Resumen de Delineación de suelos en un área metropolitana mediante el empleo de ondas Rayleigh de alta frecuencia
J. Badal, U. Dutta, N. Biswas, F. Gómez, F. Serón
We use high-frequency Rayleigh waves generated by an electromagnetic vibrator system in or order to identify the lateral extent of soil classes in a small area as the metropolitan area of Anchorage, Alaska. From phase delay times between two sensors, the phase velocity of the fundamental mode at each measurement site is computed. Then, a stochastic inversion scheme allows to invert phase velocity of the waves, and to obtain the shear wave velocity structure of the area in terms of local seismic velocities between 100 and 500 m/s approximately, in the upper 0-30 m depth interval. On the basis o f these local velocities, and with the purpose of getting a proper view of the study area, we apply a spatial prediction method based on an interpolation algorithm involving finite differences. Thus, through spatial prediction and visualization, we obtain 3D images for the geometry and S-wave velocity structure o f soils underling the study area within the reliable depth interval. These images are shown as horizontal slices at gradually increasing depths, and three-dimensional blocks as defined by characteristic velocity ranges, which enable to see in detail the extent o f soils both laterally and with depth.
