In this paper, the sedimentation of clayey slurry is studied using Kynch's theory. This theory is attractive as the only property needed, the permeability, can be determined from the surface settlement curve. The assumption in Kynch's theory that the settling velocity is a function of the concentration alone is investigated first and found to depend also on the initial condition; an indication of the effect of flocculation. The theory is then reformulated and it is shown that the permeability‐versus‐void‐ratio relationship of the slurry can be determined from its surface settlement versus time curve. Modifications that still maintained the simplicity of Kynch's theory are then introduced to account for the dependence on an initial condition that reflects the changes in the soil fabric due to flocculation. A number of experiments are then conducted and the measured surface settlement and density are compared with the predicted values. The good agreement confirms the validity of the approach adopted.

A theory is presented to evaluate pore pressures developed as a result of insertion of an open‐tipped standpipe into a saturated porous medium. An integral method is used whereby the advancing tip is represented as a moving point dislocation. Dimensionless standpipe pressure, $〈P_D-P_D^S〉\text{,}$ is uniquely controlled in dimensionless time, $t_D\text{,}$ by dimensionless penetration rate, $U_D/E_D\text{,}$ and the modulus ratio, $E_D(R_2/R_1{)}^2\text{.}$ The time lag to pressure buildup is controlled by the magnitude of the ratio of penetration rate, U, to consolidation coefficient, c, as embodied in $U_D/E_D\text{.}$ The magnitude of the pressure differential between a closed‐tip piezocone and the open standpipe piezometer is exacerbated as the parameter $E_D(R_2/R_1{)}^2$ is increased, reflecting the volume compressibility of the measuring system. At low relative penetration rates, the steady pore pressure response within the standpipe is subhydrostatic as fluid response is controlled primarily by the in situ hydrostatic pressure distribution with minimal contribution from generated pore pressures. As dimensionless penetration rate $U_D/E_D$ is increased, the standpipe response becomes greater than hydrostatic, indicating the influence of high drivage‐induced tip pore pressures on overall behavior.

Results of cyclic‐ and quasi‐static load tests carried out on concrete piles driven in Mexico City clay shed light on significant features of the behavior of floating piles under earthquake‐like conditions. The maximum bearing capacity depends on the rate of loading: the higher the rate, the higher the capacity. The rate of loading has a similar effect on the slope of the land versus displacement P‐δ curve. The modulus of reaction under vertical cyclic load is constant over a wide range of cyclic‐load amplitudes. Pile penetration is small whenever the total applied load (sustained plus cyclic) does not exceed a threshold load approximately equal to the bearing capacity defined by conventional procedures. If critical load is surpassed, increasingly larger pile penetrations occur and pile capacity loss may follow. Results of cyclic simple shear tests on undisturbed clay samples show the existence of a stress limit beyond which the induced shear strains increase at higher rates. The clay loses about half of its original undrained strength after being remolded at constant volume.

Results of consolidated isotropically undrained triaxial tests (CIU) on samples of reconstituted sands are presented to establish the conditions required to induce strain‐softening during monotonic loading. It is found that the mean steady‐state line (F line), commonly used for the evaluation of liquefaction potential, is not uniquely related to void ratio for a given sand. Rather, the tests reveal that initial effective confining stress also influences the undrained behavior of granular material. Furthermore, the tests confirm the existence of upper and lower limits of the F line, which are defined as the UF and LF lines, respectively. The minimum undrained strength corresponds to the LF line and thus is smaller than the mean steady‐state strength. The minimum undrained strength depends upon the initial state defined by both void ratio and effective confining stress. The initial state also controls the shape of the stress‐strain curve.

Available consolidated isotropically undrained triaxial tests (CIU) on samples of reconstituted sands are analyzed in terms of the UF and LF lines to establish the conditions required to induce strain softening during monotonic loading. Tests on other sands than those tested by the writer support the view of the existence of upper and lower limits of the F line (steady‐state line), which are defined as the UF and LF lines, respectively. The minimum strength (LF line) of any sand is dependent upon the initial state. Unlimited and limited flow are observed for samples consolidated within three regions, which are defined in a state diagram. The limits between these regions appear to be related to the slope, λ, of the UF line. Finally, the value of the ratio of the minimum strength from the LF line and the steady‐state strength from the UF line is also dependent upon λ.

Earth structures such as embankments and excavations are constructed sequentially, and for realistic modeling of these structures the construction sequences should be simulated as accurately as possible. This paper addresses the problems associated with accurate incremental excavation modeling using an efficient finite element‐based excavation analysis algorithm that satisfies the uniqueness principle for cutting in an elastic material and a new stress‐point integration algorithm for the modified Cam‐Clay model that is both accurate and stable. The combined excavation and stress‐point algorithm is unconditionally convergent at subfailure condition and is shown to perform extremely well on an intensive accuracy analysis designed to model the process of sequential excavation in a modified Cam‐Clay soil under plane strain, axisymmetric, and three‐dimensional configurations. Both drained and undrained conditions are considered in the analyses. The paper ends with an example of braced wall movement prediction in a soft bay mud deposit near San Francisco Bay to demonstrate the practical application of the proposed solution.

The use of numerical methods such as finite elements to make accurate predictions of failure or collapse of geomaterials must utilize a suitable failure criterion that is able to represent the shear strength for all stress paths likely to be encountered. The best‐known failure criterion is that of Mohr‐Coulomb, but several others have been proposed. Using a dimensionless form of principal stress space, this paper reviews some of these other criteria in a unified way by presenting them in terms of the equivalent Mohr‐Coulomb friction angle implied at various locations on their periphery. Circular conical surfaces in stress space can greatly overestimate the strength of soil for certain stress paths, and sometimes contain singularities as implied by an equivalent friction angle of 90°. Noncircular conical surfaces have also been considered. These give a more acceptable range of equivalent friction angles, as they are based on actual test data. These “sophisticated” criteria can still predict equivalent friction angles that differ from each other by several degrees, however.

In this work, the plane strain pressuremeter test is examined using a finite strain elasto-plastic analysis. The pressure-meter expansion is analyzed as a finite strain problem using a Lagrangian formulation employing the ``cap model'' of DiMaggio and Sandler. The analysis is performed by modeling the pressure-meter expansion as a cavity expansion of a segment of the walls of an existing cylindrical cavity. The solution does not suffer any major inconsistencies and its success depends mainly on the use of the appropriate constitutive equation. Therefore, a more reliable analysis can be performed and more accurate soil parameters can be obtained. It is the aim of this work to evaluate the importance of some of the most commonly made assumptions in the analysis of the results of the pressuremeter test.

When calculating dynamic response of embedded foundations or piles, impedances (stiffness and damping) of the adjacent soil are needed. To account approximately for soil nonlinearity under high strain, contact deficiencies and disturbances caused by foundation installation, a cylindrical annulus of softer soil around the foundation is used. The soil properties in this weakened boundary zone differ from those of the outer zone but both regions are assumed to be homogeneous. The mass of the cylindrical annulus can be either neglected or accounted for. If this mass is considered, a seemingly more accurate approach, wave reflections from the interface between the two media can occur resulting in marked undulations of the impedances with regard to frequency and, possibly, in negative stiffness. It is the purpose of the paper to show that such undulations are unrealistic and that the impedances featuring them can be less suitable for practical application than those obtained neglecting the mass of the inner zone.

Normalized small strain Young and shear moduli of pluvially deposited predominantly silica Ticino sand are well correlated against the state parameter as defined by Been and Jefferies. The same holds true for normalized cone resistance measured during the calibration chamber tests performed on the same test sand. It is shown that also parameters obtained from other kinds of penetration tests are correlatable against the state parameter of a sand. These findings might indicate a way to rationalize the correlations between penetration resistances and stiffness of sands being the latter referred to the preyield behavior of a sand.