Akademik Veri Yönetim Sistemi
JOURNAL OF APPLIED GEOPHYSICS, cilt.244, 2026 (SCI-Expanded, Scopus)
This study applied three geophysical methods to delineate the lithology, velocities, elastic moduli of the shallow subsurface layers, classify the site, and assess the geophysical parameters with depth of the engineering site in the Kocaeli-Yazl & imath;k region of T & uuml;rkiye. The applied methods included 2D Seismic Refraction Tomography (SRT), 1D multichannel surface wave analysis (MASW), and electrical resistivity tomography (ERT). A nearby borehole data revealed a three-layer structure: a 15 m thick alluvial layer of clay, silt, and sand; an intermediate claystone unit (Aslanbey Formation) between 15 and 35 m; and a deeper volcanic basement (Sar & imath;su volcanics) beyond 35 m. The 2D SRT and MASW velocity models showed a strong correlation with this stratigraphy. In the upper 15 m, low P-wave (750-975 m/s) and S-wave (160-180 m/s) velocities indicated saturated, unconsolidated alluvium, consistent with the borehole. Between 15 and 35 m, both P- and S-wave velocities increased (to 1600-2100 m/s and 250-290 m/s), reflecting the transition to compacted claystone, again aligning with the borehole log. The m values of the 1D MASW ranged from 203.5 to 314.6 m/s, confirming the presence of weak, heterogeneous near-surface materials. According to NEHRP (BSSC, 2020) and TBEC (2018), the site is classified as D (medium stiff soil) and ZD (medium stiff to stiff rock), further supported by borehole correlations. The calculated elastic moduli and geotechnical parameters revealed an increasing material competence with depth, characterized by higher stiffness and bearing capacity in deeper layers, consistent with the claystone and volcanic basement observed in the borehole. The ERT results also supported this model, showing low resistivity values (1-25 Omega.m for Wenner configuration and 1-40 Omega