Date

2016

Document Type

Dissertation

Degree

Doctor of Philosophy

Department

Structural Engineering

First Adviser

Pessiki, Stephen P.

Other advisers/committee members

Wilson, John L.; Bocchini, Paolo; Perez, Felipe J.

Abstract

Although cast-in-place concrete structural walls have good lateral stiffness and strength, significant damage to concrete structural walls has been observed in past earthquakes. For a cast-in place concrete wall, softening of the lateral stiffness can be caused by yielding of the longitudinal steel reinforcement and nonlinear response of the concrete in compression. In addition, a cast-in-place concrete wall may have significant residual drift after an earthquake, which may hinder the immediate use and occupancy of a building with cast-in-place structural walls after an earthquake. This study addresses this potential limitation of cast-in-place concrete walls by using unbonded post-tensioned steel within a cast-in-place concrete wall.This study focuses on unbonded post-tensioned (UPT) cast-in-place concrete walls. A UPT concrete wall is expected to have good self-centering response (with little residual drift), good ductility, and significant energy dissipation capacity. Experimental and numerical studies on UPT cast-in-place concrete walls were performed.The experimental results show that the lateral load response of UPT cast-in-placeconcrete walls exhibits excellent self-centering response and energy dissipation capacity. Experimental results also show that UPT cast-in-place concrete walls are able to undergo large deformations before failure and at the drift level reached under the DBE, the damage in the walls was not serious.Numerical models of UPT concrete walls were developed and calibrated withexperimental results. Numerical analyses, including pushover analyses and nonlinear dynamic time history analyses were performed, demonstrating that UPT concrete walls perform well under the design basis earthquake and maximum considered earthquake. Incremental Dynamic Analyses (IDA) were performed. Using IDA results, prototype buildings which use the UPT concrete walls developed in this research are shown to satisfy the collapse prevention criteria of FEMA P695 (2009). Results from IDA indicate that UPT concrete walls could be designed with an R value larger than 6, and still satisfy the collapse prevention criteria of FEMA P695 (2009).

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