You can choose integral cap on the Pier Type dialog only when integral pier is selected. For this cap shape you may choose to specify slab extended beyond the cap (diaphragm) at top and bottom as flanges for cap beam. For this cap shape, the cap centerline passes through the c.g. of the cap main section and is parallel to the top surface of the cap.

For a skewed pier, specify these dimensions along the skew or perpendicular to it. For a straight cap, X1 may be set equal to X2 while X3 and X4 are set equal to zero. If you do not want to model slab as flanges, set Y4, Y5, Z4 and Z5 equal to zero.