SEISMIC PERFORMANCE EVALUATION OF STONE COLUMN AT GARONGKONG TRAIN STATION USING GROUND MOTION OF 2018 PALU EARTHQUAKE

• Main Author: Jabarudin Nur, Rizal
• Format: Theses
• Language: Indonesia
• Subjects: Teknik sipil
• Online Access: https://digilib.itb.ac.id/gdl/view/77837
• Institution: Institut Teknologi Bandung

Stone column is one of the soil improvement methods that can be used in mitigating soil settlement, stability, and liquefaction potential. Stone column can mitigate liquefaction potential with the effect of densification during construction, drainage, and reduction of soil shear stress. This study aims to determine the effect of stone column design variations in the form of area replacement ratio and shear modulus ratio on the Ru (pore water pressure ratio) value of soil and the lateral deformation of soil that occurs. In addition, the effect of the stone column on the acceleration spectra response is also evaluated. The soil data used the location of Zone 3 of Garongkong Railway Station and was evaluated using the ground motion of the 2018 Palu Earthquake. Liquefaction analysis was conducted numerically using the finite element method MIDAS GTS NX with 2D plane strain modeling. Ground motion propagation from bedrock to the ground surface of the model using DEEPSOIL software. Checks were made for before and after conditions the stone column was applied. There are 16 variations formed to illustrate the reduction in Ru value and lateral deformation that occurs. Based on the results of the analysis, it was found that the stone column can reduce the lateral deformation on the embankment surface by 77% from the condition before the presence of stone column. Stone columns can also mitigate the liquefaction potential during earthquakes by reducing the Ru value of the soil of 25% - 60% in undrained loading conditions. The trend of variation in the area replacement ratio of stone column (Ar 15-40%) and the shear modulus ratio (Gr 3- 10) which is increasing can reduce the lateral deformation of the soil and reduce the peak Ru value which is increasing. In addition, the application of stone column can influence the acceleration spectra response that occurs with a maximum decrease of 44%.