Borehole or Wire Line Logging is a structure excavated using a drilling rig to access groundwater. In this case study it is used to determine if there is an existing abandoned tunnel before the construction of the expressway. Assistant Professor Desell Suanburi helped in conducting the survey to determine if there is an anomaly underground. Once the anomaly is determined, the design of the project will somehow base if there are any underground tunnel on the survey site.
In this image you will see where the holes are drilled to check if there is a tunnel.