Author: Hubert Guyod

Publisher:

Published: 1964

Total Pages: 12

ISBN-13:

The measurement of some of the physical properties of the soils and rocks penetrated by bore holes provides information of value to the soil engineer. Electrical resistivity, radiation, and acoustical properties are particularly useful. The measurements continuously recorded in terms of depths give a detailed log on which geological and physical changes are indicated. In a typical case, the field operations are conducted as follows: (1) A small number of test wells scattered over the area of interest are drilled, cored, and logged with one or several appropriate probes; (2) additional holes are then drilled between the test wells; and (3) these holes are logged but not cored. By correlating the logs and the core data the geology of the area and some of the rock properties can be mapped. None of the methods reviewed, however, can be used to measure dynamic properties. The main advantages of geophysical logs are that detailed information is readily obtained at the well sites and at a lower cost than if each hole were cored. The equipment used for the logging of shallow holes is small, light, rugged and simple. No special technician is needed for its operation.