SCREW ANCHOR FOUNDATIONS AND RELATED INTERFACES FOR MODULAR, FABRICATED AND PREFABRICATED STRUCTURES

Abstract

A foundation system for manufactured homes, prefabricated houses, and other structures. Multiple screw anchors are bolted into the ground at the desired location of the structure. Pre-formed solid bars can be placed over the screw anchors to provide a modular foundation without pouring concrete or excavating footings. Alternatively, adapters can be attached to one or more of the bolted screw anchors to provide a pedestal to receive the leveling bar or pre-cast concrete sections.

Description

SCREW ANCHOR FOUNDATIONS AND RELATED INTERFACES FOR MODULAR, FABRICATED AND PREFABRICATED STRUCTURES BACKGROUND OF THE INVENTION Modular and prefabricated home construction offers many advantages over on-site construction. For one, modular and prefabricated homes are often built indoors in climate-controlled factories rather than outdoors. This keeps materials dry and protects them from theft and vandalism. It also avoids weather-related construction delays. Centralizing construction in a factory simplifies the process by allowing building materials to be delivered to a single location instead of multiple worksites. Furthermore, factory construction enables the use of computer-controlled guides, templates, and machinery, resulting in structures that are built with far greater precision and consistency compared to those built on-site using hand tools.Another advantage is that an entire community or even a city can be built off-site, where resources are better utilized for this purpose, and then the components are shipped to locations virtually anywhere in the world for final assembly. Modular and / or prefabricated structures still require some on-site work, but this is typically limited to site preparation, including grading, utility installation or commissioning, and foundation construction. The structures themselves are transported by truck, lifted into place on the foundation using cranes, and connected to the utilities and foundation. The process of sealing the joints and completing the utility connections usually takes less than a week. In some cases, even internal installations (e.g., plumbing and electrical) are installed at the factory. The most time-consuming and labor-intensive activity on the site is usually the construction of the foundation. After leveling and compacting the ground, the soil is excavated to make room for the foundation. In some cases, a continuous footing trench is dug around the entire perimeter of the structure. Reinforcing bars and wire are placed in the trench, which is then filled with concrete. Anchor bolts are either driven into the curing concrete or drilled and positioned after it has set, and the house is then built on top of the foundation and anchors. In other cases, the entire footprint of the structure to be built is scraped, leveled, and compacted. Concrete is then poured over the compacted footprint to create a slab upon which the house is built. Still other foundations use a combination of these techniques, or individual concrete footings and piers whereby individual piles are excavated and constructed, and the piers are built on top of the piles to establish a uniform building platform. Unfortunately, there is a disconnect between the distributed, inefficient, and low-precision techniques used to construct foundations and the highly efficient, centralized, and precise techniques and processes used to construct the prefabricated and / or modular structures themselves. This can lead to poor connections between structures and foundations, resulting in additional work on-site to shape the foundation and a loss of time and money.Similarly, builders of prefabricated structures must contract with multiple regional contractors to construct their foundations instead of simply shipping the foundation components with the rest of the modular and / or prefabricated structure. In light of these problems, this disclosure provides foundation systems, components, and related methods that greatly simplify the process of placing a foundation for prefabricated and modular building structures and ideally eliminate or at least minimize non-utility-related site work. BRIEF DESCRIPTION OF THE FIGURES Figure 1A is a conventional strip footing foundation for a building structure; Figure 1B is a cross-sectional view of the continuous footing foundation of Figure 1A; Figure 2A is a conventional pile and column foundation for a building structure; Figure 2B is a cross-sectional view of the pile foundation and pillar of Figure 2A; Figure 3A is a framework foundation according to various embodiments of the invention; Figure 3B is a precast slab section for prefabricated and modular housing according to various embodiments of the invention; Figure 3C is a cross-sectional view of the interface section of the precast slab and the framework foundation according to various embodiments of the invention; Figure 3D is a top view of the lattice interface formed in the precast slab of Figure 3C; Figure 3E is a top view of the tray covering the lattice interface of Figure 3C; Figure 4 is a flowchart detailing the steps of a method for installing a foundation such as that shown in Figures 3A-E according to various embodiments of the invention; Figure 5 is a perspective view of another precast slab for prefabricated and modular structures according to various embodiments of the invention; Figure 6A is a foundation interconnection system of frame and precast slab according to various embodiments of the invention; Figure 6B is a system for interconnecting a monopile foundation and a precast slab according to various embodiments of the invention; Figure 7A is another interconnection system for a framework foundation and precast slab according to various embodiments of the invention; Figure 7B is another interconnection system for monopile foundation and precast slab according to various embodiments of the invention; Figure 8A is a foundation interconnection system of a framework and additional precast slab according to various embodiments of the invention; Figure 8B is a system for interconnecting a monopile foundation and an additional precast slab according to various embodiments of the invention; Figure 9A is a lifting plate for lifting a precast slab according to various embodiments of the invention; Figure 9B is a part of a precast slab with an integrated lifting point; Figure 10 is a connector for joining adjacent precast slabs according to various embodiments of the invention; Figures 11A and 11B show components of a foundation of leveling blocks according to various embodiments of the invention; and Figure 12 is a flow diagram detailing the steps of a method for installing a foundation such as that shown in Figures 11A and B according to various embodiments of the invention. DETAILED DESCRIPTION OF THE INVENTION As discussed previously, modular and prefabricated housing offers many advantages over on-site construction. These advantages should be leveraged to address the growing global shortage of affordable, quality housing. However, what is missing from the modular and / or prefabricated construction paradigm is a universal foundation that allows the structure to be quickly and accurately secured to the building site, regardless of soil type, without the need to excavate and pour a custom concrete foundation. Ideally, such a foundation could be manufactured centrally and shipped with the other building components, or at least delivered to the construction site ready for assembly before the remaining modular and / or prefabricated components.To that end, the applicant for this disclosure has developed an A-frame truss foundation that is particularly suitable for this application. The system is commercially known as EARTH TRUSS. The EARTH TRUSS system consists of a pair of screw anchors that are rotated in the supporting ground at angles to each other and extend above the ground with upper legs that are joined with an adapter to form a unitary A-frame truss structure. EARTH TRUSS was originally developed to support single-axis solar trackers. When wind strikes a tracker array, the foundation must withstand large lateral loads. With monopiles, these loads impart a bending moment to the foundation components. By using A-frame trusses instead of monopiles, these lateral loads are instead translated into tension and compression in the legs. Since individual structural members are relatively good at resisting axial loads, as opposed to resisting bending, less steel can be used to support the same size tracker. EARTH TRUSS is based on a specialized machine or attachment for a general-purpose machine that uses a combination of downward force and rotation to screw screw anchors into the ground. These components and machines are easily adapted to construct robust foundations to support other structures, including modular and prefabricated homes. They can be configured as a two-legged truss, similar to single-axis tracker foundations, or even as vertical piles, depending on site conditions and shear issues.This disclosure focuses on construction systems and related methods that combine EARTH TRUSS components with precast concrete slab sections to form fast, accurate, robust and waterproof prefabricated foundations that can be built very quickly, shipped to the housing site as a kit and assembled with minimal site preparation. To that end, the present invention will now be described in the context of the figures in the drawings, where similar structures are referred to by similar designations. Figures 1A and B show a conventional strip footing foundation 10. The foundation 10 is constructed by excavating a trench around the perimeter of the intended structure (i.e., house, office, modular classroom, etc.), placing reinforcing bars, wire mesh forms, and / or other reinforcing structures in the trench, and pouring concrete over them. Concrete blocks are then used to create the foundation 14 above ground level in the poured concrete footing span 12. Alternatively, gravel 11 can be poured within the walls of the foundation 14, and a concrete slab can be poured on top of the gravel to create a slab such as slab 13.Anchors, tie rods, or other structural elements are typically inserted into the concrete block foundation before it is laid to provide attachment points for the rest of the structure. In the case of modular or prefabricated homes, these anchors will serve as the attachment points. Otherwise, if the house is built on-site, these anchors are embedded within timber beams and / or floor joists, and the house is erected from there. Figures 2A and B show another conventional foundation 20 consisting of columns 24 and piles 22. In such a foundation, individual pile sections 22 are excavated at strategic points around a site to support the load-bearing portions of the structure according to a construction plan. Timber or cardboard formwork may be placed around the excavated opening, and wire, reinforcing bars, or other structural components may be placed inside before it is filled with liquid concrete. Once the pile 22 has been set, columns 24 of concrete, timber, or steel are erected on top to form a raised, level mounting surface on which to set or build the dwelling. The columns 24 may have a cap section 26 with an integral anchor 28 that serves as a mechanical interface between the dwelling and the foundation 20. Although first developed hundreds, if not thousands, of years ago, the prior art foundations 10, 20 shown in Figures 1A / B and 2A / B are still in use today. They require substantial on-site work with local components and labor that is completely disconnected from the manufacturing process of the modular or prefabricated structure to be erected on it, as well as knowledge of the necessary foundation dimensions. As a result, even if the anchors 14 / 28 are perfectly positioned, which rarely happens, the foundation will be the least efficient or cost-effective part of the project. In a builder's or manufacturer's development project portfolio, there will be variable quality and variable expenditure depending on many local conditions (e.g., labor rates, material availability, weather, etc.).To overcome these problems, the applicant for this disclosure has proposed a system that allows foundation components to be manufactured centrally and shipped as a kit to the job site for rapid assembly. They can be shipped with other modular and / or prefabricated components or shipped separately in advance, so that the entire structure, including the foundation, can be assembled on-site without pouring concrete, extensive site preparation, or excavation. Figures 3A and 3B show the components of this novel foundation system according to various embodiments as examples of the invention. Figure 3A shows an example truss foundation 50 according to various embodiments of the invention. The example truss foundation 50 shown herein consists of a pair of screw anchors 52 bolted into the ground adjacent to each other and in a substantially common plane. When used to support single-axis trackers, this plane is usually oriented east to west; however, to support modular and prefabricated housing, they may be oriented to coincide with the orientation of the exterior walls of the structure, i.e., with some trusses oriented orthogonally or at 90 degrees to other foundations to ensure that any shear force is translated into tension and compression as required. In various embodiments, as shown, the screw anchors 52 are screwed in until they are almost completely embedded in the ground. As shown, the screw anchors 52 are elongated metal tubes that can span from one to two meters with an outside diameter of less than 100 mm. External threads 53 are located at the lower end of each anchor 52, and driving couplers 54 are attached to the opposite upper end. The driving couplers 54 can be engaged by the chuck of a rotary screwdriver to transfer torque and downward force to the screw anchors 52 for screwing them into the ground. The couplers 54 can also provide a mechanism for attaching upper legs 55 to the end of each screw anchor 52 after the screw anchor has been screwed in. The upper leg sections 55 are sleeved over the respective driving couplers 54 to extend the shaft of each screw anchor 52 above ground level.It should be noted that depending on the required height above ground level, the screw anchors 52 can be used alone, i.e., without the need for upper legs 52. A truss adapter or cap, such as adapter 60, is then used to join each upper leg 55 (or screw anchor 52) to form a unitary truss foundation 50 in the form of an A-frame. In various embodiments, and as shown, the adapter 60 provides a bearing surface 62 and may include a pedestal 64, with a threaded anchor bolt opening, an anchor protecting the pedestal 64, or other structure for mechanically coupling the adapter 60 and, by extension, the foundation 50 to the structure it will support. Figure 3B shows section 100 of a precast slab forming part of the foundation as well as the subfloor or base of the prefabricated structure according to various embodiments of the invention. In some embodiments, prefabricated modular building components can be placed directly on top of slab 100. In other embodiments, finished surfaces (e.g., radiant heat, tiles, hardwood, etc.) can be installed directly on top of the precast slab without the need for floor framing or a subfloor. In several embodiments, the precast slab 100 is formed into regular modular shapes (e.g., rectangles of 304.8 cm x 609.6 cm (10 ft x 20 ft)) that can be interconnected in common or adjacent planes to form larger structures. In other embodiments, it can be formed into custom shapes to fit the footprint of the structure.In various embodiments, precast slabs are constructed by pouring concrete into formwork that has the correct outside dimensions, is filled with reinforcing bars and / or wire, and has protrusions that create through holes or voids 108, 110, 130 at the desired locations for the foundation interface, utility connections, and / or lifting points. In some embodiments, conventional concrete mixes may be used. Others may require stronger and / or more flexible formulations to accommodate the forces of cable-based post-tensioning. In the example in Figure 3B, a series of through-holes 110 have been formed in the precast slab 100 at the points where it will be supported by foundations, such as, for example, foundation 50 shown in Figure 3A. Utility through-holes 130 can be formed separately in the center of each slab 100, or elsewhere, to allow utility connections (e.g., water, sewer, electricity, natural gas, etc.) to pass through. Smaller through-holes, such as holes 108, can be used as lifting points to allow the precast sections 100 to be fixed by cranes onto a foundation array. Perimeter cutouts 105 can be formed around the outside of each slab 100 at various points. Such cutouts 105 can be used to join one slab to an adjacent one. The cutouts 105 can also be used as lifting points, eliminating the need for separate holes 108.One or more of the through-holes 105, 110, and 130 may be reinforced with metal or preformed metal shapes that create voids, as well as with integral reinforced steel interface sections to mechanically interconnect the slab to the frame foundations or other structures. These shapes may move within the formwork before being locked in place and are numbered to specifically match the foundation requirements of the particular site. When fabricating the 100 slab, a layer of PRECON or another suitable material can be placed inside the formwork used to create the precast 100 section to form a water barrier at the bottom, as well as in utility cutouts, foundation interface openings, and lift points before the concrete is poured. PRECON is a composite sheet membrane manufactured and sold by WR Meadows of Hampshire, IL, which forms a mechanical bond with the poured concrete as it cures. It should be noted that other products from different manufacturers that function similarly can also be used. Once the concrete has set, these precast sections can be loaded onto a truck, train, or shipping container with the framing members and can be shipped as a kit for assembly on the home site. Turning now to Figure 3C, this figure shows a cross-sectional detail of a through-hole 110 for interconnecting the slab 100 with the foundation 50 according to various embodiments of the invention. In this example, the hole 110 consists of metal-reinforced side walls 113 resting against the walls 112. The metal-reinforced side walls 113 may consist of a box that sits in the formwork used to create the slab 100. In the cross-sectional view of Figure 3C, the walls 112 and the box 113 define a two-sided profile that houses the sliding transfer bar 114. In various embodiments, the transfer bar 114 fits within the extended sides 112 to allow the bar to slide along the profile in one direction (X or Y) in the plane (without movement in the Z direction).This will allow the bar 114 to move easily to compensate for any in-plane misalignment between the through-hole 110 in the foundation and the adapter 60. Figure 3D provides an aerial view of the opening 110. As shown, the transfer bar 114 may preferably have one or more long grooves 115 formed in it to compensate for misalignment in the other direction of the plane orthogonal to the direction of the bar's sliding. The groove 115 in the transfer bar 114, along with the bar's ability to move back and forth within the metal-reinforced opening 113, allows for the compensation of up to several centimeters of misalignment in two directions between the through-hole 110 and the adapter 60 without any impact on the integrity of the connection. This will prevent foundation misalignment from propagating through the building supported by the slab 100.It should be noted that, although not shown in Figure 3B, slab 100 can also have a series of anchors around its perimeter that project above the surface of slab 100 to connect to the prefabricated house, modular home, or other structure lowered and / or built on top of it. These anchors can be easily placed inside the formwork before pouring the concrete to ensure they are correctly positioned. Continuing with reference to Figure 3C, the anchor bolt 116 projects upward through the transfer bar 114 via the slot 115. In various embodiments, a tray such as tray 120 is placed in the through-hole 110 above the bar 114. A nut such as nut 118 is used to secure the tray 110 to the adapter 60 via the bolt 116. It should be noted that in various embodiments, the bolt 116 can pass from above the tray 120 to the adapter 60 through the slot 115 of the transfer bar 114. In various embodiments, once the tray 120 is secured, a layer of PRECON 122 or other suitable material can be placed on the tray 120 before filling it with concrete 124, bentonite, or other suitable filler to create a watertight seal. Figure 3D shows a portion of hole 110 viewed from above, with the transfer bar 114 and slot 115 visible from above. This view is consistent with the view after slab 100 has been lowered onto the foundation. Similarly, Figure 3E shows the same view after tray 120 has been dropped into hole 110. As can be seen, tray 100 has a relatively large opening in its bottom to allow access to the bar in different positions. Turning now to Figure 4, this figure is a flowchart detailing the steps of Method 160 for installing a foundation such as that shown in Figures 3A-E according to various embodiments of the invention. In various embodiments, the installation begins at step 162 by installing multiple screw anchors in the ground at the intended construction site. In various embodiments, this is done according to a plan adapted to the fabrication of the precast slab(s) so that the foundation pedestals align with corresponding openings in the slab. In various embodiments, this can be achieved by unrolling a mat or other template marked with the anchor locations. The mat can also serve as a vapor barrier and / or insect barrier and can be driven into the ground or otherwise secured.As discussed in more detail in this document, screw anchors can be installed in adjacent pairs, tilted towards each other to form the base of an A-frame foundation, or in other embodiments shown in this document, such as vertical monopiles. Once the screw anchors have been screwed in, the apex fittings are installed in step 164. If necessary, this may include attaching the top legs to their respective screw anchors, depending on the amount of elevation above ground required for the particular site. If the screw anchors are installed in adjacent pairs, adapters are used to join the free end of each pair of adjacent top legs. Alternatively, if the screw anchors are screwed in as vertical monopiles, one top leg is attached to each screw anchor, if necessary, and an adapter is attached to the top end of the top leg. In either case, in various embodiments, each adapter will include some leveling adjustment so that the adapters can be adjusted to be level with each other before being locked in place relative to the legs and / or anchors.In various embodiments, as discussed and shown herein, the adapters may include a pedestal, anchor, or other mechanical features to mate with and secure the precast slab. Then, in step 166, a crane is used to place one or more precast slab sections onto the pedestals and / or adapters according to the plan. Manual manipulation of the transfer bars may be performed while the slab is being lowered to allow them to be properly aligned with their respective pedestals. This can be accomplished simply by sliding. Alternatively, a tool may rotate a cam or gear that causes the transfer bar to slide in the plane. In various embodiments, the adapter may have an anchor bolt or other fastener projecting above it that engages a groove or opening in the transfer bar.Once alignment with the respective anchors has been achieved, the entire slab can be lowered to rest completely on the supported transfer bars, which in turn rest on the foundation by means of the adapter and pedestal (see, for example, Figure 3C). In various embodiments, placing precast slab sections on frame or monopile foundations can create a gap between the underside of the transfer bars and the walls of the steel reinforcement at the frame interface openings. In various embodiments, at step 168, the process is completed by securing the slab and sealing the through-holes. In various embodiments, to achieve this, an installer can approach from the top of the slab to place a bentonite clay plug in the gap between the transfer bar and the walls to prevent water from flowing past the transfer bar. Bentonite clay can be particularly useful in this application because it remains flexible for extended periods without losing its cohesion. It should be noted, however, that other materials can also be used instead of or in addition to bentonite clay.For example, foam sheets or other suitable material can be placed in the profiles below the transfer bar, as these lower profiles are not load-bearing. Once the gap has been sealed, a tray can be dropped into each opening at the framing interface. The tray can have a large cutout in its bottom to accommodate the different positions of the transfer bar and anchor. Similarly, a large retaining nut can be screwed onto the anchor before or after the tray is set. The nut will prevent it from lifting and will secure the tray to the individual framing members. In some embodiments, the tray can be lined with a sheet of PRECON or other suitable material. In some embodiments, the anchor will be pressed through the PRECON layer or an opening will be cut in it to allow the bolt to pass through.A non-shrink grout or other suitable material can then be placed in the tray. In various embodiments, this will make the lattice interface watertight and prevent water and / or moisture from passing through the interface and coming into contact with the structures or components above. It should be noted that in various embodiments, the tray can be omitted, and the non-shrinking concrete or grout can be poured directly onto a layer of PRECON in the interface opening. In locations where water ingress is not a concern, this step can be omitted or replaced with a pest barrier to prevent insects, termites, and / or rodents from passing through the foundation. Similarly, as shown in Figure 3C, the anchor bolt is shown as a static member projecting above the adapter. It should be noted that the anchor bolt can have a hexagonal or star-shaped opening on its upper surface that can receive a tool to allow rotation of the bolt.In various embodiments, the rotation can raise or lower the pedestal relative to the adapter and provide a mechanism for micro-leveling the precast slab after its placement or for leveling the pedestal relative to the surrounding pedestals before the precast slab is placed. Turning now to Figure 5, this figure shows a precast slab 200 according to various other embodiments of the invention. Instead of the large truss interface opening in the slab of Figures 3B / C, such as the openings 110 in slab 100, the foundation interface openings 210 in the slab 200 shown in Figure 5 are recessed and shaped specifically to match the geometry of the pedestals supported by each foundation. In this example, the geometry of each opening is a tapered cuboid, but it should be appreciated that other shapes, including pyramids, posts, cuboids, cones, etc., may be used instead. Like the slab 100 shown in Figures 3B / C, the slab 200 also includes utility cutouts or openings 230 and various lifting point openings 208.The lifting point openings 208 could contain a lining and a reinforcing metal bar, as shown, for example, in Figure 9B, or alternatively, they could simply be openings that receive a removable lifting plate, such as lifting plate 405 as shown in Figure 9A. Similarly, like slab 100 in Figures 3B / C, slab 200 in Figure 5 includes several coupling joints 205 around its perimeter, which in the example are shown as semicircular openings with a metal bar through them. These can be used to join adjacent slabs to form a larger slab structure, for example, with a connector such as connector 425 shown in Figure 10. In that case, the tabs 426 will fit between the wall of the opening and the bar of adjacent slabs 200, locking them together. Alternatively, or additionally, these joints can be used to hang trim pieces, pipes, ducts, or other structures, to pull communication lines, or for any other purpose. With the foundation set back from the outer edge of each slab 200, the trim pieces can be hung flush with the outer wall by means of the joints 205.As with the precast slab 100 of Figures 3B / C, the slab 200 can also be formed with a PRECON layer attached to its underside that extends around the sides and upwards into all through holes (e.g., lifting points 208, utility cutouts 230 and lattice interface openings 210). The remaining figures and the corresponding analysis show interfaces that can be used to connect precast members to truss foundations or monopile screw anchors according to various embodiments of the invention. Starting with Figure 6A, this figure shows a portion of the precast slab 200 of Figure 5 with a truss foundation 70 beneath it. The truss foundation 70 shown here consists of a pair of legs extending below and above the ground, inclined toward each other, and connected by adapter 74. In this example, the support plate 77 rests on the upper surface 75 of adapter 74. The support plate 77 may have a pair of holes 78 or other suitable features to enable it to be securely attached to adapter 74. The plate 77 may also have an integral pedestal 79 formed on its upper surface.In various embodiments, the pedestal 79 is fixed to the plate so that it can move or pivot around the plate surface in different positions to enable it to match the position of the corresponding void in the slab interface opening to compensate for any misalignment when placing slab 200. Alternatively, the interface opening 210 can also rotate or slide in the plane in a manner similar to the transfer bar shown in Figure 3C, so that each opening can be positioned directly above and in the correct rotational orientation to receive one of the pedestals.For example, as shown in the cutaway view of Figure 6A, the interface opening 210 may, in fact, be constructed from a plate captured within the opening that can slide in the X and Y directions and / or rotate in the plane to enable it to be precisely oriented so that the opening 211 is directly above the pedestal 79. In the example of Figure 6A, the washer 212 sits on the opening 210 of the interface after the slab 200 has been lowered onto the pedestals 79 to create a flat surface. An anchor bolt, such as bolt 213, can pass from above through the washer 212 and into a threaded opening in the top surface of the pedestal 79. Alternatively, the pedestal 79 can contain an anchor that projects above it. In such embodiments, the anchor bolt 213 shown in Figure 6A will be replaced by a retaining nut. Such modifications are within the spirit and scope of the invention. Although not shown, after the slab 200 has been secured with the anchor bolt or other fastener, the opening 210 containing the bolt and washer can be filled with non-shrink grout or other suitable material to create a uniform, watertight top surface for the slab 200. Figure 6B shows a slab-foundation interface similar to that in Figure 5A, but the frame foundation 70 has been replaced by a single, vertically oriented monopile foundation 80. In various embodiments, the monopile foundation 80 consists of a single screw anchor 82 bolted substantially vertically into the supporting soil with an upper leg attached to it, if required. An adapter 84, similar to the adapter 74 shown in Figure 6A, is then placed on top of the anchor or leg 82, and the remaining connections are made in the same manner as in the context of Figure 6A, with the same possible modifications. Turning now to Figures 7A and B, these figures show another example interface between the precast slab 200 and screw-anchored foundations according to various embodiments of the invention. The precast slab portion 200 is substantially the same as that shown in Figures 6A and B, with the same possible modifications. The differences lie in the adapter and the pedestal used to support it. In the example in Figure 7A, the adapters 93 are cross-shaped with four anchor bolts 96 projecting upwards into the slab 200. The support plate 240 is attached to the adapter 93 so that the anchor bolts 96 pass through it and are secured with the corresponding nuts (not shown). The pedestal 244 is formed from or attached to the support plate 240 in a tapered cuboid shape.In various embodiments, the cuboid pedestal 244 can be rotated about a pivot point on the surface of the plate 240 in the plane to allow the pedestal 240 to be aligned with the corresponding cuboid opening 231. Alternatively, the foundation interface opening 210 in the recess of the slab 200 can include a plate 230 that is trapped within the slab but can be rotated and / or moved in the X and Y directions in the plane (without changing in the Z direction) to ensure a fit between the pedestal 244 and its corresponding opening 231. In various embodiments, the washer 212 under the anchor bolt 213 can be small enough to allow it to move within the recess 210 to accommodate the fit between each pedestal 244 and its corresponding opening 231. Figure 7B shows substantially the same interface as Figure 7A, except that the truss foundation 90 has again been replaced with a vertical monopile foundation consisting of a single-screw anchor 92 screwed in a substantially vertical orientation. If required, an upper leg (not shown) can be attached to the above-ground end of the screw anchor 92. The precast slab 200 and its interface components are otherwise identical to those shown in Figure 7A. Turning now to Figures 8A and B, these figures show yet another simplified interface between the precast slab section 300 and the foundations 130 and 140, respectively, according to various embodiments of the invention. Starting with Figure 8A, the interface shown here consists of the adapter 135 with a single anchor bolt 138 projecting upward from its upper surface 137. In this exemplary embodiment, the anchor bolt 138 is received within the interface opening 312 of the recess 310 when the slab 300 is seated on the adapter 135. The large washer 315 fits over the anchor bolt 138, and the retaining nut 318 is secured to the head of the anchor bolt 318. Although not shown in this figure as an example, a plate or other force propagation structure may be placed on top of the adapter 135 to distribute the weight of the precast slab 300 over a larger surface area.Similarly, as discussed herein, the anchor bolt 138 may have a hexagonal, star-shaped, or other shaped opening in its head, such that inserting a tool into that opening and rotating it will raise the top portion 137 of the adapter 135 in contact with the slab to raise (or lower) the slab level at that interface. This can be done before, during, or after placing the slab 300 into the adapter 135. In various embodiments, the opening 312 will be much larger than the diameter of the anchor bolt 138 to compensate for any misalignment between the bolt 138 and the opening 312. Likewise, the size of the recess 310 around the opening 312 relative to the size of the washer 315 will allow the retaining nut 318 to be secured in multiple different XY locations without compromising the integrity of the connection.Figure 8B shows an interface similar to that in Figure 8A, but the truss foundation 130 has been replaced again by a vertical monopile foundation 140. The components above adapter 145 are substantially the same as those shown and discussed in the context of Figure 8A. Turning now to Figures 11A and B, these figures show yet another foundation system according to various other embodiments of the invention. The components of the system 450 include leveling bar sections 460 and screw anchor members 470. The leveling bar sections 460 can be formed from concrete, reinforced concrete, or another aggregate solution that is poured into a mold and hardened. In various embodiments, the sections are universal. In other embodiments, they can be formed to a specific dimension and numbered or otherwise marked with indications that correspond to the foundation plan of the structure. Each section 460 can include additional through-holes that enable them to be securely connected to each other and to the upper end 474 of the anchors 470.In various embodiments, and as shown in Figure 11A, the transition portion 466 of the bar may have a curved surface to enable the next adjacent section 460 to be oriented at an angle to that, provided that the openings 464 in the surface 462 are aligned. In various embodiments, the bolt or fastener passes through the washer 472 into the opening 464 and is received in the threaded opening 476 in the head portion 474 of the screw anchor 470. The underside of the section 460 rests on the support surface 475 to maintain level. In various embodiments, the head portion 474 can be rotated with a bushing-type tool to raise or lower the head portion 474, which includes the support 475, to adjust the level of the section 460 after it has been placed in the screw anchor 470. Similarly, as shown in Figure 11B, after adjacent sections have been joined by the bolt 470 to other means, an anchor such as the anchor 482 can be inserted above the bolt 470 in the hole 464, and the remainder of the hole is then filled with grout 482 or other suitable material.In various embodiments, the opening 464 will be large enough to allow the anchor bolt 480 to be moved into the proper orientation to match the rest of the structure to be placed or built on the 460 leveling bars. In various embodiments, the 460 leveling bar sections will be designed based on the specific plans of the structure to be erected so that the anchor bolts are located in the desired positions. Similarly, it should be noted that adjacent leveling bar sections can be joined directly, i.e., not by means of a screw anchor penetrating the ground. In other words, each leveling bar section can be placed on top of one or more screw anchors, but the connection between adjacent sections can be made with fittings that only penetrate the two overlapping sections and do not extend into the supporting soil below. I f\?to7f\r77f\7Γ3ΙΎ Figure 12 is a flowchart detailing the steps of a method for installing a foundation system like the one shown in Figures 11A and 11B. Method 500 begins at step 505, where the various anchors used to form the foundation are installed. As discussed herein, this may involve rotating them in the ground with a rotary driver using a combination of downward force and torque at precise locations indicated on the foundation plan. The anchors may extend around the perimeter of the structure only, or alternatively, they may also intermittently pass through intermediate perimeter connection sections as required.In various embodiments, the anchors are screwed in a vertical or orthogonal orientation to the desired placement of the leveling bars so that the height of the upper end of each anchor is very consistent in relation to other anchors in the same foundation. Subsequently, in step 510, after all the screw anchors have been consistently screwed in according to the foundation plan, the leveling bars are placed on the anchors. In various embodiments, this is achieved by hoisting each section of leveling bar with a crane and lowering it so that at least one opening formed in the bar aligns with the head of one of the corresponding screw anchors. The bar is lowered until it rests on the bearing portion of the screw anchor head. As discussed earlier in the context of Figures 11A and B, it may be possible to rotate the anchor head with a tool to raise or lower the bearing portion, thereby raising or lowering the leveling bar to level it. This process can be repeated until each leveling bar forming the foundation has been placed on the screw anchors. Subsequently, in step 515, each bar is secured to its adjacent bar. As discussed earlier, in some embodiments, screw anchors can pass through the flush bars at the overlap joint between each bar, eliminating the need for this step. In other embodiments, however, separate fittings can be passed through the overlapping portions of each adjacent bar to lock them together. Each opening through the bars, whether for joining two adjacent bars, connecting the bars to their respective screw anchors, or both, is then filled with grout or another suitable material for sealing. The joints between adjacent bars can also be grouted and / or insulated to prevent the ingress of water, air, and insects. Next, the process is completed in stage 520 by placing anchor bolts or other tie-down structures in the grouted openings to support the structure that will be set up or built on the foundation. The various precast foundations and slabs shown in this document will provide a modular, transportable, and easy-to-install system that will rapidly increase the deployment of modular and prefabricated housing and other structures. They will also provide a uniform and predictable foundation that can very accurately and consistently predict foundation costs per square centimeter, regardless of site conditions and with minimal site preparation prior to construction. The embodiments of the present inventions should not be limited in scope to the specific embodiments described herein. Indeed, various modifications of the embodiments of the present inventions, in addition to those described herein, will be evident to those skilled in the art from the foregoing description and the accompanying drawings. Therefore, such modifications are intended to fall within the scope of the following appended claims. Furthermore, although some embodiments of the present invention have been described herein in the context of a specific implementation in a specific environment for a specific purpose, those skilled in the art will recognize that their usefulness is not limited to such an implementation and that the embodiments of the present inventions can be advantageously implemented in any number of environments for any number of purposes.Therefore, the claims set forth below must be interpreted in light of the spirit and intent of the realizations of the present inventions disclosed herein.

Claims

1. A foundation system comprising: a first plurality of screw anchors; and a second plurality of leveling bar sections, each leveling bar section comprising an elongated concrete structure adapted at each end to overlap with an adjacent leveling bar section and to be supported from below by at least one of the first plurality of screw anchors.

2. The foundation system according to claim 1, characterized in that each screw anchor comprises a head portion that is received in an opening formed in one of the flush bar sections.

3. The foundation system according to claim 2, characterized in that a lower end of the head portion terminates in a support having a wider diameter than the opening.

4. The foundation system according to claim 3, characterized in that the head portion can rotate relative to the screw anchor portion to raise and lower the support relative to the screw anchor after the leveling bar portion has been lowered onto the head portion.

5. The foundation system according to claim 1, characterized in that it further comprises a fastener that passes through a portion of each overlapping leveling bar section to join them together.

6. The foundation system according to claim 5, characterized in that it further comprises at least one anchor bolt extending above at least one of the leveling bar sections.

7. A foundation system comprising: at least one screw anchor; and at least one precast concrete section that is supported by the at least one screw anchor in a preformed through hole formed in the precast concrete section.

8. The foundation system according to claim 7, characterized in that it further comprises an adapter fixed to one end above ground of at least one screw anchor to support the precast concrete section in the preformed through hole.

9. The foundation system according to claim 8, characterized in that it further comprises an anchor bolt for attaching the adapter to the precast concrete section by means of the through hole.

10. The foundation system according to claim 7, characterized in that the precast concrete section is a precast concrete slab.

11. The foundation system according to claim 7, characterized in that the precast concrete section is a precast leveling bar.

12. The foundation system according to claim 7, characterized in that at least one screw anchor comprises an elongated hollow shaft with a threaded portion at one end and a head portion at an opposite end.

13. The foundation system according to claim 12, characterized in that the head portion terminates at a lower end in a support having a larger diameter than the preformed through hole.

14. The foundation system according to claim 12, characterized in that the rotation of the head part through the precast concrete section moves the head part and the precast concrete section relative to the elongated hollow shaft.

15. A method for forming a foundation for a structure comprising: screwing at least one screw anchor into the supporting soil at a foundation site; and placing a precast concrete section over the at least one screw anchor so that it is supported by the at least one screw anchor.

16. The method according to claim 15, characterized in that screwing the at least one screw anchor comprises screwing the at least one screw anchor in a predetermined position to the support part of a precast concrete slab.

17. The method according to claim 16, characterized in that placing the precast concrete section onto the at least one screw anchor comprises placing the precast concrete slab in an adapter connected to the at least one screw anchor such that the adapter is aligned with a through hole formed in the slab. 5 18. The method according to claim 15, characterized in that screwing the at least one screw anchor comprises screwing at least one screw anchor in a predetermined position into a portion of a precast flush-bar foundation section.

19. The method according to claim 18, characterized in that 10 placing the precast concrete section on the at least one screw anchor comprises placing the precast leveling bar section on the at least one screw anchor so that a head of the at least one screw anchor is received in the opening formed in the precast leveling bar section.

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