详情

Self-Centering Bridge Bent for Accelerated Bridge Construction in Seismic Regions

项目名称：	Self-Centering Bridge Bent for Accelerated Bridge Construction in Seismic Regions
摘要：	Current design philosophy in bridge design for seismic regions aims to reduce residual displacements after an earthquake. After the Kobe earthquake, Japanese design criteria for bridges have changed to require designers to limit permanent drifts to less than 1% (Japan Road Association 2002). The aftermath of the Christchurch earthquake has highlighted difficulties in assessing future performance and repair of damage to plastic hinge zones in conventional reinforced concrete structures (Routledge et al. 2016). Low-damage ductile-jointed systems have been developed to control damage in plastic hinge regions and avoid residual displacements. These systems provide self-centering capability using un-bonded post-tensioning and axial load, and provide energy dissipation through yielding of non-prestressed reinforcement or yielding dampers. Unbonded post-tensioning, in which prestressing forces are introduced at the construction site during the erection process has been proposed for reducing residual displacements after an earthquake. Post-tensioning was combined with high-performance cementitious materials to limit damage in the hinging region by Billington and Yoon (2004). Mahin et al. (2005), Cohagen et al. (2008), Motaref et al. (2010), Restrepo et al. (2011), and Guerrini et al. (2015) who studied the benefits of introducing post-tensioning into bridge columns. However, post-tensioning which is an extra step performed at the bridge site can delay construction because of the jacking operation. In addition, stress concentration where a wedge grips the unbonded strands may reduce the cyclic stresses that anchorages can withstand (Walsh and Kurama 2012). The objectives of this research include: (1) Develop and test under cyclic loads alternative methods for constructing bridge bents in high seismic regions using self-centering in terms of post-tensioning of bridge columns; and (2) Develop analytical models for self-centering in terms of post-tensioning of columns in bridge bents under cyclic loads, which will assist in the design and implementation of such bridges. Accelerated Bridge Construction (ABC) has been practiced in many parts of the country; however, in high seismic regions the challenge of providing ductile connections between columns and footings and columns and pier-caps is a topic of research currently still in progress. All similar research carried out so far on post-tensioned columns has considered a single bridge column. The proposed research considers a two-column bent with scaled dimensions representing an actual bridge bent that has been built in the state of Utah. Moreover, the debonding of the steel bars is an innovative feature that is expected to improve displacement ductility of the bridge bent.
状态：	Active
资金：	222835
资助组织：	Office of the Assistant Secretary for Research and Technology
管理组织：	Mountain-Plains Consortium
项目负责人：	Kline, Robin
执行机构：	University of Utah, Salt Lake City
主要研究人员：	Pantelides, Chris
开始时间：	20171115
预计完成日期：	20220731
实际结束时间：	0