| dc.description.abstract | Box girder bridges are often found on long span bridges. Long span bridge needs to be divided into several groups of span to reduce deflection. Earthquake effect needs to be observed because Indonesia is located in a highly active tectonic zone. The purposes of this study are analyzing period and stiffness value, analyzing length variation effects on structure dynamics, as well as comparing the use effect of response spectrum on the base shear. Preliminary design had done based on AASHTO 2012 and SNI T-12-2004. The used load is dead load. Response spectrum based on earthquake accelerogram created using SeismoMatch v 1.3 program. Analysis of the structure dynamics were calculated with the help of MIDAS Civil program. The 4 span, 5 span, and 6 span bridges have a same natural period. Mass and stiffness of 6 span bridge has the greatest value compared to the others. Mode shapes of 4 span, 5 span, and 6 span bridges are similar. In the x direction, 4 span and 5 span bridges obtaining >90% mass participation in the 6th mode while 6 span bridge on the 7th mode. In the y direction, all bridges obtaining >90% mass participation in the 1st mode. Those bridges can be analyzed using equivalent static method. The use of response spectrum graphs based on earthquake accelerogram is more suitable for base shear calculation compared with response spectrum graphs based on RSNI 2833:2013. | id |
