Numerous methods are used to measure the permeability of clays in laboratory and in situ. It is well known that these methods lead to different k values, but, until now, no comparison with the “real in situ permeability” has been carried out. In this paper a method based on the observation of pore pressure isochrones and settlement rates under embankments is proposed to determine the “real” in situ k value at various depths and at various times and strains. This method is successfully applied to the Berthierville test embankment where different permeability tests have been carried out. The results show that on this site: the “real” in situ permeability is slightly higher than the permeability obtained by direct measurement in laboratory; the coefficient of permeability deduced from $c_{\upsilon }$ values strongly underestimates the in situ permeability; and the coefficient of permeability measured with the self‐boring permeameter is representative of the “real” in situ permeability while the coefficient measured by means of pushed‐in‐place piezometers underestimates it.

This paper proposes a simple, practical method of three‐dimensional stability analysis for concave slopes in plan view using the equilibrium concept. The force equilibrium and the moment equilibrium conditions over failure mass are satisfied in the analysis. The results obtained using this three‐dimensional method show that the stability of concave slopes in plan view increases as the relative curvature radii $R_0/H_0$ decrease, and the influence of plan curvature on the stability of concave slopes in plan view changes when the lateral pressure coefficient of soil $K_a$ is different. When the ratio $R_0/H_0$ is relatively small, the slip surface passes not through the toes of concave slopes in plan view, but above them. Finally the results obtained through this three‐dimensional method for a straight slope under six different conditions are compared with the results calculated through six two‐dimensional methods.

A parametric study of elliptical tubes deeply buried in uniform elastic ground is reported. The static tube response is determined using both analytical and numerical methods for a range of tube geometries and ground and interface conditions. The structural response is evaluated for both rigid structures and structures that are flexible in bending. The solutions are presented in a series of figures, and a simple procedure is developed for calculating distributions of hoop force, bending moment, and radial deflection by means of simple hand calculations. An example problem is included to demonstrate the effectiveness of the simplified analysis.

Cyclic triaxial tests and cone penetration tests performed in large-scale triaxial samples are used to evaluate the effects of prior cyclic-strain history on the liquefaction and penetration resistances of a fine, uniformly graded sand. Prior cyclic-strain history is found to increase both liquefaction and cone-sleeve friction penetration resistance (f_s), but has no significant effect on cone-tip penetration resistance (q_c). This, in turn, suggests that cone-tip penetration resistance represents a somewhat conservation basis for evaluating the liquefaction resistance of sandy soils with beneficial prior cyclic-strain histories (prior seismic histories), and also has ramifications with regard to the reliability of soil classifications based in part on the ratio q_c/f_s in soil with prior cyclic-strain histories.

A procedure that allows for the influence of the greater soil-mass stiffness between piles is described for calculating group settlement interaction factors. For the calculation of the settlement of a pile due to the presence of an adjacent pile, a weighted average of the soil moduli near the pile and between the piles is used with the classical Mindlin equation of elasticity. This procedure leads to decreased interaction between piles, and therefore to smaller group settlement and more uniform distributions of load, than are obtained by the conventional analysis in which the soil-mass modulus is assumed to be equal to the soil modulus near each pile. When applied to a recent series of field tests, the modified procedure is found to predict the group performance more closely than does the conventional procedure.

Data on pipeline damage rates for several earthquakes has been compiled and correlated with various ground motion parameters depending on the intensity of the ground shaking. For transient, low-intensity ground shaking occurring at large distances from the actual faulting, both the ground velocity and ground strain have been correlated with pipeline damage. For the limited data set used, both parameters correlated well with the frequency of pipeline damage. Pipeline damage in a region of high-intensity ground shaking located near the surface expression of a fault is correlated with permanent vertical ground displacement measured after the earthquake. The results indicated a strong correlation exists between the rate of pipeline damage and permanent ground displacement. Limits on the applicability of the results and recommendations for further study are given.

Elastic stress distributions due to self-weight in embankments are analyzed with the finite element method (FEM). The results are compared with available analytical solutions. It is demonstrated that analytical solutions that assume biharmonic equation is invariant under conformal transformations render significantly lower stress distributions than the FEM results.

The limitations of the compression index $C_c$ as an indicator of soil compressibility are demonstrated and the usefulness of the relationship $C_c$ = 0.007(LL. - 10) is questioned. (Note: LL = liquid limit.) Using experimental data from three soil groups of widely differing properties, it is shown that soils having the highest values of $C_c$ and LL are not necessarily those of the highest compressibility. The parameters CR [+$C_c$/(1 + $3_o$)] or $m_v$ are better indicators of compressibility and peak values of these parameters do not coincide with peak values of $C_c$. The plasticity index, or position on the plasticity chart, is shown to provide a more reliable guide to soil compressibility than the liquid limit.