Patent Publication Number: US-2018044908-A1

Title: Cold-formed steel support wall and method of installation

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims the benefit of U.S. Provisional Appl. No. 62/372,547 filed Aug. 9, 2016, the disclosure of which is herein incorporated by reference in its entirety. 
    
    
     BACKGROUND 
     The present invention relates to a cold-formed steel support wall (CFSSW) system and, more particularly, to a method of application which substantially or completely eliminates the need for concrete in the construction of a foundation for a building. 
     The construction and building industries have long used concrete for providing structural support to buildings in adverse soil conditions. A mass of concrete, reinforced with rebar, has been the building standard for foundations of residential and commercial applications. 
     The CFSSW provides compressive resistance for the weight of the structure. Building planning must meet applicable design criteria. Building and structures, and all parts thereof, shall be constructed to safely support all loads, including dead loads, live loads, roof loads, flood loads, snow loads, wind loads and seismic loads as prescribed by the International Residential Code (IRC). The construction of buildings and structures shall result in a system that provides complete load path capable of transferring all loads from their point of origin through the load-resisted elements to the foundation. Additionally, buildings shall be constructed in accordance with provisions of the code and subsequent criteria shall be established by local jurisdiction and set forth in references to wind, flood, termite and decay. 
     The CFSSW provides lateral resistance from outside forces such as wind. Basic wind speeds for 50-year mean recurrence intervals are referenced prominently in coastal regions of the United States. Values are nominal design 3-second gust wind speeds ranging from 90 to 150 mph. Construction in regions where the basic wind speeds equal or exceed 110 mph shall be designed in accordance with, but not limited to, one of the following: 
     Southern Building Code Congress International Standard for Hurricane Resistant Residential Construction (SSTD 10); or 
     Minimum Design Loads for Buildings and Other Structures (ASCE-7); or 
     American Iron and Steel Institute (AISI), Standard for Cold-Formed Steel Framing-Perspective Method for One- and Two-Family Dwellings (COFS/PM). 
     The CFSSW provides axial resistance from outside forces such as rising water when properly secured to an engineered pile. Flood plains are determined by regional guidelines set forth by FEMA. Most prominent adjustments to required base flood elevations are found in the Gulf Coast region after natural disasters such as hurricanes Rita and Katrina. 
     Lateral and axial resistance prevents overturning should natural forces present a danger to the structural integrity of the foundation and building. 
     The CFSSW system comprises metal which is impervious to rot, decay and infestation from termites. Geographical maps indicating the highest probability for termite and decay are also focused on the Gulf South region of the United States. 
     SUMMARY 
     The original purpose of a CFSSW is to lead the way for a reduction in consuming natural resources such as wood friction piles and concrete used in creating a foundation system for a structure targeting specific needs for the Gulf Coast that require raised elevations above base flood elevation dictated by FEMA. This invention and method of installation can be universally used in regions well beyond the Gulf Coast. Industry wide, production of molten steel, which is the raw material for manufacturing CFSSW, is created by using as much as 64 percent recyclable materials such as metal scraps from reclaimed automobiles and appliances. 
     U.S. application Ser. No. 10/974,964 and US Publication Nos. 2005/0144892 A1 and US 2006/0053732A1 describe a similar structure with the application of being a joist to span a distance between opposing walls. The use for this is to provide structural support for a floor, roof, or the like. Other examples of cold-formed steel applications are shown in US Publication No. 2002/0020138 A1 and 2003/0084637 A1 as well as U.S. Pat. Nos. 5,113,631 and 5,496,425. 
     The above structures, however, do not address the issue in this invention of using CFSSW as the preferred method of design and application to become the supporting wall that creates positive attachment to the top of the pile cap or footing, through the CFSSW, to the floor system of the structure. This invention eliminates the need for a monolithic or continuous grade beam and piers typically created by concrete reinforced with rebar. 
     Embodiments of the present invention contemplates design drawbacks associated with the prior art and provisions for constructing a foundation system using masses of concrete reinforced with rebar to provide support and resist movement from lateral forces. 
     It is, therefore, an object of embodiments of the present invention to provide a novel foundation design and structure that is capable of enhancing the total overall load capacity and resistance to over turning by creating a positive connection from the piling or footing below the ground line, through the CFSSW, to the structure. 
     The construction and building industries have long used concrete for providing structural support to buildings in adverse soil conditions. From the beginning, a mass of concrete, reinforced with rebar, has been the building standard for foundations of residential and commercial applications. The CFSSW provides compressive resistance for the weight of the structure. The CFSSW provides lateral resistance from outside forces such as wind. The CFSSW provides axial resistance from outside forces such as rising water when properly secured to an engineered pile. Lateral and axial resistance prevents overturning should natural forces present a danger to the structural integrity of the foundation and building. The CFSSW system consists of metal which is impervious to rot, decay and infestation from termites. The CFSSW is also reusable in the event of changes made to the foundation after installation and creates options for the consumer to have an approved foundation installed for a temporary structure. 
     This and other objects of embodiments of the present invention are achieved through a provision of a CFSSW system, which can be installed in situ for supporting a structure above the ground. The CFSSW system has a positive attachment to the pile caps or footings at or slightly above grade and the floor system of the structure. One of the embodiments provides for the reduction of use of natural resources. Another advantage is compatibility to creating an aesthetically pleasing finished product using light weight exterior finishes such as stucco or HardiePlank siding. 
     These and other advantageous features will become apparent to those reviewing the disclosure and drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  shows an orthogonal view of the cold formed steel support wall assembly to one embodiment. 
         FIG. 2  shows a detailed view of a typical truss configuration for a support wall assembly of  FIG. 1 . 
         FIG. 3  shows a detailed cross section view of a typical bottom chord of a truss for the support wall assembly of  FIG. 1 . A top chord assembly would be identical to the bottom chord only in reverse orientation. 
     
    
    
     DETAILED DESCRIPTION 
     Referring generally to the figures, disclosed herein is a cold formed steel foundation system capable of supporting a building above grade to meet or exceed building code requirements set forth by a governmental agency such as FEMA for new construction in designated flood plain zones for residential and commercial applications using light weight, recyclable building material such as galvanized cold formed steel members. The cold formed steel members are assembled in a truss configuration to support building construction above the ground. A typical configuration consisting of a combination Howe and “K” trusses as shown. The precise configuration of the trusses is dependent upon the specific building to be supported and by site conditions. 
       FIG. 1  shows an orthogonal view of the cold formed steel support wall assembly according to one embodiment of the present invention. As shown in  FIG. 1 , the Main Trusses  1 ,  2  and  3  comprise (MT  1 ,  2  and  3 ) of a cold formed steel assembly in Howe Truss design while the Cross Trusses  1 - 4  (CT  1 ,  2 ,  3  and  4 ) are oriented toward the center in “K” Truss design. Contact with the ground is achieved by vertical support (VS typical) mechanically fastened to a concrete or steel pile or to some other stable support designated by the engineer of record for the specific structure. 
       FIG. 2  shows a detailed view of a typical truss configuration for a support wall assembly of  FIG. 1 . The truss shown is configured based on a specific structural analysis for a particular application. Each subsequent application requires similar analysis to assure compliance with applicable codes and standards. Member sizes, numbers and sizes of connectors, and truss geometry are dependent upon the specific analysis. 
     The depiction illustrates typical location of structural members. Double 550NF150-43 vertical members at the corners (DBL 550), diagonal 550NF150-43 (DIA 550), single 550NF150-43 at 2′ on center (SGL 550), a top chord composite assembly (TC), a bottom chord composite assembly (BC) and 43 MTh×4″ strap spanning the entire truss located equally distant between the top chord and bottom chord perpendicular to the vertical members (STP). 
     Top and bottom chords are composite members consisting of two 43 MIL angles attached to the web of the 550NF150 base member with four #12 sheet metal screws (SMS) per foot per angle. The long legs of the angles are also attached to the flanges of the 550NF150-43 with one #12 SMS at the midpoint between panel points. 
     Vertical members are attached to the chords with a minimum of 6 #12 SMS per side (12 total). Three #12 SMS on each side are placed at the intersection of the flanges of the chord base section and web member. 
     Diagonal members are attached to the chords with 6-11 #12 SMS per side (12-22 total). Three #12 SMS on each side are placed at the intersection of the flanges of the chord base section and web member. 
     In this example, top chord loads vary from 4850 pound compressions to 2650 pound tension; bottom chord loads vary from 4710 pound compression to 2280 pound tension. Web member load ranges vary from 8280 pound compression to 5940 pounds tension. Composite mechanical properties of the top and bottom chords are Ix=5.85 in 4 , Iy=2.44 in 4  and Area=1.078 in 2 . Properties may vary with selection of composite section elements and the results of analysis. 
     A continuous 43 MIL×4″ strap is attached to each side of the truss at the midpoint of the web members with four #12 SMS per intersection. A shorter truss may not require this strap. 
       FIG. 3  shows a detailed cross section view of a typical bottom chord of a truss for the support wall assembly of  FIG. 1 . The side angle members consist of 4½″×2½″—43 MTh L-angle (4.5×2.5 L) while the bottom is a 550NF150-43 MIL C-channel (550 C) mechanically fastened to each other using #12 SMS in designated locations specified by the engineer of record. 
     As shown in  FIGS. 1 and 2 , to install a cold-formed steel support wall system  100 , a plurality of cold-formed steel support wall (CFSSW) sections  50  are provided and connected to one another at predetermined locations specified by an engineer of record. The bottom of the wall sections are connected to tops of exposed pile caps or footings  60 . The tops of the wall sections are connected to the bottom of the floor of a structure of a building. A positive connection is created from the top of the pile cap or footing  60  to the structure of the building using the cold-formed steel support wall  100  in a manner that eliminates and or significantly reduces the need for concrete commonly used in a foundation. 
     In some embodiments, the plurality of CFSSW sections  50  are attached to each other using fasteners described by the engineer of record. In other embodiments, the plurality of CFSSW sections and attaching them to the top of the pile cap or footing protruding from the grade of soil. In some embodiments, the connection is in the form of a bolt extending from the bottom of the CFSSW chord  51  to the load transfer device at the top of a steel helical pile  60 . 
     The CFSSW sections  50  may be attached or connected to the top of the pile cap or footing protruding from the grade of soil. In some embodiments, the connection is a bolt extending from the bottom of the CFSSW chord to an approved anchor system such as a cast in place bolt, commonly referred to as a “J” bolt or other form of threaded rod, at the top of a concrete mass which encapsulates the butt of a friction pile  60  made of wood, fiberglass, concrete, or other suitable material for soil conditions. In other embodiments, the CFSSW sections  50  may be attached to the top of the pile cap or footing  60  using a bolt from the bottom of the CFSSW chord  51  to an approved anchor system such as a hold down bolt, commonly referred as a Simpson Strong-Tie, Titen HD 1 , or comparable bolt, at the top of a concrete mass which encapsulates the butt of a friction pile  60  made of wood, fiberglass, concrete, or other suitable material for soil conditions. 
     In certain embodiments, the CFSSW sections  50  are attached the top of the pile cap or footing  60  and operationally connected to each other at a point of connection such that reversing the method of assembly severs the connection between the CFSSW section  50  and the pile cap or footing  60 , allowing substantially all of the CFSSW section  50  to be retrieved for subsequent re-use. 
     After attaching the CFSSW sections  50  to the top of the pile cap or footing  60  protruding from the grade of soil, the CFSSW sections  50  may then be covered by a cement fiber industry siding product such as HardiePlank 2  lap siding for aesthetic appearance. In some embodiments, the cover includes prefabricated decorative panels composed of reconstituted marble, granite and other stone products such as Eco Walls North America′ faux stone siding for aesthetic appearance. In other embodiments, the cover is a high density polymer product such as Texture Plus 4  faux stone siding for aesthetic appearance. In yet other embodiments, the cover is comprised of a stucco exterior finish, built on site, using typical methods of lath and plaster assembly for aesthetic appearance. In yet other embodiments, the cover is comprised of a wood industry siding product such as cedar milled siding or T-111 panels for aesthetic appearance. In certain embodiments, the CFSSW sections  50  are attached to each other using fasteners described by the engineer of record and are configured to allow for access panels to be configured at key locations for use of installation and maintenance by other trades, such as plumbers and electricians under the structure. 
     It is important to note that the construction and arrangement of the various exemplary 
                                          1  Simpson Strong-Tie   Titen HD   www.simpsonanchors.com       Company Inc.         2  James Hardie   HardiePlank   www.jameshardie.com       International   Lap Siding         3  Eco Walls North   Exterior panels   www.ecowallsnorthamerica.com       America         4 Texture Plus   Exterior panels   www.textureplus.com                    
embodiments are illustrative only. Although only a few embodiments have been described in detail in this disclosure, those skilled in the art who review this disclosure will readily appreciate that many modifications are possible (e.g., variations in sizes, dimensions, structures, shapes and proportions of the various elements, values of parameters, mounting arrangements, use of materials, colors, orientations, etc.) without materially departing from the novel teachings and advantages of the subject matter described herein. For example, elements shown as integrally formed may be constructed of multiple parts or elements, the position of elements may be reversed or otherwise varied, and the nature or number of discrete elements or positions may be altered or varied. The order or sequence of any process or method steps may be varied or re-sequenced according to alternative embodiments. Other substitutions, modifications, changes and omissions may also be made in the design, operating conditions and arrangement of the various exemplary embodiments without departing from the scope of the present invention.