Experimental and theoretical response of multiphase porous media to dynamic loads. Annual report No. 2, 1 July 1986-30 June 1987

This report summarizes results of a combined theoretical and experimental investigation of wave propagation and liquefaction from high-intensity dynamic loading of saturated porous media. This work presents results obtained during the second year of a three-year research effort. Theoretical derivations describing undrained hydrostatic and uniaxial strain loadings were obtained and incorporated into a numerical code (NKOCP) which models the two-phase undrained response of saturated soils and rocks. Numerical calculations of the response of saturated rock and soil compare very well with laboratory data in which both the soil and rock are liquefied during the unload portion of the cycle. Theoretical and numerical solutions for the speed and damping of waves of the first and second kind in fully coupled two-phase media are also presented. Parameter studies of the influence of frequency and variations in material properties on wave speed and damping are performed.