PARAMETRIC STUDY OF SEISMIC FRAGILITIY CURVE IN RESIDUAL SOIL

• Main Author: Adrian Fauzan, Rakhadiaz
• Format: Theses
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/46700
• Institution: Institut Teknologi Bandung

Earthquake in Indonesia is one of the natural phenomena that often occurs. The acceleration induced from the earthquake may damage the structure in the building even to the point of collapse. For this reason, efforts are needed to find out how much the effects of acceleration induced due to the earthquake on the building. In this case, the building to be investigated is a tunnel. Examining the influence of the depth of the tunnel position (depth of 6 meters, depth of 12.5 meters, and depth of 36 meters), the influence of the thickness of the tunnel lining (0.3 meters; 0.4 meters; and 0.5 meters), the influence of the class of land sites (Sd and Se), and the effect of tunnel diameter on the seismic fragility curve in the tunnel (6.65 meters and 13.3 meters) are objectives in this research. The earthquake loads are 0.1 g; 0.3 g; and 0.5 g. Based on the variations that have been mentioned, 24 cases were modeled. To determine the damage condition of certain structures, we need the bending moment value of the tunnel during an earthquake and a static load. Aid is needed from the software to get the bending moment quickly. The software used is FLAC 2D which uses finite difference methods. To check the reliability of FLAC 2D in modeling, analytical solution is used. To run the simulation, input parameters needed are soil parameters, structural parameters, and interface parameters. The earthquake parameter used is a shallow crustal earthquake named Whittier Narrows-01 because the tunnel location was close to the source of the earthquake in the form of a fault. It should also be considered that the grid and time step when an earthquake is applied so that the resulting model can be optimized. The tunnel will be modeled by the New Austrian Tunneling Method construction stage. The structural damage conditions modeled include: minor, moderate, and extensive. The results obtained from this research that Sd site class is less vulnerable to earthquake than Se site class. Then, the deeper the tunnel, the more resistant the tunnel is to earthquakes. Furthermore, the larger the diameter of the tunnel, the more vulnerable the tunnel is to earthquakes for the case of the Sd site class. However this case is invalid to the case of the Sb site class. In that case, the wider the tunnel, the stronger the tunnel is from an earthquake. Next, the thinner the tunnel lining, the more resistant the tunnel is to earthquakes.