Investigating the Effect of Near-Fault Earthquake Parameters on the Behavior of Horizontally Curved Bridges

To design safe transportation systems, it is unavoidable to completely recognize the complicated behaviors of bridges under earthquake. The past earthquakes showed that horizontally curved bridges are highly affected by earthquakes, especially near-fault earthquakes, due to irregular geometry. The previous studies indicated that magnitude; PGV and TP have been the three most effective near-fault-earthquake parameters. In the present study, the attempts were made to determine the effect of these parameters on such bridges using a verified software model by a field test and analyzing two horizontally curved bridges. Three suites of near-fault records were used in order to conduct time-history analysis with three parameters, namely magnitude, PGV and TP. In each suite, two of these parameters are almost constant and third parameter is variable in order to observe its effect on result. The results indicated that the change in PGV has the most significant effect on the behaviors of such bridges. Also, the effect of TP increases in longer bridges. If the difference between lateral displacement of two ends of deck is considered as criteria for assessing potential of Deck rotation, increasing in bridge length and being in near-fault area can lead to increase in bridge deck rotation behavior, respectively up to 2.37 and 2.47 times.