Development of three-dimensional seismograph for evaluation of seismic effects of earth disturbances

This research presents the development of a triaxial seismograph; a device used to measure ground vibration levels in three perpendicular directions. The device comprises three triaxial geophone networks that can be positioned at three different points on the ground surface to measure ground vibration levels, five 24-bit analogue-to-digital converters (ADCs) to digitize the geophones' analogue outputs, an Arduino-Mega microcontroller that coordinates the operations of the system’s components, five multiplexers (MUXs) which serves as an interface switch between the ADCs and the microcontroller, a Liquid Crystal Display (LCD), and a MicroSD card for data storage. Comparative analysis of the data measured by the seismograph with that of a standard seismograph showed a very good relation and this demonstrates the reliability of the developed device. After calibration, the seismograph can measure ground vibration levels in terms of peak particle velocity (PPV) ranging from 0.000017 mm/s to 143 mm/s with a sensitivity of 0.00000424 mm/s. Fast Fourier Transform (FFT) analysis of the result of vibration tests carried out at various field locations indicates that the seismograph performed satisfactorily according to the design specifications. Also, from the analysis, it was seen that the vibration amplitudes obtained at each site locations are slightly above the threshold limit. Cost analysis reveals the affordability of the seismograph compared to standard models, making it a viable option for laboratories, research, and demonstrations. The cost-effectiveness and accuracy of the device enhances its utility, positioning it as a potential replacement for more expensive options in the market.