Near-surface characterization and delineation of 2-D shear wave velocity profile from geologically complex landscape of Kangra Valley, NW Himalaya, India

摘要

The geotechnical characterization for delineating stiffness parameters is important to aid safe engineering foundations. TheMultichannel Analysis of Surface Waves (MASW) was utilized to estimate shear wave velocity (Vs) profile and near-surfacematerial characterization. The initial reconnaissance surveys allow optimization of acquisition parameters for seismic datarecording that controls signal penetration and attenuation. The gathering of multiple records with several receivers in thesurface-wave inversion technique progressively enhanced the dynamic characterization of the sediments. The 2-D geneticalgorithm was used for the inversion of dispersion curve. The seismic data was processed to prepare multiple 1-D and 2-Dshare wave velocity (Vs) profiles. The depth of exploration in 2-D profiling varied from 25 to 52 m. The average Vs of thetop 30 m soil column was used to classify the site as per National Earthquake Hazards Reduction Program (NEHRP) classification.The analysis reveals the majority of sites come under soil class D (Vs_(30) = 180-360 m/s) and class C (Vs_(30) = 360-760 m/s). The response analysis performed for different sites reveals variation in spectral acceleration at 10 Hz (single-storybuildings) ranging from 0.09 to 0.5 g and at 5 Hz (double-story buildings) ranging from 0.13 to 1.7 g. The present studyalso discusses the variation of stiffness parameters across the study region to understand the subsurface heterogeneities andallowable bearing capacity for a safe engineering foundation for constructing earthquake-resilient in the area.