GREEN RECYCLED MATERIAL COMPONENT WET WELL
A wet well design that utilizes recycled material in sectional components to construct wet wells on site is disclosed. Traditional wet well components are made of pre-cast concrete. Green Recycled Material Component Wet Well components are constructed using recycled plastic, recycled steel and recycled Styrofoam. The method described herein for constructing the components and assembling the wet well on site addresses several logistical problems associated with the pre-cast concrete design including reducing project start to completion time, delivery costs, large crane rental costs and power line relocation costs. This design also enables construction of oblong wet wells in medians and other restricted areas as components can be straight or curved sections. Finally, this design eliminates the shifting of traditional cement well components due to uplift from underground water pressure through the use of a new anchoring system. Shifting can result in groundwater intrusion into the well.
1. Field of the Invention
The present invention relates to waste water wet wells and more specifically to a design for the construction of wet wells using recycled materials and a mechanical anchoring system.
2. Description of the Related Art
In the construction of waste water wet wells, pre-cast concrete cylinders and concrete slabs are the traditional components.
The design of the Green Recycled Material Component Wet Well introduces an environmental friendly method of constructing wet wells through the use of recycled discarded materials in the construction of waste water wet wells that are primarily constructed underground. The materials include:
-
- a) all plastic discarded from plastic products (recycled plastic),
- b) discarded Styrofoam (polystyrene plastic) from packaging, cups, plates and other uses,
- c) crushed auto body and truck steel scraps in the form of welded wire mesh.
The Green Recycled Material Component Wet Well is greener than green because it recycles recyclables. Up to 80% of the material used to construct the wet wells comes from recycled products. Since the wet wells are underground and out of sight, materials that would be objectionable to architects for use on above ground projects due to color and surface finish are able to be used in this design. At the end of the useful life of the wet well, 80% of the recycled material is once again recyclable resulting in minimum environmental impact from disposal.
The Green Recycled Material Component Wet Well saves energy. Due to the low density of the materials used, energy consumed in the handling, transporting, loading and installing the wet well components consumes less than 50% of the energy consumed vs. each conventional pre-cast concrete wet well component. For example, a traditional pre-cast concrete wet well component having an 8 inch wall, an 8 foot diameter, a height of 10 feet and approximate weight of 20 tons requires the use of a 30 ton capacity crane to unload and install these concrete units at the well site. In comparison, the heaviest module (Module “H”) used in the Green Recycled Material Component Wet-Well has an 8 inch wall, an 8 foot diameter, a 6 foot height and weighs 4.5 tons. Transporting 20 ton cement modules requires far more fuel than that used to transport the components for the 4.5 ton “H” module. Eliminating fuel consumption for transporting the 30 ton capacity crane to the job site adds to the energy savings. These “H” modules can be unloaded and installed on site using 5 ton mechanical hoists. The energy used in dismantling the Green Wet Well at the end of its useful life is only a small fraction of that required to dismantle and dispose of the traditional concrete well.
The Green Recycled Material Component Wet Well solves logistic problems at any site with significant cost savings. Wet wells are often located in congested areas with narrow streets and pedestrian sidewalks. These sites typically have high voltage overhead power lines installed to serve the community. When 30 ton cranes are required to install traditional concrete wet wells, the tall booms require overhead electrical wires to be rerouted resulting in very high power line relocation costs increasing the total project budget. In addition, since cooperation with power company staff is required throughout the process, those experienced in the art are aware of the related logistical delays that often occur and the resulting extended disruptions to neighborhood services. In other situations, multistory high rises having several levels of underground parking areas produce large quantities of irregular waste water. The practical solution is to install a wet well located in the lowest level of the building. If this wet well requirement is overlooked in the construction of the building and the need is realized after one or more floors have been constructed, the installation of pre-cast concrete is impossible due to parking garage ceiling height dimensions and limited access. In both cases, the Green Recycled Material Component Wet Well is the effective solution. The small sized components can be assembled and installed on site under overhead power lines using a five ton hoist eliminating the need for power line relocation and in the case of a hi-rise building, working within ceiling height restrictions.
The Green Recycled Material Component Wet Well is the only solution to other restricted sites as well. Often, wet well sites are restricted in one dimension in such a way that the installation of a conventional pre-cast concrete wet well with the desired diameter cannot be achieved. For example, many public sites are located in street medians and are restricted in one dimension. Green Recycled Material Component Wet Well components provide for oval cross section wet wells to be constructed where the short diameter is determined by the restricted site dimension while the long diagonal will be as required by the optimal number of pumps.
The Green Recycled Material Component Wet Well reduces delivery response time for construction orders. Pre-cast concrete requires an average of 10 to 30 days for scheduling and production response time. Concrete curing time is about 28 days. Loading, transporting and unloading concrete well components takes 2 to 3 days. The minimum time from order placement to delivery of the conventional cement components is 40 to 60 days. Green Wet Well components have storage capabilities and delivery sizes that enable them to be maintained as local shelf items, available for delivery in 3 to 5 business days.
Finally, recent testing of a major re-pump station revealed several problems with the traditional cement wet well design in all coastal areas that are at or near sea level. These locations are subject to buoyancy pressure from ground water saturation conditions. During times of heavy rains or flooding, wet wells experience sufficient force to lift vertical components in such a way as to allow ground water to infiltrate the wet well by separation of the components at the connecting joints. Residual infiltrated debris left between joints make infiltration continuous. Moreover, at the gravity sewer pipe point of entry to the wet well, the water seal will break due to the uplift movement creating a permanent infiltration location. This was confirmed by tests using measuring devices known by those skilled in the art that test inflow water to a wet well and outflow water from the wet well. The test returned data whereby outflow readings measurably exceeded inflow readings. In a contained environment, the measurements should be equal or rationally close. The variance was measurable to the point that financial loss to the processing facility was occurring because the clean ground water entering the wet well increased energy costs from pumping the additional waste water. The energy and chemical processing plant treatment costs increase due to the increase of incoming flow to the plant. Environmental effects result when treating pure ground water because additional chemicals treating clean ground water increase chemical production and usage. The Green Recycled Material Component Wet Well eliminates the separation of the joints through the use of mechanical fasteners that are part of this Green Recycled Material Component Wet Well design resulting in savings to governing agencies and less chemicals impacting the environment.
SUMMARYIn view of the deficiencies of traditional pre-cast cement wet wells described above, one objective of the present invention is to provide a design that utilizes recycled materials in the construction of wet wells.
It is a further objective of the present invention to provide components made of recycled materials for the construction of wet wells having significantly less weight than the traditional pre-cast cement wet well sections eliminating logistical problems associated with the cement wet well design.
It is a further objective of the present invention to provide components made of recycled materials for the construction of wet wells having an oblong shape in order to provide service in restricted areas.
Finally, it is an objective of this design to provide a mechanical fastener system that prevents the Green Recycled Material Component Wet Well from separating due to buoyancy forces occurring in all coastal areas where ground flooding could occur.
The design of the present invention stacks 2, 3, 4 and 5 modular cylinders for any required depth of 12 feet, 18 feet, 24 feet and 30 feet. The modular cylinders are made using recycled materials including Styrofoam. Reinforcing mesh, water proofing and protective paint are used on the interior and the exterior of the components. Various top and bottom slabs are used and discussed in the detailed description section.
The following legend is provided at the opening of this descriptive section for easy reference when abbreviations are found throughout the DETAILED DESCRIPTION section. While not completely exhaustive, any abbreviations or symbols not in the legend will be interpretable to those skilled in the art:
- W.U.S. is a wall unit segment of a module
- Di is the inner diameter of the module in feet
- Do is the outer diameter of the well in feet
- Dbs is the wet well bottom slab diameter in feet
- Dm is the module mean of the inner and outer diameter in feet
- t is the module wall thickness in feet
- H is the depth of the module in feet
- h is the thickness of the wet well bottom slab in feet
- ρc is the specific weight of concrete in air measured in lb/ft3
- ρcw is the specific weight of concrete in water measured in lb/ft3
- ρw is the specific weight of water measured in lb/ft3
- α is the symbol for angle
- bx is Horizontal stress also known as “hoop” stress in lb/in2
- by is Vertical stress also known as “bending” stress in lb/in2
- {right arrow over (w)}well represents the weight of a wet well in lbs
- {right arrow over (B)} represents buoyant force in lbs
- {right arrow over (F)}UPL represents uplift force on the modules, cylinder and wet well in lbs
- Vconyard3 is the volume of concrete in cubic yards
- J is an index of 1 to 5 as indicated in Table 6 A (Tables 1A through 8C are located at the end of this DETAILED DESCRIPTION section)
- L is the length of the straight wall in an oval wet well in feet
- (ρW.U.S.)J is the weight of the W.U.S. of a module that is installed at a depth of “J”, where J can be 1, 2, 3, 4 or 5 corresponding to depths of 6 ft, 12 ft, 18 ft, 24 ft and 30 ft of water.
- (ρW.L.F.)J is the weight of one linear foot of the straight wall having an installation depth of J
- Wi,J
module lb is the structural weight of modules with inner diameter Di and installed at a depth of J where J can be 1, 2, 3, 4 or 5 corresponding to depths of 6 ft, 12 ft, 18 ft, 24 ft and 30 ft of water - Wcircular cylinderlb is the structural weight of a cylinder in lbs
- Wi,L
oval J is the weight of oval modules with a circular diameter of Di and a length of L installed at a depth of J where J can be 1, 2, 3, 4 or 5 corresponding to depths of 6 ft, 12 ft, 8 ft, 24 ft and 30 ft of water in lbs - {right arrow over (B)}circular module is the buoyant force on a circular module in lbs
- {right arrow over (B)}oval is the buoyant force on an oval module in lbs
- {right arrow over (F)}module J uplift is the uplift force on module J in lbs
- {right arrow over (F)}oval(i,L,J) is the uplift force on an oval module J with diameter Di and straight wall L installed to a depth of J in lbs
Green Wet Well—Green Recycled Material Component Wet Well Structure (herein after also referred to as the Green Wet WellFIG. 8 )
The Green Wet Well
The modular cylinder is a unit of wet well construction.
The top 1 and bottom 16 circular frames are identical and are made of recycled plastic with an inner diameter equal to that of the desired wet well diameter. Each top frame 1 and bottom frame 16 is made of frame sections. Each section has a length of 38 inches on the inner side. The number of these sections in each wet well will be equal to the number of feet in the diameter of the wet well. For example, eight sections are required for a wet well having an eight foot diameter.
Vertical MembersVertical members 2 are made from recycled PVC material having dimensions of: width=2 inches, depth=4 inches and height=68½ inches. These vertical members 2 connect the top 1 and bottom 16 circular frames together. In each wet well, the number of vertical members 2 is twice the number of feet of its diameter. For example, 8 foot, 10 foot and 12 foot diameter wet wells would be constructed with 16, 20 and 24 vertical members 2 respectively. The verticals members 2 are placed in a 4 inch wide by ½ inch deep circular groove cut into the top 1 and bottom 16 circular frames. These members 2 will be installed at 18.85 inches (18⅞ inches) center to center of the inner circle of the frames 1 and 16.
Connecting AnglesGalvanized 2½ inch by 2½ inch by 3/16 inch angles 3 having a length of 3¾ inches with the necessary holes attach the top 1 and bottom 16 frames to the vertical members 2.
Space RefillSpace refill 4 is the space between the vertical members 2 that will be filled by pieces of high density, low quality (referring to the products color and surface finish so that recycled materials are used) Styrofoam. The Styrofoam occupies space refill 4 dimensions of 18 inches wide by 4 inches deep by 68 inches high and a curvature matching with 4 inch width by ½ inch groove for the top 1 and bottom 16 frames.
Inner Surface ReinforcementThe inner surface reinforcement 5 is constructed from cold worked welded wire mesh with yield strength of 70,000 psi to 80,000 psi. The required reinforcement has been calculated and limited gauges have been selected to reduce the number of stacked items. The required reinforcement and related gauges for each Module H
The inside cover 8 is a shield and protects the space refill 4 and supporting members 2 from physical damage, water penetration and deterioration of the inner surface reinforcement 5 by corrosive in-flow gases. The design engineer has several choices for the construction of the inner shield including:
A—Concrete StuccoThe simplest method is to apply an inner surface stucco layer 6 to the inner surface reinforcement 5. Stucco having a minimum 2 inch thickness for module H in
To make the structure watertight, the stucco should be rich in portland cement. The strength of the stucco should be 4000 psi or higher. The stucco should be applied to the structure by use of a high pressure stucco pump. Water proofing and protective paint 7 that is tar base or epoxy is to be applied to the inner surface stucco layer 6 to prevent corrosive elements from penetrating into the stucco and corroding the inner surface reinforcement 5.
One piece of plating that is minimum 36 gauge stainless steel of 316 or preferred 317 stainless steel grade with a full width of 6 feet to be secured to the inner one inch thick stucco surface 6 with stainless steel 316 grade self tapping screws or stainless steel tapcons. The attachment should be with 7 screws on each vertical 2 starting 3 inches from top 1 and bottom 16 frames with spacing 11 inches center to center.
C—Galvanized Sheet Metal & PVCA layer of recycled PVC having a 1/16 inch minimum thickness is to be glued to one piece of hot deep galvanized sheet metal having a width of 6 feet and a minimum thickness of 24 gauge secured to the inner surface reinforcement 5 with stainless steel 316 grade set screws. The attachment should be with 7 screws on each vertical 2 starting 3 inches from top 1 and bottom 16 frames with spacing 11 inches center to center.
D—Galvanized Sheet Metal and PaintA layer of hot deep galvanized sheet metal having a width of 6 feet and a minimum thickness of 24 gauge is to be secured to the inner surface reinforcement 5 with stainless steel 316 grade set screws. The attachment should be with 7 screws on each vertical 2 starting 3 inches from top 1 and bottom 2 frames with spacing 11 inches center to center. The inner sheet metal surface is to be sprayed with tar based or epoxy paint.
Angle Fastening ScrewsAngle fastening screws 9 connect each vertical PVC member 2 to the top 1 and bottom 16 frames by way of the four angles 3 with a minimum of eight self tap screws 9 that are ¼ inch diameter by 1¾ inch length with coarse pitch. These angle fastening screws 9 are the same in H module in
Angle bolts 10, nuts and washers fasten each vertical member 2 to the steel angles 3. There are to be four angle bolts 10, four nuts and eight ⅛ inch flat washers (two washers on each steel angle 3). The size of the angle bolt 10 should not be less than ⅜ inch diameter by 2½ inch length.
Vertical Member Connecting BoltsThe vertical members 2 are connected to the top circular frame 1 and the bottom circular frames 16 by vertical member connecting bolts 11. The vertical member connecting bolts 11 are used to strengthen the connection of the top 1 and bottom 16 circular frames which are also connected to the vertical members 2 by the connecting angles 3 and the angle fastening screws 9. One vertical member connecting bolt 11 per angle is to be used. The dimensions of the bolts should not be less than ⅜ inch diameter by 2¼ inches. Four vertical member connecting bolts 11 are required per vertical member 2 as there are two connecting angles 3 that attach the bottom circular frame 16 to the bottom of the vertical member 2 and two that attach the top circular frame 1 to the top of the vertical member 2.
Outer Surface ReinforcementThe outer surface reinforcement 12 is similar to the inner surface reinforcement 5. Cold worked welded wire mesh with yield stress of 70,000 psi to 80,000 psi is to be used and is applied to the vertical members 2 using staples or other suitable hardware. The required reinforcement has been calculated and limited gauges have been selected to reduce the number of stocked items needed to be maintained in the inventory. The required reinforcement and related gauges for each module
The outer surface reinforcement 12 is to be covered with stucco 13 having a minimum application width of 2 inches for module H in
Depending on the outer surface soil composition and underground water quality at the site, it may be necessary to spray the outside surface of the outer surface stucco layer 13 with a tar base or epoxy protective paint 7. This will provide the outside stucco surface water proofing and another protection layer 14.
Module FIGS. 1 & 2 Module Connecting BoltsModules
1—Rate of Flow in the Future
The projected increased rate of flow in the future helps the designing engineer to select a top slab with three or four hatches.
A—Aluminum three hatch top slabs 19
B—Aluminum four hatch top slabs 18
2-Site Restriction
Top slab construction is determined by assessing site restrictions and installation difficulties.
A—The traditional concrete slab works well in open access sites where the site is clear from existing overhead power lines and the use of a heavy crane to install the concrete slab is not restricted. The slab has a diameter of 8 feet to 12 feet, a thickness of 10 inches to 12 inches with a weight of 6,500 to 17,000 pounds. The top view of the concrete three hatch top slab 21 and the concrete four hatch top slab 20 is provided in
B—A light weight top slab is preferable in areas where heavy cranes do not have practical access without re-routing power lines and obtaining power company associated permits which can be time consuming and costly. A light weight top slab made from “H” shaped aluminum has a 5/16 inch to ½ inch thick corrugated aluminum plate. The top view of the light weight three hatch top slab 19 and the light weight four hatch top slab 18 is provided in
In order to calculate the structural weight of the module
-
- 1—Length: The length is the same as the height of the module
FIGS. 1 & 2 which is 6 feet. - 2—Width: The length of the arc of the inner circle of the wet well with a central angle of α=2π/D radian, (360°/D degree central angle). This width is relatively constant in all wet wells regardless of diameter Di and it is equal to 3.14 feet.
- 3-Thickness: The thickness is 8″ for all H modules
FIG. 1 and 7″ for all L & M modulesFIG. 2 .
For each type of moduleFIGS. 1 & 2 , the weight of the W.U.S. 24 is constant and independent of the well diameter. Modules H, M and LFIGS. 1 & 2 have different wall construction measurements and therefore, will have different constant values for the weight or their respective W.U.S. 24.
- 1—Length: The length is the same as the height of the module
When the wet well is installed underground at a site having a high underground water table, the buoyancy effect of water is to generate uplift force that works to push the wet well out of the ground.
This design applies the highest uplift force possible in the calculations. Buoyancy force is a function of both the underground water level and the water level inside of the wet well. The most extreme condition occurs when the wet well is empty and the site is flooded.
Section 1—Buoyancy in Traditional Pre-Cast Wet Wells 17- Di is the inner diameter of the well 17 in feet,
- Do is the outer diameter of the well 17 in feet,
- Dbs is the bottom slab 27 diameter in feet,
- Dm is the mean of the inner and outer diameter in feet,
- t is the wall thickness in feet,
- H is the depth of the well 17 in feet and
- h is the thickness of the bottom slab 27 in feet.
Not shown inFIG. 6 but used in formulas: - ρc is the specific weight of concrete in air measured in lb/ft3,
- ρcw is the specific weight of concrete in water measured in lb/ft3 and
- ρw is the specific weight of water measured in lb/ft3.
A—Structural Weight
Wet well structural weight could cancel out all or part of buoyant force. In the calculation of the structural weight, the weight of the top slab should not be included so that structural weight=bottom slab 27 weight+cylinder weight yielding Equation (1):
Wwell=ρc×[(π×Dbs2×h/4)+π×Dm×t×H]
Wwell=π×ρc/4×(h×Dbs2+4t×H×Dm) (1)
B—Buoyant Force
The buoyant force of water corresponding to the worst condition for design parameters is given by Equation (2):
{right arrow over (B)}=ρw×[(π×Dbs2×h/4)+πDo2×H/4]=π/4×ρw×(Dbs2×h+Do2×H) (2)
C—Uplift Force
The net uplift force that pushes the wet well 17 out of the ground is calculated by Equation (3):
{right arrow over (F)}UPL={right arrow over (B)}−{right arrow over (W)} (3)
Equation (4):
{right arrow over (F)}UPL=π/4×ρw×(Dbs2×h+Do2×H)−π/4×ρc×(Dbs2×h+4t×H×Dm)
{right arrow over (F)}UPL=π/4×ρw×Do2×H−π/4×[(ρc−ρw)×Dbs2×h+4×ρc×t×H×Dm]
{right arrow over (F)}UPL=π/4×[ρw×Do2×H−(ρc−ρw)×Dbs2×h−4×ρc×t×H×Dm] (4)
D—Dead Weight as the Counter Balance for Uplift
To cancel the effect of uplift force, the traditional method is to add additional concrete to the structure.
Let the {right arrow over (F)}UPL=in equation 4 above be equal to zero and Equation (5) be:
{right arrow over (F)}UPL=(ρc−ρw)×Vconft3 or
{right arrow over (F)}UPL=(ρc−ρw)×Vconyard3×27 ft3/yard3 (5)
Substituting equation 4 in 5 will result in Equation (6):
Vconyard=π/108×[ρw×Do2×H−(ρc−ρw)×h×Dbs2−4×ρc×t×H×Dm]/(ρc−ρw) (6)
- Do, Din, Dm, h, H, t, have been explained above and
- Vconyard3 is the volume of concrete in cubic yards as counter balance downward force to cancel the uplift force.
For example, let the following be the dimensions for the selected wet well 17 applied toFIG. 6 : - Di=8.00 feet
- Do=9.67 feet
- Dbs=11.00 feet
- Dm=8.83 feet
- t=0.83 feet
- H=24.00 feet
- h=1.00 feet
- ρc=150.00 lb/ft3 (specific weight of concrete in air)
- ρcw=87.80 lb/ft3 (specific weight of concrete in water)
- ρw=62.20 lb/ft3 (specific weight of water)
Substituting the numerical values in equation 6, the amount of required concrete in cubic yards is calculated:
Vconyard3=(3.14/108)×[62.2lb/ft
Vconyard3=(3.14/108)×[139,590−10,623.8−105,536]/87.8lb/ft
Vconyard3=7.76 yards3
As mentioned and as shown in
Step 1—Calculate the weight, buoyant force and uplift force on the modules
Step 2—Calculate the total weight, buoyant force and uplift force on the Green Recycled Material Component Wet Well cylinder 29;
Step 3—Calculate the total weight, buoyant force and uplift force on the Green Recycled Material Component Wet Well
Step 4—Calculate the maximum uplift force and the number of mechanical anchors 25 and 26 in
Step 5—Calculate the uplift force on the modules'
1-A Green Module's
1-A-1 Green Modules
The most common Green Recycled Material Component Wet Well design applies to wet wells with circular cross sections (round wells). The weight of the module
Let: (ρW.U.S.)J be the weight of the W.U.S. of a module
And let: Di be the inner diameter of the cross section circle in feet. Common values of Di are 6 ft, 8 ft, 10 ft and 12 ft. The general equation for the structural weight of modules
Wi,Jlbmodule=Di×(ρW.U.S.)J (7)
The numerical values for (ρW.U.S.)J (J=1 to 5) are given in Table 2.
1-A-2 Green Modules
The weight of an oval module
- (ρW.U.S.)J is the weight of a W.U.S. having an installation depth of J and
- (ρW.L.F.)J is the weight of one linear foot of the straight wall having an installation depth of J.
The general equation of oval Green modulesFIGS. 1 & 2 is given by Equation (8)
Wi,L
The numerical values of (ρW.U.S.)J and (ρW.L.F.)J are given in Table 2.
1-B Green Modules'
The buoyant force of water associated with the worst site condition, that being a saturated and flooded site with a completely empty wet well
1-B-1 Buoyant Force on Green Modules
The general equation for the buoyant force of water on a green module
{right arrow over (B)}circular module=π/4×H×ρw×(Di+2t)2 (9)
- H is the height of the module
FIGS. 1 & 2 in feet, - Di is the inner diameter of the circle's cross section in feet,
- t is the thickness of the module's
FIGS. 1 & 2 wall in feet and - ρw is the specific gravity of water in lbs/ft3=62.2 lb/ft3.
1-B-2 Buoyant Force on Oval Modules
The general equation of buoyant force on a module
{right arrow over (B)}oval=π/4×H×ρw×(Di+2t)2+ρw×H×L×(Di+2t)
{right arrow over (B)}oval=ρw×H(Di+2t)[π/4(Di+2t)+L] (10)
H, Di, t and ρw have the same values as those given in step 1-B-1 and L is the length of straight wall in feet.
1-C Uplift Force on Green Wet Well Modules
The uplift force on submerged and empty modules
{right arrow over (F)}UPL,J={right arrow over (B)}J−{right arrow over (W)}J (11)
1-C-1 Uplift Force on Circular Green Module J
Uplift force on module J having a circular cross section and an inner diameter Di can be calculated by substituting equations (7) and (9) in equation (11) to arrive at Equation (12) Table 6A:
Fmodule J uplift=π/4×H×ρw×(Di+2t)2−Di×(ρW.U.S.)J(J=1 to J) (12)
1-C-2 The Uplift Force on Oval Module J
The uplift force on oval module J can be calculated by substituting equations (8) and (10) in equation (11) resulting in Equation (13) Table 6C:
{right arrow over (F)}module J uplift=ρw×H(Di+2t)[π/4(Di+2t)+L]−Di×(ρW.U.S.)J−2L×(ρW.L.F.)J (13)
- J is 1 to 5 as indicated in Table 4 A,
- L is the length of the straight wall in feet,
- (ρW.U.S.)J is the unit weight of the Wall Unit Segment in pounds and
- (ρW.L.F.)J is the weight of one linear foot of straight wall of oval module J.
The numerical values for (ρW.U.S)J, (ρW.L.F.)J, {right arrow over (W)}circular(i,J), {right arrow over (W)}oval(i,J), {right arrow over (B)}circular(i), {right arrow over (B)}oval(i,L), {right arrow over (F)}circular uplift(i,J), and {right arrow over (F)}oval(i,L,J) are calculated for (J=1 to 5) and are provided in Tables 4A and 4B.
Green Wet Well cylinders 29 are made using stacks of 1 to J modules
2-A Green Wet Well Cylinders' 29 Structural Weight
The structural weight of the green cylinder 29 is the summation weight of J modules
2-A-1 Weight of a Circular Green Wet Well Cylinder 29
The structural weight of a cylinder made from “J” circular modules
- (ρW.U.S.)J is the module's J unit weight of a Wall Unit Segment.
2-A-2 Weight of an Oval Green Wet Well Cylinder 29
The structural weight of a cylinder 29 made from a J oval module
- (ρW.U.S.)J is the module's J unit weight of a Wall Unit Segment and
- (ρW.L.F.)J is the module's J unit weight of one linear foot of the wall.
2-B Green Wet Well Cylinder 29 Buoyant Force
The buoyant force of water on a green cylinder 29 made of J modules
2-B-1 Buoyant Force of a Circular Green Wet Well Cylinder 29
The buoyant force of water on circular cylinders made of J modules
- tJ is the wall thickness of module J in feet,
- H is the height of the module
FIGS. 1 & 2 in feet, - Di is the inner diameter of the circle's cross section in feet and
- ρw is the specific gravity of water in lbs/ft3=62.2 lb/ft3.
2-B-2 Buoyant Force of an Oval Green Wet Well Cylinder 29
The buoyant force acting on a Green Wet Well cylinder 29 with an oval cross section made from J oval modules
2-C Green Cylinder 29 Uplift Force
The uplift force on the Green Wet Well cylinder 29 results from the cylinder 29 structural weight and buoyant forces acting on the cylinder 29 vertically but in opposite direction of each other. Cylinder 29 uplift force can be obtained by subtracting the cylinder 29 weight from its buoyant force as General Equation (18) Table 7C:
{right arrow over (F)}cylinder
2-C-1 Uplift Force on Circular Cylinders 29
The uplift force on a green cylinder 29 made from J modules
- J is the number of modules
FIGS. 1 & 2 in a stack of cylinders (J=1 to J).
2-C-2 Uplift Force on Oval Cylinders 29
The uplift force acting on an oval cylinder 29 with any inner diameter and straight wall of can be evaluated by Equation (20):
- {right arrow over (F)}oval cylinder
J is the uplift force acting on oval cylinders 29 made of J number of modulesFIGS. 1 & 2 in pounds.
The values of structural weights, buoyant force and uplift for Green Wet Well cylinders 29 are given in Tables 5A, 5B and 5C.
A Green Wet Well
3-A Wet Well Bottom Slab 27 Weight
The effect of the bottom slab 27 in the wet well
a) to enclose the bottom of the cylinder 29 and
b) to counter balance part of the uplift force on the well
3-A-1 Circular Green Wet Well Bottom Slab 27
In all wet wells, whether the traditional pre-case concrete design 17 or the Green Recycled Material Component Wet Well design
3-A-1a Weight of the Circular Bottom Slab 27
The structural weight of the circular bottom slab 27 is given by Equation (21):
{right arrow over (W)}circular bottom slablb=π/4×ρc×h×Dbs2=π/4×150 lbs/ft3×h×Dbs2
{right arrow over (W)}circular bottom slablb=118×h×Dbs2 (21)
where:
- Dbs is the diameter of the bottom slab 27 in feet,
- h is the thickness of the bottom slab 27 in feet, usually 1 foot and
- ρc is the specific gravity of concrete, ρc=150 pounds per cubic foot.
3-A-1b Weight of the Oval Bottom Slab 27
The structural weight of the bottom slab 27 of an oval wet well
Wbottom slab ovallb=ρc×h×(π/4×Dbs2+L×Dbs)
Wbottom slab ovallb=ρc×h×Dbs×(π/4×Dbs+L) (22)
- ρc is the specific gravity of concrete, ρc=150 pounds per cubic foot,
- h is the thickness of the bottom slab 27 in feet, usually 1 foot,
- Dbs is the diameter of the bottom slab 27 in feet, Dbs=Di+2×(t+k),
- t is the thickness of the well cylinder 29,
- k is the uplift friction key, k=6 inches to 10 inches,
- L is the length of the straight wall of the oval module
FIGS. 1 & 2 and - Wbottom slab ovallb is the weight of the bottom slab 27 in pounds.
3-B Buoyant Force on the Bottom Slab 27
The buoyant force on the bottom slab 27 for wet wells
3-B-1 Buoyant Force on the Circular Bottom Slab 27
Buoyant force on the circular bottom slab 27 is given by Equation (23):
{right arrow over (B)}circular bottom slablb=ρw×h×(π/4×Dbs2)=π/4×ρw×h×Dbs2 (23)
3-B-2 Buoyant Force of the Oval Bottom Slab 27 is given by Equation (24):
{right arrow over (B)}bottom slab ovallb=ρw×h×Dbs×(π/4×Dbs+L) (24)
3-C Uplift Force on the Wet Well Bottom Slab 27 Equation (25):
{right arrow over (F)}bs={right arrow over (B)}bs−{right arrow over (W)}bs (25)
3-C-1 Uplift Force on the Circular Bottom Slab 27
The uplift force on the circular bottom slab 27 can be obtained by substituting the Equations (23) and (21) in Equation (25) resulting in Equation (26):
{right arrow over (F)}bs=π/4×ρw×h×Dbs2−π/4×ρc×h×Dbs2
{right arrow over (F)}bs=π/4×h×Dbs2×(ρw−ρc)
{right arrow over (F)}bs=π/4×(62.4−150)×h×Dbs2
{right arrow over (F)}bs=(−)87.6×h×Dbs2 (26)
- ρw, ρc are the specific gravity of water and concrete having values of 62.4 pounds per cubic foot and 150 pounds per cubic foot respectively.
3-C-2 Uplift Force on the Oval Bottom Slab 27
The uplift force on the bottom slab 27 of an oval wet well
{right arrow over (F)}bs oval=ρw×h×Dbs×(π/4×Dbs+L)−ρc×h×Dbs×(π/4×DbsL)
{right arrow over (F)}bs oval=h×Dbs×(π/4×Dbs+L)×(ρw−ρc)
{right arrow over (F)}bs oval=(−)87.6×h×Dbs×(π/4×Dbs+L) (27)
3-D Weight, Buoyant Force and Uplift Force on the Complete
Wet well (Cylinder Plus the Bottom Slab)
The cylinder 29 is enclosed by adding the bottom slab 27 thereby forming the complete wet well
3-D-1 Weight of the Circular Green Wet Well
The structural weight of a circular wet well
- Wcircular welllb is the structural weight of circular wet well (cylinder+bottom slab)
FIG. 8 in pounds, - Di is the inner diameter of the well
FIG. 8 in feet, - (ρW.U.S.)J is the unit weight of a Wall Unit Segment of module J with a width of 3.14 feet, height of H and thickness of t,
- is the summation of Wall Unit Segment weights of J number of modules
FIGS. 1 & 2 , - h is the thickness of the bottom slab 27 in feet and
- Dbs is the bottom slab 27 diameter in feet.
3-D-2 Weight of an Oval Green Wet Well
The structural weight of an oval Green Wet Well
- ρc, ρw are the specific gravity of concrete and water having values of 150 pounds per cubic foot and 62.4 pounds per cubic foot respectively,
- H, Dbs, Di, and
- are the same as in 3-D-1,
- L is the width of the straight wall of the oval modules
FIGS. 1 & 2 in feet and
- is the summation of “weight of one linear foot of wall” of J number of modules and it is equal to:
[(ρW.L.F)1+(ρW.L.F.)2+ . . . +(ρW.L.F.)J]
3-E Buoyant Force of Water on Complete Green Wet Wells
The general equation for the buoyant force on the Green Wet Well
3-E-1 Buoyant Force on the Circular Green Wet Well
The buoyant force on the circular Green Wet Well
3-E-2 Buoyant Force on the Green Oval Wet well
The buoyant force of water acting on the Green Wet Well
3-F The Uplift Force on the Green Wet Well
The uplift force on complete circular and oval cross section Green Wet Wells
{right arrow over (F)}D
3-F-1 Uplift Force on the Circular Green Wet Well
3-F-2 Uplift Force on the Oval Green Wet Well
The general equation for uplift force on the oval wet well
With Equations (34) and (35), the uplift force acting on the submerged Green Wet Well
Step 4—The Maximum Uplift Force and the Number of Mechanical Anchors 25 and 26 Necessary to Counter Balance that Uplift Force on the Wet Well
The general equation of the Green Wet Well
{right arrow over (F)}D
In the above equation, the value of the structural weight as WD
4-A Counter Balance Force on the Green Wet Well
The uplift force on wet wells
4-B Mechanical Anchors 25 and 26 as Counter Balancing Force
In the Green Recycled Material Component Wet Well
4-C Standard Anchor 25 & 26 Having 40,000 Pound Capacity
These mechanical anchors 25 & 26, shown in detail in
(1) A low pitch helical steel cutting blade with 8 inch diameter and dual cutting edges 33,
(2) A low pitch helical steel cutting blade with 10 inch diameter and dual cutting edges 34,
(3) Seamless steel pipe 31, six feet in length and three inches in diameter with thread 31 for extension at the end,
(4) Extension pipe 36, same as in (3), six feet in length and three inches in diameter with thread 31 at one end and an eye 32 or eye nut at the other end,
(5) 100% reusable/recyclable materials and
(6) a minimum 40,000 pound axial compression load capacity with 50% of capacity (20,000 pounds) to be used as the conservative allowable force in the design.
4-D Required Number of Anchors 25 and 26
After uplift force of {right arrow over (F)} has been calculated by using Equations (34) and (35), the required number of standard anchors 25 and 26 can be calculated by Equation (36):
N={right arrow over (F)}lb/40,000 lbs (36)
- N is the required number of anchors 25 and 26 that are needed to counter balance the uplift force (rounded up).
FIG. 8 shows the method of anchoring a Green Wet WellFIG. 8 made of four modulesFIGS. 1 & 2 .
The Green Wet Wells
5-A The Joint's Uplift Force in a Circular Wet Well
The uplift force on each module
- {right arrow over (B)}J is the buoyant force on each module of J and
- {right arrow over (W)}J is the weight of each module of J.
Substituting the values of {right arrow over (B)}J and {right arrow over (W)}J, the following general equation for uplift force of the joints in the wet wellFIG. 8 will be obtained and is Equation (38):
The joint uplift force calculated by Equation (38) works to separate two connected modules
Table 8 identifies the uplift for each module
5-B Mechanical Anchor and Anchor Location
In Green Wet Wells
-
- 1 Bottom slab anchors 25 and top anchors 26 are positioned as shown in
FIG. 8A with the top anchors 26 installed at the elevation 6 feet to the bottom frame of module M-L1. - 2 Half of the anchors will be bottom slab anchors 25 and the other half will be top anchors 26.
- 3 A minimum of three bottom slab anchors 25 should be installed at 120 degrees from each other.
- 4 It is recommended a minimum of 6 anchors 25 and 26 be used including 3 bottom slab anchors 25 and 3 top anchors 26 at the elevation of 6 feet from the surface.
- 5 When the minimum of 6 anchors 25 and 26 is used to neutralize the uplift force on a wet well, bottom slab anchors 25 are to be 120 degrees off each other and top anchors 26 are to be 120 degrees off each other but bottom slab anchors 25 are at 60 degrees in respect to top anchors 26 as shown in
FIG. 8B .
- 1 Bottom slab anchors 25 and top anchors 26 are positioned as shown in
Claims
1. Green wastewater pump station circular and oblong wet wells constructed by stacking 2, 3, 4 and 5 modular circular cylinder and straight sections for required well depths of 12′, 18′, 24′ and 30′ respectively and having a mechanical anchoring system; said modular cylinder and straight sections constructed from recycled plastic, recycled Styrofoam and recycled steel scraps in the form of welded wire mesh forming the walls of the wet well and by wet well top and bottom slabs enclosing the modular cylinder wet well walls; said circular and straight sections comprising identical top and bottom frames made of recycled plastic with an inner diameter equal to the desired wet well diameter, vertical members constructed from recycled PVC materials, Styrofoam space refill that fills the space between the vertical members, connecting angles used to connect said vertical members to said top and bottom frames and module stacking connecting bolts that connect said top module frames to vertically stacked bottom module frames; said vertical members having layers of wire mesh reinforcement attached by staples to vertical members' inner and outer surfaces; said inner vertical member surfaces having stucco, stainless steel or galvanized sheet metal coverings and said outside surfaces to be covered by stucco; said mechanical anchoring system consisting of top modular cylinder helical ground anchors and wet well bottom slab helical ground anchors having a minimum 40,000 lb. axial compression load capacity and each comprised of a seamless steel pipe six feet in length and three inches in diameter with two low pitch helical steel cutting blades and being threaded at the top end for attachment to a second seamless steel pipe six feet in length and three inches in diameter threaded at the bottom connecting end and having an eye at the top of it's end; said anchoring system helical steel cutting blades comprising a bottom blade cutting diameter of 8 inches and a top blade cutting diameter of 10 inches and installed with a minimum of 3 top modular cylinder anchors per top modular cylinder installed at a depth of 6 ft. below the top of the well surface and at 120 degrees off each other and 3 bottom slab anchors per modular cylinder attached to the wet well bottom slab at 120 degrees off each other and at 60 degrees in respect to the top modular cylinder anchors.
2. Circular and straight sections recited in claim 1 having a length of 38 inches on the inner side and vertical members, said vertical members connecting the top and bottom frames and having dimensions where the width is 2 inches, the depth is 4 inches and the height of each vertical member is 68.5 inches,
3. Vertical members recited in claim 1 wherein the vertical members are placed in a 4 inch wide by ½ inch deep groove cut into the top and bottom frames recited in claim 1 and installed at 18.85 inches center to center of the inner circle of the frames.
4. Inner and outer surface reinforcing layers of wire mesh recited in claim 1 constructed from cold worked welded wire mesh with yield strength of 70,000 psi to 80,000 psi applied to the vertical members by staples or other suitable hardware.
5. Space refill recited in claim 1 constructed from high density recycled Styrofoam having dimensions of 18 inches wide by 4 inches deep by 68 inches high and a curvature matching with 4 inch width by 0.5 inch groove for the top and bottom frames.
6. Connecting Angles recited in claim 1 that are galvanized having dimensions of 2.5 inches by 2.5 inches by 0.1875 inches and a length of 3.75 inches with the necessary holes to attach the top and bottom frames to the vertical members.
Type: Application
Filed: Nov 30, 2012
Publication Date: Jun 5, 2014
Inventor: Nasser Fred Mehr (Fort Lauderdale, FL)
Application Number: 13/691,418
International Classification: B09B 1/00 (20060101); F16L 3/00 (20060101); F16L 9/00 (20060101);