girder bridge
A bridge whose main structural element is a horizontal beam (girder). Common in civil engineering contexts.
この川には古い桁橋が架かっている。
An old girder bridge spans this river.
Compound of 桁 (keta, 'beam, girder') and 橋 (hashi, 'bridge'). The reading けたばし is a straightforward combination of the two elements.