GROUTING DETECTION IN OVERBREAK OF TWO CIRCUMVENTION TUNNELS AT WAY SEKAMPUNG DAM, PRINGSEWU, LAMPUNG USING GROUND PENETRATING RADAR

• Main Author: Yudza Ghifari, Faris
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/46044
• Institution: Institut Teknologi Bandung

Ground penetrating radar is a technique that uses high-frequency radio waves that produce high-resolution data in a short amount of time. This technique uses electromagnetic waves that move at certain speed that determined by the permittivity of the material. One of the first surveys that conducted with ground penetrating radar was carried out in 1970 for ice sounding. These days, ground penetrating radars are used in civil engineering, such as tunnel. The circumvention tunnel in the way dam will be filled with water. To detect the results of grouting that has been done so that it can be decided whether it is necessary to do grouting again or not, this study was conducted. Data was collected with an unshielded ground penetrating radar (reversed) with frequency of 100 MHz and 250 MHz that synchronized with the desertgold program. The tracks used during the survey are divided into three tracks in each tunnel and data collection by crossing method was done in 10 points at tunnel one, and 8 points at tunnel two. The length distribution of the track depends on field conditions such as the presence of grouting machines and water leakage. Dewow, Remove DC, Remove Global Background is used to reduce the effects of noise. Data processing is carried out with the MatGPR program. From the radargram data, it can be concluded that the second tunnel must be grouted as soon as possible than the first tunnel.