Microzonation of Banja Luka for performance-based earthquake-resistant design

A note on peak accelerations computed from sliding of objects during the 1969 Banja Luka earthquakes in former Yugoslavia

“…As can be seen in Fig. 6, the acceleration values estimated from sliding of objects are close to the acceleration values determined by Lee et al [15] for the probability of 0.2 in 50 years for the rectangular pulses, and for the probability of 0.1 in 50 years for the sinusoidal pulses. These probabilities are in compliance with the return periods of about 500 years for events such as the 1969 Banja Luka main shock, which are indicated by the recurrence relation for the greater Banja Luka region [14].…”

“…Comparison of peak ground accelerations based on sliding of objects to the average peak accelerations determined in a recent probabilistic seismic-hazard analysis of Banja Luka by Lee et al [15] shows that accelerations evaluated in this study correspond to the probability levels of at least one exceedance between 20% and 10% in 50 years (that is, to the return periods of 224 and 475 years, respectively).…”

“…Recently, Lee et al [15] presented new microzonation maps for the city of Banja Luka based on the uniform-hazard-spectrum (UHS) methodology [29,[12][13][14]. While the acceleration values presented in the IZIIS microzonation map [28] are scaled to match the effects of the 1969 earthquake with M¼6.4 and their spatial distribution depends only on the local soil characteristics, maps presented by Lee et al [15] are based on probabilistic seismic hazard analyses, which also take into account the temporal and spatial distribution of regional seismicity and variations in the soil [25] and deep geological site conditions [30,31].…”

“…As new instrumental data becomes available and microzonation tools are developed, it is necessary to re-evaluate older microzonation methods so that the next generation of structures can be designed based on balanced and more accurate estimates of future strong motion demands [33]. With modern proposals for seismic microzonation of cities like Banja Luka [15], it becomes timely to reevaluate the older data on strong motion amplitudes and to test the consistency with new estimates. To this end, in this note we will revisit the data on sliding and overturning of objects described by Stojković et al [28] and estimate the peak accelerations in the urban area of Banja Luka.…”

“…To this end, in this note we will revisit the data on sliding and overturning of objects described by Stojković et al [28] and estimate the peak accelerations in the urban area of Banja Luka. We will also compare these estimates with recorded peak accelerations since 1971 and the recent mapping of microzonation in the same area [15]. We will not consider a detailed comparison of our estimates of peak accelerations with those of Stojković et al [28].…”