Dynamic Analysis of PSC T-Beam & Box Girder Bridge

The pre-stressed concrete bridges have excellent riding characteristics that minimize traffic vibrations, torsional rigidity, less likely to crack prematurely continuous span, strength and the most noteworthy characteristic is natural frequency of vibration hardly matches with vehicle frequency therefore attained spacious acceptance in freeway, highway flyovers, and in modern metro rail systems. As bridges are the important structures should be capable to withstand static as well as dynamic loads specially, earthquake-induced load to achieve a structure that behave at the level of life safety under enormous earthquakes. The present article shows the linear dynamic behavior of T-beam girder and box girder bridge deck and compares static as well as dynamic behavior. Response spectrum analysis has been performed by using FEM based software in order to check the resonance criteria of bridge and to determine most favorable option from above two. The results show that response parameters for box girder such as bending moment, shear forces, deflection, time period, base reaction, longitudinal stresses and shear stresses are increases as the span length increases while fundamental frequency decreases. From the study it is finalized that box girder is the conservative solution as compared to T-beam girder bridge superstructure.