Abstract: A reinforcing structure is provided for supporting a joint of two cable tray sections, wherein each of the two cable tray sections includes a side rail having a planar body member, a bottom edge and a top edge, and wherein the joint is positioned over a structural support member. The reinforcing structure may include a top member; a body member extending substantially perpendicularly from the top member; and a bottom member extending substantially perpendicularly from the body member. The bottom member may be configured for mounting on the structural support member. The bottom member may be configured to receive the bottom edge of the side rail. The top member may include an inside edge configured to support the planar body member of the side rail when the bottom edge of the side rail is received into the bottom member.