Post Tension and Cantilever Connection Assembly for a Modular Construction

A vertical structural connection assembly allowing a modular construction to be made with a plurality of modular units without any required welding on-site. A pin on top of each column of the modular units allows construction crews to easily stack the units one on top of one another. A cantilever plate is included within the connection assembly which is configured to couple to a cantilever beam, thereby providing a means for a corridor, balcony, overhanging roof, or other construction element to be added to the modular construction. A tie connection attaches on the face of the modular units via a welded bolt or outrigger, and/or placed on adjacent connection assemblies between stacked modular units. The tie connection maintains the horizontal connection while allowing adjacent modular unit to move up and down independently, for example, during a seismic event, while still maintaining a horizontal distance there between.

BACKGROUND

Field of the Technology

The invention relates to the field of assembling modular construction units, and in particular a method and apparatus allowing for modular construction units to be stacked on one another without additional welding.

Description of the Prior Art

Modular construction is a type of construction whereby components of a building are prefabricated in modular assemblies offsite and are then assembled onsite into a finished building, in conjunction with site-built elements. Modular construction processes save significant time on a construction site, so the more that pre-assembly offsite is possible, often the lower the cost and greater the savings for the user.

Modular units must be structurally connected in a way that forms the resulting structure of the finished building, and many of the existing forms of connection produce unwanted consequences that can be structural, economic for the real estate developer, or aesthetic in nature. This can be especially challenging when constructing in seismic zones, where the right balance of rigidity and flexibility in a system are difficult to achieve economically and with standard off-the-shelf parts.

For example, existing steel systems when stacked in a seismically active zone will fail without the additional presence of a steel structure exterior to the modules bracing them in place. Such external structures are costly and take extra time to construct on-site. Traditional steel welding on a construction site is also quite costly.

Previous vertical post-tensioning connection systems, such as the POSCO horizontal connector plate, patented in South Korea, allows for a vertical post-tension cable to pass through it while connecting units horizontally one-to-another on each level of the building. However, when analyzed through an FEA method for U.S. seismic zones, the units need to be placed too far apart to be economical as too much real estate is wasted between columns of adjacent units. Furthermore, these plates have structural failures after only 2-3 stories.

BRIEF SUMMARY

The current invention solves several known challenges with modular construction, namely wherein modular prefabricated units or apartments are stacked adjacent to one another, for example below, on top of, and next to each other. The current structural system for stacking volumetric modular units solves many of the problems which have eluded earlier attempts from all around the world. The current structural system enables higher stacks, i.e. in some cases up to 6 stories, of steel module frames to be formed that are self-supporting seismically and, even without an adjacent stack or exterior structure, they are sufficiently strong to carry both the gravity and lateral loads of seismic movement. This presents significant time and cost savings on the construction site where they are used. The current invention does this primarily by facilitating a vertical post-tensioned structural connection vertically through the columns of the modular frames, with a few unique features of the column endpoints where the post-tensioning cable or rod passes through. The current invention allows a modular building to be created without any required welding on-site. Instead, using vertical post tensioning and a uniquely designed “pin” on top of each column allows construction crews to easily stack the units one on top of the other due to the tapered shape of the pin. A penetration in the pin allows it to dually serve as a pick point for the rigging crew to attach the lifting lugs for craning the module off of the truck and into place within the larger overall modular construction. The pin has a vertical penetration that allows for the post-tensioning cable to run through it and through the column to tie together the structure of the building. The current invention enables a modular frame to be connected vertically with the benefits of a post-tension system (faster stacking, no welding on-site) while reducing the horizontal connection between modules (and modular stacks) to a simple adjustable rod or tie connection between each horizontally adjacent module. The tie connection can be a readily available, off the shelf product, and attaches on the face of the units to a welded bolt or outrigger at the top and/or bottom of each module frame, and/or placed on a shim plate between stacked units that receives the readily available adjustable rod. The tie connection maintains the horizontal connection while allowing columns to move up and down independently.

Many modular frames are typically custom-designed and custom-manufactured for each unique project and site condition which makes it difficult for a modular product maker to achieve efficiencies of scale by keeping the frames the same for every single production run. The current invention allows the factory to make every frame and corner column identical in the factory and use interchangeable, non-welded plates atop the nodes to support different building conditions such as balconies and/or corridors in the field. This again makes the stacking and assembly process faster in the field and reduces the need for skilled labor to assemble the units with support features on site.

In certain embodiments, the components of this feature and interchangeable plates include column tops which have a welded square plate on the face that functions as a support for a site-placed corridor/balcony support plate. Each column top has penetrations to fit around the welded bolts that are disposed on top of each column.

In certain other embodiments, flat plates are used at each column node after a unit is installed on-site, before another unit is stacked above. Flat plate variations have any necessary penetrations to fit around drift pins or column nodes on the tops of units. Flat plates can be shaped as square corner plates that are flush with the face of the module and serve simply to shim the module to a height that matches other plates atop the other columns. Additionally, flat plates may also be longer, more rectangular plates that are placed in the same location but which extend past the face of the module in varying lengths to support various lengths of balconies or corridors, depending on the rest of the building design. In the case of a corridor or balcony, once another module is placed on top of all the shim and support plates that are disposed on the lower module, the longer plates serve as a support to which other building structures may be bolted.

The current invention provides a connection assembly for a modular construction. The connection assembly comprises a side plate coupled to a first modular unit, a cantilever plate disposed between the first modular unit and a second modular unit, and an end plate coupled to a cantilever beam. The second modular unit is disposed on top of the first modular unit.

In one embodiment, the side plate is coupled to a vertical surface of a column of the first modular unit, and the cantilever plate is disposed over a top surface of the column of the first modular unit.

In another embodiment, the end plate coupled to the cantilever beam is removably coupled to the side plate, and where the cantilever plate is removably coupled to the cantilever beam.

In a further embodiment, the cantilever plate disposed between the first modular unit and the second modular unit is disposed across a corresponding cross sectional area of a first column within the first modular unit and a second column within the second modular unit.

In one embodiment, the connection assembly also comprises at least one means for fastening disposed through the side plate, and a tie connection removably coupled to the at least one means for fastening disposed through the side plate. The at least one means for fastening that is disposed through the side plate is specifically disposed through the end plate coupled to the cantilever beam. Additionally, the tie connection is configured to rotate about the at least one fastening means disposed through the side plate, according to certain embodiments.

In another embodiment, the cantilever plate comprises at least one guide pin and a cable pin. The cable pin comprises a shaft defined through its vertical height.

The invention also provides a modular construction comprising at least two modular units, a connection assembly coupled to each of the at least two modular units, and a tie connection coupled to each connection assembly that is coupled to each of at least two modular units. The at least two modular units are disposed horizontally adjacent to each other, according to certain embodiments.

In another embodiment, the construction assembly coupled each of the at least two modular units comprises a side plate coupled to one of the at least two modular units, a cantilever plate disposed on top of one of the at least two modular units, and a first plurality of fasteners configured to couple the cantilever plate to a cantilever beam. Here, each connection assembly further comprises an end plate coupled to the cantilever beam and a second plurality of fasteners configured to couple the end plate coupled to the cantilever beam to the side plate coupled to each of the at least two modular units. According to certain embodiments, the tie connection coupled to each connection assembly is coupled to the at least two of the second plurality of fasteners. The tie connection is further configured to rotate about the at least two of the second plurality of fasteners.

In one particular embodiment, the cantilever plate comprises at least one guide pin and a cable pin, where the cable pin comprises a shaft defined through its vertical height.

The invention also provides a method for constructing a modular construction, the method comprising disposing a first modular unit horizontally adjacent to a second modular unit, disposing a cantilever plate on a top surface of the first and second modular units, and then stacking a third modular unit on top of the cantilever plate disposed on either the first or second modular unit. Next, a tie connector is coupled to at least one fastener disposed on the first modular unit and to at least one fastener disposed on the second modular unit.

In one embodiment, the method further comprises disposing a compressible pad between the first and second modular units.

In another embodiment, the method also includes coupling a cantilever beam to the cantilever plate disposed on either the first or second modular unit and then coupling the cantilever beam to a side plate coupled to either the first or second modular unit.

In a further embodiment, stacking the third modular unit on top of the cantilever plate disposed on either the first or second modular unit specifically comprises inserting at least one guide pin disposed on the cantilever plate into the third modular unit.

According to one embodiment, stacking the third modular unit on top of the cantilever plate disposed on either the first or second modular unit comprises inserting a cable pin disposed on the cantilever plate into the third modular unit and then disposing a conduit within the third modular unit through a shaft defined through a vertical height of the cable pin and into either the first or second modular unit.

In a further embodiment, the method includes compensating for relative vertical movement between the first and second modular units by rotating each lateral end of the tie connector about the at least one fastener disposed on the first modular unit and the at least one fastener disposed on the second modular unit, respectively.

The disclosure and its various embodiments can now be better understood by turning to the following detailed description of the preferred embodiments which are presented as illustrated examples of the embodiments defined in the claims. It is expressly understood that the embodiments as defined by the claims may be broader than the illustrated embodiments described below.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Greater detail of the current invention may be seen inFIGS.1-3which show an example of the current modular unit connection assembly denoted generally by reference numeral10. The connection assembly10is seen inFIG.1when it is used in conjunction with four adjacently disposed modular units, namely two laterally adjacently disposed upper units1′,1″ and two laterally adjacently disposed lower units2′,2″. Each of the upper and lower units1,2comprise a plurality of vertically orientated columns1a,2a, as well as a plurality of horizontally orientated beams1b,2b. Where a column1a,2ameets a beam1b,2b, a corresponding corner junction1c,2cis formed. For purposes of clarity, the beams of the left most units1′,2′ as seen inFIG.1are labeled as1b′,2b″, while the beams of the right most units1″,2″ are labeled as1b″,2b″.

In certain embodiments, the corner conjunction2cof each of the adjacent lower units2′,2″ comprises a side plate12that is coupled to a column's outer surface as best seen inFIGS.2A and2B.FIG.2Ais a side cross sectional view of the connection assembly10seen inFIG.1, whileFIGS.2B-2Dillustrate the same connection assembly10with the upper modular unit1′ removed for clarity purposes. According to certain embodiments, the side plate12is welded to the outer surface of the corner conjunction2c, however other known construction means such as bolts, adhesives, or other fixtures may also be used. In certain embodiments, each side plate12is preferably comprised of metal or metal alloys, however other equivalent materials may also be used without departing from the spirit and scope of the invention. Additionally, each side plate12may be coupled to the outside surface of the modular unit1,2where each respective corner junction2cis disposed, however in other embodiments each side plate12may be coupled directly to the column2aand/or the beam2bwhich forms the corner junction2citself.

The connection assembly10further comprises a cantilever plate14which is configured to be inserted, slid, or otherwise disposed between the top of the column2aof a lower unit2′,2″ and the bottom of the column1aof an upper unit1′,1″. The cantilever plate14is preferably comprised of metal or metal alloys, however in other embodiments other materials such as plastic or plastic composites, rubber, or other equivalent materials may also be used. As best seen inFIGS.2A-2C, the cantilever plate14is disposed across the cross sectional area defined between the columns1a,2aand extends outward in a perpendicular orientation relative to a vertical axis of the columns1a,2aof the modular units1,2. In certain embodiments, each corner junction2ccomprises its own corresponding cantilever plate14, therefore when two adjacent lower modular units2′,2″ are disposed next to one another as seen inFIGS.1,5A, and7A, both the side plates12and their respective cantilever plates14are also adjacently disposed to one another in parallel and separated by a relatively small horizontal distance.

According to certain embodiments, each cantilever plate14may be held in place between an upper modular unit1and lower modular unit2by the weight of the upper modular unit1pressing down upon the cantilever plate14, however in certain embodiments the cantilever plate14may be coupled to either or both of the upper and lower modular units1,2by a weld, adhesive, or other coupling means. In certain embodiments, coupling between an upper modular unit1′,1″ and a lower modular unit2′,2″ is done using a column end cap30as seen in the cross section view ofFIG.3Aand the magnified view ofFIG.3B. Each column end cap30comprises a lower plate32disposed below the cantilever plate14. According to some embodiments, the lower plate32forms a portion of the cantilever plate14, however in other embodiments, the lower plate32is a separate component which is coupled directly to the modular unit. In certain embodiments the lower plate32comprises a plurality of drift pins34and a cable pin36extending vertically from the lower plate32, through a corresponding or matching set of apertures or penetrations defined in the cantilever plate14, and terminating within a bottom portion of the column1aof the upper modular unit1. The plurality of drift pins34and cable pin36help limit the relative movement between the upper modular unit1and the lower modular unit2once connected, as well as serve as connection points for construction workers to quickly and easily dispose and align each upper modular unit1with the lower modular unit2to be disposed directly beneath it. Greater detail of the cable pin36is seen inFIG.3Bwhich illustrates a cross sectional view of the cable pin36. In certain embodiments, the cable pin36comprises a hollow, vertically orientated shaft38defined through the height of the cable pin36, as well as an aperture39defined through the diameter of the cable pin36. The vertical shaft38allows cables, electrical lines, plumbing, and other conduits inserted through the corresponding columns1a,2aof the modular units1,2to be easily passed there through so that they may be connected to the entire modular construction100, regardless of how many stories the completed or final modular construction100may have. The aperture39in turn provides a purchase point or means for a crane or other piece of construction equipment to grip or couple to the modular unit1,2so as to assist in the transportation and stacking of the modular unit1,2.

Returning toFIGS.2A-2D, according to certain embodiments a cantilever beam16is coupled to the connection assembly10through an end plate18which is in turn coupled to a lateral end of the cantilever beam16. The end plate18is preferably comprised of metal or metal alloys, however other equivalent materials may also be used. The end plate18is also preferably coupled to a lateral end of the cantilever beam16by a weld, however other coupling means such as bolts or other fixtures may also be used. In one embodiment, to couple the cantilever beam16to the side plate12of the connection assembly10, a plurality of apertures or perforations defined in the end plate18are aligned with a corresponding plurality of apertures or perforations defined in the side plate12. A plurality of bolts20or another fixture now known or later devised are inserted therethrough and then fixed into place by a corresponding plurality of nuts22or other coupling means, thereby coupling the end plate18of the cantilever beam16directly to the side plate12of the connection assembly10. A second plurality of bolts20are threaded through the cantilever plate14and directly into a plurality of apertures defined in a top surface of the cantilever beam16, thereby coupling a bottom surface of the cantilever plate14to the top surface of the cantilever beam16. The same process may be repeated for the adjacent connection assembly10, thereby providing a parallel pair of cantilever beams16extending outward from the stack of modular units1,2. In one embodiment, the bolts20and nuts22used to couple the end plate18to the side plate12are identical to the bolts20and nuts used to couple the cantilever plate14to the cantilever beam16, however in certain embodiments, the bolts20and nuts22used to couple the end plate18to the side plate12may differ in size from those used to couple the cantilever plate14to the cantilever beam16.

InFIGS.5A and5B, a modular construction100comprising two adjacently disposed modular units1′,1″ is seen with a pair of connection assemblies10coupling the modular units1′,1″ together and a plurality of cantilever beams16extending perpendicularly outward from a corresponding plurality of end plates18.FIG.5Cshows an alternative embodiment of the modular construction100′ wherein the modular construction100′ comprises two stories, for example two adjacent top modular units1′,1″ disposed above two adjacent bottom units2′,2″. Each modular unit1,2comprises a cantilever beam16coupled to a corresponding connection assembly10, with the center most disposed connection assemblies10coupling the two adjacent bottom units2′,2″ together as well as accommodating the two adjacent top units1′,1″. Once coupled, the cantilever beams16may provide architectural support for any number of auxiliary or supplemental structures that are to be part of the modular construction100, including but not limited to a corridor or hallway, a balcony102for the upper modular units as seen inFIG.11, a patio or awning for the lower modular units, a sign or billboard to be disposed on the side of the modular construction, or any other desired construction element. Through the use of the cantilever plate14being inserted between the columns1b,2bof the upper and lower modular units1,2, the connection assembly10is able to provide a support element which is capable of bearing any related gravitational and moments of force or torque placed upon it by the modular construction100.

Turning toFIGS.7A-7Cas well as returning toFIG.1, when two connection assemblies10of two adjacent modular units1,2are closely disposed to another, a tie connection24is disposed between them in order to accommodate relative movement between the modular units1,2during a seismic event. In certain embodiments, the tie connection24comprises an elongated body26and a matching or symmetrical pair of eyelets28that are disposed on either lateral end of the body26. The body26is rigid and does not compress, bend, or fold when large longitudinal or rotational forces are applied to either lateral end of the body26. In certain embodiments, the body26and the eyelets28may be relatively flat or thin so as to form a small profile with the respective connection assemblies10, however in other embodiments both the body26and the eyelets28comprise a radius or a rounded thickness which in turn protrude from the surfaces of the connection assembly10. In some embodiments, the tie connection24as seen inFIGS.4A and4Bcomprises two halves or parts24a,24bwhich are joined together by a central portion24cwhich comprises a reduced diameter or cross section relative to the halves24a,24bof the tie connection24comprising the eyelets28. In some embodiments, the tie connection24as seen inFIG.9comprises a substantially tapered shape, namely with the center of the body26comprising a first diameter or width which smoothly increases to a second diameter which comprises the eyelets28.

The tie connection24in some embodiments is coupled to a pair of adjacently disposed end plate18portions of each connection assembly10. In one embodiment, each eyelet28is disposed or threaded over a corresponding pair of bolts20that extends from the side plate12and through the end plate18before the nut22is coupled and then tightened thereto as best seen inFIG.7A, thereby “sandwiching” each eyelet28between the nut22and the outward facing surface of the end plate18. In another embodiment, each eyelet28comprises a sufficient diameter so as to accommodate both the bolt20and its corresponding nut22, allowing the tie connection24to be installed after the cantilever beams16have been coupled to the side plates12as discussed above. In all embodiments, while each eyelet28is sufficiently sized as to accommodate either the diameter of a bolt20or the diameter of a bolt20in combination with the diameter of a nut22, the eyelet28is sized to permit rotational movement about the bolt20and/or the bolt20and nut22. Additionally, whileFIG.7Ashows the tie connection24being coupled between an upper, outwardly disposed bolt20disposed through each adjacent end plate18, it is to be expressly understood that the tie connection24may be coupled to any combination of bolts20disposed in either end plate18. The coupling process for the tie connection24may be repeated for each of the modular units within the modular construction, namely between each of the horizontally disposed or adjacent modular units on each of the floors or levels within the modular construction. The connection assembly10and tie connection24are preferably disposed on both the front and back of each of the modular units within the overall modular construction, however in certain embodiments connection assemblies10and tie connections24may be used anywhere along the entire shared lengths of the modular units. In other words, the connection assemblies10and tie connectors24are preferably used to couple two adjacent modular units at their respective lateral ends, however in an alternative embodiment, one or more connection assemblies10and tie connectors24may also be disposed along their respective longitudinal lengths as well.

During a seismic event, any modular units1,2, within the modular construction will undergo both vertical and horizontal displacement for a possible extended amount of time. This can be devastating for modular units1,2within a stacked modular construction since so little space is present between each of the units which can then result in repeated physical impact between modular units. However, because the tie connection24is disposed between two horizontally adjacent modular units and comprises a rigid, non-compressible body26, any relative horizontal movement between each modular unit is reduced if not eliminated, thereby preventing impact between the modular units. Additionally, because each eyelet28of the tie connection24is free to rotate about its respective connection point or bolt20, relative vertical movement between adjacent modular units is compensated for. Specifically, when two horizontally disposed modular units undergo a vertical displacement, the tie connection24disposed there between will rotate about its respective connection points accordingly via the eyelets28spinning or rotating about its corresponding bolt20. In this manner, vertical movement of one modular unit relative to an adjacent modular unit is compensated by the eyelet28rotating a corresponding amount about the bolt20on the connection assembly10that is experiencing the vertical displacement. In certain embodiments, because both eyelets28of the tie connection24may rotate about their respective bolts20, the tie connection24may rotate in both a clockwise and counterclockwise direction at either lateral end, alternating or in sequence, for the duration of the seismic event while still maintaining a rigid or inflexible support in the horizontal direction provided by the inflexible body26of the tie connection24. After the seismic event, the modular units1,2within the modular construction cease any relative vertical movement, allowing the tie connection24to return to a substantially horizontal position as seen inFIGS.1and7A.

In certain other embodiments seen inFIGS.7B,7C,10A, and10B, a neoprene pad40is disposed between adjacent modular units1,2and their respective connection assemblies10. In one embodiment, the pad40is substantially rectangular or cuboid shape as seen inFIG.8. The pad40in one particular embodiment comprises a first thickness of 2 and ⅜ inches as seen inFIG.10Awhere the pad40is disposed between two adjacent modular units1′,1″ before a seismic event takes place. After the seismic event begins, the modular units1′,1″ may move closer together, thereby compressing the pad40to a second or smaller relative thickness of 1 inch as seen inFIG.10Baccording to certain embodiments. After the seismic event ends, the modular units1′,1″ move apart and return to their original positions, thereby allowing the pad40to once again expand into the first thickness seen inFIG.10A. However, according to certain other embodiments, the pad40comprises a different width, height, depth, or material other than what is explicitly shown so as to provide a different configuration or level of compression when undergoing stress during a seismic event. After installation, the pad40may further prevent impact between adjacent modular units by compressing and cushioning each adjacent modular unit during a seismic event.

Many alterations and modifications may be made by those having ordinary skill in the art without departing from the spirit and scope of the embodiments. Therefore, it must be understood that the illustrated embodiment has been set forth only for the purposes of example and that it should not be taken as limiting the embodiments as defined by the following embodiments and its various embodiments.