Highly realistic analysis of the consolidation of soft clays is possible within the framework of the traditional concepts of soil mechanics. A practical method is described for predicting the magnitude and rate of settlement and pore water pressure dissipation. Detailed interpretation and evaluation of the consolidation properties of soft clays, including the compressibility parameters, preconsolidation pressure and coefficient of permeability are presented. These properties can be determined from the standard oedometer test with direct permeability measurements. Computer procedure ILLICON, using multi‐layer analysis, includes any variation of consolidation parameters with depth. The proposed method for evaluating the consolidation parameters, and settlement and pore water pressure analyses is illustrated using case histories of two test fills on soft clays. Excellent agreement is obtained between the computed behavior and field observations.

Permeability tests were performed in the laboratory on compacted clay to study the effects of type of permeameter, hydraulic anisotropy, diameter of test specimens, storage time, and desiccation cracking. Essentially identical hydraulic conductivities were measured with compaction‐mold, consolidation‐cell, and flexible‐wall permeameters. With good bonding between lifts, hydraulic conductivity was isotropic. Test specimens having a diameter of 15 cm were twice as permeable as specimens having a diameter of 4 cm, but this difference is too small to be of any consequence. There was no tendency for hydraulic conductivity to increase with increasing storage time. Desiccation cracks in compacted clay close only partially when the clay is moistened and permeated, unless substantial effective stresses are applied to aid in closing the cracks.

A technique for the analysis of 1‐D pollutant migration through a clay layer of finite depth is presented. This formulation includes dispersive and advective transport in the clay as well as geochemical reactions and permits consideration of the depletion of contaminant in the landfill with time as well as the effect of ground‐water flow in a permeable stratum beneath the clay layer. A limited parametric study is presented to illustrate the effect of considering these factors in the analysis. It is shown that for most practical situations the concentration of contaminant within the ground water beneath the landfill will reach a peak value at a specific time and will then decrease with subsequent time. It is shown that the magnitude of this peak concentration and the time required for it to occur are highly dependent upon the mass of contaminant within the landfill and the sorption capacity of the clay. Other important factors which are examined include the thickness of the clay layer, the advection velocity (relative to the dispersivity), and the ground‐water flow velocity in any permeable strata beneath the clay layer. The implications of these results for optimizing the design of clay liners is then discussed.

Design methods for vertical anchors subjected to horizontal pullout forces are reviewed. Theoretical predictions are compared with results from conventional tests on 2 in. (50 mm) models and centrifugal tests representing 39.4 (1 m) prototypes in dense sand. Good agreement is found between force coefficients from theories for 39.4 in. (1 m) anchors, provided a mobilized friction angle in the mass is used in the analyses. A lack of consistent agreement for 2 in. (50 mm) anchors is attributed to inherent difficulties in obtaining reliable data for small models at low stress levels. Anchor geometry is adequately accounted for by a theoretical shape factor derived by the writers.

Replacement of the old Lock and Dam 26 on the Mississippi River involves construction of one of the largest systems of cellular cofferdams ever built. Preliminary analyses using conventional theories led to sometimes contradictory recommendations about the cofferdam design. To help resolve outstanding issues, instrumentation was placed on the first‐stage cofferdam, and finite element procedures were developed for analysis of the cofferdam. Three different two‐dimensional finite element procedures were generated, including axisymmetric, vertical slice, and generalized plane‐strain models. The alternative approaches allowed prediction of cofferdam response for the most important design conditions and at the critical locations. In all models, allowances were made for nonlinear soil response, slippage on the sheet‐pile‐soil interfaces, staged construction simulation and seepage effects where appropriate. Further, a means was provided to accommodate the effect of sheet‐pile interlock yielding, which led to an orthotropic response of the cellular cofferdam. Predicted behavior from the finite element models was found to be consistent with observed trends. The models appear to have considerable potential for use in future designs.

A punch-through failure of a jack-up platform can occur as a result of an overall instability of the structure on the seabed even when the seabed has bearing capacity increasing with depth. The instability is analogous to the overturning of a top-heavy ship and to the Euler buckling of an inelastic strut. The instability starts when a small tilt of the structure causes an increase in the reaction on a penetrating leg which is greater than the increase in bearing resistance associated with the added penetration. The limiting weight and height to which a jack-up remains stable on a given foundation depends on the sequence of jacking and preloading of the legs.