Compared with Biot model and BISQ model,the modified BISQ model is easy to express and calculate with similar results to the former two models,being a feasible and new BISQ model.

Considering the compression of soil grain and pore fluid as well as viscid coupling of pore fluid and soil skeleton, the scattering problem of incident plane P_1 wave (fast compressional wave) by an infinite cylindrical shell embedded in isotropic saturated soils is studied by adopting the amended Biot model.

The compression of soil grain and pore fluid and viscid coupling of pore fluid and soil skeleton were considered, and amended Biot model was adopted to numerically analyze the influence of incident angle of P_1 wave on vibration characteristics of building foundation with different modules when the reflection and transmission of incident P_1 wave at the interface of saturated soil and building foundation occurred.

Considering the compression of soil grain and pore fluid and viscid coupling of pore fluid and soil skeleton,elastic wave scattering by a saturated cylinder in saturated soils was studied by adopting amended Biot model,amplitude equations of potential functions of scattered wave fields and refracted wave fields were obtained,and the variation curves of back-scattered form functions with normalized frequencies and circumferential distribution curves of radical displacements of various normalized frequencies were numerically analyzed.

The reflection and backscattering coefficients from BICSQS model,which is abbreviated from the Biot model with contact squirt flow and shear drag,and Biot-Stoll model Seafloors are calculated and compared by poroelastic interface scattering formula. In addition,the effect of bulk relaxation frequency and shear relaxation frequency on the coefficients of BICSQS model is analyzed.

Based on the modified Biot′s theory of two-phase porous media, a study was presented on seismic reflection and transmission coefficients at an air-water interface of saturated porous soil media.

The maximum attenuation determined from spectral analysis of the measured signals closely matches the characteristic frequency predicted by the Biot model.

Mathematical models under research are the Biot model and its generalization by consideration of viscous stresses inside liquids.

Distinctions of wave propagation in the context of the Biot model and its generalization are shown.

The data can be accounted for by a Biot model of the 3He liquid in the porous aerogel.

The effective model of a stratified solid-fluid medium as a special case of the Biot model

Based on clear physical concepts, complete nonlinear dynamic equations of two-phase media are derived by using classic mechanical principle directly. Then, two conditions under which the nonlinear equations can be linearized are expounded. The conditions are that varieties of the porosity and density with spatial position are much smaller than those with time in the dynamic process, and alterations of the displacement and pore fluid pressure induced by porosity or density changes can be omitted. Thus, the variables...

Based on clear physical concepts, complete nonlinear dynamic equations of two-phase media are derived by using classic mechanical principle directly. Then, two conditions under which the nonlinear equations can be linearized are expounded. The conditions are that varieties of the porosity and density with spatial position are much smaller than those with time in the dynamic process, and alterations of the displacement and pore fluid pressure induced by porosity or density changes can be omitted. Thus, the variables of displacement and pore fluid stress are decoupled with porosity and density variables, and can be resolved independently. Furthermore, the inconsistency that the porosity and density keeping constant is in contradiction with the compressible pore fluid and deformable skeleton assumption in two phase models (including Biot′s) is also clarified through linearization. After comparing some two phase models, the following conclusions are obtained. Firstly, the only differences between them lie in the constitutive relation; secondly, the soil mechanics′ model is a special case of the Biot′s and Zienkiewicz′s model.

The slow compressional wave (P2 wave) in porous media based on BISQ model is investigated. The low frequency approximate expression for velocity and attenuation of P2 wave is presented. Compared with Biot model, BISQ model predicts that the attenuation of P2 waves is very large at low frequency and decreases with increasing characteristic squirt flow length ( R ), the velocity low frequency limit is not zero and decreases with increasing R , variation of the ratio of pore fluid displacement to bulk...

The slow compressional wave (P2 wave) in porous media based on BISQ model is investigated. The low frequency approximate expression for velocity and attenuation of P2 wave is presented. Compared with Biot model, BISQ model predicts that the attenuation of P2 waves is very large at low frequency and decreases with increasing characteristic squirt flow length ( R ), the velocity low frequency limit is not zero and decreases with increasing R , variation of the ratio of pore fluid displacement to bulk displacement is similar to that of attenuation and its phase is different from that of Biot model. The seepage flow induced by P2 wave at the fluid porous media interface is larger than that of Biot model. For the sake of contrast, the properties of the fast compressional wave are also presented. Two conclusions are induced from the BISQ model: there is no squirt mechanism in inviscid fluid saturated porous media and there is no “dynamic compatibility” phenomenon in viscid fluid saturated porous media.

In situ compressional wave velocity and attenuation measurements were made at 2 carbonate sediment sites over a frequency interval between 20 and 100 kHz. Velocity dispersion, while slight, appears in the data. Velocities increase from 1691 to 1708 m/s at Site H3 and from 1579 to 1585 m/s at Site H4 as the frequency increased. Effective attenuation ranges from 15 to 75 dB/m at Site H3 and from 22 to 62 dB/m at Site H4. Parameters determined by core analysis were fixed in Biot-Stoll models and inversion of velocity...

In situ compressional wave velocity and attenuation measurements were made at 2 carbonate sediment sites over a frequency interval between 20 and 100 kHz. Velocity dispersion, while slight, appears in the data. Velocities increase from 1691 to 1708 m/s at Site H3 and from 1579 to 1585 m/s at Site H4 as the frequency increased. Effective attenuation ranges from 15 to 75 dB/m at Site H3 and from 22 to 62 dB/m at Site H4. Parameters determined by core analysis were fixed in Biot-Stoll models and inversion of velocity and attenuation data was used to evaluate the 6 unmeasurable parameters. It is found that Site H3 (porosity is 44%) has lower tortuosity, higher permeability and average pore radius than Site H4 (porosity is 56%)after inversion. Good fits were achieved for both velocity datasets, but corresponding modeled attenuation is low. An increase in the low frequency logarithmic decrement well above Stoll’s recommended values allowed fits to both velocity and attenuation very well.