Abstract:
This study presents an investigation of buried metal object in Bangkok soft clay which has
high electrical conductivity using electrical resistivity imaging (EI) as aimed to be applied
for an application of underground infrastructures investigation planning and development
such as gas pipeline, water line, or other buried metal objects. However, the electrical
resistivity survey method has the best performance when applied over resistive terrain.
This study, a metal cube about the size of 1 x 1 x 1 m was buried at 0.5 m-depth in the
Bangkok soft clay ground. Afterward, 3D electrical resistivity imaging using pole-pole
electrode configuration and 2D electrical resistivity imaging using Wenner electrode
configuration had been performed to investigate a buried metal cube. The initial investigation
result, 3D resistivity result hard to indicate buried metal object as it presents unclear shape.
Next, the electrical wire was connected from buried object to the positive pole of the 12 v
battery as aimed to make a contrast of electrical properties between the metal object and
soft clay media. The final 3D resistivity result indicates the shape and position of buried
metal more correctly. 2D resistivity imaging result at the initial stage indicates no buried
metal object. After the buried metal object was connected to the battery, it has clearly
identified in the 2D resistivity result.