Franz N. Rad
Date of Award
Master of Science (M.S.) in Civil & Environmental Engineering
Civil and Environmental Engineering
Reinforced concrete construction -- Design and construction, Reinforced concrete -- Testing, Buildings -- Retrofitting, Reinforced concrete buildings -- Evaluation
For the past decade or more, the structural engineering profession has been using the nonlinear static procedure (NSP) or pushover analysis. Modeling for such analysis requires the determination of nonlinear properties of each component in the structure, quantified by strength and deformation capacities, which depend on the modeling assumptions. Pushover analysis is carried out for either user-defined nonlinear hinge properties or default-hinge properties, available in some programs based on the FEMA-356 such as SAP2000. While such documents provide the hinge properties for several ranges of detailing, programs may implement averaged values. In the realm of retrofitting of existing structures, few tested procedures have been identified such as steel jacketing and carbon fiber reinforced polymer (CFRP) composite jacketing system techniques in order to increase lateral stiffness of existing structures. Several methodologies have been developed using these processes in recent years. In some cases, the codes require non-linear analysis for the verification of design proposed for a retrofitting a structure.
In this study, the seismic behavior of a typical residential building in South of Tehran, Iran, was investigated by performing static pushover analysis before and after retrofitting the columns. In the selected reinforced concrete (RC) structure, seismic analysis was performed for the structure retrofitted by two methods: 1) Steel jacketing and 2) CFRP jacketing technique assuming full composite action between jacketing and the existing concrete columns. By using nonlinear static (pushover) analysis, the performance level of structural members were evaluated for all structures, before and after retrofitting. The selected model building is a good representation of all typical residential buildings constructed in 1970’s in Iran. These structures are almost always without proper seismic detailing. In this study, to investigate the effectiveness of the retrofitting systems, a comparative study was performed.
Nahavandi, Hamidreza, "Pushover Analysis of Retrofitted Reinforced Concrete Buildings" (2015). Civil and Environmental Engineering Master's Project Reports. 21.