Constructing multi-story buildings using stacked structural steel wall trusses
10584485 ยท 2020-03-10
Assignee
Inventors
Cpc classification
E04B2001/199
FIXED CONSTRUCTIONS
E04B1/2403
FIXED CONSTRUCTIONS
E04B2001/2451
FIXED CONSTRUCTIONS
E04B2001/3583
FIXED CONSTRUCTIONS
International classification
Abstract
The present Stacked Wall Truss Construction and its use in multistory buildings makes use of prefabricated modular wall elements (100) that are interconnected in three dimensions to enable the rapid completion of building construction with improved quality of construction over that found in traditional multi-story building construction. The resultant building is a structural steel frame without the use of stacking columns. Vierendeel trusses (100) with vertical members (101-105) of tube steel are used, thereby the construction process becomes stacking trusses fit up as complete walls, not erecting columns. An inner Mating Member (131-135) enables each truss to be near perfectly positioned on top of the installed truss below.
Claims
1. A method for constructing a multi-story building, comprising: constructing a foundation to support walls of the multi-story building, including a plurality of mating anchors embedded in the foundation, each mating anchor having a top protruding from the foundation; assembling a plurality of wall trusses, each consisting of a moment frame that includes a plurality of vertical members, adjacent ones of which are interconnected only at the top and bottom by horizontal beams, spanning the space between adjacent vertical members and connected to a respective side of the vertical members, the interconnection being fixed joints that are capable of transferring and resisting bending moments, wherein at least two vertical members at each end of the wall truss comprise hollow members; setting the bottom of the hollow members of the vertical members of a set of wall trusses over the protruding top of the mating anchor embedded in the foundation; and filling the hollow members with a predetermined amount of material that forms into a solid mass to create fixed joints.
2. The method for constructing a multi-story building of claim 1, for each floor of the multi-story building, further comprising: inserting a mounting member into the top of the hollow members for each wall truss, where the mounting member protrudes above the top of the hollow tube in which it is inserted; and stacking additional wall trusses on top of the existing wall trusses installed for the floor below, by setting the bottom of the hollow members of a set of wall trusses over the protruding top of the mounting member of the existing wall trusses of the floor below.
3. The method for constructing a multi-story building of claim 2, further comprising: filling the mounting members and hollow members with a predetermined amount of material that forms into a solid mass to create fixed joints.
4. The method for constructing a multi-story building of claim 1, wherein the step of assembling comprises: manufacturing wall trusses comprising Vierendeel trusses with vertical members of tube steel interconnected at the top and bottom by horizontal beams that form rectangular openings, as a frame with fixed joints that are capable of transferring and resisting bending moments.
5. The method for constructing a multi-story building of claim 4, wherein the step of manufacturing further comprises: constructing rigidly-jointed trusses having only vertical members interconnected by the top and bottom horizontal beams which connect to a side of the vertical members which face adjacent vertical members.
6. The method for constructing a multi-story building of claim 1, wherein the step of assembling comprises: manufacturing wall trusses comprising a plurality of vertical members of tube steel aligned in a linear array, with adjacent ones of the vertical members being interconnected by a top beam spanning the space between adjacent vertical members and a bottom beam spanning the space between adjacent vertical members, the interconnection being fixed joints that are capable of transferring and resisting bending moments.
7. The method for constructing a multi-story building of claim 6, wherein the step of manufacturing comprises: interconnecting the bottom beams such that the vertical members of tube steel protrude below the chords beams a predetermined distance.
8. The method for constructing a multi-story building of claim 1, further comprising: attaching floor shelves to the top horizontal beam of a lower one of adjoining stacked wall trusses, wherein the floor shelves extend in a horizontal dimension from the face of the adjoining stacked wall trusses into the interior of the multi-story building.
9. The method for constructing a multi-story building of claim 8, further comprising: depositing floor modules on top of the floor shelves to span the distance between facing wall trusses, wherein the floor modules extend only between the interior faces of the wall trusses.
10. A multi-story building comprising: a plurality of wall trusses interconnected in a three dimensional matrix to form both a plurality of multi-story external walls to enclose a volume of space and a plurality of internal structural partitions which are connected together and to the external walls in at least two planar layers to provide lateral support to the external walls to which they are interconnected; wherein each of the wall trusses, comprises a moment frame that includes: at least first and second parallel oriented, spaced apart hollow columns, each having a top end and a bottom end, adjacent ones of which are interconnected only at the top and bottom by horizontal beams, spanning the space between adjacent vertical members and connected to a respective side of the vertical members, the interconnection being fixed joints that are capable of transferring and resisting bending moments; wall truss mounting members, each insertable into a top ends of the hollow columns of a first wall truss, and the bottom ends of the hollow columns of a second wall truss that is vertically positioned on top of the first wall truss; and joint material, inserted into the wall truss mounting members, and the associated hollow columns, that forms into a solid mass to create fixed joints between the first wall truss and the second wall truss.
11. The multi-story building of claim 10 further comprising: a mating anchors embedded in the foundation, each mating anchor having a top protruding from the foundation for inserting the protruding top of the mating anchor into the bottom of the hollow members of the vertical members of a preconfigured set of wall trusses.
12. The multi-story building of claim 10, wherein said wall trusses further comprise: joint material, inserted into the hollow columns associated with the mating anchors, that forms into a solid mass to create fixed joints between the preconfigured set of first wall trusses and the foundation.
13. The multi-story building of claim 10 wherein said wall trusses comprise: vertical Vierendeel trusses with vertical members of tube steel, adjacent ones of which are interconnected at the top and bottom by horizontal beams that form rectangular openings, as a frame with fixed joints that are capable of transferring and resisting bending moments.
14. The multi-story building of claim 10 further comprising: a plurality of floor shelves, attached to the top horizontal beam of a lower one of adjoining stacked wall trusses, wherein the floor shelves extend in a horizontal dimension from the face of the adjoining stacked wall trusses into the interior of the multi-story building.
15. The multi-story building of claim 14 further comprising: a plurality of floor modules deposited on top of the floor shelves to span the distance between facing wall trusses, wherein the floor modules extend only between the interior faces of the wall trusses.
16. The method for constructing a multi-story building of claim 8, further comprising: installing a plurality of floor joists on top of the floor shelves that extend in a horizontal dimension from the face of the adjoining stacked wall trusses into the interior of the multi-story building, to span the distance between facing wall trusses.
17. The method for constructing a multi-story building of claim 16, further comprising: depositing prefabricated floor modules on top of the floor joists to span the distance between facing wall trusses, wherein the prefabricated floor modules extend only between the interior faces of the wall trusses.
18. The multi-story building of claim 12 wherein said wall trusses further comprise: a first beam and a second beam each having a first end and a second end, wherein the first end of the first beam and the first end of the second beam are connected to a side of the top end and the bottom end, respectively of the first hollow column and the second end of the first beam and the second end of the second beam are connected to the side of the top end and the bottom end, respectively of the second hollow column to form a rectangular wall segment.
19. The multi-story building of claim 12 wherein said wall trusses cornprise: a plurality of vertical members of tube steel aligned in a linear array, with adjacent ones of the vertical members being interconnected by a top beam spanning the space between adjacent vertical members and a bottom beam spanning the space between adjacent vertical members, the interconnection of the beams and the vertical members being fixed joints that are capable of transferring and resisting bending moments.
20. The multi-story building of claim 19, wherein said wall trusses cornprise: bottom beams interconnecting adjacent vertical members such that the vertical members of tube steel protrude below the bottom beams a predetermined distance.
21. The multi-story building of claim 14, further comprising: a plurality of floor joists installed on top of the floor shelves that extend in a horizontal dimension from the face of the adjoining stacked wall trusses into the interior of the multi-story building, to span the distance between facing wall trusses.
22. The multi-story building of claim 21, further comprising: prefabricated floor modules deposited on top of the floor joists to span the distance between facing wall trusses, wherein the prefabricated floor modules extend only between the interior faces of the wall trusses.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
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DETAILED DESCRIPTION OF THE INVENTION
(15) As shown in
(16) Unlike traditional Vierendeel trusses, the horizontal chords or Wall Truss Beams 111-114 and 121-124 do not span the entire length of the Wall Truss 100 and cap the individual Wall Truss Columns 101-105, but instead the Wall Truss Columns 101-105 extend beyond the top and bottom horizontal chords, such that the chords interconnect the Wall Truss Columns 101-105 in a segmented manner. Thus, the horizontal chords do not provide the vertical load carrying capacity, but function to secure and brace the vertical Wall Truss Columns 101-105 to enable them to carry vertical loads and to provide shear capacity for the Wall Truss 100.
(17) The Wall Truss 100 shown in
(18) Floor Shelves 141-144 are placed on the top surface of the top horizontal Wall Truss Beams 111-114, and may be tack welded in place to hold them in place until the Wall Truss 100 above is installed, which can optionally be used to sandwich the Floor Shelves 141-144 between the top horizontal beam of a lower Wall Truss 100 and a bottom horizontal beam of a Wall Truss placed on top of this Wall Truss as shown in
(19) The Stacked Wall Truss Construction as illustrated in
(20) The Stacked Wall Truss Construction enables the construction of multi-story buildings in a highly modular manner because, in addition to the modular Wall Trusses 100, the modular Floor Modules 161, 162, shown in
(21) Traditional Types of Multi-Story Building Construction
(22) There are several traditional types of multi-story building construction: Poured Concrete frame buildings, Pre-Cast Concrete frame buildings, conventional Structural Steel building frames, conventional wood frame buildings, and Masonry construction.
(23) Poured Concrete Frame Buildings: In most parts of the world, poured-in-place concrete frame buildings are the norm. For each successive floor, columns are poured, a beam is poured on top of the columns to link the columns together, and then a floor is formed and poured on top of the beams and spanning between them to form a monolithic concrete frame. Vertical and shear loads from above are transmitted through the concrete floors downward to columns, beams, and floors in the structure below. This structure takes advantage of the huge compressive capacity of concrete in that, using the third floor as an example with a 20-story building, the vertical compressive loads and the shear loads associated with wind and earthquake of the 17 floors of the building above bear directly on and get transferred through the concrete third floor to the second floor below. Vertical reinforcing steel is placed, typically sticking up and out of columns to extend through beams and floors and into the columns above to provide for vertically continuous tensile strength, which the concrete by itself does not have. Tensile strength is a part of developing required shear strength in the frame of the concrete building.
(24) Pre-Cast Concrete Frame Buildings: Concrete can be pre-cast into 2D or 3D shapes as a means to construct the frame of a structure. These are hoisted into position on the building and affixed together, most commonly via welding steel that spans from an embedded plate in one pre-cast member to a similar embedment in the adjacent pre-cast member. The pre-cast sections have the required structural capacity for vertical loads and shear, as do the connections between the pre-cast sections. Pre-cast frames can include columns, or else the vertical loads would be designed to be carried in wall sections.
(25) Conventional Structural Steel Building Frames: Structural steel has enabled building construction to heights not formerly possible. Steel is a very high strength material, and has considerable strength in both tension and compression (unlike concrete which has just high compressive strength without reinforcing steel). With this high strength material, columns are customarily provided, most often at a significant spacing between them to create column-free open space on floors, and very importantly these columns stack on top of each other and are directly connected together. A continuous vertical load path results where loads transfer from column to column down through the building. This is totally different than the poured concrete frame where the columns are not continuous, as each floor separated them. Horizontal beams are provided that affix to columns, and these beams brace the columns, create shear capacity in the overall frame, and support floors by transferring the floor weight over to the columns. As buildings get tall, the columns get big, and the beam sizes need to grow to stabilize the vertical columns and to create shear capacity in the overall frame of the tall building. This works well. We are all familiar with the look of a structural steel framed building and the heavy scale of the column and beam framework, and the resultant ability to build high, wide open floor plans and also to create broad, open window sections in exterior walls.
(26) Conventional Wood Frame: This building architecture became common when trees were sawn into dimensional lumber of consistent sizes. This enabled wood framing to proliferate in areas where forests are common.
(27) Masonry Construction: Perhaps one of the oldest construction techniques is Masonry construction. Making bricks and then laying the bricks into walls is not only a historic practice but remains a common practice in modern construction. Masonry walls are used to create load bearing walls, where loads from above are supported by the masonry, and masonry walls are also utilized in non-load bearing configurations such as the in-fill walls of a poured concrete frame building. Masonry can develop relatively high compressive strength including both the bricks and mortar, but (unreinforced) masonry is a low strength material in tension. Accordingly, there are limitations in the application of Masonry construction; further, masonry is laid by hand so quality and appearance are inherently prone to variability.
(28) Another distinction in types of multi-story construction is the use of trusses. This building component can be found in all four traditional types of multi-story building construction, and it is further described in the next section.
(29) Basic Truss Technology
(30) The Wall Truss 100 can be fabricated using either braced frames or moment frames from a structural standpoint. Shear loads in a braced frame are carried by bracing members; shear loads in moment frames are carried by the moment capacity of the connections between the members of the frame. In the present Stacked Wall Truss Construction, the Wall Trusses 100 are demonstrated using a Vierendeel truss configuration. Basic truss technology and Vierendeel truss characteristics are described below.
(31) In engineering, a classic truss is a structure that consists of two-force members only, where the members are organized so that the assemblage as a whole behaves as a single object. A two-force member is a structural component where force is applied to only two points. Although this rigorous definition allows the members that form a truss to have any shape and be interconnected in any stable configuration, trusses typically comprise five or more triangular units constructed with straight members whose ends are connected at joints referred to as nodes. In this typical context, external forces and reactions to those forces are considered to act only at the nodes and result in forces in the members which are either tensile or compressive. For straight members, moments (torques) are explicitly excluded because, and only because, all the joints in a truss are treated as revolutes, as is necessary for the links to be two-force members.
(32) A traditional planar truss is one where all the members and nodes lie within a two-dimensional plane, while a space truss has members and nodes extending into three dimensions. The top beams in a truss are called top chords and are typically in compression, the bottom beams are called bottom chords and are typically in tension, the interior beams are called webs, and the areas inside the webs are called panels. A truss consists of typically straight members connected at joints, traditionally termed panel points. Trusses are typically geometric figures that do not change shape when the lengths of the sides are fixed and are commonly composed of triangles because of the structural stability of that shape and design. A triangle is the simplest comparison, but both the angles and the lengths of a four-sided figure must be fixed for it to retain its shape.
(33) A truss can be thought of as a beam where the web consists of a series of separate members instead of a continuous plate. In the truss, the lower horizontal member (the bottom chord) and the upper horizontal member (the top chord) carry tension and compression, fulfilling the same function as the flanges of an I-beam. Which chord carries tension and which carries compression depends on the overall direction of bending.
(34) A variation of the planar truss is the Vierendeel truss which is a structure where the members are not triangulated but form rectangular openings and is a frame with fixed joints that are capable of transferring and resisting bending moments. Vierendeel trusses are rigidly-jointed trusses having only vertical members interconnected by the top and bottom chords which connect to a side of the vertical members which face adjacent vertical members and at a location a predetermined distance below the top of the vertical members. The chords are normally parallel or near parallel. Elements in Vierendeel trusses are subjected to bending, axial force, and shear, unlike conventional trusses with diagonal web members where the members are primarily designed for axial loads. As such, it does not fit the strict definition of a truss (since it contains non-two-force members); regular trusses comprise members that are commonly assumed to have pinned joints, with the implication that no moments exist at the jointed ends. The utility of this type of structure in buildings is that a large amount of the exterior envelope remains unobstructed and can be used for fenestration and door openings as shown in
(35) Concrete Technology
(36) Concrete is a composite material composed of coarse aggregate bonded together with a fluid cement which hardens over time. Most concretes used are lime-based concretes such as Portland cement concrete or concretes made with other hydraulic cements, such as fondants. In Portland cement concrete (and other hydraulic cement concretes), when the aggregate is mixed together with the dry cement and water, they form a fluid mass that is easily molded into shape. The cement reacts chemically with the water and other ingredients to form a hard matrix which binds all the materials together into a durable stone-like material. Often, additives (such as pozzolans or super plasticizers) are included in the mixture to improve the physical properties of the wet mix or the finished material. Most concrete is poured with reinforcing materials (such as rebar) embedded to provide tensile strength, yielding reinforced concrete. Thus, concrete can be poured into a form or column and will conform to the shape of the form, hardening in place to lock the elements in a durable stone-like material.
(37) Stacked Wall Truss Construction
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(39) In this structure, each Wall Truss 1-4, as shown in
(40) A sequential set of images to illustrate the construction method using the Wall Trusses of the present invention comprises
(41) As shown in
(42) Floor Modules
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(46) Floor Cross-Section
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(50) Roof
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(52) In the multi-story residential building application described herein,
(53) Foundation
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(55) The distinction between the present Stacked Wall Truss Construction and the prior art grows with the design and construction of the floors and horizontal components of the building frame. The prior art structural steel frame had substantial horizontal beams framing into the individual steel columns, while the present Stacked Wall Truss Construction does not. By placing vertical Wall Trusses in an orthogonal arrangement, vertical Wall Truss Columns of the Wall Trusses that are perpendicular to one another are affixed together, thereby preventing lay-over of each Wall Truss in the opposite direction to its plane. So unlike traditional structural steel building construction that requires heavy steel beams to restrain horizontal movement of the individual steel columns, and to provide a frame with shear capacity, the geometry of the Stacked Wall Truss Construction of orthogonally positioned vertical Wall Trusses connected at their ends and also on Wall Truss Columns not on the end inherently controls and stabilizes the Wall Truss Column movement that would otherwise occur in plan view. Therefore, no heavy steel beams or customary individual column/beam structure is necessary to create a braced frame or Special Moment Frame. Instead, a dispersion of smaller Wall Truss Columns (as small as 66 in a 14-story building) is created and a dispersion of shear elements is created by virtue of a large number of Wall Trusses that each provide shear capacity, going both plan directions, resulting in an adequate level of aggregated shear capacity without the development of shear capacity in the classic individual steel column/beam frame.
(56) The distinction grows further with the installed floors, which are Floor Modules of light gauge steel or joist types that are preassembled into a coordinated assembly that sits on top of the Floor Shelf located near the top of the Wall Trusses. The Floor Shelf is a tray for the Floor Modules. So when the Wall Trusses are installed on a particular floor of a building, a continuous Floor Shelf has been created in hallways, rooms, apartment units, and outdoor balcony areas such that the Floor Modules of the pre-made hallways, rooms, apartment units, and outdoor balcony areas can be lifted with the crane (where these pre-made Floor Modules are staged for assembly in close proximity to the crane) and they are quickly and efficiently dropped into place. There is no need to make a connection to the building frame before the crane can let go as the Floor Modules just rest on the Floor Shelf with no need for precise positioning. All these Floor Modules sit on a perimeter Floor Shelf of a given building area, and a gap is typically provided on 4 sides to enable easy positioning of the Floor Module, so just drop the Floor Module on the Floor Shelf and move on. Later, by hand or otherwise, the Floor Modules can be moved a bit one way or the other as needed by an inch or two to achieve desired alignment. It requires little skill and is difficult to install incorrectly. Then a concrete Topping Slab is poured on top of the Floor Modules to create a fireproof, soundproof, structural diaphragm, which can also be polished to be the finished floor surface. The resultant floors are implemented without a thick concrete slab capable of spanning across rooms as is present in the traditional poured-in-place concrete building, and also without the heavy individual steel column/beam frame as in classic structural steel construction.
(57) From a structural steel design standpoint, the Wall Trusses can either be a braced frame or a Moment Frame or Special Moment Frame. As a braced frame, a diagonal piece of steel or other brace is installed in at least one bay of each Wall Truss. The diagonal functions as a shear brace in that Wall Truss, greatly increasing its capacity to resist folding in the direction of the Wall Truss. A Special Moment frame is created when, by virtue of just the geometry of the Wall Truss and its members and their connection together, the Wall Truss has shear capacity to resist laying over in the direction of the Wall Truss and functions with the inherent shear capacity of a Vierendeel Truss. Moment Frames flex in the cycle loading of earthquakes and with wind loading, as opposed to just being a rigid braced frame; therefore, Moment Frames tend to perform better and are preferred in tall multi-story buildings and in high seismic load areas. Both implementations work, and the architecture and design engineering of the present art can be either.
(58) The Thin Concrete Wall Panel of the preferred embodiment of the multi-story building is either poured against the pre-made Wall Truss in an on-site forming system, or they are fabricated as another pre-made assembly that is simply affixed to the Wall Trusses. Either way, in the preferred embodiment of the present art, when you hoist a wall frame, it consists of the structural elements, installed utilities, walls, wall finishes, etc. There is no requirement to return to place hand laid brick as in-fill as is done in the traditional poured-in-place concrete buildings today. Hoist the Wall Trusses, place the Floor Modules, pour the Topping Slabs, connect the utilities that have been preinstalled in the Modular Elements at the Utility Interconnect Locations, then move onward and upward.
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SUMMARY
(60) The present Stacked Wall Truss Constructions and their use in the construction of multi-story buildings departs from the traditional methods of constructing multi-story buildings by the use of prefabricated modular Wall Trusses that are interconnected in three dimensions to enable the rapid completion of building construction with improved quality of construction over that found in traditional multi-story building construction. Further, additional Modular Elements including Floor Modules and Kitchen Modules compliment the Wall Trusses to create a fully modular program of building construction that can be quickly and efficiently accomplished. The resultant building is really a structural steel frame without the use of traditional, heavy, individual stacking columns and beams, since the vertical Wall Trusses create smaller continuous vertical steel elements by virtue of the design configuration and vertical assembly of the Wall Trusses, thereby building construction becomes a process of stacking Wall Trusses, not individual, heavy steel columns and beams. An inner Wall Truss Column Mating Member can be placed hanging out of the bottom of each Wall Truss or sticking out of the top of lower Wall Trusses to enable a Wall Truss placement to be near perfectly positioned on top of the installed Wall Truss below.