The influence of surcharge and submersion of sand on the uplift performance of a single helical screw anchor is presented. An experimental investigation is conducted on shallow anchors installed in dense dry and submerged sands subjected to a surcharge intensity of 7.35 kN/m². Test results are compared to those of anchors installed in sands with free surface. The application of a surcharge on the sand surface results in an increase in the uplift capacity of shallow anchors. For both dry and submerged sands, the contribution of the surcharge to the uplift capacity decreases with the increase of the embedment depth of the anchor. A normalized factor is established to express the applied surcharge in terms of the acting overburden pressure. Nondimensional equations of the parameters affecting the uplift capacity and the intensity of the applied surcharge were proposed. It has been shown that the negative effect of submersion on the anchor's pullout capacity can be offset by applying surcharge on the sand surface.

A general method is presented for the prediction of earthquake‐induced permanent deformations of foundations resting on sand. Predictions arebased upon experimental results from common static and cyclic tests; they may take into account various boundary and drainage conditions and require reduced computational effort. The method uses and further develops previous work aimed at the prediction of permanent drift of offshore foundations due to the action of ocean waves. The basic concepts of the method are presented in detail, with emphasis placed upon the introduced improvements and modifications. The versatility of the constitutive laws used to describe permanent strain accumulation in the sand is demonstrated through comparison with data from cyclic laboratory tests. The overall accuracy of the method is evaluated on the basis of actual field observations and experimental measurements.

An analytical approach has been developed to predict permanent settlements of foundations subjected to earthquake shaking. The validity of this approach is evaluated through comparison with results from centrifuge tests simulating the response of a tank foundation resting upon saturated sand and subjected to earthquake‐like shaking. Analyses are carried out for different values of soil permeability to back‐calculate the in situ permeability of the sand and demonstrate the effect of partial drainage. Good correlation exists between predicted and measured response for in situ permeability within the range of laboratory measured values. The results also demonstrate that partial drainage may occur even during high‐frequency dynamic loadings, with significant effect on settlements and excess pore pressures.

Smear effects due to the installation of prefabricated vertical drains were studied in the laboratory using special equipment and in the field using a full‐scale test embankment. The prefabricated vertical drains were installed by two different sizes of mandrel. The test results showed that the smear zone can be assumed to be twice the equivalent mandrel diameter and the horizontal permeability coefficient in the smeared zone, $k_h^{\prime }\text{,}$ was approximately equal the vertical permeability coefficient in the undisturbed zone, $k_v\text{.}$ A faster settlement rate and higher amounts of compression were observed in the small mandrel area than in the large mandrel area, suggesting lesser smear effects in the former than in the latter. The total settlement prediction using the method of Skempton and Bjerrum of 1957, with stress distribution using Poulos's 1967 method, yielded reasonable agreement with the observed values. More accurate settlement‐rate predictions can be obtained using Asaoka's 1978 method when the prediction was based on settlement data having at least 60% consolidation.

A comprehensive set of dimensionless graphs of complex‐valued dynamic interaction factors versus frequency is presented for vertical, horizontal, and rocking harmonic excitation at the head of each pile. These readily applicable graphs have been developed with a rigorous analytical‐numerical formulation for two idealized soil profiles (a homogeneous half‐space and a half‐space with modulus proportional to depth) and three pile separation distances (3, 5, and 10 pile‐diamcters). A wide range of values has been parametrically assigned to pile slendcrncss and pile‐to‐soil stiffness ratios. The results are discussed at length to gain valuable insight into the nature of dynamic pile‐soil‐pile interaction. Gcotcchnical and earthquake engineers can use the presented graphs exactly as they use the classical interaction factors for static deformation analysis of pile groups.

A series of strain‐controlled model pressuremeter tests were performed in cohesive soils inside a calibration chamber. Stress disturbance was introduced by unloading or preloading surrounding soil prior to the pressuremeter expansion. Pressuremeter tests with variable strain rates were also performed without the stress disturbance. The chamber testing technique enabled these tests to be conducted under highly controlled and repeatable conditions. Comparisons were made with $K_0$‐triaxial and oedometer test results of the same clays. The study shows that the initial shear modulus and undrained shear strength are sensitive to both strain rates and soil disturbance. The influence of these two factors depends on the stress history of the soil and mode of stress disturbance. This paper describes the results of the chamber pressuremeter tests and discusses the practical implications of the study.

Nearly all limit equilibrium‐based computer programs for slope stability analysis are able to search for the critical slip surface and the associated minimum factor of safety. However, the vast majority of these programs use relatively inefficient search routines. A structure is developed to enable a more robust search algorithm—the simplex method of Nelder and Mead—to be readily incorporated into any existing limit equilibrium‐based slope stability program. An application is provided to illustrate that the simplex‐based search algorithm is accurate, efficient, and quite reliable. Extensions to other problems in geotechnical analysis and design also are described.

Simulations of construction of a 40‐ft‐deep braced excavation in saturated clays in Chicago have been made using a coupled finite element formulation. Surface and subsurface ground movements, pore water pressures, and sheet‐pile deflections are measured throughout construction at the site and are compared to results of the simulations at key stages of the excavation. The finite element simulations closely modeled all phases of construction including sheet‐pile installation and the actual duration of construction. Computed sheet‐pile deformations agreed quite well with those observed throughout all stages of excavation and bracing. Soil deformations, ground surface settlements, and pore pressures agreed reasonably well with observations until an incipient shear surface developed within the soil mass as the unsupported height of the wall reached as much as 19 ft. Parametric studies assess the importance of modeling the sheet‐pile installation, the effects of different types of assumed constitutive responses, the impacts of assumed boundary conditions, and importance of closely modeling the actual construction process. The importance of the available resistance of the soil on the passive side of the excavation in controlling ground movements is demonstrated. Anisotropy is a factor that must be considered when evaluating potential ground movements associated with a proposed excavation through soft to medium clays.

The generalized expressions for the finite and infinitesimal strain components in the spherical and cylindrical polar coordinates have been derived. These expressions are then used to determine the strain components for both incompressible and compressible soils during plane strain conditions and cone penetration. The analysis for strains developed during dummy cone penetration in loose to medium‐dense Edgar sand is performed using displacements measured by the stereo technique. The circumferential strains computed for Edgar sand match those derived for loose Chattahoochee sand. There is a certain depth below which the pile or cone penetrations can be treated as deep penetrations. This depth varies with the relative density of the sand and increases with increase in the relative density. In shallow cone penetrations, the surface of the sand is free to heave, and therefore particles tend to return to their original positions when the tip has penetrated deeper than these particles. In deep penetration, the overburden pressures are significant and do not permit any heave at the surface.