Modelado de la propagación de ondas compresionales en medios poroelásticos y su aplicación en la geotécnia.

Abstract

The propagation of waves plays a fundamental role in areas of Civil Engineering such as geotechnics and structural theory, because through it the mechanical and dynamic behavior of the soil and the interaction between soil and structure are studied. Due the soil exhibits the properties of a uid-saturated porous medium, much of the soil wave propagation studies have been based on Biot's poroelastic media theory. These media di er considerably from those constituted by a single phase, due mainly to the presence of uid in the pores and to the existence of three body waves e.g. slow P wave, fast P wave and S wave. However, the Civil Engineering has put special interest to the study of the S wave and the corresponding horizontal movement of the soil produced by this wave. However, the increase in compression damage of the structures in recent years, due to strong vertical movements, evidences the need to know the vertical response of the soil induced mainly by the propagation of P waves. Therefore in this work the mechanism of propagation of P waves in the context of Biot Theory is invetigated. It establishes the equations that govern the propagation of P waves in soils and through an analytical approach the characteristics of attenuation and dispersion of these waves are studied, in addition to their individual contributions in the soil response. On the other hand a numerical development of the equations is carried out to graph the propagation of waves P in time. In this work it is shown that the attenuation and dispersion characteristics of the P waves are dependent on geotechnical parameters such as: permeability, porosity and compressibility modules of the solid and uid phases, both in high and low frequencies, the latter being interest for Civil Engineering, so that the vertical components of soil movement must be studied more rigorously to know their contributions in the dynamic response of the site.