Use of seismic waves for the characterization of soil properties
Mohammad Harunur Rashid Meer
Date of Issue2008
School of Civil and Environmental Engineering
Seismic waves can be employed in the field and in the laboratory for characterizing soil. Seismic waves propagating through soils induce very low level of strains. Using the framework of linear elasticity, the wave propagation velocity can be linked to the elastic parameters of the soil. This study investigates soil properties using elastic waves in the field as well as in the laboratory. Continuous Surface Wave (CSW) and microtremor surveys were conducted at seven sites in Singapore. Borehole logs were available for all the sites. Pulse transmission tests using ultrasonic velocity test system were conducted in the laboratory. The Spatial Auto-Correlation (SPAC) method was used to analyze the data from microtremor survey to compute the dispersion curve. The dispersion curves obtained from the CSW and microtremor surveys for the same site were not coincidental but the discrepancy did not have any significant effect on the shear wave velocity profile. To obtain the shear wave velocity profile from the dispersion curve, wavelength-depth factor and linear inversion methods were used. The depth of investigation obtained from microtremor surveys was limited by array size. Because of site constraint, the array size of the microtremor is limited to 10 m with the maximum depth of investigation limited to 16 m. A modified wavelength-depth method was developed in this research and the method was verified using data from published literature.