When conducting geotechnical studies or investigations, geotechnical engineers and geologists collect data on the physical characteristics of both soil and rocks. Their studies are meant to design structural earthworks and foundations. Also, these studies help engineers perform earthwork repairs that may be necessary because of subsurface environment changes.
Geotechnical studies include surface and subsurface exploration, collection of soil samples, and laboratory analysis. The samples must be examined before a location is developed. An etude geotechnique can help prevent human and material damage because of catastrophes such as foundation cracks and earthquakes. Engineers may perform the studies by visually assessing a site or study the soil using technologies and laboratory tests.
A geotechnical study can include geophysical methods, photogrammetry, and geologic mapping. Geologists are concerned with soil conditions and determine the size of the structure that may be safe for the soil being examined. Additionally, the study may reveal problems that may be hard in an earthquake such as soil liquefaction. This study can also be used for finding a formation such as bedrock that can support a structure when an earthquake occurs. The soil of a certain location must be examined before construction to prevent foundation collapse. The examination determines the soil’s nature and bearing capacity to establish a stable foundation.
Because of the rapid progress in geotechnical studies, they are conducted more accurately and quickly than ever. They now use ground penetrating radar for subsurface imaging. Using the reflected electromagnetic radiations from the subsurface structures, data are obtained for analysis. Also, engineers use antennas for transmission and getting signals. The reflection seismology principles can be used in rocks, pavements, structures, soil and ice, as well as freshwater for sensing material changes, matter, voids, and cracks. Engineers use this technique to discover buried structures, as well as identify contaminated landfills and contaminated areas. They also use a geographic information system or GIS for remote sensing, photogrammetry, and land survey.
Engineers or technicians perform geotechnical testing to understand characteristics like the physical properties underneath a work site. The tests include the following:
- Test pits. This involves digging a pit manually or using an excavator to disclose the subsurface conditions to the desired depth.
- This test is similar to test pits but the pit is elongated over a distance to establish changes in the subsurface conditions over different worksite portions.
- This test allows for the assessment of density through standard penetration testing, so rock and soil samples are removed for assessment and testing.