Circle

A Circle is defined by a center point and a radius. In bridge drawings you'll use it for piles in foundation plans, dowels and anchor bolts in details, drilled-shaft centerlines, hole layouts, plan-view circular columns, and any feature that's truly circular rather than a polygonal approximation.

To draw: click once to place the center, then click again to set the radius. The radius is the distance between the two click points. A dashed preview line during drawing shows the current radius.

Geometry

Name: Identifier within the parent CAD document. Must be unique.

Level: The layer controlling color, line weight, and dash style. Common assignments: "Piles" for foundation plans, "Hardware" for dowel and anchor bolt symbols.

Center X: Horizontal coordinate of the circle's center.

Center Y: Vertical coordinate of the circle's center.

Radius: Distance from the center to the circle. Must be positive.

Diameter (readonly): Twice the radius. Shown for convenience when dimensioning by diameter.

Circumference (readonly): Length around the circle. Useful for rebar length take-offs on circular columns.

Area (readonly): Plan area enclosed.

Editing

Move the center: drag the center handle to translate the circle.

Resize: drag any of the four quadrant handles (top, bottom, left, right) to change the radius. The center stays fixed; the radius updates symmetrically.

Snap: other shapes can snap to the center and to the four quadrant points (cardinal points on the circle).

Offset: create a concentric copy at a fixed distance — useful for showing pile-cap clearances around piles.

Notes

When the parent CAD document is driven by an alignment, the circle's center is bent onto the alignment, but the circle stays a circle (it does not warp into an ellipse over a horizontal curve). This is the right behavior for piles and anchor bolts — they should remain round in plan even when the bridge is curved.

If you need a circular shape that does warp with the alignment (e.g., a circular hatch pattern that follows the bridge curvature), use a Container with a closed polyline approximating the circle.