Advances in the State-of-Practice of Geotechnical Investigation in India

With greater emphasis on in situ testing and the introduction of digital data acquisition, geotechnical investigation practice in India is advancing leaps and bounds. With a variety of tests now available, the data can be analyzed effectively to improve the quality of geotechnical parameters and enhance its reliability. Energy correction of SPT offers a scientific way of standardizing the energy transferred to the split spoon sampler and minimizes the scatter/error in the values. Electric cone penetration test is very reliable since it is independent of operator and results are repeatable. Pressuremeter tests have become quite popular in India over the last two decades. The test causes minimum disturbance to the in situ soils. Geophysical tests such as resistivity tests, cross-hole seismic tests and SASW/MASW provide a quick assessment of shear wave velocity profiles and low-strain dynamic behavior. Various correlations are available between CPT, pressuremeter and SPT as well as shear wave velocity which are not only consistent, but also form the basis of selecting design parameters which are representative of the in situ conditions. The paper highlights the various technologies available in the country together with a case study demonstrating the application of these tests.