Patent Publication Number: US-2013239516-A1

Title: Moment Resistant Building Column Insert System And Method

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation application of U.S. patent application Ser. No. 11/801,815 filed May 10, 2007, which is incorporated herein by reference. U.S. patent application Ser. No. 11/801,815 is a continuation in part application of U.S. patent application Ser. No. 11/373,719 filed Mar. 10, 2006, which is hereby incorporated by reference. 
    
    
     FIELD OF THE INVENTION 
     The invention relates generally to building structures. More particularly, the invention relates to a building column insert that provides a moment-resistant alignment and connection between columns and beams, and column splices. 
     BACKGROUND 
     It is currently desirable to use moment-resistant structures in construction of new buildings because they offer fewer restrictions for design and more useful space, while adhering to building design codes. The moment-resistant structures must meet building code standards that require the moment-resistant connections to deflect and absorb energy resulting from earthquakes or high winds. A rigid joint is typically used to resist lateral forces by holding columns and beams fixed in relation to one another. As a result, the joints can become highly stressed during a seismic event. In a moment-resisting structure, the vertical and lateral loads are resisted by the bending strength of the beams and columns. Modern building codes require the strength of the columns and beams be proportioned to prevent column failure by allowing permanent deformation in the beam prior to any column failure. The greatest demand on the columns and beams occurs at and adjacent to the joints between columns and beams. 
     Moment-resistant frames are most often made of structural steel with bolted or welded joints. Bolted moment frames require plates welded to the ends of beams, that are in turn bolted to the column. Successful moment-resisting frames provide a ductile structure that will distort prior to failure and if properly detailed will not fail in a brittle manner. These frames develop their resistance to lateral forces through the flexural strength and continuity of the beam and column. 
     An acceptable moment-resisting beam column joint must remain rigid to the point of beam failure. Often, the Reduced Beam Section (RBS) is used to provide a “fuse” in the beam where failure occurs while the joint between the column and beam remains rigid. To accomplish this the joint must resist compression and tension forces produced by the bending in the beam at the beam flanges. 
     In the past most columns and beams have been “I” shaped members called wide flange sections. The top and bottom of the “I” section is the flange. Typically the beams frame into the column flange, which is the “strong axis” direction of the section. The beam flanges are usually welded to the flange(s) of the column. This configuration gives the column-beam joint great strength in one direction. To provide the same strength in the other direction, at 90 degrees from the first direction, some columns in the structure must be rotated or loads must be resisted in the “weak axis” direction of the column. This would require a stronger column to resist weak axis loads and use of configurations for weak axis column joints. Most small buildings require columns that must resist loads in each direction. This is a problem for “I” section columns in that much larger columns would be required to resist weak axis loads. 
     In contrast, Hollow Square Sections (HSS) have the same properties in each direction. Using hollow square tube sections for columns can make design and detailing essentially the same in each direction and the same column can be used for moment resisting connections in each direction. However, the HSS column presents a challenge in another way from the typical “I” section column in making the moment-resisting connection between the beam and the column. 
     A problem arises when assembling the beams to the columns where multiple beams and columns are required. With bolted moment frames using HSS columns, a through-bolt connection could be used to secure the beam end plate to the column. However, when multiple columns and beams are used to span a length of building, the use of through-bolts would necessitate aligning and securing multiple beams simultaneously to the columns. In the case of a linear span, the assembly process requires the holes of a first beam end plate to be aligned with the through-holes in a column and aligning the holes of a second, opposing beam plate with the column through-holes, then inserting the through bolts in each hole for tightening with nuts and washers. It would be necessary to install all the beams at each line and level simultaneously. This process could be slow, difficult, expensive or very impractical. 
     In the ongoing effort to improve building frame construction that better handles severe lateral loads, such as earthquake and high-wind loads, much attention has been focused on the manner in which upright columns and horizontal beams are connected. Attempts to addresses this issue include a column-beam interconnect with the ends of beams joined to columns using nodes of intersection and collar structures that surround the sides of the column as taught by Simmons et al. (U.S. Pat. No. 6,837,016). Other attempts include Okawa et al., (U.S. Pat. No. 5,410,847) who teaches a rod-like orthogonal metal connector provided in concrete structure members with junction hardware to connect a steel member to the structure member. Chen, (U.S. Pat. No. 5,595,040) teaches a beam-to-column connection for connecting an H-beam to a column surface, where the connection is defined at an end of the H-beam having a web plate and a pair of flange plates. Houghton (U.S. Pat. No. 6,138,427) teaches a moment resisting, beam-to-column connection, using two gusset plates attached to a column and extending along the sides of a beam and having connecting elements, where the connecting elements are bolted, riveted or welded to the beam along its longitudinal direction and to the gusset plates. Katayama et al. (U.S. Pat. No. 6,532,713) teaches a composite beam connected to a column by inserting a mortise pin into a bottom hole of a column and then inserting a locking pin into a through-hole of the mortise pin and the horizontal hole of the column such that joint of the composite beam and the column is firmly secured. Further, Briggs (U.S. Pat. No. 3,593,477) teaches a concrete beam reinforcement anchor embedded in the concrete, which has a plane surface in the side-face of the beam or column for bolting a beam thereto. Additionally, Sato et al. (U.S. Pat. No. 5,012,622) teach a solid concrete core thrust into a column, which then disallows the use through-bolt assembly and necessitates a clamping assembly that has limited utility. 
     These and other designs and systems have been used to make this connection but they are considered costly, less flexible or impracticable to build. Accordingly, there is a need to develop a system that allows for the less expensive assembly of the beams to the columns in moment frames. It would be considered an advance in the art using through bolts to connect beams to columns without the need for multiple beams to be installed at the same time, thus simplifying assembly for faster and less expensive construction. 
     SUMMARY OF THE INVENTION 
     To address the needs in the art, a moment resistant building column insert is provided that includes an insert column of generally tubular shape, a pre-hardened structural filler disposed within the insert column, a pattern of through-holes transverse to a length of the insert column and through the pre-hardened structural filler, at least a pair of erection through holes disposed through a wall of the insert column, at least a pair of threaded elements incorporated to an inner wall of the insert column and disposed concentric to the pair of erection holes, a threaded element cover disposed over each threaded element, where the threaded element cover is surrounded by the pre-hardened structural filler, where the threaded element cover forms a cavity around the threaded element within the pre-hardened structural filler, where the threaded element cover is disposed to protect the threaded elements from contamination by the structural filler, and an insert positioning element is disposed axially along the column, where the insert positioning element includes a positioning through-hole disposed for receiving a hoist end there though, where the moment resistant building column insert is disposed inside a bottom end of a first building column and inside a top end of a second building column, where the moment resistant building column insert joins the first building column to the second building column. 
    
    
     
       BRIEF DESCRIPTION OF THE FIGURES 
       The objectives and advantages of the present invention will be understood by reading the following detailed description in conjunction with the drawing, in which: 
         FIG. 1  shows an exploded perspective view of a moment resistant building column insert system according to the present invention. 
         FIGS. 2(   a )- 2 ( d ) show some embodiments of the erection insert according to the present invention. 
         FIGS. 3(   a )- 3 ( d ) show some variations of the threaded element with the insert according to the present invention. 
         FIGS. 4(   a ),  4 ( b ) show perspective views of the moment resistant building column insert system according to the present invention. 
         FIGS. 5(   a )- 5 ( c ) show embodiment of the moment resistant building column insert system according to the present invention. 
         FIGS. 6(   a ),  6 ( b ) show an exploded perspective view and a collapsed perspective view of another embodiment of the moment resistant column insert invention. 
         FIG. 7  shows the steps of using the moment resistant building column insert system according to the present invention. 
         FIG. 8  shows the steps of using the embodiment of  FIGS. 5(   a )- 5 ( c ) according to the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Although the following detailed description contains many specifics for the purposes of illustration, anyone of ordinary skill in the art will readily appreciate that many variations and alterations to the following exemplary details are within the scope of the invention. Accordingly, the following preferred embodiment of the invention is set forth without any loss of generality to, and without imposing limitations upon, the claimed invention. 
     The present invention makes possible the erection of beams to columns, and the installation and pretension of the connection bolts possible in a single stop to each beam-column joint in the field. The current invention shortens the process of installing the connection bolts and, prior to pretensioning the connection bolts, filling the entire column with grout or concrete and waiting for the filler to harden to sufficient strength to resist the pretensioning of the connection bolts, then pretensioning the bolts. This would require multiple trips to each beam. The current invention saves time, and reduces labor and material costs. In the invention, erection bolts are temporary bolts that hold the beam in place against the column with the holes in the beam end-plate (mounting plate) aligned with the through-holes in the column and insert. The erection bolts enable the erection of beams to the columns without the necessity of installing the connection through-bolts at time of erection. Once the hole patterns of the mounting plate, column and insert are aligned, connection through-bolts are installed to provide the connection strength needed to make a rigid beam-column moment joint. These bolts must be pretensioned after installation to achieve the strength needed to hold the moment joint rigid. Without the pre-hardened structural filler in the insert, according to the current invention, the column would deform or crush due to the pretensioning. 
     Referring now to the figures, the current invention provides a moment resistant building column insert system  100 , where  FIG. 1  shows an exploded perspective view of one embodiment of the invention. The moment resistant building column insert system  100  includes a building column  102 , where in this figure the building column  102  is generally tubular shape having at least one pattern  104  of through-holes transverse to a length of the tube. Additionally, the invention has an insert  106  shown here as a column insert of generally tubular shape, where the insert  106  may also be a plate having the through-hole pattern  104 , as will be apparent by the description below. A hardened structural filler  108  is disposed within the insert  106  and the column  102 . The insert  106  has least one pattern  104  of the through-holes transverse to a length of the insert  106  and there is at least one through-hole pattern  104  through the structural filler  108 . Shown in the exploded view of  FIG. 1  is at least one threaded element  110  incorporated to an inner wall  112  of the insert  106  and disposed concentric to at least one of the insert through-holes, or referred to here as an erection through-hole  114 . Further, a threaded element cover  116  is disposed over the threaded element  110 , for preventing the filler  108  entering the hole of the threaded element  110  when the filler  108  is in a non-hardened state. An insert positioning element  118  is disposed axially along the insert  106 . The insert positioning element  118  is a hole for receiving a hoist end there through. According to the current embodiment, the positioning element  118  is embodied in the hardened structural filler  108  that is affixed inside the insert  106 . The positioning element  118  enables alignment of the through-hole pattern  104  of the insert  106  with the through-hole pattern  104  of the column  102 , where the insert  106  is sized to fit within the column  102 . The building column insert system  100  further has at least one beam  120 , where the beam  120  includes a mounting plate  122  attached to a beam end  124 . The mounting plate  122  includes mounting plate through-holes  126  arranged in the pattern  104 , where the mounting plate  122  abuts an outside wall  128  of the column  102 . Further included is at least one erection connector  130 , where in the figure the erection connecter  130  is shown as an erection bolt  130 . Here the erection bolt  130  spans through the mounting plate  122 , through a wall of the column  102 , through a wall of the insert  106  and into the threaded element  110  for tightening, where the beam  120  is then desirably positioned on the building column  102 . The building column insert system  100  further includes at least one set of mounting plate connector hardware that includes a mounting plate through-bolt  132 , a mounting plate nut  134 , and a mounting plate washer  136 . According to the current invention, with the insert  106  positioned in the column  102 , the through-hole pattern  104  on the mounting plate  122  is aligned with the through-hole pattern  104  on the column  102  and the through-hole pattern on the filler  108 , and the erection connector  130  is secured to the threaded element  110  for holding the beam  120  in place while the mounting plate connector hardware ( 132 , 134   136 ) are assembled, where the mounting plate through-bolts  132  are inserted through the mounting plate holes  126 , the column holes  138 , the insert through-holes  140 , the filler through-holes  142 , through the mounting plate washers  136  and into said mounting plate nuts  134 , whereby the mounting plate hardware is tightened. Shown in  FIG. 1  is a pair of opposing beams  120  and mounting plates  122  positioned on each side of the column  102 , where it is understood that one or more beams  120  could be assembled to the column  102 . Further shown in  FIG. 1  are cavities  144  in the hardened structural filler  108 , where the cavities  144  are created when the structural filler  108  is added to the insert  106  in a non-hardened state to fully surround the lengths of the temporary mounting through-bolts (not shown) and the threaded element covers  116 , then solidifies. Once hardened, the temporary mounting through-bolts (not shown) are removed to reveal a pattern of through-holes  104  in the insert  106  and hardened filler  108 . 
     The building column  102  can have any cross-section such as circular, rectangular, square or polygonal, for example. Additionally, the column insert  106  can have any cross-section such as circular, rectangular, square, linear or polygonal, for example, where a linear cross-section is for a plate insert  106 . 
     In  FIG. 1 , the threaded element  110  is shown as a square bolt, however according to one embodiment, the threaded element  110  can be an erection through-hole  114  that is threaded (see  FIG. 3(   a )), where the threaded element cover  116  would protect the threads from becoming covered with the filler  108  before it solidifies. The structural filler  108  can be concrete, grout, plastic, epoxy or a compression resistive material. 
       FIGS. 2(   a )- 2 ( d ) show some embodiments of the erection insert  106 . As shown in  FIG. 2(   a ), the erection insert  106  can be a plate insert  200  having the hole pattern  104 , where the plate insert  200  abuts the column inner wall  113 , and where the hole pattern  104  of the plate insert  200  is aligned with the hole pattern  104  of the column. The plate insert  200  is then fixedly attached to the inner wall of the column  102 , where the attachment may be done using screws, welding or its equivalents, for example. The alignment through-holes  114  on the plate insert  200  can have a threaded element  110  fixedly attached to the side of the plate insert  200  that is opposite the side abutting the inner wall of the column  102 , or the threaded element may be positioned concentric with the plate insert  200  using a nut cage (see  FIG. 3(   c )). 
       FIG. 2(   b ) shows an extended plate insert  202  that has an extended hole pattern  204 , where the extended hole pattern  204  has additional through holes for attaching the extended plate insert  202  to the column  102  and providing additional strength at the connection between the mounting plate  122  and the column  102 . 
       FIG. 2(   c ) shows an erection insert plate  206  having the alignment through-holes  114 , in addition to plate attachment holes  208 , where the plate attachment holes  208  can be attachment screw holes to attach the erection insert plate  206  to the inner wall of the column  102 . In this embodiment, the erection insert plate  206  has a pair of alignment through-holes  114  that are positioned concentric with the alignment through-holes  114  of the column  102 , where the attachment screws are inserted through plate attachment through-holes in the column (see  FIG. 4)  and into the plate attachment holes  208  of the erection insert plate  206  and tightened to secure the erection insert plate  206  to the inner wall of the column  102 . This embodiment of the invention enables simplified alignment of the through-hole pattern  104  of the mounting plate  122  with the through-hole pattern  104  of the column  102 . Referring to  FIG. 1  and  FIG. 2(   c ), The erection connector  130  is inserted through the alignment through-holes  114  of the mounting plate  122 , through the alignment through-holes  114  of the column  102 , through the alignment through-holes  114  of the erection insert plate  206  and into a threaded element  110  that is attached to the erection insert plate  206 . In one embodiment of the invention, the erection insert plate  206  can be a threaded nut  110  aligned with the alignment through-holes  114  of the column  102  and attached thereto. 
       FIG. 2(   d ) shows an insert  106  as an column insert  210  of generally tubular shape having the through-hole pattern  104  and the alignment through-holes  114 . 
       FIGS. 3(   a )- 3 ( d ) show some variations of the threaded element  110  with the insert, where  FIG. 3(   a ) shows the threaded element  110  as a threaded through-hole  300 . According to this embodiment, the erection insert plate  206  is attached to the column inner wall  113  using attachment screws (see  FIG. 4(   a )) screwed into the column  102  and into the plate attachment holes  208  of the erection insert plate  206 .  FIG. 3(   b ) shows the plate insert  200  having the hole pattern  104 , where the threaded element  110  is aligned with the erection through-hole  114  of the plate insert  200  and welded thereto (not shown). The plate attachment holes  208  are shown as an example of how the plate insert  200  may be attached to the column inner wall  113 , however the plate insert  200  may be attached using welding or its equivalents (not shown).  FIG. 3(   c ) shows the extended plate insert  202  having a nut cage  302  attached thereto, where the nut cage  302  holds the threaded elements  110  in alignment over additional alignment through holes  210  of the extended hole pattern  204  and over the alignment through-holes  114 .  FIG. 3(   d ) shows the insert  106  as a column insert  212  of generally tubular shape. The insert column  212  has the through-hole pattern  104  with the threaded elements  110  fixedly attached to the insert inner wall  112  and concentric to the alignment through-holes  114 , where it is understood that the threaded elements  110  may be attached using welding or its equivalents (not shown). It should also be apparent that the securing of any embodiment of the insert  106  to the column  102  to abut the column inner wall  113 , with the hole pattern  104  of the insert  106  aligned with the hole pattern  104  of the column  102 , can be done using the attachment screws and the attachment holes  208  or by welding or its equivalents (not shown). 
     Regarding  FIGS. 2 and 3 , if one of the plates ( 200 ,  202 ,  208 ) is used instead of the tubular insert  210 , then all or part of the column  102  must be grouted prior to pretensioning the connector bolts  132 . Here, the advantage in using an insert plate ( 200 ,  202 ,  208 ) is the ability to use an erection bolt  130  to erect the beam  120  to the column  102 , one beam  120  at a time when multiple beams  120  must be connected to the same column. The longer insert plate  202  can also increase column  102  bending capacity where the ends of the plate  202  are connected to the column  102 . 
       FIGS. 4(   a ) and  4  ( b ) show perspective views of the moment resistant building column insert system  100  according to one embodiment of the invention.  FIG. 4(   a ) shows a perspective cutaway view of the embodiment, where opposing beams  120  are attached near the top of the column  102 . The current invention includes a top plate  400  attached to the top of the building column  102 , using welding for example, where the top plate  400  provides additional lateral strength at the top of the column  102 . Further shown is the erection connector  130  inserted through the mounting plate  122 , through a wall of the column  102 , through a wall of the insert  106  and into the threaded element  110 , where the threaded element  110  has a threaded element cover  116  to shield the threaded element  110  from the structural filler  108  before it is hardened.  FIG. 4(   b ) shows a perspective partial cutaway view showing the moment resistant building column insert system  100  of  FIG. 4(   a ) where the top plate  400  is shown secured to the top of the column  102 . 
     Another embodiment of the moment resistant building column insert system  100  is shown in  FIGS. 5(   a )- 5 ( c ). Shown is a first column  500  of generally tubular shape having a first column top end  502  and a first column bottom end  504 . Additionally shown is a second column  506  of generally tubular shape having a second column top end  508  and a second column bottom end  510 , where the second column bottom end  510  has a pattern of through-holes  512 , shown here with connectors  130  installed therein, that are transverse to the length of the tube  506 . 
     Shown in  FIG. 5(   b ) is a column insert  106 , where the insert  106  is sized to fit within the building columns ( 500 ,  506 ). An insert bottom section  514  is fitted into the first column top end  502  and welded  518  thereto, where the insert  106  has a top section  516  with insert through-holes  518  arranged in the pattern of the second column bottom end  510  through-holes  512 . The system  100  uses the insert connecters including a threaded element  110  incorporated to the insert inside wall  112  and concentric to the pattern of through-holes  512  in the column insert  106 . Here the threaded elements  110  are shown as a nut cage  302  that is welded to the insert inner wall  112 , where other threaded elements  110  may be used. 
     The insert top section  516  is inserted to the second column bottom end  510  and the hole patterns  512  of the second column  506  and the insert  106  are aligned, where the erection connecters  130  are inserted to the through-holes  512  and into the threaded elements  110  and tightened thereto. According to one embodiment, the threaded element  110  is a threaded through-hole  300  in the insert, or the threaded element  110  is a nut attached to the insert  106  as discussed in  FIG. 3 . 
     In another aspect of the embodiment shown in  FIG. 5 , the building columns ( 500 ,  506 ) can have a cross-section such as circular, rectangular, square of polygonal, and the insert  106  can have a cross-section such as circular, rectangular, square and polygonal. 
       FIGS. 6(   a ) and  6 ( b ) show an exploded perspective view and a collapsed perspective view of another embodiment of the moment resistant column insert invention. Shown is a modular moment resistant building column insert  600  that has an insert column  106  of generally tubular shape. The insert  106  holds a hardened structural filler  108  disposed within the insert  106  having a pattern of through-holes  204  transverse to a length of the insert column  106  and through the structural filler  108 , where the through-hole pattern  204  shown is for the extended plate of  FIG. 3(   c ) and it should be understood that other hole patterns may be used. The filler  108  has at least one cavity  144  positioned where over the beam erection through-hole  114 , not seen in the drawings but an arrow is provide in  FIG. 6(   a ) to indicate one possible location. Further, there is at least one threaded element  110  incorporated to an insert inner wall  112  and disposed concentric to the erection through-hole  114 , where a threaded element cover  116  is disposed over the threaded element  110 ; it is the threaded element covers  116  that create the cavities  114  when the non-hardened filler  108  surrounds the covers  116 . An insert positioning element  118  disposed axially along the column  106  is provided, where the positioning element  118  enables alignment of the insert through-hole pattern  104  with a through-hole pattern  104  of a building column  102 . The insert  106  is sized to fit within the building column  102 .  FIG. 6(   b ) shows the modular moment resistant building column insert  600  that is to be positioned inside a column  112  (not shown). 
     In one aspect of the current embodiment, the insert column  106  can have a cross-section such as circular, rectangular, square or polygonal. 
     In other aspects, the threaded element  110  can be a threaded through-hole in the insert  106  or a nut attached to the insert  106 . 
     In another aspect of this embodiment, the insert positioning element  118  is a hole for receiving a hoist end there through (not shown). And, in a further aspect, the structural filler  108  can be concrete, grout, plastic, epoxy or compression resistive material. 
     A general method of using the moment resistant building column insert system  100  and a modular moment resistant building column insert  600  is shown by the steps in  FIG. 7 . The steps include providing a building column  700 , wherein the building column is generally tubular shape provide with at least one pattern of through-holes transverse to a length of the tube. And providing an insert  702  such as a plate or a column of generally tubular shape, and providing at least one pattern of through holes  704  transverse to a length of the insert. At least one threaded element is provided  706  that is incorporated to an inner wall of the insert and disposed concentric to one of the insert through-holes, and at least one threaded element cover is provided  708  disposed over the threaded element. Providing a hardened structural filler  710  disposed within the insert, where the provided pattern of through-holes  706  are transverse to a length of the insert tube and through the structural filler. An insert positioning element is provided  712  that is disposed axially along the insert. The positioning element enables alignment of the insert through-hole pattern with the column through-hole pattern, whereby the insert is sized to fit within the column. The method further includes providing at least one beam and mounting plate  714 , where the beam has the mounting plate attached to a beam end, and the mounting plate has through-holes arranged in the pattern, where the mounting plate abuts an outside wall of the column. Additionally the method includes providing at least one erection insert connector  716 , where the insert connecter has an erection bolt, where the erection bolt spans through the mounting plate, through a wall of the column, through a wall of the insert and into the threaded element, whereby the beam is positioned on the building column. The pattern of mounting plate through-holes are aligned with the pattern of column through-holes  118  and the erection connector is secured to the threaded element  720 . Further, the steps include providing at least one set of mounting plate connector hardware  722 , where the mounting plate connector hardware has a mounting plate through-bolt, a mounting plate nut, a mounting plate washer. Additionally, the mounting plate through-bolts are inserted through at least the mounting plate holes, the column holes, the insert through-holes, the filler through-holes, and into the mounting plate nuts, where the mounting plate connector hardware is then tightened  724 . 
     The method of using the moment resistant building column insert system  100  as shown in  FIGS. 5(   a )- 5 ( c ) is shown by the steps in  FIG. 8 . The steps include providing a first column  800  of generally tubular shape having a first column top end and a first column bottom end, providing a second column  802  of generally tubular shape having a second column top end and a second column bottom end column, where the second column bottom end has through-holes arranged in a pattern that are transverse to a length of the tube. The method further includes providing a column insert  804 , where the insert is sized to fit within the building columns, and the insert has a top half having through-holes arranged in the pattern and a bottom half inserted to the first column top end  806  and welded thereto. The insert top end is inserted to the second column bottom end  808  and the second column hole pattern is aligned with the insert hole pattern  810 . Additionally provided are insert connectors, where the insert connecter have a threaded element incorporated to an inside wall of the insert and concentric to the column insert through-hole, and an erection bolt, where the erection bolts are inserted  812  through the building column through-holes, through the column insert though holes and into the threaded elements and tightened thereto. 
     The present invention has now been described in accordance with several exemplary embodiments, which are intended to be illustrative in all aspects, rather than restrictive. Thus, the present invention is capable of many variations in detailed implementation, which may be derived from the description contained herein by a person of ordinary skill in the art. For example, in one variation the connection plate can be flush, or nearly flush, with the top and bottom of the beam. Larger bolts, or an increased number of bolts, could be used to connect the beam to the column and produce the rigid moment connection desired. In another variation, where greater stiffness in one direction is needed for structure, rectangular columns can be used with the longer direction of the rectangular column in the stiffer direction needed. Further, the beams can be sloped to match a roof structure slope and still connect to the column as a rigid moment connection. An additional variation may occur when beams are framed into a column at a 90-degree angle, the beam positions can be off-set vertically to allow the through-bolts to pass one another in the column, and still produce a rigid connection in each direction. In a further variation, the erection insert can be used with columns that will be completely grouted to provide greater vertical capacity to aid in the erection of the beams. 
     All such variations are considered to be within the scope and spirit of the present invention as defined by the following claims and their legal equivalents.