Hinged arch bridge

Springing point hinge (left) and crown hinge (right) on a three-hinged arch bridge in Namur, Belgium

A hinged arch bridge is one with hinges incorporated into its structure to allow movement. In structural engineering, a hinge is essentially a "cut in the structure" that can withstand compressive forces. In a steel arch the hinge allows free rotation,^[2] somewhat resembling a common hinge. The most common hinged arch bridge varieties are the two-hinged bridge with hinges at the springing points and the three-hinged bridge with an additional hinge at the crown of the arch; though single-hinged versions exist with a hinge only at the crown of the arch. Hinges at the springing point prevent bending moments from being transferred to the bridge abutments. A triple-hinged bridge is statically determinate, while the other versions are not.