Patent ID: 8789337

Claim:
A precast concrete foundation unit for use in constructing a combination precast and cast-in-place concrete foundation structure, the precast concrete foundation unit comprising: a first elongated upright wall member and a second elongated upright wall member spaced apart from the first elongated upright wall member to define a channel therebetween, and multiple upright supports located within the channel, each of the multiple upright supports extends laterally between the first elongated upright wall member and the second elongated upright wall member of the first precast concrete foundation unit to (i) define multiple spaced apart cells along a length of the channel and (ii) rigidly connect the first elongated upright wall member and the second elongated upright wall member, each of the multiple cells is open at both the top and the bottom, a receiving channel is located atop each of the multiple upright supports; wherein bottom surfaces of each of the inner elongated upright wall member, the outer elongated upright wall member and the multiple upright supports of the first precast concrete foundation unit lie in a common plane; at least some of the multiple upright supports include at least one flow opening extending from cell to cell for permitting cast-in-place concrete to flow from one cell through the upright support to another cell during pouring, wherein the flow opening is spaced above the bottom surface of the support and below a top surface of the support so as to be completely surrounded by precast concrete of the upright support.