Hybrid Sliding-Rocking (HSR) Segmental Bridges

Published February 23, 2019 This content is archived.

Graduate Students: Petros Sideris

Principal Investigator: Amjad Aref

Co-Principal Investigator: Andre Filiatrault

Project Completion Date: 09-01-2012

A novel damage-resistant system that combines accelerated bridge construction (ABC) with seismic resilience and is suitable for applications in seismic areas.


This research introduces the concept of hybrid sliding-rocking (HSR) precast concrete post-tensioned segmental members for seismic applications in bridges. The HSR members lie into the framework of accelerated bridge construction techniques (ABC) and are primarily intended for applications in moderate and high seismicity areas. The HSR members combine two fundamental components, namely the HSR segmental joints, and the internal unbonded post-tensioning. The HSR joints utilize relative segment-to-segment sliding (joint sliding) and gap opening (joint rocking) to mitigate the applied seismic loading. Joint sliding offers energy dissipation with minor structural damage as well as moderate self-centering characteristics. On the other hand, joint rocking offers high self-centering capabilities that deteriorate at larger rocking rotations due to the resulting concrete crushing. The response of HSR joints is affected by the geometry of the post-tensioning (PT) system along the member length. Hence, linear or nonlinear PT geometry may be used to control joint and member response properties. Two distinct types of HSR members were further studied: (i) HSR members with slip-dominant joints and linear PT geometry (abbreviated as HSR-SD members), and (ii) HSR members with rocking- dominant joints and nonlinear PT geometry (abbreviated as HSR-RD members).


The concept of HSR bridges was evaluated through a two-phase experimental study. The first phase included shake table testing of a large-scale (~ 1:2.39) single-span bridge specimen incorporating a HSR-RD superstructure and two HSR-SD single-column piers. Nearly 150 seismic tests were conducted including far-field and near-fault input motions scaled to different seismic hazard levels. The second phase included quasi-static testing of the HSR-SD piers with a sequence of displacement-controlled loading cycles of increasing amplitude that eventually reached a drift ratio of approximately 15%. The experimental findings from the large-scale seismic and quasi-static testing programs were complemented by frictional/shear testing of HSR joint interfaced and tensile testing of monostand-anchor systems (i.e., unbonded monostrands with their anchorage setups at their ends).



This project is supported by the Federal Highway Administration of the U.S. Department of Transportation