Effective Use of SPT: Hammer Energy Measurement and Integrated Subsurface Investigation

Anbazhagan, P and Ayush, K and Yadhunandan, ME and Siriwanth, K and Suryanarayana, K and Sahodar, G (2022) Effective Use of SPT: Hammer Energy Measurement and Integrated Subsurface Investigation. In: Indian Geotechnical Journal .

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Abstract

Standard Penetration Test is a widely used geotechnical exploration test worldwide. SPT is easy to perform and is cost-effective; hence, it has become prevalent. Several factors affect the test results, i.e., the number of blows (N-value) for penetration of the sampler into the soil at any given depth. Among those factors, hammer energy (EH) is the most important. Even though it's important, there have been limited attempts to correlate EH with different subsurface properties, which are later estimated using N-values. Several empirical relations have been developed between N and subsurface properties, both static and dynamic, predominantly in developed countries, which can be used only to a region and a particular EH value. However, the influence of considering proper in-situ hammer energy in these correlations is not clearly understood yet and thus, it is still not practised in many developing countries. This study highlights the importance of hammer energy in N-value corrections and studies the effect of hammer energy on soil properties like low strain shear modulus and SBC values and integrates with the subsurface imaging methods to determine spatial variation of these parameters. The influence of different SPT corrections is studied along with the effect of including energy measurements in analyzing the correlation between the SPT N and soil properties such as, SPT and low strain shear modulus. To address the highly localized interpretation of SPT restricted to a borehole, and to understand the spatial distribution of these design parameters across the study area, a 2D subsurface profile has been generated using geophysical tests, which was later integrated with the borehole data. © 2022, The Author(s), under exclusive licence to Indian Geotechnical Society.

Item Type:	Journal Article
Publication:	Indian Geotechnical Journal
Publisher:	Springer
Additional Information:	The copyright for this article belongs to Springer
Keywords:	Boreholes; Cost effectiveness; Developing countries; Hammers; Shear flow; Shear strain; Shear waves; Soil testing; Soils, Energy; Investigation; Low strains; N value; SBC; Soil property; Spatial variability; SPT N-value; Subsurface; Subsurface properties, Elastic moduli
Department/Centre:	Division of Mechanical Sciences > Civil Engineering
Date Deposited:	18 May 2022 10:37
Last Modified:	18 May 2022 10:37
URI:	https://eprints.iisc.ac.in/id/eprint/71853

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