Title: Evaluation of ASCE 41 Modeling Parameters for Slender Reinforced Concrete Structural Walls

Author(s): Anna C. Birely, Laura N. Lowes, and Dawn E. Lehman

Publication: Symposium Paper

Volume: 297

Issue: 1-18

Appears on pages(s):

Keywords: ASCE 41; reinforced concrete; walls; flexure-control; acceptance criteria; plastic hinge rotation.

DOI: 10.14359/51686901

Date: 3/6/2014

Abstract:
ASCE/SEI 41-06 provides guidelines for evaluating the seismic adequacy of existing buildings. For nonlinear dynamic analysis of a building, ASCE 41 provides modeling parameters to define the backbone curve for the response of structural components. Seismic adequacy is then determined by comparing simulated response to predetermined acceptance criteria. In the reinforced concrete (RC) community, there is interest in evaluating the modeling parameters and acceptance criteria for RC components, and if deemed necessary, developing updated values that reflect the current state of understanding of the seismic performance of RC components. For some structural components (e.g. columns), large databases of experimental data can be used to develop empirical acceptance criteria that reflect the behavior of the component. In the case of slender structural walls, relatively limited tests have been conducted such that sufficient variation in critical design and loading characteristics including shape, aspect ratio (elevation and cross-sectional), confinement, and axial load are not represented by experimental data to justify use of an experimental database to develop acceptance criteria. Evaluation of this limited set of experimental data indicates current ASCE 41 modeling parameters and acceptance criteria for flexure-controlled walls is inappropriate, generally resulting in overprediction of wall deformation capacity at high axial load ratios and underprediction at low axial load ratios and low shear demands. Although suitable for evaluation of criteria, the data set is not sufficiently varied such that revised provisions can be developed. To overcome the lack of sufficient experimental data, a parameter study was conducted to provide data to support development of updated acceptance criteria. The parameter study was conducted using a modeling approach validated to provide accurate simulation of flexural failures in slender reinforced concrete walls. Simulation results were used to develop preliminary recommendations for revised modeling parameters for slender RC walls. An evaluation of these simulation results and preliminary recommendations for revised flexure-controlled RC wall modeling parameters are presented in this paper.