Citation

Mathangi B, Zaalishvili VB, Ganapathy GP. Environ. Sci. Pollut. Res. Int. 2023; ePub(ePub): ePub.

Copyright

(Copyright © 2023, Holtzbrinck Springer Nature Publishing Group)

DOI

10.1007/s11356-023-30809-w

PMID

37996577

Abstract

Landslides are one of the prevailing threats to life that cause huge loss to the environment. Around 3.7 million km(2) of the area is exposed to landslides globally, and 820,000 km(2) is at high risk for landslides in India. Rainfall and earthquakes are the two primary landslide-causing variables in India. The Nilgiris district which is in the south-western part of India is more prone to rainfall-induced landslides. This study intends to calculate the depth of the slip surface on a slope (Lovedale area, the Nilgiris) in the event of a future landslide using Multichannel Analysis of Surface Waves (MASW) and validate using bore log data. During November 2009 rainfall, a shallow landslide occurred at the toe of this slope. There is a greater chance that a landslide will occur again in the event of rainfall in the future. To comprehend how the sub-strata vary, and to forecast the depth of a prospective failure surface, the shear wave velocity (Vs) obtained from MASW proved beneficial. Slip surfaces, one at a shallow depth and another at a deeper depth, were found based on the shear wave velocity and bore log data. The importance of the MASW output in the engineering properties of soil was also studied. The compressional velocity (V(p)) and shear wave velocity obtained from MASW were evaluated for their applicability in calculating the elastic moduli of soil. It was established that shear wave velocity was of greater significance than compressional velocity. The MASW results can be further used as a preliminary data for analysing the stability of the slope, reactivation of landslides, and landslide early warning system.

Language: en

Keywords

Landslides; MASW; Shear moduli; Slip surface; Weak zone; Young’s moduli