Ground Surface Quality Assessment Using P-wave Velocity from 2-D Seismic Refraction Method

Abstract

A good strength level of the ground surface is the main concern in an area with rapid housing infrastructure development, such as Baitussalam district-Aceh Besar, Indonesia. A seismic refraction method was applied with three similar profile lines using PASI 16S – 24P equipment and 10 Hz vertical geophones to identify the sub-surface layer. The result was processed using Winsism software and Surfer 8. The results of seismic refraction were deduced and correlated with conventional geotechnical investigation obtained by a previous study. The results of 3 survey lines show that the area has two main layers. The first layer was interpreted as overburden (soil and clayey sand) with a compressional wave velocity (Vp) value of fewer than 1.8 km/s. The second layer produces a high velocity of more than 2 km/s. This second layer is interpreted as highly to moderately weathered rock. The results of seismic refraction surveys of the present study suggest a reasonably good correlation with the standard penetration test (SPT) and rock quality designation (RQD) obtained in the previous investigation. The strength level of the second layer showed N-SPT of 65 and RQD of at least 50%.

Integrated Geophysical Analysis for Landslide Risk Mitigation: A Case Study on the Weak Zone Area of Jantho-Lamno Route, Aceh, Indonesia

“…Our original achievement lies in the precise differentiation of rock layers and the identification of both weakened upper layers and potential slip planes in deeper formations. By correlating seismic [6,7,8] and resistivity data [9,10,11], the study predicts landslide-prone zones and contributes to a deeper understanding of geological features that contribute to slope failures [12]. This integrated approach not only surpasses the limitations of singular geophysical techniques but also offers a more effective means of formulating targeted protective measures to enhance the resilience of critical transportation routes.…”