While various engineering projects involving electro‐osmotic stabilization and consolidation of fine‐grained soils have been implemented with considerable success, attempts to estimate the progress of consolidation, even in laboratory experiments, have been far from satisfactory. This paper appraises the difficulties associated with the interpretation of experimental results of laboratory electro‐osmotic oedometer tests using the one‐dimensional linear theory of electro‐osmotic consolidation. In particular, it is examined if the accuracy of prediction can be improved by a more appropriate analysis of the distribution of electrical potentials within the laboratory sample.

The sensitivity of a waste disposal impoundment's leachate collection system performance to a range of design parameter values is investigated based on a computer modeling study. The piezometric head distribution in a vertical cross section of the impoundment is simulated using the finite element method to solve the combined equation of motion and continuity for two‐dimensional flow through a saturated anisotropic porous media. The design parameters studied include saturated waste depth; ground slope; underdrain spacing; and the hydraulic conductivities of the waste, clay liner, drainage blanket, and drain filter. The emphasis in this investigation is on the effect of the design parameters on the hydraulic pressure distribution directly above the clay liner which underlies the waste. The results of the study indicate that the three key parameters controlling the hydraulic pressure on the liner are the underdrain spacing and the hydraulic conductivities of the underdrain filter and the drainage blanket between the waste and clay liner.

A finite element method of analysis for seismic response of fluid‐structure problems is presented. Displacement model finite elements are used in the fluid region, leading to simple fluid‐structure interface conditions. The methodology has been used in a parametric study of seismic hydrodynamic forces on rock slopes. Parameters considered in the study are: height of the slope; depth of water; slope of the rock face; and, the earthquake base motion. A method for evaluation of seismically induced movements of submerged rock slope is presented. Calculation of seismically induced movements are a major step in the evaluation of the seismic stability of submerged rock slopes.

A numerical procedure is developed for a rational quantification of uncertainties in the probabilistic consolidation solution of soil mediums with spatial variability. The Alternating Direction Explicit Procedure (ADEP), combined with an Integrated Finite Difference Method (IFDM), is extended to multidimensional systems with unknown boundary conditions. Multidimensional soil variability and water flow, ensemble property of the soil medium and scaledependent variability are considered in the development of the solution model. The assessment and influence of soil variability input is based upon an extensive consolidation test program conducted on samples taken from a tidal marsh deposit in Maryland. The results of the analyses indicate that the expected value of the probabilistic solution is almost identical to the conventional deterministic solution, and that the uncertainty due to material variability, for most soils, is not as significant as reported previously by other researchers.

A power plant is being founded on bored concrete piles which penetrate 30–40 m of compressible soil and are socketed into rock. An integrity testing program of these cast‐in‐place piles included shaft coring, compression testing of concrete cores and geophysical sonic logging of core holes. Sonic logging along the core hole was performed with a downhole probe containing a 40 kHz transmitter and multiple receivers. The intensity (attenuation) of the sonic signal has been shown to be a more reliable indicator of concrete quality than P‐wave velocity. By normalizing the intensity of the energy arrival against the maximum intensity observed in the pile being tested, a correlation with concrete compressive strength as measured by core crushing was identified. Finally, the use of multiple pipes cast into piles has been shown to be an effective way to test piles without coring. This technique permits performance of both near‐field and cross‐pile testing to evaluate the majority of the shaft area.

The cyclic strength of sand deposits is influenced by a number of factors including density, grain size, previous loading history, in situ stresses, age, particle shape and structure. In the case of uncompacted tailings sands, of concern because of their high potential for liquefaction, a number of these factors do not show a large variation. Test data on uncompacted tailings sands which the practicing engineering could use to obtain a preliminary estimate of cyclic strength parameters are compiled and reviewed. Data from 20 tailings and 13 non‐tailings materials is presented for comparison purposes. The correction for relative density for normalizing test data is discussed. A Modified Stress Ratio (MSR) plot is suggested which enables the determination of cyclic strength parameters for the anisotropically consolidated case from strengths on isotropically consolidated samples. The accuracy of this determination is adequate for engineering purposes. Finally, a method outlining the use of compiled data for evaluation of cyclic strength of tailings sands is presented.

A time‐dependent plasticity model for rocks and soils based on Perzyna's elastic/viscoplastic theory is presented, wherein the plasticity yield function is patterned after the inviscid cap model developed over the last decade by Sandler et al. Three aspects are addressed: (1) Theoretical review and development; (2) numerical solution strategies suitable for a displacement‐based finite element method; and (3) illustrative examples of model behavior and comparisons with experimental data. The numerical solution algorithm employs a one‐parameter time integration scheme which provides options for explicit or implicit methods. Nonlinear equations resulting from the implicit method are solved by a Newton‐Raphson iterative technique, and efficiency versus accuracy studies are reviewed. Parameter identification and comparison of the model with experimental data is demonstrated for hard limestone in a variable loading history, soft sedimentary rock in triaxial creep tests, and well‐graded sand in slow and rapid loading (ground shock). It is concluded that the viscoplastic cap model is capable of adequately representing the time‐dependent behavior of soil and rocks for a wide range of loading environments. Limitations of the model are noted, and recommendations for improvement are offered.

The design, construction, and performance of an approach embankment constructed on soft soil is reviewed. Due to the poor subsoil conditions, the design included a combination of surcharge fills, stage construction, installation of vertical drains, and a horizontal fabric layer. Predictions of the behavior of such combined systems are extremely difficult. Field measurements of movements of and within the subsoil are thus necessary and can correct soil parameters from laboratory tests and improve existing calculation models. To investigate the behavior of the embankment during construction field measurements of horizontal and vertical movements with a combined settlement‐inclinometer tube were undertaken. During and after the field tests FE‐analyses were performed using the developed soil data. The analyses show that early measurements of movements can assist in correcting laboratory data. Thus changes in stage construction and in the design of vertical drains during the construction procedure are possible. Due to the chosen construction procedure a more economical design of a pile foundation against horizontal forces induced by the abutment fill could be used.