Quasi‐static field equations for fully saturated porous elastic media, based on Biot's theory (1972‐1973), established in the writer's previous works (1989‐1990) are used in order to describe the behavior of such materials under wave ocean loading. A brief description of cross anisotropy with a vertical axis of symmetry (orthotropy) is given. The five independent elastic parameters of anisotropic materials are clarified. The field equations are modified and adapted for application to anistropic cases. A numerical procedure (finite element discretization) for the motion equations of an orthotropic saturated poro‐elastic seabeds is presented. The accuracy of the chosen algorithm is discussed. The wave‐induced pore pressures, effective stresses and displacements in an anisotropic submarine sediment are investigated. The results illustrate a significant influence of elastic anisotropic parameters on the wave‐induced pore pressures, effective normal stresses, shear stresses, horizontal and vertical displacements at the bed surface and in depth. A parametric study is performed in order to clarify the effect of the orthotropic constants for a sandy soil. The response of an isotropic seabed with a finite thickness to a harmonic wave loading is compared with an orthotropic case.

A new approach to the topic of numerical description of void characteristics of noncohesive soils and similar granular materials is presented. Based upon a simple stochastic model of the void structure and void sizes, theoretical equations are derived by means of which the void ratio of a soil can be calculated from its grain‐size distribution. The calculations also give information about type of grain structure, and the grain size that separates fixed grains and possible loose grains is determined. The equations also consider grain shape, degree of densification, and size of compaction container. Results of numerous laboratory compaction tests on uniform to broadly graded sand, gravel, and crushed‐rock materials confirm the general forms of the derived equations and are the basis for evaluation of certain parameters. In a companion paper, the theory is extended to hydraulic conductivity (and, in a forthcoming paper, to filter performances).

On the basis of a stochastic theory for the void‐size distribution in noncohesive soils and similar granular materials presented in a companion paper, equations for representative grain sizes in the two terms of the Kozeny‐Carman equation are derived. The equations are valid only for homogenous soils having a high degree of dehsification and a grain structure without loose grains. The pore velocity is assumed to be constant everywhere in the void space, and the hydraulic gradient is calculated by means of averaging local hydraulic gradients over the void space. The local hydraulic gradients are assumed to be given by a Kozeny‐Carman equation, with the local mean void chord length as pore diameter. Results from large‐scale permeameter tests on gravel and crushed rock support the derived equations and are the basis for evaluation of numerical coefficients.

This paper describes the stress‐strain response of a cohesive soil subjected to stress‐induced anisotropy. A directional shear cell (DSC) is utilized in the experiments. The DSC is capable of applying independently controlled normal and shear stresses on four vertical faces of the cubical specimen under plane strain conditions, thereby controlling the magnitude and orientation of the principal stresses that are applied to the specimen. In the experiments reported herein, the fabric anisotropy in the soil is induced by preloading. The initial loading direction coincides with the material principal axes, and the directions of the reloading principal stresses are applied in discrete jumps at specified orientations relative to the direction of the initial loading. When the specimens are reloaded at the various orientations of the principal stress directions, the results reveal the pronounced effects of the stress‐induced fabric anisotropy, as indicated by significant variations in the stress‐strain responses. The stiffness moduli significantly decrease and the maximum strain and the volumetric strain increase with the increasing rotation angle of the stress direction.

This paper presents a compilation of resonant‐column and cyclic simple‐shear test results on dynamic moduli and damping factors of soft marine clays. These tests were conducted on 38 undisturbed samples of soft marine clays recovered from five offshore sites. Sample depths ranged from 17 to over 300 ft below seafloor. The test clays had water content ranging from 36 to 86% and plasticity index ranging typically from 30 to 50%. Small‐strain moduli of the test clays were found proportional to consolidation stress and they also depend on void ratio and plasticity index. Normalized shear‐modulus curves and damping curves of the test clays were very similar to those for various onshore and offshore clays. The results of this study may be used to make a preliminary estimate of the dynamic properties of marine clays and to confirm field and laboratory tests on such clays.

As high earth dams, deep compacted highway embankments, and Other thick compacted fills become more common, it is imperative that engineers consider and control the potential for wetting‐induced collapse in compacted fills. Problems associated with collapse settlements in compacted fills include damage to structures and foundations placed on fills; cracking and slope failure within fills; damage to pavements and subgrades placed on highway embankments; piping, seepage losses, and failure in earth dams; as well as distress or failure of underground utilities. In contrast to naturally deposited soils, whose potential for collapse is determined by natural processes, an engineer can control the potential for collapse in a compacted fill during the placement process. In this paper, a synthesis is presented of the writers' experience, research, and extensive literature review of the mechanisms causing collapse, soil parameters affecting the occurrence and magnitude of collapse, and case histories in which substantial damage from collapse settlements has occurred.

Various schemes are considered in order to stabilize a road cut along a scenic highway in Massachusetts. These schemes include a drained rock blanket, rock blanket with brush‐layer inclusions, and a composite drained rock buttress and earthen brush‐layer fill. A brush‐layer fill consists of alternating layers of compacted soil and live cut stems that eventually root and sprout. Scenic and environmental considerations in combination with stability analyses dictate the use of a compsite drained rock and earthen brush‐layer fill. The rock section is placed at the base or toe of the slope. Placement of a rock buttress at the toe provides an extra margin of safety by interception of the critical toe failure surface through the rock. Live cut branches in the overlying earthen fill act as both reinforcements and horizontal drains. Adventitious rooting along the length of the imbedded stems provides secondary stabilization. Stems and branches of plant species are used that root readily from cuttings such as willow and dogwood.

This paper presents results of a study on the feasibility of using pozzolanic western coal fly ash, either by itself or mixed with sand, as a construction material for waste‐containment liners and impermeable covers. Liners can be constructed from pozzolanic fly ash or fly ash‐sand mixtures to meet the usual requirement for the permeability to be ${10}^{-7}\mathrm{cm}/s$ or less. This paper reports an investigation of the effects of long‐term permeation of inorganic leachate solutions on such liner materials. The effluent leachate was tested to determine changes in chemical composition (in particular pH, boron, and heavy metals) due to leaching from the liner. The inorganic solution had no detrimental effect on liner permeability; in fact, the permeability decreased over time. The main chemical change in the permeate solution is an increase in pH, because the fly ash is highly alkaline. This had the beneficial effect of precipitating the heavy metals within the liner, so heavy metals in the effluent were minimal. Overall, the use of compacted pozzolanic fly ash as a liner material appears to be feasible in terms of its physical properties and chemical attributes.

The performance of riprap with a slope on the order of 1.5:1 to 2.3:1 was evaluated at 14 different dam sites in the James Bay Territory in Northern Québec. The field investigations included gradation measurement at each site and have allowed a back analysis of the performance using the wave height experienced by the riprap since reservoir filling. The wave prediction method recommended by the U.S. Army Corps of Engineers in 1984 and the Hudson stability formula have allowed a back analysis in good agreement with the observed field performance for regular gradation riprap. For riprap containing a significant portion of fine material, the observed damage was always more severe than predicted using the median weight. The results of the study show that for steep slopes the inclusion of fine stones in the riprap is detrimental to the stability.

Experimental and theoretical studies on the effects of the coefficient of earth pressure at rest $\left(K_0\right)$ and overconsolidation ratio (OCR) on the uplift capacity of foundations in sand, with special reference to screw anchors, are presented. Previous contributions on the determination of $K_0$ and OCR are reviewed. Tests are conducted on prototype model screw anchor installed in dense, medium, and loose sands. The sand was placed according to a calibrated placement technique to achieve predetermined relative densities. Vibratory densification was used in compacting the sand, and this resulted in overconsolidated material. The stresses within the sand were measured by stress transducers inside the testing tank. Based on stress measurements, the values of the OCR were determined for all tested depths and sand types. Based on data reported in the literature, a semi‐empirical relationship was proposed to relate the uplift capacities of screw anchors installed in overconsolidated sand to those of anchors installed in normally consolidated sand. Good agreement was observed when present experimental results were compared with results of a theory reported in the literature after incorporating the effect of the overconsolidation.