Percussion sounding
The method used in percussion drilling consists of the free fall of a weight over the bottom of the well, thus cutting each of the interposed rocks into fragments. Within this specific type of probing, there are also the options of doing it manually or mechanically and with or without water circulation during the procedure.
It is important to emphasize that the percussive sounding allows the definition of the geological profile of the territory, it also evaluates the consistency and compactness of the soils and the level of the water table. As the method most used by civil construction, both in Brazil and in many other countries, it follows the following guidelines for the percussion sounding procedure: what is the type of land and work to be carried out.
Subsequently, tripods with pulleys and ropes are mounted to provide support so that the handling of the equipment is possible and satisfactory. One of the main advantages of the percussion mode is its very low cost per meter of territory that is drilled, which makes it the most used method in industrial research and tests, as it allows the collection of larger samples.
However, as with other types of drilling in mining, its main disadvantages should be mentioned, namely:
• Impossibility of drilling sloping territories and soils;
• Its low performance in rocks and harder soils;
• Higher probability of contamination of samples taken from the soil;
• Difficulties in making petrographic identifications regarding composition, texture and structure, for example, of the sediment.