Cutwater

Cutwater is a sidepiece constructed adjacent to the piers of bridges that are on the streambed to control the current (Figure 1.). Likewise, flood splitter and starling terms are used in the terminology of architectural engineering.

The design of cutwater is based on the technique of prow or nosing. It is a triangular protrusion, which is called selyaran in Turkish, at the upstream of the bridge to direct the water through the openings and to avoid the piers to be abraded with the effect of flowing water (Zhao and Tonias, 2012) (Figure 2.); and is a circular, rectangular or polygonal protrusion, which is called mahmuz in Turkish, at the downstream of the bridge to prevent the piers against the vortex that water would constitute while leaving the bridge behind (Hosking, 1843) (Figure 3.). The designs of cutwaters have shown limited changes by the effect of the problems experienced since the ancient period (Tanyeli, 2018). However, in cold environments, the cutwaters are designed with an almost an angle of 45° through the upstream of the bridge in order to lift the submerged ice and transform the horizontal force reasoned by the current into vertical force so that the submerged ice and water flow on both sides of the pier. This type of cutwater is called starkwater (Wikipedia, 2012) (Figure 5., Figure 6.).

Cutwaters would be constructed either on both upstream and downstream faces of the bridge or only on a single facet of the bridge. The construction of cutwater on different faces is based on the current and the design of the piers (Hosking, 1843).

The construction technique of cutwaters in historical bridges is generally stone (mostly cut stone) (Figure 2., Figure 3.) or brick masonry since the Roman period (Alaboz, 2008) (Figure 4.).

The examples of timber cutwaters are limited (Figure 5.). The base of the cutwater is mostly stone or brick masonry even if the upper parts are timber. The concrete cutwaters are seen in later bridge examples (Zhoa and Tonias, 2012) (Figure 6.).