Patent Application
20250019958
An aspect of the present disclosure is a structural unit that includes an inner frame having at least one side, an outer frame having at least three sides, and a connecting element, where both the inner frame and the outer frame are positioned parallel to a first reference plane (the xy-plane), the inner frame is positioned within the outer frame, the connecting element physically connects the inner frame and the outer frame, and the connecting element is positioned parallel to the first reference plane.
In some embodiments of the present disclosure, the inner frame may have a cross-sectional shape that is at least one of circular, elliptical, rectangular, and/or polygonal. In some embodiments of the present disclosure, the outer frame may have a cross-sectional shape that is at least one of triangular, rectangular, and/or polygonal. In some embodiments of the present disclosure, the inner frame and the outer frame may form a space, and the connecting element may be positioned within the space. In some embodiments of the present disclosure, at least a portion of the inner frame may be in direct physical contact with the outer frame. In some embodiments of the present disclosure, the inner frame may not be in direct physical contact with the outer frame.
In some embodiments of the present disclosure, the outer frame may have a square cross-sectional shape having four sides, and the inner frame may have a circular cross-sectional shape having one continuous side. In some embodiments of the present disclosure, the structural unit may include two or more connecting elements. In some embodiments of the present disclosure, a structural unit may have two or more inner frames, where each of the two inner frames is positioned within the outer frame.
An aspect of the present disclosure is a structural system that includes at least one structural unit as described. In some embodiments of the present disclosure, a structural system may include two or more structural units and a vertical support, where each structural unit may be positioned adjacent to at least one other structural unit, and the vertical support is positioned between two structural units. In some embodiments of the present disclosure, the vertical support may be constructed using at least one of a wooden beam or a metal beam. In some embodiments of the present disclosure, a structural system may include two or more structural units and a horizontal support, where at least one structural unit is positioned in physical contact with the horizontal support.
In some embodiments of the present disclosure, a structural system may include a first group of structural units and a second group of structural units, where the first group includes two or more structural units, the second group includes two or more structural units, and both the first group of structural units and the second group of structural units are positioned parallel to a first reference axis (the x-axis). In some embodiments of the present disclosure, the first group may positioned above the second group relative to a second reference axis (the y-axis). In some embodiments of the present disclosure, a structural system may further include an extension physically attached to at least one of the structural unit or a horizontal support and the extension is positioned parallel to a reference axis (the y-axis).
An aspect of the present disclosure is a housing system that includes a structural system as described herein, and a wall unit, where the wall unit is positioned adjacent to the structural unit. In some embodiments of the present disclosure, a wall unit may include a vertical beam and horizontal beam. In some embodiments of the present disclosure, at least one of the vertical beam and the horizontal beam may be constructed of a wood. In some embodiments of the present disclosure, the wall unit may further include at least one support rod physically attached to at least one vertical beam and/or horizontal beam.
An attainable housing solution for Alaska faces numerous challenges, despite the state's abundance of timber resources. Remote and predominantly Alaska Native communities—many facing community relocation due to climate change—are burdened by insufficient, unhealthy, and inefficient housing. Most new residential construction being built today are not simple to build, do not utilize local lumber resources, and they are not moveable, convertible, retrofittable, or expandable-all characteristics that housing should be in the Alaskan context and many other extreme environments. Thus, there remains a need for sustainable housing options as well as structures and systems designed for the construction of sustainable housing, in addition to other structures.
Some embodiments of the present disclosure are illustrated in the referenced figures of the drawings. It is intended that the embodiments and figures disclosed herein are to be considered illustrative rather than limiting.
The embodiments described herein should not necessarily be construed as limited to addressing any of the particular problems or deficiencies discussed herein. References in the specification to “one embodiment”, “an embodiment”, “an example embodiment”, “some embodiments”, etc., indicate that the embodiment described may include a particular feature, structure, or characteristic, but every embodiment may not necessarily include the particular feature, structure, or characteristic. Moreover, such phrases are not necessarily referring to the same embodiment. Further, when a particular feature, structure, or characteristic is described in connection with an embodiment, it is submitted that it is within the knowledge of one skilled in the art to affect such feature, structure, or characteristic in connection with other embodiments whether or not explicitly described.
The present disclosure relates to structural units and structural systems that, among other things, can be used to construct buildings that can be substantially airtight, energy efficient, cost effective, and operational in extreme temperature environments. In some embodiments of the present disclosure, the structural units are modular, interchangeable, exchangeable, transposable, and/or customizable, enabling the quick and easy assembly of a variety of structures, including residential and commercial buildings and spans such as bridges.
The structural systems described herein include structural units that provide “building blocks” which may be linked in both horizontal and vertical directions. The units may also be linked and oriented in a horizontal plan for applications like decking, floors, or roofs. These structural units may be site assembled, disassembled, reassembled, and reconfigured in-situ and can simultaneously provide vertical support, lateral support, and seismic resistance (torsional resistance). The units may be unitized, assembled into larger blocks, cassettes, panels, or columns, on or off-site, and be installed as a unitized prefinished assembly or as an unfinished structural assembly
The most basic “building block”, referred to herein as a “structural unit” includes an inner frame, which in some embodiments of the present disclosure includes a steel ring, which is connected via a connecting element such as a gusset, a web, a plate, and/or spokes to an outer frame, which in some embodiments is square or rectangular in shape. The result is analogous to a steel I-beam where the inner frame is functionally the bottom flange of the I-beam, the outer frame is the top flange, and the connecting element between the inner frame and outer frame is the connecting plate of the I-beam. Unlike an I-beam, the structural units described herein provide structural support in all directions including resisting twist. In some embodiments of the present disclosure, a structural unit may be similar to a type of box beam than an I-beam depending on the geometry of the inner frame and/or the outer frame and the connecting element between the inner frame and outer frame. In this way, the structural units of the present disclosure are more analogous to a reinforced concrete wall. In some embodiments of the present disclosure, the structural units of the present disclosure can be easily combined to build useful structures by utilizing standardized dimensions and connection points in a variety of sizes that are interchangeable. The result is a structural unit that can be easily produced, shipped, handled, and rapidly assembled and capable of meeting a broad range of structural applications.
The structural units can be linked together horizontally to produce a torsion resistant truss and be further combined to create a grid akin to a torsion box or box truss that performs like a robust space frame. The structural units can also be combined vertically to create seismic and shear resistant columns, cores, or walls. This combination of vertically and horizontally linked structural units results in a matrix, i.e., structure, where the forces are distributed throughout all the structural units while continuing to provide a direct vertical load path. The structural units can also be combined and stacked with the outer frame positioned in the diagonal direction in which case the vertical loads are transferred, distributed, and transferred through the adjacent structural units. The structural units may also be used as connecting nodes between structural beams. The ability of the structural units to share and distribute loads enables them to be used to create comparatively lightweight and rigid structures. With these properties, it is possible to construct steel structures that have the rigidity of reinforced concrete. Unlike reinforced concrete, the units can be easily disassembled and reused. The building blocks can also be tuned to meet a wide range of engineering load requirements, including torsional stiffness, vertical and lateral loads, and cyclical loads, stiffness, and/or ductility.
Panel A of
Referring again to Panel A of
Referring again to Panel A of
Panel A of
An example of a connecting element 130 is also illustrated in both Panels A and B of
Referring to Panel B of
Panel A of
Referring again to
Referring to
In addition,
Further, like a connecting element 130 occupying a fraction, SAc, of a space 140, e.g., the interstitial spaces formed between an inner frame 110 and an outer frame 120, the total area positioned within and including the sides of an inner frame 110 can occupy a fraction of the space positioned within and including the sides of an outer frame 120. As defined herein, the fraction of space, SAf, of an inner frame 110 positioned within the space of an outer frame 120, is defined as the surface area of the inner frame 120 in the xy-plane, e.g., the surface area contained within the sides 115 defining the inner frame 110 divided by the surface area contained within the sides 125 defining the outer frame, e.g., the surface area contained within the sides 124 defining the outer frame. For example, if an outer frame 120 has a square shape and an inner frame 110 also has a square shape that is formed to be just marginally smaller than the outer frame 120, such that all of the outer surfaces of the sides 115 of the inner frame 110 are in direct contact with all of inner surfaces of the sides 125 of the outer frame 120, SAf equals to 1.0. On the other extreme, if no inner ring 110 is provided at all, SAf equals zero. For the case of a circular inner frame 10 positioned concentrically within a square outer frame 120, where the diameter of the circle equals the length of a side of the square, which equal one, SAf equals ˜0.79: the surface area of a circle divided by the surface area of a square, (π(1)2/4)/(12). In some embodiments of the present disclosure, a fraction of space of an outer frame 120, SAf. occupied by an inner frame 110 may be between greater than 0.0 and less than 1.0, or between 0.10 and 0.90, or between 0.10 and 0.90.
The exemplary elements of a structural unit 100 may be constructed of flat sheets and/or plates of materials, for example plates constructed of steel. However, materials having other forms may be used, for example sheets of corrugated metal. This is illustrated in the exemplary structural unit 100C in
In some embodiments of the present disclosure, an outer frame 120 may have a first length in a first reference direction (the z-axis direction, e.g., depth) between 2 inches and 24 inches or between 3 inches and 16 inches. In some embodiments of the present disclosure, an outer frame 120 may have a second length in a second reference direction (the x-axis direction, e.g., width) between 8 inches and 288 inches or between 16 inches and 144 inches. In some embodiments of the present disclosure, an outer frame 120 may have a third length in a third reference direction (the y-axis direction, e.g., height) between 8 inches and 288 inches or between 12 inches and 144 inches.
In some embodiments of the present disclosure, an inner frame 110 may have a circular cross-sectional shape and a diameter between x inches and y inches or between a inches and b inches. In some embodiments of the present disclosure, an inner frame 110 may have a first length in the first reference direction (the z-axis direction, e.g., depth) between 2 inches and 24 inches or between 3 inches and 16 inches, where the first length (e.g., depth) of the inner frame 110 is less than or equal to the first length (e.g., depth) of the outer frame 120. In some embodiments of the present disclosure, an inner frame 110 may have a second length in the second reference direction (the x-axis direction, e.g., width) between 8 inches and 288 inches or between 12 inches and 144 inches, where the second length (e.g., width) of the inner frame 110 is less than or equal to the second length (e.g., width) of the outer frame 120.
In some embodiments of the present disclosure, wherein an inner frame 110 may be constructed using at least one of steel, aluminum, a wood, a composite, a polymer, and/or concrete. In some embodiments of the present disclosure, an outer frame 120 may be constructed using at least one of steel, aluminum, a wood, a composite, a polymer, and/or concrete. In some embodiments of the present disclosure, an inner frame 110 and an outer frame 120 may be physically connected by at least one of a weld, stamped or pressing together and/or connected by a continuous formed piece of material, fastened by adhesive, mechanically fastened, and/or connected as a single unit by diecast, injection molded, cast, forged, or machined. In some embodiments of the present disclosure, an inner frame 110, an outer frame 120, and a connecting element 130 may be physically connected by at least one of a weld, stamped or pressing together and/or connected by a continuous formed piece of material, fastened by adhesive, mechanically fastened, and/or connected as a single unit by diecast, injection molded, cast, forged, or machined.
As described above, a plurality of structural units 100 may be combined along with other elements to form structures. A simplified example of a structure 200 is illustrated in
The depth (in the z-axis direction) and width (in the x-axis direction) of a vertical support 210 may be adjusted as needed. In the examples shown in
The vertical support positioned between the structural units was a H.S.S steel tube ⅜″ thick×3″ wide×5″ deep×3′-9½″ long. The vertical support had a four-hole pattern at the top and bottom of the 5″ deep side facing the adjacent structural units with weld nuts for ½″ bolts welded into the post. The structural units were bolted to the posts with ½ bolts through the outer frame into the weld nuts in the post. Above the steel vertical supports were T-shaped knife plates which were fastened to the top corners of the structural units and were positioned in the center of the glulam wood posts. Above the knife plates and on either side of the wood posts were support tie-rod connector brackets which were bolted through the knife plate and wood post and through the T-shaped knife plate into the top corners of the structural units. These tic-rod connections transferred all the live lateral loads from the cross-bracing tie-rods into the structural units and steel vertical supports. The knife plates were fabricated with mild A36 steel ¼″ thick×5″ wide×14″ long base×9½″ high knife plate. The base and vertical knife plate were staggered welded together with 3/16″×1-2″ long filets.
The tie rod connections were fabricated with mild A36 steel ¼″ thick×5″ wide×9½″ tall×5¼″ long at the base. The tie rods pinned to the gusset, which was A36 steel ¼″ thick×3″ wide at the top and tapers to 5″ wide at the bottom. The gussets were welded on the centerlines with staggered 3/16″×1-2″ filet welds. Connecting to these brackets were ⅝″ clevis yokes and ⅝″ grade B7 steel tie rods. A right-hand threaded clevis yoke was used at one of each rod and a left hand threaded clevis yoke on the other end. This allowed the tie rods to be tensioned by rotating the rods. The clevis yokes were drop forged with ⅝″-18 threads. The overall length of the rod was 7′-3″ with 4″ threading at each end. The rods were pinned at the top to connectors that were fabricated with A36 steel×¼″ thick×5″ wide×5¼″ long on the horizontal plate×7¼″ long on the vertical plate with a ¼″×3″×5″ gusset stagger weld on the centerline of the angle with 1-2″× 3/16″ filets. The vertical wood posts were 3¼″ wide×5½″ deep×8′-4¼″ long glulams. The distance between the centerline of the posts was 49″ and the distance between the centerline of the beams at the top of the assembly to the centerline of the beams which sit directly above the structural units was 97″. The distance between the centerline of the beams positioned directly above the structural units to the center of the beam of the bottom of the structural unit (not shown) was 49″. The wooden beams located at the top of the structural units are not structurally required.
While a great deal of cold climate building science focuses on wall systems and insulation, walls are simple compared to roofs and foundations. Considering increasing infrastructure damage due to flooding, erosion, and permafrost degradation in many regions, foundations are the biggest challenge facing housing and infrastructure in Alaska and all Arctic, sub-Arctic, and temperate regions impacted by permafrost degradation, erosion, and a similar set of conditions. The structural units and structural systems described herein provide tools to the designer or architect to address these challenging problems.
There is a distinction between a foundation being “out of level”, which does not involve twisting or distortion in the foundation, versus “out of plane”, which means foundation components are at different heights in relationship to each other. Being out of plane puts a great deal of stress on the building that, left unaddressed, causes structural damage and impacts to the efficiency of the building envelope. Foundations designed to remain in plane regardless of being out of level are more robust and much easier to level. Examples include welded, skiddable foundations as used in the oil industry and in Antarctica for modular buildings that are towed across country.
In some embodiments of the present disclosure, the structural systems 105 described herein begin with one or more structural units 100. Other features and elements include vertical supports 210, horizontal supports 205, extensions 310, and footings 315, where each of these have been described. Of course, other elements and components may be added as needed. In some embodiments of the present disclosure, a vertical support 210 may be a 4-foot-long metal post that connects to the glulam frame post (of a wall unit 220) above it and to approximately 4-foot by 4-foot structural units 100 on either side. In some embodiments of the present disclosure, a structural system 105 may include a lower corner bracket that links end wall units and side wall units.
In some embodiments of the present disclosure, when a structural system 105 as described herein is used to construct foundations, an adjustable jack may be positioned directly under a vertical support 210. In some embodiments of the present disclosure, there may only be a jack every 12 feet or under every third vertical support 210 (or fewer or more, depending on the specific load design criteria and environmental conditions). Ellis jacks can also be used for temporary support while assembling the foundation. The structural systems 100 described herein dp not require an Ellis jack—that element could be replaced with any screw, hydraulic, electric, or air jack capable of lifting the house. Replacing it with an adjustable post that uses clamps, pins, or shims may be feasible but may result in the use of separate jacks and the introduction of a hard jacking point to lift the building to make any adjustments.
An extension 310 is a structural connection penetrating the building envelope. In some embodiments of the present disclosure, an extension 310 may connect to the bottom of a vertical support 210 and two adjacent structural units 100. In some embodiments of the present disclosure, an extension 310 may essentially be a steel post that functions as a spacer, will create a gap between the adjustable jack below it and the bottom of the vertical support 210 and structural units 100 above it to allow for the prefinished insulated panels (of wall units 220) to be applied to the bottom of the building without interfering with the adjustable jack.
In some embodiments of the present disclosure, both faces of a vertical support 210 may be substantially symmetrical, with no front or back and identical points of attachment on both sides. Although, in some embodiments of the present disclosure, all vertical supports 210 may be substantially identical, they have three different attachment scenarios depending on location. There are “corner vertical supports” (2 per corner), “jack vertical supports” that are attached to Ellis jacks, and “free span vertical supports”.
In some embodiments of the present disclosure, the two offset corner vertical supports 210 each connect to a lower corner bracket on one side, to a square structural unit on the other side, to the timber posts above them, to the brackets for tension rods (cross bracing to transfer loads), and to an adjustable Ellis jack via an adapter below them.
In some embodiments of the present disclosure, jack vertical supports connect to structural units 100 on either side, to the timber post (e.g., a horizontal beam 224) above them, to the support rod 226 brackets, to the floor trusses, and to adjustable Ellis jacks via an adapter below them.
In some embodiments of the present disclosure, free span vertical supports have the same attachments as jack vertical supports except there is no Ellis jack below them. All vertical supports may also connect to and support any external landings, decks, and stairs, and the entire foundation system must allow access to the back side of the façade to avoid inaccessible interstitial spaces/inner wall cavities.
In some embodiments of the present disclosure, vertical supports can be shipped easily as separate components. They are separate from the wall timber posts (e.g., vertical beams 222 and horizontal beams 224), as opposed to 12-foot-long combined wall and foundation posts. The bottom of each upper timber post connects to the lower vertical supports with a knife plate bracket, which could come prefabricated (welded on) along with gussets (i.e., connecting elements 130) for the cross-bracing connections, but that hardware is not desirable if unneeded, so it is decoupled. There are no integrated support brackets, meaning that brackets for the trusses, for joists, for posts, etc., are all individual components that bolt into the vertical support. This “catalog of parts” approach means easier shipping and handling and the ability to purchase only the elements needed for a specific application.
Decoupled components also enable greater flexibility in building configurations. By decoupling the knife plate and cross bracing brackets that tie into the top of the vertical support and to the adjacent structural units, wall posts may be eliminated under certain conditions to accommodate an 8- or even 12-foot frame opening (for a garage door or sliding glass door). Also due to its decoupled components, the structural systems described herein may work with many other types of wall systems (panelized, frame, SIP, etc.).
In some embodiments of the present disclosure, a vertical support may utilize permanently welded-in attachment points because it may be difficult to reach in and tighten both sides to connect multiple components into it. In some embodiments of the present disclosure, a structural system may include welded studs, which would allow an assembler to attach other components from both sides. However, those may not be removable because they can create a captured space, and may need to be removed to expand the building.
In some embodiments of the present disclosure, a vertical support may have the same 4-hole pattern at the top to connect to a timber post and at the bottom to connect it a jack adjustable foundation support, but the bottom may include an additional 5th center hole. This extra hole can be used for inserting an eye bolt for a ground anchor tie down for high wind locations.
In some embodiments of the present disclosure, the finished dimensions of a vertical support may be at least approximately 3.5″ wide and not exceeding approximately 5.5″ in depth. These dimensions are designed to work with 4×4 foot timber frame posts (of a wall unit 220) but could work with 4×8s or 4×10s (feet×feet). For this example, a vertical support itself cannot exceed the dimensions of a 4×6—it can accommodate deeper posts and maintain grid consistency as long as additional depth is shifted to the exterior because additional post depth cannot be pushed to the interior. The ability to work with a range of post sizes and have the overall system remain the same could allow the foundation (i.e., the structural system 105) to support larger loads (a larger, 2 or 3-story building).
In this example, a structural unit was approximately 5″ deep and approximately 4′ by 4′ square (i.e., outer frame 120) with a circle (i.e., inner frame 110) inside of it that transfers all the loads. Five inches is the standard width of steel flat bar, and another reason for making the structural units are approximately 5″ deep is that pallets are 40″×48″, so eight 5″-deep frames can be stacked on one pallet. This width also works well with the 5.5″ width of 4×6 lumber or an actual 6″ glulam, and it will not work if it is deeper than the framing material because it will create interfacing challenges and impact grid consistency.
For structural systems 105 described herein, a structural unit 100, like a wall unit 220, may be designed designed to have approximately 49″ centers instead of the typical 48″ centers enabling the wall unit 220 to accept a mounted façade panel. It could be adapted to an approximately 48″ center for typical construction, in which case the structural unit would be 0.5″ shorter in both directions. Regardless of its size, in some embodiments of the present disclosure, a structural unit may have a square-shaped outer frame 120 constructed to a circular-shaped inner frame 110.
Additional and heavier hardware and material may be used in structural units designed for extreme environments with higher engineering design criteria and the structural systems described herein can accommodate those extremes. Some locations may not need as robust a system as one designed for use in the Arctic, and the design can simply have costs (weight, material, etc.) removed for the same system to handle low seismic zones or environments with less or no snow loads. There will likely be light, medium, and heavy versions (thicknesses) of the steel flat bar in the structural unit. As with a wall unit 220, another role of a structural unit 100 is to maintain grid consistency and meeting the desired functionalities of a structural system 105. Expansion of, for example a foundation, would not be feasible without a foundation system designed specifically for expanding.
As in wall unit 220, a 3-piece corner assembly may be utilized in a structural system 105 designed for a foundation to prevent the captured corner condition, maintain grid consistency, and allow for expansion. In alignment with upper timber corner posts, two corner vertical supports are offset, forming a 90 degree inside corner, and are connected by a structural lower steel corner bracket that ties the two corner vertical supports together, linking the end wall to the side wall.
In some embodiments of the present disclosure, a lower corner bracket may bolt to the upper frame's steel corner bracket and it may bolt down into a plate at the bottom of the corner vertical supports, tying all three components together and bolts to the adjustable foundation jack. With this configuration, all 12 feet of a corner are continuously supported, although not by a single element. This lower structural bracket is also designed to allow cross bracing from corners and allow racking from end walls to transfer diagonal loads into the side walls.
The two corner vertical supports, combined with the lower corner bracket, may form a square that matches the top plate of the adjustable Ellis foundation jack. A foundation jack may be centered to support both corner vertical supports and the steel corner bracket-nothing is cantilevered.
It is desirable that a lower steel corner bracket be removable without needing to remove any of the adjacent components. Avoiding captured components is difficult, and decoupling the corner bracket allows the system to be expandable in phases, and while the structure (e.g., a building) is in use. The building may be expanded without opening the wall until the last stage, and the panels that come off the end or side wall that are removed may be reinstalled on the addition. To expand, the lower outside insulated corner panel may be removed, exposing the structural steel corner bracket and two corner vertical supports. The corner bracket may be removed without removing any other components, including the adjustable foundation jack and the upper corner bracket. The element may be removed while retaining structural integrity at the corner, and a structural unit may be added in its place and foundation expansion could continue as described above without any interfacing conflicts.
Prior to developing this corner system, it was assumed that the foundation (and house) would only be expandable in one direction. With it, the building could be expanded in either or both directions. Other modular building systems have designed methods to expand the house itself, but none, to our knowledge, addresses expansion of the foundation. This limitation is not significant in the lower 48 or on solid ground but attempting to expand homes in Alaska/on unstable ground without a connected comprehensive foundation presents a high potential of racking and failure.
A conditioned utility corridor can provide flexibility in air distribution. When a structural system like that described herein is expanded, a utility corridor may also be expanded—the home addition has a utility corridor that connects to the original to support shared air, power, and water distribution. Cold outside air may be mixed with heated air in the plenum and released through floor vents, and if new rooms are added, the flexible ventilation system is already there for rerouting of electrical and air ducts. With typical home expansion, it is very difficult to tie in new electric, plumbing, and air distribution, but a conditioned utility corridor allows direct and seamless tie in for MEP without material loss.
For a hypothetical 24′×36′ long building, assembling with the assistance of equipment would allow sections of the foundation to be assembled and then stood up. Building by hand only, the sequence of assembly using a structural system as described herein would begin by assembling and temporarily bracing one corner and two 12-foot sections at 90 degrees from it. Once a crew sets a targeted number of structural units with vertical supports connecting them, a fourth vertical support may be posted/bolted to an Ellis jack which is connected to the ground pad and the system would not need further bracing. The assembly sequence would be: 1) lay out all ground contact pads; 2) bolt an Ellis jack to one corner pad (with only one bolt at first, to allow it to rotate until the section is set); 3) attach (bolt) a corner assembly to the top of the Ellis jack (a corner assembly is two 4-foot vertical supports and one corner connector); 4) temporarily brace that initial corner post; 5) add structural units to either side of the initial corner assembly vertical supports and temporarily support them; 6) add vertical supports to the sides of the structural units; 7) repeat two times: mount two additional structural units and vertical supports in each direction and 8) bolt the third vertical support in both directions to an Ellis jack and the jack to the ground pad.
This building sequence for the structural system described herein has many advantages: it accommodates a typical building sequence from the foundation and floor up, as opposed to balloon framing where a crew drops the floor between the posts. It gives a crew a square and entirely assembled foundation in which to set the trusses, thus enables a crew (including a crew of only two people) to ensure the floor and trusses are squared and entirely assembled before they ever start applying posts. They can then work off the floor to set wall posts and top beams. The latter could be done with merely a step ladder off the floor, as opposed to trying to set a top beam approximately 16 feet off the ground.
In some embodiments of the present disclosure, a wall unit 220 used to build a structure may have approximately 49-inch centers instead of the typical 48-inch centers because the frame must accept the mounted façade panels. The approximately 49″ centers allow for standard 4×8 sheet materials, like the panels are made from, to mount to the frame with the bolts from the pressure plate gasket system between them and the pressure plates clamping their edges. This approximately 1-inch gap in the structural system is extremely advantageous because it provides broad tolerance for panels with some dimensional discrepancy. In other words, it does not need prefabricated components like panels, doors, and windows to have accurate dimensions.
A wall unit prototype was assembled with approximately 3½″×6″ glulam posts and beams. The glulams were dried and acclimatized indoors for a period of time before being dimensioned and jointed (i.e., straightened and squared) to finished lengths, widths, and depths. They were then sanded out or finish-planed in preparation for sealing. To help stabilize the glulams, all lumber components were properly finished (and finished substantially equally on all sides, ensuring the ends, cut, and holes were substantially sealed). Finishing utility-grade (i.e., not architectural-grade) glulams also explored the aesthetic viability of this more affordable engineered wood product in exposed interior applications.
Next, the orientation of each post and beam was determined and ends labeled as needed: location, top/bottom, and interior/exterior faces. The steel brackets were used as guide jigs in combination with the appropriate drill bit size to drill all the holes. Prior to applying the finish, the frame components were sanded lightly one final time. The structural system's prototype frame's base coat was mineral oil cut with odorless mineral spirit and the top-coat was #2-pound cut shellac, 2-part dewaxed garnet, 1-part dewaxed amber, and 1-part dewaxed super blond. Shellac was used because it is non-toxic, applies quickly, is sap resistant, is an excellent vapor retarder, and has a pleasant feel and appearance. Shellac also watermarks so there was condensation or a leak, it would be obvious where it occurred.
The wall unit prototype initially validated the use of 4×6″ glulam beams and posts for the frame of a wall unit. Importantly, the wall unit prototype also validated that those glulam beams could be replaced with conventional 4″×6″ lumber posts. Modeling indicated that a range of other engineered wood products such as LVL could make adequate frame components, or potentially PermaPosts. In some embodiments, properly dried and finished 4″×6″ white spruce posts may perform well and remain adequately stable and true within the tolerances of the gasket system to compensate for wood movement.
In some embodiments, the frame material for constructing a wall unit may not be wood: it could be made from a variety of materials that meet both structural and sustainability design criteria. The materials and products for the system may be determined by proximity and other factors in the region. The final design of the façade of a panel attachment system will be a determining factor for the type of framing material that can be accommodated. To date, the prototypes used in the structural systems described herein have used engineered wood products to reduce the chance of wood movement that might impact the gasket seal.
While the frame demonstrates that normal, utility grade glulams (engineered lumber from second-growth trees) can be finished and used, the locally purchased commercial glulam beams (made from second growth Douglas Fir, likely from the Pacific Northwest) were not properly dried: there were active pitch pockets, indicating that the temperature was not high enough in the kiln to sterilize the wood and set the sap. This means that they are more prone to rot and movement.
Some of the 2-by material in the glulams used had as few as 3-4 rings per 1.5″ due to fast growth, meaning the quality of wood in construction has declined in recent decades. Slower growing second growth Alaska wood is higher quality than lower 48 second growth. White Spruce may be more flexible than Doug Fir, but a second growth Doug Fir board may have 3 rings per inch, whereas a White Spruce board may exceed 30 rings per inch. Because structural analysis of the frame indicated conventional lumber met the criteria, it is almost certain that Alaskan local lumber would be sufficient.
The role of the corner design in grid consistency (where “grid consistency” refers to the placement of a plurality of structural units in 2D and 3D space) and meeting the desired functionalities of the system cannot be overstated. The corner posts should maintain the grid, be removable, and allow for building expansion. In some embodiments of the present disclosure, this may include the use of two offset corner posts to form an inside corner. The two offset corner posts in the timber frame may be connected with a steel upper corner bracket that ties two timber posts together and sets on and bolts into the lower corner structural bracket. Specifically, it may bolt into the lower corner bracket to allow lower bracket removal without exposing the upper bracket. Corners typically have a single post, and a single corner post design can be optimized for a layout that reduces waste on the exterior or the interior, but not both. By decoupling the corner, grid reference lines can be maintained, and both the interior and exterior can be optimized to a 4-foot grid for minimal material processing and waste. Even with deeper posts, corner elements are the components that change-they must be larger to accommodate the larger depth of frame, but the rest of the structural system may remain the same. This approach allows for customization options without custom design work. Decoupling the corner is also the key to future expansion or contraction of the structure while maintaining grid consistency.
In some embodiments of the present disclosure, the structural systems described herein may utilize through bolting for structural connections and includes three reusable connection types: 1) through bolting with a typical nut and bolt; 2) through bolting with a T-nut, where the nut is permanently embedded in the timber. In the case where both sides of a connection cannot be reached and to avoid removing layers to tighten or remove a fastener, the load design criteria can be met with T-nuts; and bolting with the use of threaded wood insert nuts where through-bolt connections are not needed, and structural needs can be met with this product. A prototype included three different sizes of threaded insert nuts: 1) ⅜×1″ for the metal frame brackets; 2) 5/16×1″ for mounting the base plate (of the pressure plate gasket system) and for mounting the Unistrut; and 3) ¼×1″ for mounting electrical boxes, the exterior door, and for future interior furnishings/fixtures.
Douglas Fir is notoriously difficult to drill and screw by hand when precision is critical. The difference between the density of the summer and winter growth rings causes drill bits and fasteners to deflect off the dark hard grain and find the path of least resistance through the soft grain. Guides are needed to resist deflection that can cause missed layout and inserts installed out of perpendicularity. Without quality guides, it would be difficult for less experienced people to achieve consistent results using a cordless drill. While manufacturing could easily address this challenge in production, the goal is a building system that is still simple enough for a small shop or individual to be able to produce the wood components with a simple affordable template and guide set using local wood resources.
Ceiling beams were drilled in location using the bracket as the template and drilling halfway through from both sides.
The brackets for connecting diagonal bracing in a wall unit may be symmetrical, which is particularly important when designing for unskilled labor. The same interchangeable bracket can be used on the left or right side and on the top or bottom of each frame bay, where a bay is the empty space defined by structural components, for example the beams used to make a wall unit. In some embodiments of the present disclosure, the number of bracket variants from 6 to 2, which not only simplifies assembly but cuts costs by streamlining manufacturing. In some embodiments of the present disclosure, there are only two fastener sizes used: ½-inch threaded connections and ¼-inch threaded machine screw or bolt connections.
At least some of the hardware, elements, features describes herein may be manufactured from hot rolled mild steel flat bar. In some embodiments of the present disclosure, cross bracing tension rods may cold rolled steel, which is dimensionally truer and has a better matrix and grain than hot rolled but is more expensive and not made from recycled steel. In some embodiments of the present disclosure, cold rolled steel may be used where aesthetics, structural performance, and dimensional tolerances cannot be met by more affordable hot rolled steel. The US is the world leader in recycled steel and the industry is getting closer to being able to use recycled steel in cold rolled production, which would be a preferred material.
Several knife plate brackets (see
To ensure racking resistance (shear bracing), support rods 226 were installed for cross bracing inside the test hut frame bays in several sections. The rods were left hand threaded on one end and right hand threaded on the other, allowing them to be tensioned. Where rods crossed, a turnbuckle was installed in the center of one rod and the crossing rod was installed through the eye of the turnbuckle. Using ½″ rod, turnbuckles were not necessary to allow the rods to cross, but they would be combined with larger diameter rods with centered symmetrical attachment points. Off-setting attachment points adds complexity to the layout and fabrication of the hardware, and turnbuckles address this issue. Homes in low wind, seismic, and snow load zones could reduce the amount of seismic resistance hardware. The tension rods themselves constitute an adjustable shear resistance system that enables alterations to the home.
Because of the two different wall systems, the structural units experienced peak strain in different locations on the unit. In both instances, the locations where the peak strain occurred can be reinforced with simple adjustments to the connection between the frames and/or the profiles used to form the inner and outer frames without any changes to the overall dimensions, or changes to the points of attachment, or a decrease in any of its functionality.
The ability to be adjusted to meet a wide range of engineering load requirements and applications makes the circular inner frame and square outer frame a unique structural unit that is not solely dependent on increasing the thickness and size of the material to increase strength. Using c-channel in the ring and c-channel in combination with corrugation in the outer frame is only one of many ways in which the strength could be increased and total material and weight decreased.
Example 1. A structural unit comprising: an inner frame comprising a side; an outer frame comprising three sides; and a connecting element, wherein: both the inner frame and the outer frame are positioned parallel to a first reference plane (the xy-plane), the inner frame is positioned within the outer frame, the connecting element physically connects the inner frame and the outer frame, and the connecting element is positioned parallel to the first reference plane.
Example 2. The structural unit of Example 1, wherein the inner frame has a cross-sectional shape that is at least one of circular, elliptical, rectangular, or polygonal.
Example 3. The structural unit of either Example 1 or Example 2 wherein the outer frame has a cross-sectional shape that is at least one of triangular, rectangular, or polygonal.
Example 4. The structural unit of any one of Examples 1-3, wherein: the inner frame and the outer frame form a space, and the connecting element is positioned within the space.
Example 5. The structural unit of any one of Examples 1-4, wherein at least a portion of the inner frame is in direct physical contact with the outer frame.
Example 6. The structural unit of any one of Examples 1-5, wherein the inner frame is not in direct physical contact with the outer frame.
Example 7. The structural unit of any one of Examples 1-6, wherein: the outer frame has a triangular cross-sectional shape having three sides, and the inner frame has a circular cross-sectional shape having one continuous side).
Example 8. The structural unit of any one of Examples 1-7, wherein: the outer frame has a square cross-sectional shape having four sides, and the inner frame has a circular cross-sectional shape having one continuous side.
Example 9. The structural unit of any one of Examples 1-8, wherein the structural unit comprises two or more connecting elements.
Example 10. The structural unit of any one of Examples 1-9, comprising two or more inner frames, wherein each of the two inner frames is positioned within the outer frame.
Example 11. The structural unit of any one of Examples 1-10, wherein the outer frame has a first length in a first reference direction (the z-axis direction, e.g., depth) between 2 inches and 24 inches or between 3 inches and 16 inches.
Example 12. The structural unit of any one of Examples 1-11, wherein the outer frame has a second length in a second reference direction (the x-axis direction, e.g., width) between 8 inches and 288 inches or between 16 inches and 144 inches.
Example 13. The structural unit of any one of Examples 1-12, wherein the outer frame has a third length in a third reference direction (the y-axis direction, e.g., height) between 8 cm and 288 cm or between 16 cm and 144 cm.
Example 14. The structural unit of any one of Examples 1-13, wherein the inner frame has a circular cross-sectional shape and a diameter between 8 inches and 288 inches or between 12 inches and 144 inches.
Example 15. The structural unit of any one of Examples 1-14, wherein: the inner frame has a first length in the first reference direction (the z-axis direction, e.g., depth) between 2 inches and 24 inches or between 3 inches and 16 inches, and the first length of the inner frame is less than or equal to the first length of the outer frame.
Example 16. The structural unit of any one of Examples 1-15, wherein: the inner frame has a third length in the third reference direction (the y-axis direction, e.g., height) between 8 inches and 288 inches or between 12 inches and 144 inches, and the third length of the inner frame is less than or equal to the third length of the outer frame.
Example 17. The structural unit of any one of Examples 1-16, wherein: the inner frame has a second length in the second reference direction (the x-axis direction, e.g., width) between 8 inches and 288 inches or between 12 inches and 144 inches, and the second length of the inner frame is less than or equal to the second length of the outer frame.
Example 18. The structural unit of any one of Examples 1-17, wherein the inner frame is constructed using at least one of steel, aluminum, a wood, a composite, a polymer, or a concrete.
Example 19. The structural unit of any one of Examples 1-18, wherein the outer frame is constructed using at least one of steel, aluminum, a wood, a composite, a polymer, or a concrete.
Example 20. The structural unit of any one of Examples 1-19, wherein the inner frame and the outer frame are physically connected by a weld, stamped or pressing together and/or connected by a continuous formed piece of material, fastened by adhesive, mechanically fastened, and/or connected as a single unit by diecast, injection molded, cast, forged, or machined.
Example 21. The structural unit of any one of Examples 1-20, wherein the inner frame, the outer frame, and the connecting element are physically connected by a weld, stamped or pressing together and/or connected by a continuous formed piece of material, fastened by adhesive, mechanically fastened, and/or connected as a single unit by diecast, injection molded, cast, forged, or machined.
Example 22. A structural system comprising a structural unit according to any one of Examples 1-21.
Example 23. The structural system of Example 22, further comprising: two or more structural units; and a vertical support, wherein: each structural unit is positioned adjacent to at least one other structural unit, and the vertical support is positioned between two structural units.
Example 24. The structural system of either Example 22 or Example 23, wherein the vertical support comprises at least one of a wooden beam or a metal beam.
Example 25. The structural system of any one of Examples 22-24, further comprising: two or more structural units; and a horizontal support, wherein: at least one structural unit is positioned in physical contact with the horizontal support.
Example 26. The structural system of any one of Examples 22-25, wherein the horizontal support comprises at least one of a wooden beam or a metal beam.
Example 27. The structural system of any one of Examples 22-26, comprising: a first group of structural units; and a second group of structural units, wherein: the first group comprises two or more structural units, the second group comprises two or more structural units, and both the first group of structural units and the second group of structural units are positioned parallel to a first reference axis (the x-axis).
Example 28. The structural system of any one of Examples 22-27, wherein the first group is positioned above the second group relative to a second reference axis (the y-axis).
Example 29. The structural system of any one of Examples 22-28, further comprising: an extension physically attached to at least one of the structural unit or a horizontal support and the extension is positioned parallel to a reference axis (the y-axis).
Example 30. A housing system comprising: a structural system according to any one of Examples 22-29, and a wall unit, wherein: the wall unit is positioned adjacent to the structural unit.
Example 31. The housing system of Example 30, wherein a wall unit comprises a vertical beam and horizontal beam.
Example 32. The housing system of either Example 30 or Example 31, wherein at least one of the vertical beam and the horizontal beam are constructed of a wood.
Example 33. The housing system of any one of Examples 30-32, wherein the wall unit further comprises at least one support rod physically attached to at least one vertical beam or horizontal beam.
As used herein the term “substantially” is used to indicate that exact values are not necessarily attainable. By way of example, one of ordinary skill in the art will understand that in some chemical reactions 100% conversion of a reactant is possible, yet unlikely. Most of a reactant may be converted to a product and conversion of the reactant may asymptotically approach 100% conversion. So, although from a practical perspective 100% of the reactant is converted, from a technical perspective, a small and sometimes difficult to define amount remains. For this example of a chemical reactant, that amount may be relatively easily defined by the detection limits of the instrument used to test for it. However, in many cases, this amount may not be easily defined, hence the use of the term “substantially”. In some embodiments of the present invention, the term “substantially” is defined as approaching a specific numeric value or target to within 20%, 15%, 10%, 5%, or within 1% of the value or target. In further embodiments of the present invention, the term “substantially” is defined as approaching a specific numeric value or target to within 1%, 0.9%, 0.8%, 0.7%, 0.6%, 0.5%, 0.4%, 0.3%, 0.2%, or 0.1% of the value or target.
As used herein, the term “about” is used to indicate that exact values are not necessarily attainable. Therefore, the term “about” is used to indicate this uncertainty limit. In some embodiments of the present invention, the term “about” is used to indicate an uncertainty limit of less than or equal to ±20%, ±15%, ±10%, ±5%, or ±1% of a specific numeric value or target. In some embodiments of the present invention, the term “about” is used to indicate an uncertainty limit of less than or equal to ±1%, ±0.9%, ±0.8%, ±0.7%, ±0.6%, ±0.5%, ±0.4%, ±0.3%, ±0.2%, or ±0.1% of a specific numeric value or target.
The foregoing discussion and examples have been presented for purposes of illustration and description. The foregoing is not intended to limit the aspects, embodiments, or configurations to the form or forms disclosed herein. In the foregoing Detailed Description for example, various features of the aspects, embodiments, or configurations are grouped together in one or more embodiments, configurations, or aspects for the purpose of streamlining the disclosure. The features of the aspects, embodiments, or configurations, may be combined in alternate aspects, embodiments, or configurations other than those discussed above. This method of disclosure is not to be interpreted as reflecting an intention that the aspects, embodiments, or configurations require more features than are expressly recited in each claim. Rather, as the following claims reflect, inventive aspects lie in less than all features of a single foregoing disclosed embodiment, configuration, or aspect. While certain aspects of conventional technology have been discussed to facilitate disclosure of some embodiments of the present invention, the Applicants in no way disclaim these technical aspects, and it is contemplated that the claimed invention may encompass one or more of the conventional technical aspects discussed herein. Thus, the following claims are hereby incorporated into this Detailed Description, with each claim standing on its own as a separate aspect, embodiment, or configuration.
This application claims priority from U.S. Provisional Patent Application No. 63/513,603 filed on Jul. 14, 2023, the contents of which are incorporated herein by reference in their entirety.
This invention was made with United States government support under Contract No. DE-AC36-08GO28308 awarded by the U.S. Department of Energy and Grant No. 21-DG-11100106-804 awarded by the U.S. Department of Agriculture/Forest Service. The government has certain rights in this invention.
| Number | Date | Country | |
|---|---|---|---|
| 63513603 | Jul 2023 | US |
