Shallow Reflection Seismic Shear-wave Velocity Analysis on Paved Soils Using a Land Streamer Unit

Abstract

As part of the Project “Management of Georisk” of the Federal Institute for Geosciences and Natural Resources (BGR), Hannover, high resolution shear-wave reflection seismic was applied in the Indonesian province Nanggroe Aceh Darussalam in cooperation with the Government of Indonesia and local counterparts. Target was earthquake site effect classification in the city of Banda Aceh and the surrounding region of Aceh Besar. Using a land streamer system was advantageous in the populated area and for an easy recording operation. Additionally, paved roads, compacted dirt roads or concrete surfaces suppress Love waves and refracted waves, if the soil layer below the surface is of lower seismic velocity. The recorded wave field of single records often includes direct and reflected SH shear-waves only in such cases, allowing RMS-velocity-depth determination on site. Because RMS-velocity is higher than mean velocity, this gives a good estimation of the mean shear-wave velocity-depth function. Results show that shear-wave reflection seismic in combination with Land Streamer is a useful tool to evaluate the soil stiffness in populated urban areas. The specialized seismic system for compacted soil surfaces allows a wide range of applications within cities, industrial sites, paved roads and also on small dirt roads.