What Does Indirect Exploration Methods Mean?
Indirect exploration methods include geophysical investigation methods such as sounding, and seismic reflection and refraction. Indirect exploration defines boundaries between the different soil compositions by measuring and observing changes in the soil's electrical resistivity, velocity of waves or in its magnetic and electrical field.
The indirect methods do not give information about the engineering properties of the soil and should be used in conjunction with direct methods such as boring and percussion drilling.
Trenchlesspedia Explains Indirect Exploration Methods
Indirect methods include sounding and penetration tests including static and dynamic cone penetration tests. Geophysical site investigation methods are simple, quick and physical in nature, making them environmentally friendly and cheap. The same field data can be used to draw different inferences.
Some of the geophysical methods commonly used are seismic refraction and reflection, crosshole testing, downhole testing, spectral analysis of surface waves (SASW), ground penetrating radar (GPR), electromagnetic wave measurement and induced polarization.