Response spectra for the seismic evaluation of buildings

Opisane su metoda postupnog guranja (Pushover Analysis) i metoda spektra kapaciteta (Capacity Spectrum Method) koje se primjenjuju u seizmičkoj procjeni postojećih i novih zgrada. Nelinearnim statičkim proračunom dobiva se krivulja kapaciteta konstrukcije, a zahtjev potresa predstavljen je spektrima ubrzanja. Obje krivulje su u formatu spektralno ubrzanje - spektralni pomak. Usporedba kapaciteta konstrukcije i zahtjeva potresa daje podatke o mogućem odgovoru konstrukcije na potres.Two methods that are used in the seismic evaluation of existing and new buildings, i.e. the pushover analysis and the capacity spectrum method, are described. The capacity curve for structures is obtained by nonlinear static analysis, and the earthquake demand is represented through acceleration spectra. Both curves are in the spectral acceleration - spectral displacement format. The comparison of structural capacity and earthquake demand provides an answer about possible response of structures to earthquake action

Pushover analysis and failure pattern of a typical masonry residential building in Bosnia and Herzegovina

The paper discusses the behavior of a typical masonry building in Bosnia and Herzegovina built in the 50’s without any seismic guidelines. A global numerical model of the building has been built and masonry material has been simulated as nonlinear. Additionally, calculations done with a "less" sophisticated model are in a good correlation with the finite element method (FEM) calculations. It was able to "grasp" the damage pattern; not as detailed as in the FEM calculations, but still quite good. On the basis of this it may be concluded that in this case calculation with Frame by Macro Elements (FME) program could be recommended for future analysis of this type of structures, having quite good results with a less computation time. However, in the need for more precise results FEM should be utilized

Calculating displacement of unsymmetrical multistory buildings exposed to seismic action

Predložena je približna metoda za proračun maksimalnih horizontalnih pomaka nesimetričnih višekatnica izloženih potresu, a nazvana je metodom ekvivalentne elastične krutosti Promatrana je višekatnica malog, srednjeg i većeg ekscentriciteta. Dobiveni pomaci uspoređuju se sa odgovarajućim rezultatima nelinearnog dinamičkog proračuna. Rezultati se veoma dobro slažu u srednjim katovima, na vrhu zgrade približna metoda daje nešto nepovoljnije rezultate, ali u prihvatljivim granicama.Authors propose an approximate method for calculating maximum horizontal displacement of unsymmetrical multistory buildings exposed to earthquake action. The method is known as the method of equivalent flexural stiffness. The multistory building of low, medium and high eccentricity is monitored. The obtained data are compared with appropriate results of nonlinear dynamic analysis. A very good correspondence has been registered for stories in the middle of the building, while results are somewhat less favorable for the top of the buildings, although they are still within acceptable limits

Capacity degradation and crack pattern development in a multi-storey unreinforced masonry building

U radu je prikazana seizmička procjena tipične višekatne nearmirane zidane stambene zgrade bez serklaža. Numerička analiza provedena je pomoću metode konačnih elemenata koristeći eksperimentalne podatke o kvaliteti materijala konstitutivnih elemenata ziđa i armiranog betona. Proračun je proveden nelinearnom statičkom metodom postupnog guranja (eng. Pushover Analysis) i nelinearnom dinamičkom metodom u vremenu (eng. Time History Analysis). Uspoređen je razvoj pukotina dobivenih primjenom obje proračunske metode kao i dijelovi histereznih krivulja.A seismic assessment of a typical unreinforced masonry residential building without tie beams is presented in the paper. The numerical analysis was conducted according to the finite-element method using experimental data on the quality of the masonry constitutive elements and reinforced concrete. The computation was made using the nonlinear static pushover analysis and nonlinear dynamic time history analysis. The crack development pattern was compared for the procedures, as well as parts of the hysteresis curves

Calculating displacement of unsymmetrical multistory buildings exposed to seismic action

Predložena je približna metoda za proračun maksimalnih horizontalnih pomaka nesimetričnih višekatnica izloženih potresu, a nazvana je metodom ekvivalentne elastične krutosti Promatrana je višekatnica malog, srednjeg i većeg ekscentriciteta. Dobiveni pomaci uspoređuju se sa odgovarajućim rezultatima nelinearnog dinamičkog proračuna. Rezultati se veoma dobro slažu u srednjim katovima, na vrhu zgrade približna metoda daje nešto nepovoljnije rezultate, ali u prihvatljivim granicama.Authors propose an approximate method for calculating maximum horizontal displacement of unsymmetrical multistory buildings exposed to earthquake action. The method is known as the method of equivalent flexural stiffness. The multistory building of low, medium and high eccentricity is monitored. The obtained data are compared with appropriate results of nonlinear dynamic analysis. A very good correspondence has been registered for stories in the middle of the building, while results are somewhat less favorable for the top of the buildings, although they are still within acceptable limits