Subsurface exploration involves characterizing the arrangement and relevant physical properties of the soil and rock strata that underlie a site. GEM provides and utilizes a wide range of exploration, sampling and testing services including:
- Research of existing data including: air photographs, topographic maps, geologic maps, soil surveys, previous boring and test data.
- Surface reconnaissance to identify: rock outcrops, sinkholes, landslides, past filling, seepage, subsidence, previous structures, etc.
- Soil & rock exploration including: hand auger borings; backhoe excavations; auger borings with powered equipment; direct push sampling; rotary core drilling; and air track drilling.
- Field testing including: Standard Penetration Tests, cone penetrometer tests, plate bearing tests, field CBR tests, and hydraulic conductivity tests.
- Groundwater monitoring including: observation wells and piezometers or slotted well casing installed in the boreholes.
- Geophysical methods including: ground-penetrating radar, seismic refraction, resistivity, micro-gravity, radiation, and others.
- Instrumentation to monitor subsurface behavior including: slope movement, settlement, subsidence and groundwater levels.
- Laboratory testing of soil and rock materials including: index properties, tri-axial shear, consolidation, CBR, and slake durability.