Geotechnical survey is an engineering geological study that determines the physical and mechanical properties of soil and subgrade. Although not a direct surveying task, geotechnical investigation is closely related to geodesy and topographic surveying.
Geotechnical survey objectives:
- Determine soil layer composition and thickness
- Evaluate soil bearing capacity
- Determine groundwater level
- Assess foundation solution suitability
- Identify construction risks
Investigation methods:
- Boreholes - soil sample acquisition for analysis
- Cone penetration test (CPT) - soil resistance measurements
- Dynamic probing - rapid soil investigation
- Test pit excavation - visual soil inspection
- Laboratory analyses - detailed soil tests
Connection with surveying:
- Borehole positioning - coordinate determination with GNSS
- Borehole elevations - connection to height system
- Topographic plan - displaying borehole locations
- Cross-sections - soil layer visualization
Geotechnical report contains:
- General territory characteristics
- Borehole location plan
- Soil profiles and descriptions
- Laboratory test results
- Conclusions and recommendations
When is geotechnical survey needed?
- Before any building construction
- For road and bridge design
- For underground structure planning
- In areas with complex soil conditions
- For building reconstruction with additional loads
Investigation scope:
Number and depth of boreholes depends on:
- Building size and significance
- Soil complexity level
- Building code requirements
- Historical data about the territory
Quality geotechnical investigation prevents foundation problems and ensures sustainable building operation.