This Architectural Drawing of AutoCAD of Bottom layer of reinforcement of pile cap. The term "pile cap" may be used to describe a reinforced concrete slab constructed on top of a group of foundation piles to evenly displace or spread the load they are to carry. The pile cage has vertical reinforcement held together by outer and inner rings. The Reinforcement in pile construction include: Vertical Reinforcement. Outer Ring Reinforcement. Inner Ring Reinforcement. For more details and information download the drawing file.