ABSTRACT
Drilling operation for the geotechnical survey is a challenge in an urban area. Seismic Refraction Test is an effective way to map overburden soil & depth of rock without carrying out the drilling operation. This case study presents the comparative analysis between Seismic Refraction profiles of soil/rock with drilled borehole data along the proposed alignment. From the available seismic refraction data, detailed velocity-depth model of the soil and rock was derived and was utilized to map geotechnical profile of the stretch. Seismic refraction is geophysical principle governed by Snell’s law. It depends on the fact that seismic waves have different properties in the different type of soil or rock. Also, the waves are refracted when they cross the boundary between different types of soil or rock. This method of geotechnical analysis can be helpful to provide geotechnical data for Tunneling under dense urban agglomerations where drilling operation is not feasible.
