<![CDATA[Seismic site characterization is needed for earthquake risk mitigation and also for geotechnical infrastructure design. Multichannel Analysis of Surface Waves (MASW) can be used for seismic site characterization. The method extracts shear-wave velocity (Vs) profiles from surface wave analysis that reveal geotechnical conditions and subsurface structures. This study aims to characterize the subsurface layers using the MASW method in Aceh Besar. Data acquisition was carried out along three measurement profiles, each 69 meters long and with a receiver spacing of 3 meters. Shear-wave velocities (Vs) of the subsurface soil and rock layers were estimated using dispersion curve analysis and 1D inversion. The surface wave spectral analysis produced a high-quality dispersion at the fundamental mode frequency of 20–30 Hz. The inversion process, validated by an excellent misfit curve, yields a seven-layer Vs model with RMS values mostly below 0.01. The 2D pseudo-section models based on 1D inversion results show a subsurface stratification consisting of a soft to medium overburden (Vs < 350 m/s) layer of 15 meters thick, followed by a transition zone of dense soil, and engineering bedrock (Vs > 750 m/s) found at a depth of 30 to 40 meters. In general, lateral variations were identified as undulating bedrock topography and local basin structures. Based on SNI 1726:2019, the site is classified as Medium Soil (SD) to Very Dense Soil (SC), with an estimated Vs value influenced by the thickness of the surface sediment. These results provide a valuable overview of subsurface conditions from site characterization and can serve as a basis for geotechnical planning in the study area.]]>
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