ABSTRACT
Pergola structures also known as elevated slab structures are used in rail bridges where the rail alignment crosses over features such as roads and rail tracks at very large skews. These structures have become quite useful and popular in high speed rail projects where the track alignment is such that the avoidance of large skews is not possible. A pergola structure consists of two lines of several multi-span frames spanning the features crossed. In each multi-span continuous frame, standard precast pre-tensioned concrete (PC/PS) wide flange girders or for shorter spans PC/PS box girders placed in the transverse direction support a concrete deck slab that carries the guide way. The transverse girders are supported by two longitudinal reinforced concrete or post-tensioned edge beams. Each edge beam is supported by single columns through a pinned connection or a bearing. In this paper, the design requirements of track structure interaction analysis required in high speed rail structures are explained. Also steps taken to design the pergola structures in order to comply with the tight design criteria are discussed. Design details such as the edge beams, joints between pergola frames and transitions from pergola structures to other superstructure types are provided.
