Geophysical investigations are a part of geotechnical site surveys.
Purpose:
- continuous investigation of the geological profile and finding irregularities of and changes in the geological environment in space and time;
- correlation of data resulting from drilling and surveying operations;
- application of an optimal site survey methodology depending on the specifics of the site and geotechnical conditions.
Tasks:
Building a structural model of the future construction site
The geophysical methods used by the company allow making express assessment and building physical-and-geological models of the target area at an early stage of the site surveys.- Rock physics analysis
The rock parameters of interest are: density, fracturing, moisture, ice content, electrical resistance, polarizability, and electrochemical reactivity.
- Hydro-geological investigations
Detection and tracking of impermeable beds and permeable masses; ground water level evaluation; determining the thickness of aquifers; detailed sectional layering of boreholes with detection of impermeable and permeable sections; description of physical and chemical properties of groundwater.
- Researching exogenous physical-and-geological phenomena and processes
Delineation, monitoring and forecasting of the processes, and detection of risk areas for construction..
- Exploration of building material deposits
Mapping of areas wherein there is rock that could be used as building material.
- Highway condition monitoring
Using geophysical methods to detect hidden local irregularities, ballast pockets, mud pockets, and subsidence of the toes of embankments built on soft soil (sludge, peat, putrid mud, etc.) which may lead to deterioration of highways and railways.
- Finding pipelines and electrification networks
To prevent technical failures, the spatial positions of underground pipelines, cable lines and other industrial and municipal utilities that cannot be accessed from the surface are determined remotely and with sufficient accuracy.
- Seismic micro-zoning
Where sites of new construction, overhaul, reconstruction and rehabilitation have areas wherein the seismicity is 7 points or higher, geophysical methods are used to calculate seismic-wave velocities at the depth down to 25 m from the surface of the construction site, physical properties of soil, and boundaries of rock mass.
The geophysical methods being used are: electrical exploration (electrical tomography, vertical electromagnetic sounding, electrical profiling, measuring of permanent and variable natural fields and stray currents), geomagnetic exploration (including gradiometry), seismic prospecting (seismic tomography, refracted wave method, reflection method), ground penetrating radar, logging (gamma-ray logging, electrical resistivity logging, spontaneous potential logging, caliper measurement, deviation surveys, resistivity logging, video logging), electric-contact dynamic sounding.
