Geological surveys are aimed at identifying qualitatively and quantitatively the existing problems in the underground by analyzing the surface data (surface geological and geophysical mapping or hydrogeological drillings).
The geological surveys are needed especially in the hillside and mountainous areas having as final purpose the identification of the underground geological structure, the lithologic sequence, systems of downthrouws and fissures, delimitation of useful rocks areas, landslides, etc.
Applications of the geological survey :
The applications of geological studies are diverse, ranging from pre-purchase or sale analysis of the land in areas with underground problems, up to the exploitation of useful rocks for gravel pits, of the mineral deposit, coal deposits, etc.
GEOTECHNICAL STUDIES AND THEIR IMPORTANCE
In human history there are several resounding failures of design and execution of construction projects that could only be corrected as a result of extensive field investigations thus avoiding demolition. The need for correct execution of a geotechnical study is unquestionably mandatory. They consist of: geotechnical and geophysical investigations, geotechnical laboratory analysis of soil samples, soil data interpretation and recommendations for the construction of foundations according to the existing soil types.
The importance of a correctly performed geotechnical study is often underestimated due to a lack of information regarding its real applications, such as :
1. Proper sizing of the supporting structure;
2. Obtaining the real costs of construction;
3. Estimation of proper construction time schedules;
4. Eliminating unpredicted problems given by soil instability during the construction works;
5. Extending the life span of a building;
PRELIMINARY GEOTECHNICAL STUDY
Due to the need of assessing the quality of land from a point of view related to buildings, it is advisable to perform a preliminary geotechnical study.
This documentation can be used for the preliminary design phases (pre-feasibility study for urban development projects). The preliminary geotechnical approval cannot substitute the geotechnical study necessary for designing every working project. It is drawn based on a small number of field investigations, depending on the importance and volume of the investigation.
FINAL GEOTECHNICAL STUDY
It represents the basic geotechnical documentation used for the design of any building or for the consolidation, rehabilitation and refurbishment of existing buildings. The documentation is an integral part of the technical project required by law, by the Law no. 50 of 29.07.1991, updated on 16.10.2006.
Geotechnical studies are prepared based on the norm NP 074/2014 for :
- Civil construction works
- Industrial and commercial constructions
- Agrozootechnical construction works
- Hydro technical construction works
- Telecommunications infrastructure
- Transport infrastructure (road systems, bridges, tunnels, railways)
- Urban and municipal construction works
- Photovoltaic and wind farms
Geotechnical studies include :
- Documentation and site localization
- The prospecting of the land on which the building will be located by geotechnical drillings/open pits (ditch, pit)/static penetrations and/or dynamic/geophysical research (electrometry)
- Soil sampling (disturbed and undisturbed) and water (if applicable)
- Professional laboratories analysis of the samples of the collected soil (to identify the physico-mechanical parameters and to determine the degree of aggressiveness of the water on concrete and metal)
- Preparing of the geotechnical study itself by interpreting field and laboratory information obtained and recommendations for foundation
- Verification of documents prepared by an MLPAT authorized expert, the AF requirement and drawing of the geotechnical presentation.