components 12 such that when two building components 12 have their respective enlarged ends 14 abutted against each other their respective channels 16 will form a cavity 18 therebetween as most readily seen in fig3 the channels 16 are sized and shaped to receive a suitable reinforcing post 26 which extends through the entire column of building components 12 and projects into a hole 30 formed in the substratum which will typically be soil 32 the reinforcing post 26 can be of any suitably rigid material though a relatively corrosion resistant steel is preferred furthermore though the reinforcing post 26 is shown to have a cross section similar to that of an i beam other forms are possible finally and in accordance with the preferred embodiment of this invention weldability is also a necessary characteristic for the reinforcing post 26 as will be described below with reference to fig2 a pair of plates 20 are shown as being secured to opposing walls of each channel 16 the plates 20 are preferably integrally cast with the building components 12 though it is foreseeable that the plates 20 may be secured to their respective channel 16 by other suitable methods such as with fasteners the plates 20 are positioned within the channels 16 such that when the reinforcing post 26 is received within the cavity 18 at least a portion of.