Geotechnical Engineering Areas of Activities

In-Situ Geotechnical Investigations

The in situ Geotechnical investigations are an essential and integral part for the design of any engineering structure. Geotechnical engineering department with its experienced manpower and state of the art equipment is actively involved in numerous projects both in India and its neighboring countries. Around 160 sponsored projects in different areas of construction viz., hydroelectric, mining, petroleum, atomic and nuclear sectors are completed in the last 25 years of the establishment of this Division at NIRM. 

The in situ geotechnical investigations carried out are viz., in situ stress measurements by hydraulic fracture test, in situ deformability measurements by plate load test and in situ Shear measurements by and direct shear test. The investigations carried out comply with ISRM or ASTM or IS standards. 

Hydraulic fracturing is one of the indirect method to determine the in situ stress state of the rock mass under study. The stability of the underground opening is enhanced when the long axis of the structure is oriented parallel to sub-parallel to the major horizontal principal stress direction. 

The in situ modulus of deformability (Em) is one of the engineering properties of rock mass. It is a basic input parameter used for the design of underground excavations viz., caverns, tunnels, shafts and foundations viz., dam, powerhouse and ventilation stack. 

The in situ shear parameters (cohesion and internal friction angle) is one of the engineering properties of the rock mass. It is a basic input parameter used for the design of underground excavations viz., caverns, tunnels, shafts and foundations viz., dam etc.