward the cylindrical body210from the one or more base side walls244). One or more fill openings240,242may be defined in the one or more upper surface portions246of the base form230.

In one or more embodiments, such as shown inFIG. 4C, a single upper surface246is formed integrally with the side walls244of the base form230. As such, the base form230forms a closed box with only the fill openings240,242providing access to the base interior volume232. In this manner, the base form230can be secured to an interior surface217at the first end212of the cylindrical body210between the base interior volume232and the interior material holding volume220defined by the cylindrical body210. For example, the upper surface portion246may be secured to the interior surface217at the first end212of the cylindrical body210by fiberglass lay-up materials to form an overlay298. Likewise, the upper surface portion246may be secured to the exterior surface219at the first end212of the cylindrical body210by fiberglass lay-up materials to form an overlay296.

Further, the base form230may include reinforcement material252(e.g., rebar) positioned in the interior volume232of the base form230. For example, such reinforcement material may be positioned in the base form230prior to enclosing the volume defined thereby.

In the alternative, rather than a single surface portion246being formed integrally with the side walls244, a construction similar to that described with reference toFIG. 3may be used. For example, one or more layers (e.g., a formed FRP disc or FRP circular element) may be secured to an interior surface217at the first end212of the cylindrical body210between the base interior volume232and the interior material holding volume220defined by the cylindrical body210.

In other words, wet well apparatus200may be similar to the apparatus shown inFIG. 3. However, inFIG. 3, the layer(s)186are secured after the fill material150is flowed into the base form130. Contrary toFIG. 3, the wet well apparatus200provides an upper surface portion246within the interior of the cylindrical body210prior to flowing fill material250into base interior volume232. With the upper surface portion246within the interior of the cylindrical body210, the fill material250can be provided through one or more of fill openings240,242.

One skilled in the art will recognize that the fill openings240,242may be formed in any suitable location that provides access to the base interior volume232defined by base form230. However, it is beneficial to have all the defined fill openings only accessible within the interior of the cylindrical body210of the wet well apparatus200such as shown by fill openings242, as opposed to those outside of the cylindrical body210. In such a manner, for example, in one or more embodiments, if all the fill openings242are in the interior, the cylindrical body210acts as a shield to protect workers in the hole (e.g., when the base form230is filled with flowable file material250during on-site installation below grade). Further, for example, the openings242do not need to be sealed if in the interior as they are within a sealed and fluid-tight container (e.g., the base form and cylindrical body are formed in a fluid-tight connection). Fill openings240are shown in dashed form as they would typically not be used due to the advantages of using only interior fill openings242.

One or more exemplary installation methods shall be briefly described with reference to theFIGS. 2-4. In one or more embodiments, base form130may be made separately from cylindrical body110. The two parts may then be secured together using fiberglass lay-up materials (e.g., such as shown inFIG. 2D) and according to standard lay-up processing. In one or more other embodiments, base form130may be provided separately from the cylindrical body110, and situated at the bottom of the opening or hole190in the ground for the wet well apparatus100. The lay-up work may be done in the hole if the opening is of sufficient diameter to permit work therein. However, the wet well apparatus100to be installed may be provided in any suitable manner.

With a hole190provided in which the wet well apparatus100is to be installed, the wet well apparatus100is set or positioned into the hole190. The installation method then includes providing a flowable fill material150(e.g., concrete) within the base interior volume132defined by the base form130while the wet well apparatus100is in the hole190. The cylindrical body110, or the walls thereof, at least in one embodiment, act as a shield to protect workers in the hole (e.g., when the base form130is filled with flowable file material150during on-site installation below grade, when additional apparatus is installed, etc.). In other words, for example, the present invention may eliminate the need for additional shield apparatus typically necessary during installation of a tank in a hole190. However, the fill material may be provided into the base form130at the factory or above grade on-site, and then the filled wet well apparatus moved into the hole at the installation site.

As shown inFIG. 2D, the box-like base form130may be filled to the level of the first end112with concrete150. However, in one or more embodiments, it may be filled further up the cylindrical body110. The concrete may be optionally reinforced with rebar152or other reinforcing materials. Given the fluid-tight containment provided by the combination of cylindrical body110and the base form130, the concrete150may be left open, without providing a danger of pores or leakage.

In an alternate embodiment, it may be desirable to provide an FRP floor on top of the concrete150such as illustrated inFIG. 3, for instance, to avoid filling and cracking of the concrete, or attack of the concrete by the materials to be held in the wet well apparatus100. For example, as illustrated inFIG. 3, a round section or disk of one or more FRP layers186is prepared to the desired dimension and lowered into the interior of the well apparatus100. Once atop the upper surface184of the concrete150, the one or more FRP layers186(e.g., a single piece, impermeable FRP element) may be sealed to the cylindrical body110on the interior thereof, such as with use of conventional lay-up processes. This generally creates overlay188, roughly opposite the exterior overlay160. For example, at least in one embodiment, the overlays188and160combine to seal the concrete filled base form to the exterior and interior of the cylindrical body110.

Alternatively, a prepared wet well apparatus200can be provided according to the embodiment illustrated inFIG. 4A-4C. The base form230may be a continuous single piece construction exhibiting a top246that is integral and continuous with sides244and the base bottom240of the base form.

The base form230may be secured to the cylindrical body210by overlay296(i.e., exterior) and/or overlay298(i.e., interior). As shown in the embodiment described with reference toFIG. 4, rebar252or other reinforcement material is “pre-positioned” within the base interior volume232, for instance, by the simple expedient of using a frame that distances the rebar an adequate amount from top and bottom of the base frame230, or by any other suitable manner.

Preferably, only fill openings242(e.g., pour holes) in the interior of the cylindrical body210are provided for introduction of fill material250(e.g., concrete). For example, the concrete fills the base form230and cures therein. Thereafter, the fill openings242may be sealed (although not necessarily). For example, FRP lay-up materials may be used, a mesh layer may assist in the lay-up process, or any other suitable manner of sealing the openings may be performed.

The complete disclosure of the patents, patent documents, and publications cited in the Background, the Summary, the Detailed Description of Exemplary Embodiments, and elsewhere herein are incorporated by reference in their entirety as if each were individually incorporated. Exemplary embodiments of the present invention are described above. Those skilled in the art will recognize that many embodiments are possible within the scope of the invention. Other variations, modifications, and combinations of the various components and methods described herein can certainly be made and still fall within the scope of the invention. Thus, the invention is limited only by the following claims and equivalents thereto.