PERFORMANCE-BASED PLASTIC SEISMIC DESIGN OF RC STRUCTURES CONSIDERING SOIL-STRUCTURE-INTERACTION

Abstract

Performance-Based Plastic Design (PBPD) method is widely extended for seismic design of building structures. A pre-selected target drift and yield mechanisms are used as key performance objectives. In this research, reinforced concrete special moment frames (RC SMF) were used in four architypes concrete structures designed according to both ACI-318/ASCE-07 and PBPD. RC SMF was also combined with a homogeneous soil half-space to provide a simplified Soil-Structure-Interaction (SSI) model. Six types of clay and sandy soils were considered in this study. In addition to considering pile caps and piles foundation system to provide a soil-pile-structure-Interaction (SPSI) model. Nonlinear lateral load-transfer from the foundation to the soil is modeled using p-y curves for soft clay soil that was considered in this study. Numerical results obtained using soil-structure-interaction model conditions were compared to those corresponding to fixed-base support conditions, such as fundamental time period, structural capacity, storey displacement and storey drift. On the other hand, incremental dynamic analysis (IDA) in addition to pushover analysis were conducted under a set of ground motion records, and scaling peak ground acceleration to an increasing design acceleration. Five levels of performance based seismic designs, namely: operational phase (OP), immediate occupancy (IO), damage control (DC), life safety (LS), and collapse prevention (CP), were considered to assess structural performance. Numerical results obtained for fixed-base support conditions, and fragility curves for several performance limits were generated for both types of models.