Before we can start any construction on a site we need to know a lot of things about the area. We can’t just dig up and start laying the foundation without knowing whether the soil strata there will even support our intended structure. We also need to know the availability of groundwater and other waterbodies, in case of making residential buildings, to make our structures habitable.
Geotechnical assessment is a report done by geotechnical engineers covering all this query in details and with proper metrication. The report is done stage by stage through site characterization, soil sample testing and laboratory testing.
Site Characterization and Setting
Geological setting and site characterization is a study of the type of soil sedimentation present. It involves the preparation of the geological map of the site. Classification of the soil zones and presence of ground water table is also investigated in this stage.
Field work in geotechnical assessment involves boring auger holes to perform dynamic penetration testing. It also involves multiple in situ tests like shear strength, compressibility, permeability and SPT tests. Creation of test pits and sampling of materials for lab test is also part of this stage.
Lab Report Preparation
Test samples from the site are analysed at laboratories with high end equipment. Laboratory testing involves simple process like classification and index testing of soil to complex test like triaxial test. Investigation of gases, frozen soil within the sample are also done at this stage. Offshore laboratory testing includes vital information like water content, bulk and dry density and qualitative carbon component.
This is a generic view and outline of how geotechnical assessment is done. To get more idea on the various methods of field and lab test in geotechnical engineering keep following our page.