ANALYSIS OF PALU IV BRIDGE FAILURE DUE TO PALU AND DONGGALA EARTHQUAKE ON 28TH SEPTEMBER 2018

• Main Author: Habib Supriadi, Ginanjar
• Format: Theses
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/42501
• Institution: Institut Teknologi Bandung

The Collapse of Palu IV Bridge during the 28th September 2018 Central Sulawesi earthquake was one of the highlight events for representing the destructive effect of a 7.4 magnitude earthquake that was followed by a tsunami. So far, the causes of bridge collapse have been limited to hypotheses based on field observation. There are several theories regarding the collapse of the Palu IV Bridge such as failure of bearings due to the large demand of base shear, buckling in the arch ribs or the failure of the main girder. In this study, the bridge will be modeled on a full scale using finite element software Midas Civil. First, the bridge will be checked using the same codes as the original design to acquire the model that represents the real condition of the bridge. Next, the bridge will be checked with the most recent codes to determine the bridge’s condition before the earthquake. All locations where possible failures occurred will also be checked such as bearing failure, buckling on the arch ribs and also a failure on the tie beam. Finally, Non-Linear Static Pushover Analysis will be carried out to obtain the displacement capacity of the bridge, the sequence of plastic hinges formation and the performance level of the bridge. The results of the elastic linear analysis indicated that the main failure occurred in the connection between the superstructure and substructure, where both the anchor bolts and the bearings capacity were not able to withstand the shear forces due to the earthquake load. Meanwhile, pushover analysis shows that the performance of superstructure elements are at the level of fully operational for the longitudinal direction of the bridge and operational for the transverse direction. In pushover analysis, the bearing’s anchor bolts are assumed to have sufficient capacity to withstand shear force from earthquake load.