Date of Award
Doctor of Philosophy (PhD)
Civil, Environmental & Architectural Engineering
Abbie B. Liel
Keith A. Porter
Ross B. Corotis
Performance-based earthquake engineering (PBEE) provides a framework to quantitatively assess the seismic risks to buildings and explicitly consider building seismic performance in the design process. This thesis utilizes PBEE to enhance the understanding of the seismic performance of RC frame buildings by: (1) estimating the performance of buildings retrofit to standardized levels using existing retrofit design documents; (2) quantifying improvements in seismic performance possible through retrofit design; (and 3) evaluating the vulnerability of reinforced-concrete (RC) buildings to vertical ground shaking.
To evaluate the performance of retrofit RC frame buildings, a set of 3-, 6-, and 9 story RC frame buildings is designed to the Uniform Building Code of 1967 (International Conference of Building Officials, 1967). 1967-era buildings are then retrofit to ASCE 41 standards (ASCE, 2013). The performance of each building is evaluated using a rigorous PBEE framework developed by the Pacific Earthquake Engineering Research (PEER) Center and damage observations are compared with ASCE 41 estimated damage levels. In many cases, retrofit buildings perform better than ASCE 41 performance definitions. In other cases, the performance of retrofit buildings appears to be consistent the ASCE 41’s stated performance goal.
Subsequently, improvements in seismic performance from retrofitting are quantified though the identification of dimensionless indicators of retrofit effectiveness. Here, improvements in performance - i.e. retrofit effectiveness - are defined as reductions in collapse risk (quantified by the mean annual frequency of collapse) and earthquake-induced repair costs. The results demonstrate that a combination of strength-based and ductility-based indicators best describes improvements in mean annual frequency of collapse from seismic retrofitting. However, strength-based indicators (particularly those that relate strength capacity to the spectral demand) are correlated with reductions in earthquake-induced repair costs.
Finally, the vulnerability of ductile and nonducitle RC buildings to vertical ground shaking is quantified using PBEE methods. Building geometries include symmetric layouts and layouts that contain cantilever overhangs. Results show that the performance of buildings containing cantilevered sections is more impacted by vertical ground shaking than the performance of buildings with symmetric layouts. Furthermore, nonductile buildings are found to be more severely impacted by vertical ground shaking than ductile buildings.
Harrington, Cody Conroy, "Advancement of Performance-Based Earthquake Engineering for RC Frame Buildings: Application to Retrofit Design and Consideration of Vertical Ground Motions" (2016). Civil Engineering Graduate Theses & Dissertations. 50.