Conventionally, a first loading modulus and a limit pressure are obtained from a pressuremeter test curve. This article shows how much information on the soil modulus can be obtained from a pressuremeter test. Soil moduli vary with the strain level. The pressuremeter modulus is measured at a large strain level; it is shown how an unload reload cycle can be used together with the hyperbolic stress strain model to find a soil modulus at any strain level. Soil moduli vary With the level of stress confinement. It is shown how an unload‐reload cycle can be used together with a power law to find the stress dependency of the soil modulus. Soil moduli vary with the number of unload reload cycles. One pressuremeter test with 100 unload‐reload cycles is presented; it is shown how the modulus and the plastic strain vary with the number of cycles.

Axisymmetric (shaft) excavations are quite common in the construction industry (e.g., inspection or access chambers and excavations for bored piles or piers). The stability of an axisymmetric excavation in clay with uniform undrained shear strength profile is reviewed. A wall failure mechanism is found to be the most critical when both wall failure and base failure are considered. Based on this, upper‐bound calculations are carried out for an axisymmetric excavation in clay with undrained shear strength varying linearly with depth. Stability charts are also presented for the critical wall failure mechanism. In normally consolidated clays, with zero shear strength at the ground surface, axisymmetric excavations are shown to be unstable if not supported. The width of the settlement zone adjacent to the excavation is found to be approximately equal to 0.4 times the depth of the excavation.

The current design practice for filters in earth and rock fill dams is an outgrowth of a well known concept proposed by Terzaghi. The main effect of amplifications that investigators have added to the Terzaghi criteria is to permit the use of widely graded sand‐gravel mixtures as filter materials. The use of these criteria without consideration of the erodibility characteristics of the core material and crack potential of the filter has caused near failure and total failure of several dams. A new method is presented for quantifying the erodibility of soils based on the use of critical shear stress, TC, developed due to hydraulic flow in the cracked zone of a dam. The limitation of the classification proposed for evaluating erosion from a knowledge of Atterberg limits of soils is considered. A direct correlation between the critical shear stress required to cause erosion and the piping failure of several dams whose filters were designed under the Terzaghi criteria, is presented. Core fines with TC values less than $4\mathrm{dynes}/{\mathrm{cm}}^2$ have been shown to be one of the contributing factors causing piping failure of dams. The need to correctly quantify erodibility and to carry out filtration tests using the eroded fines and proposed filter material is recommended for the safe design of protective filters. Research is necessary to determine the percent of fines less than #200 sieve size needed in a filter in order that it will retain fines which have been eroded and also so that it will not sustain a transverse crack.

This paper summarizes existing consolidation data for various slurried mineral wastes; specifically, compressibility and permeability. It describes the state‐of‐the‐art in field and laboratory tests for measuring the consolidation properties of these very soft sediments. It briefly reviews computer programs that have been written to analyze finite strain consolidation. A design methodology is developed in detail for rapid calculation of storage capacity of disposal ponds under a variety of conditions. Finally, a methodology for determining preliminary design consolidation properties is described that is based on the Atterberg limits of the waste material.

The low-amplitude shear modulus, G_o, of cohesive soils is needed for evaluation of dynamic response of soil masses or foundation systems. Previous studies have shown that there may be a correlation between G_o and the static shearing strength, τ_max, but the importance of the variables involved is not clear. An experimental program to evaluate the influence of average confining pressure, σ¯_o, and overconsolidation ratio, OCR, on a kaolinite clay is described. Vac-Aire extruded samples of this clay were subjected to resonant column tests to determine G_oand consolidated-undrained triaxial tests determined τ_max, under similar confining conditions and strain rates. Results of this investigation showed that ratio G_oτmax is not a constant value even for a single clay soil. A significant effect is produced by variations in σ¯_o and OCR which can produce errors of ± 50%. Therefore, use of τ_max to estimate G_o is a crude procedure at best.

Design charts for performing total stress stability analyses of cohesive slopes subjected to strip loads and square loaded areas are developed. The charts for strip-load provide solutions for different load widths and thus are expected to complement existing solutions. Results show that for square loaded areas, end effects can have an important effect on the magnitude of the critical load causing failure. These effects are especially important when the factor of safety of the slope due to its weight only is close to unity. For many practical situations, three-dimensional effects would increase the plane strain critical load by a factor of 5 to 10.

A method for three-dimensional stability analysis has been developed and applied to 18 case histories of embankment failures. Results show that end effects generally increase the conventional plane strain factor of safety by 10 4 5%. A revised field vane correction versus plasticity index relationship is 10% lower than that recommended by Bjerrum in 1972 and should represent a better estimate of the ``true'' in situ undrained shear strength.

Terzaghi's intergranular stress, or effective stress, can be formulated through application of averaging theory to the primitive momentum balance equations. Careful examination of the resulting development reveals the simplifying assumptions inherent in the effective stress concept in both saturated and unsaturated flow.

Research into reinforced clay using triaxial testing of reinforced and unreinforced samples of saturated remolded clay shows that continuous impermeable reinforcement can cause a reduction in strength under rapid loading. This reduction in strength is caused by the generation of high pore-water pressures, near the center of the sample, which migrate radially outwards causing a net reduction in the effective minor principal stress. The same effect is observed with permeable reinforcement at wide spacings. At closer spacings the permeable reinforcement acts as a drain allowing for partial dissipation of high pore-water pressures. This results in an increase in strength even for rapid rates of loading. Impermeable reinforcement can be associated with an increase in strength when the clay is not fully saturated. Test data indicate a linear relationship between reinforced sample strength and the degree of saturation independent of cell pressure. Test results are presented and analyzed for the effects of permeable and impermeable reinforcement spacing in saturated clay. Similarly, test results are presented for partially saturated clay with impermeable reinforcement.

Engineering designers involved with projects with the Arabian Peninsula may encounter potentially expansive soils. This paper develops a hazard map as a preliminary guide to potential expansive soils. The hazard map is based upon geological inference, regional experience, and limited test results.

The results of an investigation on the dynamic property of a subcoal material using ultrasonic wave velocities are reported. It is demonstrated that it is possible to generate and detect the ultrasonic compressional and shear waves in a subcoal strata material. From these generated waves it is possible to determine the elastic constants of the subcoal strata. By using statistical analysis significant correlations are found to exist between the material strength and ultrasonic waves