Vol.14, No1, 2014, pp. 17–28
UDC 625.745.12:624.042.7

Presented in this paper are the results of the analysis of seismic performances of an overpass founded on piles, in interaction with the soil, located over the E75 Highway Novi Sad - Belgrade, as part of the Kovilj loop. Applied methods include: non-linear static push-over (NSPA) analysis, target displacement analysis, parametric target displacement analysis, vulnerability and reliability analysis. The overpass is modelled and taken into consideration for seismic effects along its transverse direction as a 2D planar model. Modelling of elastic-plastic strain is performed using plastic hinges, whereas the development of non-linear strain is considered using the incremental-iterative method. It is determined that the failure mechanism of the system occurred because of the plasticization of column ends, and it is maintained as such until the end of the non-linear analysis, along with the changes of performance states in plastic hinges. System vulnerability analysis has shown that up until the point where S_a = 0.2g, nearly all levels of damage are initiated, however, already at values of S_a ≈ 0.3g, significant damages to the overpass are expected along the transverse direction with the probability of P ≈ 1. On the other hand, reliability analysis of the overpass shows that reliability of R > 0 is achieved for S_a < 0.23g for levels of significant damage and for lower ones.

Keywords: overpass, earthquake, non-linear pushover analysis (NPA), plastic hinges, performance states