Advanced hardware and software approach to seismic site response investigations
Abstract
Vibration measurement is an essential aspect of modern geotechnical engineering. It is particularly vital task for measuring the dynamic soil parameters, estimating seismic hazards and evaluating influence of industrial, traffic and construction vibrations on the surrounding buildings, structures and their elements. Meanwhile, commercial exploration seismic stations and data acquisition systems require significant professional knowledge and training in geophysics or vibration measurement, as well as practical skills and experience in adjusting data acquisition parameters. Furthermore, available seismological investigation and vibrometry sensors are not universally suitable for field applications in geophysical studies, soil-structure interaction investigations or structural vibrations. The frequency range suitable for seismic studies and industrial vibration measurement vary from 1 Hz to 300 Hz with sensitivity corresponding to the expected vibration level. To address these challenges, the first part of this thesis was focused on developing an innovative data acquisition system and sensors that are easy to use in a wide range of field applications.
Geophysical techniques, including the Multichannel Analysis of Surface Waves (MASW) and Horizontal to Vertical Spectral Ratio (HVSR) methods, are gaining popularity in site investigations and seismic hazard characterization applications. The second part of this thesis involved conducting field studies using MASW and HVSR methods to evaluate the influence of challenging site conditions such as sloping surface topography, complicated soil stratigraphy and sloping bedrock boundaries on the results of the applied methods.
The application of theoretical or numerical models of site amplification often poses a challenge under real field conditions. In the third part of the thesis, an analytical model was developed to allow for the removal of site effects from strong motion records and proposed a method for HVSR curve parameterization that resulted in an analytical expression for the amplification factor based on HVSR results.