The first thing is to look at bridge bearing design at both ends. Most of the cases one end of the bridge will be fixed with the platform and other end will be sliding end on the platform. The bearing designs will show the gap axial and lateral.
Next the pipe runs between two platform linking the bridge.
The pipework on fixed end is normally anchored and relative displacement as advised by DANB is applied. A proper flexibility with loops are provided on sliding end of platform.
A fatigue check is required based on the no of deterministic wave cycles at different wave heights.