SUBSURFACE IMAGING AND FORWARD MODELLING USING GROUND PENETRATING RADAR: FINAL ASSESSMENT OF THE GARUDA WISNU KENCANA (GWK) PROJECT IN BALI

• Main Author: ROTUAH MUNANDAR NIM: 12314009, JOREINHARD
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/28314
• Institution: Institut Teknologi Bandung

<p align="justify">Investigation of the presence of underground cavities and subsurface features is important due to its utility in testing the deficiency of building construction. It is done to prevent subsidence even collapse. Ground Penetrating Radar (GPR) is a non-destructive and effective method that has been proven to image and detect any features beneath the surface with high resolution profiles. This method uses dielectric permittivity, conductivity, and magnetic permeability. This research is focused on analyzing the presence of cement-filled cavities and other features with GPR modelling in the project area of Garuda Wisnu Kencana (GWK), Bali. GPR probing was carried out along 9 parallel traverses in the N-S direction and another 9 in the E-W direction using the RAMAC/GPR 100 MHz with unshielded antenna mode. Before real data testing, forward modelling was performed by displaying the synthetic radargram profiles of several measurement lines using MATLAB code from James Irving, 2005. Then, the result will be correlated with geoelectric interpretation results that have been acquired in 2013. Regions with amplitude contrast indicate the presence of cement-filled cavities and other features. To validate the presence of these anomalies, researcher do the frequency characteristics to find the distribution of the frequency content of signals. The contrast between concrete frequencies are higher than cement and limestone.<p align="justify">