Seismic Methods

Folic R., Cosic M.: Seismic Methods (presentation)

The authors of the presentation, on the basis of the analysis of several thousand scientific papers, presented their original systematization of nonlinear seismic methods for structural performance analysis, which were developed in the last twenty years. Nonlinear seismic methods are generally classified into two groups: Nonlinear Static Analyses (NSA) and Nonlinear Dynamic Analyses (NDA). The analyses of non linear seismic structural response were classified separately from the target displacement analysis which defines the relationship of the seismic demand and the seismic response. On the other hand, the classification was also conducted depending on whether a nonlinear response of the system is obtained by the implementation of incremental-iterative procedures or by the implementation of semi-iterative and/or semi-incremental procedures. Nonlinear Dynamic Analyses were classified according to the concept of mathematical formulation, i.e. whether they are based on only one dynamic analysis, several dynamic analyses or are solved in combination with other methods. By implementing the conducted systematization and classification of nonlinear seismic methods, on can very efficiently consider which type of method is optimal for structural analysis and which type of method should be taken into account in the phase of preliminary and final analyses in the course of scientific research and professional projects.

Nonlin Quake software

Cosic M., Brcic S., Folic R., Susic N.: Nonlin Quake Software (presentation)

The presentation shows the original developed software NonlinQuake for performance-based seismic analysis of 3D structural models. Software Nonlin Quake consists of several independent compatible softwares that implements: create a database of two componential ground motion records (GMR), generation and processing of multicomponential GMR, creating incomplete and complete nonstationary artificial accelerograms, deterministic and probabilistic seismic hazard analysis, generation and processing of multicomponential response spectras, analysis of design parameters, processing of pushover curves and surfaces, calculation based on hybrid incremental nonlinear static-dynamic analysis, target displacement analysis, analysis and scaling of response spectras and analysis of target displacement envelope. For four considered methods for analysis of system performances: nonlinear static pushover analysis (NSPA), incremental nonlinear dynamic analysis (INDA), incremental dynamic analysis (IDA) and hybrid incremental nonlinear static-dynamic analysis (HINSDA), flow charts are shown.

Soil-Pile-Pier Interaction

Cosic M., Folic B., Folic R., Susic N.: Soil-Pile-Pier Interaction (presentation)

The purpose of this presentation is to show the methodology for performance-based seismic evaluation of soil-pile-bridge pier interaction using the incremental nonlinear dynamic analysis (INDA). The INDA analysis was post processed separately for the pier and for the pile, so that the constructed PGA=f(DR) curves are in the capacitive domain. For these curves the authors identified the IO, CP and GI performance levels, while the regression analyses were conducted based on the specific DR and PGA parameters. Fragility curves were constructed based on the solutions of regression analysis and the probability theory of log-normal distribution. Based on the results of fragility analysis, reliability curves were also constructed.