Role of Vp/Vs and Poisson’s Ratio in the Assessment of Foundation(s) for Important Civil Structure(s)

Vp/Vs and Poisson’s ratio (σ) of subsurface strata are important parameters in the foundation study for the assessment of lithology, quality and strength of the rock, structural disturbances and saturation condition prior to the construction of huge civil structure like Nuclear Power Plant. The present work in this paper, showing the evaluation of overburden thickness, assessing quality and compactness of rock and identifying structural disturbance using Vp/Vs and Poisson’s ratio, is based on the fact that Vp/Vs is a better indicator of lithology (Mokhtar et al. in Porosity and heterogeneity effect on Vp/Vs ratio in carbonate rocks from a reservoir in the Middle East, Milan, 2012) than individual velocity values i.e. Vp and Vs. Moreover Vp/Vs and Poisson’s ratio both indicate the quality of rock (Bahremandi et al. in J Sci Res Rev 12:015–019, 2012) and structural disturbances within rock in terms of cracks, fractures or joints (Barton in Rock quality, seismic velocity, attenuation, and anisotropy, Taylor & Francis, London, 2006) etc., which is helpful in deciding the load bearing capacity of the foundation. The value of Vp and Vs, used in this paper, are taken from four research papers where Vp and Vs as a function of depth are studied with examples of Kalpakkam Nuclear Power Project, Tamilnadu (Boominathan in Curr Sci 87(10):1388–1397, 2004), Kakrapar Atomic Power Plant, Gujarat (Wadhwa et al. in J Ind Geophys Union 13(1):9–16, 2009), Kaiga Atomic Power Plant, Karnataka (Wadhwa et al. in J Ind Geophys Union 14(1):21–30, 2010) and Tarapur Atomic Power Plant, Maharashtra (Wadhwa et al. in J Ind Geophys Union 9(2):137–146, 2005) in Indian subcontinent.