Access Type

Open Access Dissertation

Date of Award

January 2012

Degree Type

Dissertation

Degree Name

Ph.D.

Department

Civil and Environmental Engineering

First Advisor

Gonkang Fu

Abstract

ABSTRACT

RELIABILITY AND EFFECT OF PARTIALLY RESTRAINED WOOD SHEAR WALLS

by

JOHN J. GRUBER

MARCH 2012

Advisor: Dr. Gongkang Fu

Major: Civil Engineering

Degree: Doctor or Philosophy

The prescriptive design of the most widely used residential building code in the United States, the IRC, allows the use of partially restrained wood shear walls to resist wind and seismic loads. Wind load is the most common controlling lateral design load for these structures. In contrast, the complimenting building code, the IBC, requires either a restraining dead load or a mechanical hold down device to resist overturning. To prescribe a safe structure, it is important to know the effect of partial restraint on the overturning resistance of wood shear walls constructed in accordance with the IRC and equally important whether the partially restrained wood shear walls provide the same level of reliability as fully restrained wood shear walls for wind load. This is the focus of this research.

Twenty five Monotonic tests were conducted of 4' x 8' wood shear walls with five varying restraining methods (wall types). There were five sets of five wall types. One of the sets had only an anchor bolt, three sets had different dead loads with one anchor bolt, and one set had a mechanical hold down. The results of the test program were used to determine the partial restraint effect, create a nonlinear finite element model, and to determine the statistical data required to perform a Monte Carlo simulation of the wall behavior.

The Monte Carlo simulation result was used to calibrate a nonlinear partial restraint factor to a target reliability index of 3.25. The calibration was performed for both ASD and LRFD load combinations as required by the IBC. The research concludes with a closed-form solution, including the calibrated nonlinear partial restraint factor developed, to determine the unit shear capacity of a partially restrained or fully restrained (with dead load or mechanical hold down) wood shear wall constructed in accordance with the IRC by utilizing the fully restrained nominal unit shear values of AF&PA's Special Design Provisions for Wind and Seismic.

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