Development of a device for soil profiling based on the measurement of microtremors

Abstract

Geophysical survey is one of methods used in mining industries, petroleum explorations, groundwater explorations, earthquake studies, and geotechnical site investigations. In this study, an exploration system is developed to determine shear wave velocity profiles from records of small vibrations on ground surface (Microtremors). A microcomputer (Raspberry Pi), a 24bit analog-to-digital converter and geophones are used for measuring microtremors and wirelessly sending the observed data to a smartphone. The vibration records are then analyzed in the smartphone for the shear wave velocity profile based on the spatial autocorrelation (SPAC) method and a artificial neural network (ANN). The predictions from the developed system were found to be agreed with a downhole test result at Chulalongkorn University when measuring in a suitable radius.