Construction system

An improved system for constructing load-bearing structures for multistory buildings and the like on a foundation, with prefabricated sets of interconnectable girder members, connecting plate members and attachment means for selectively securing the girder and plate members to one another, the improvement comprising:

• the girder members being prefabricated in a plurality of incrementally different lengths and having flanges with a web portion therebetween forming channel-shaped cross-sections of uniform web width, at least some of the girder members being vertically-oriented;
• each of the plate members being formed with flanges to form receiving channels of uniform web width and cross-section, the respective web widths at each end of each girder member and each receiving channel being dimensioned to enable portions of each to nest snugly one inside the other, the receiving channels being directed to bear and transmit primary loads between the girder members of successive building stories, the primary loads being borne by and transmitted between the girder and plate members in planes defined by the nested webs, the flanges of the nested ends bearing against one another to provide high rotational rigidity and overall frame stiffness;
• the attachment means being engageable with nested portions of both the girder and plate members to provide full surface engagement of the nested web portions, whereby a plurality of structures for buildings, of varied size and shape, may be easily constructed from sets of prefabricated girder members and prefabricated connecting plate members secured together by the attachment means;
• and
• means for securing at least some of the vertically-oriented girder members to the foundation.