(1) Selection of equipment
There are more than a dozen data observation devices for high-density electrical method. In actual work, due to factors such as time, it is impossible to observe each device. Individual devices must be selected for data collection in a targeted manner. As we all know, the quality of measured data is the key to the success or failure of interpretation. Different arrangement devices should be selected according to different geological tasks to achieve the best exploration effect.
(2) Selection of electrode spacing
The electrode spacing of high-density electrical method includes the power supply electrode spacing and the measurement electrode spacing. The power supply electrode spacing directly affects the detection depth, while the measurement electrode spacing affects the lateral resolution of the detection. Therefore, when designing the electrode spacing, both the detection depth and the lateral resolution must be fully considered. Studies have shown that the dipole-dipole device has the best resolution, followed by the dipole device, and the symmetrical quadrupole is the worst.
(3) Data observation
In actual work, in addition to selecting a suitable observation device, data observation is also an issue that must be considered. Because the power supply current is limited, in order to obtain reliable data, the observed electrode potential cannot be too small. Under the same pole distance, the observed potential difference of the dipole-dipole device is smaller than that of the two-pole device and the symmetrical quadrupole.
(4) Interpretation of results Under the use of reasonable methods, the effective interpretation of data is the key to application. The high-density electrical profile is an apparent resistivity imaging map. The high-resistance area represents dense rock mass, good integrity, and low water content; the low-resistance area represents water-bearing, loose and broken rock mass or fractured water-bearing zone. Karst cavities show high-resistance areas, and caves filled with clay and water show low-resistance areas. Most karst caves and karst fracture zones are partially filled, with cavities in the upper part and loose filling in the lower part. The upper part shows high resistance and the lower part shows low resistance, forming a discontinuous beaded combination abnormal area.
