ABSTRACT
Bridges are counted as a part of road facilities to serve the purpose of transportation. Most bridges are designed and built to satisfy their roads’ requirements. To satisfy requirements of a road alignment, the axis of a bridge may have to be curved in both horizontal and vertical directions, and the finished grade of bridge deck must comply with the transverse slopes set forth in road geometries. Also, a bridge has to be designed under certain engineering aesthetic guidelines, which may force a bridge axis, profiles, or its components in curve or complex shapes. In other words, both the bridge axis and a bridge component are more complex than what they are usually described in mathematics and mechanics models.
