EFFECT OF 3-D WAVE PROPAGATION ON RESPONSE SPECTRA IN SOFT SOIL BASIN

• Main Author: Aprinda, Nela
• Format: Final Project
• Language: Indonesia
• Subjects: Teknik sipil
• Online Access: https://digilib.itb.ac.id/gdl/view/82584
• Institution: Institut Teknologi Bandung

The basin effect, which refers to the phenomenon of earthquake wave trapping and reverberation in soft sedimentary deposits underlain by the basin bedrock structure, has a significant influence on earthquake wave propagation. Previous studies have shown that 1-D and 2-D modelling are inadequate for predicting spectral responses in basin edge areas prone to earthquake damage. Therefore, this study aims to determine the scale factor of the 1-D wave propagation analysis results by conducting 3-D wave propagation analyses in the centre and edge regions of the basin using PLAXIS 3D software. The scale factor of the 2-D to 1-D analysis results is compared with that of the 3-D to 1-D analysis results to determine the accuracy of the spectral response prediction in the basin edge area. The influence of basin width on the results of earthquake wave amplification was also evaluated by modelling variations in basin width. The results show that the scale factor obtained from 2-D modelling tends to be lower than the scale factor obtained from 3-D modelling. This indicates that the 1-D and 2-D modelling are not accurate enough to predict the response spectra at the basin edge. The variation of the modelled basin width also affects the amplification results obtained.