Explanation: IGS is Indian Geotechnical Society. This body gives the general guidelines to be followed while conducting a geotechnical investigation. The head office is in Delhi.

Explanation: Geosynthetics are synthetic products (polymeric). The eight categories are geotextiles, geogrids, geonets, geomembranes, geosynthetic clay liners, geofoam, geocells and geocomposites.

Explanation: Piezometer is used for long term investigation of ground water tables in cut and fill areas. They are also used to determine if there is upward or downward gradient of water.

Explanation: The main functions are separation, reinforcement, filtration, drainage and containment.

Explanation: CPT is cone penetration test and SPT is standard penetration test. CPT is more popular than SPT because of higher accuracy, speed, more continuous soil profile and less cost.

Explanation: The first step is reconnaissance (visual inspection, maps, photos, etc.). The next step is exploration (geophysical, electrical, pits, etc.). The last step is field tests (vane shear, pumping, penetration, etc.).

Explanation: Geocell is also called a cellular confinement system. It has a 3D honeycombed structure, which is filled with compacted soil to make it a confinement system.

Explanation: NDT is non-destructive technique and is a modern tool for geotechnical investigation. A ground penetrating radar which utilizes radar pulses for subsurface imaging is used.

Explanation: Geomembranes are thin sheets of polymeric material and are impermeable. They are widely used for linings and coverings of liquid or solid storage facilities.

Explanation: Pumping in the test is a field test to determine permeability of soil. All the others are used to test geosynthetics.

Explanation: Geo-physical methods use the principle that physical properties of soil vary for different types of soils. It is an indirect method of geotechnical investigation.