The design of buried pipelines in areas of vertical ground movement is governed, in part, by the magnitude of the forces imposed on the pipe and the displacements at which they are developed. An experimental study of these effects, dealing in particular with the influence of soil density and depth of burial, is described. The results compare well with several published models for medium and dense sand, but measured values of uplift resistance are much lower than predicted for loose contractive sand. A simplified procedure that can be applied to the design of buried pipelines is given.

The results of an experimental program to assess the response of buried pipes to lateral ground movements are presented. The effects of pipe depth, soil density, pipe diameter, and pipe roughness are considered, and test results are compared with published analytical models and experimental data. The results indicate the need to consider vertical equilibrium in predicting the horizontal response of buried pipelines, and the data agree well with several analytical models that include this effect. Pipe surface roughness was found to have little effect on response. Soil density has a large effect on displacements required to mobilize the maximum force but a relatively small effect on the value of the residual force at large displacements for depths typical of transmission pipelines. The study concludes with a simplified design procedure for predicting pipeline response to lateral ground movements.

A major slide occurred in the upstream slope of the Lower San Fernando Dam immediately following the earthquake of February 9, 1971. Previous analyses of this slide have been based on evaluation of seismic shear stresses and the results of cyclic triaxial tests. These previous analyses fail to explain several key features of the slide. The re‐analysis presented herein, which is based on the concepts of liquefaction, steady state strength, and flow slide stability analysis, and on the data obtained during the previous analyses, is consistent with the principal features of the observed slide. The estimated in situ undrained steady state strength is substantially lower than the undrained strength measured in conventional laboratory tests due to the sample densification that normally occurs during sampling, handling, setup, and consolidation of loose sandy soils. An interpretation of the limited data on undrained strength available for the San Fernando Dam indicates that the soils that liquefied had very low undrained steady state strengths.

The Strain Path Method provides an integrated and systematic framework for elucidating and predicting pile foundation behavior, interpreting in situ tests, assessing sampling disturbance effects and, in general, approaching “deep geotechnical problems” in a consistent and rational manner. This article describes the fundamentals of the method and presents solutions for the effects of quasi‐static undrained penetration of piles, cones and samplers on the deformations and strains in saturated isotropic clays. Procedures to determine penetration stresses and pore pressures and extensions of these solutions in an approximate form to more realistic conditions (e.g., anisotropic clays and drained penetration in sands) by means of the Strain Path Method are outlined. Estimates of undrained soil distortions due to sampler penetration indicate the necessity of reevaluating standard sampling and laboratory testing procedures utilized at present to estimate the in situ behavior of foundation soils, especially in the cases of soft clay deposits.

This study presents procedures with which one can predict the equilibrium water content, in-service, of a clayey pavement subgrade. Mercury intrusion and pore-size distribution of a specimen of the soil at the in-service fabric are utilized to establish the soil moisture characteristic curve. The procedures are relatively quick, reasonably routine, and reproduceable. Predictions are believed reliable for sites where the soil water suctions are in excess of 500 cm (16 ft) of water depending upon the soil.