Title: Design Methodology for Unbonded Post-Tensioned Rocking Walls

Author(s): Qingzhi Liu, Catherine W. French, and Sri Sritharan

Publication: Structural Journal

Volume: 121

Issue: 4

Appears on pages(s): 75-85

Keywords: aspect ratio; confinement reinforcement; precast; rocking wall; seismic.

DOI: 10.14359/51740571

Date: 7/1/2024

Abstract:
Unbonded post-tensioned rocking walls have demonstrated superiorseismic performance with greatly reduced damage and excellentself-centering behavior. Current design guidelines (ACI 550.7)and representative research on rocking walls are summarized inthis paper. Some inconsistencies and voids in the major designparameters for rocking walls are identified. A brief description isprovided for two rocking-wall specimens tested under quasi-staticcyclic loading. Force flow and failure mechanisms of rocking wallsobserved from the tests were studied, and it is discovered that theyare very different from those of special structural walls. The test datashowed that the concentration of compressive strain in concrete atthe corners of rocking walls was a local behavior such that theneed for confinement reinforcement higher above the toe regionwas diminished. Fiber grout weaker than concrete in rocking wallsused as ductile bearing materials at the wall-foundation interfaceis a reasonable alternative to ACI 550.7. Design recommendationsfor height and volumetric ratio of confinement reinforcementare provided. A requirement for the aspect ratio of rocking wallsstricter than that in ACI 550.7 is proposed to prevent shear slidingof the walls.