Cyclic simple shear testing is considered to be one of the most appropriate ways of reproducing in the laboratory the stresses that would be experienced by an element of soil in level ground subjected to earthquake loading. The main drawback in cyclic simple shear testing concerns the lack of complementary shear stresses on the specimen vertical boundary. Therefore, a selection of the proper specimen size, i.e., proper diameter versus height ratio, must be carefully considered. To investigate the specimen size effect on the primary dynamic (cyclic) soil properties, namely the shear modulus and damping, a large‐scale simple shear apparatus was constructed. In it, specimens having diameters from 3–12 in. and heights from 0.25–4.0 in. could be tested. Thus a wide range of diameter to height ratios could be obtained. The paper presents a comprehensive study of the effect of the specimen size on the cyclic properties of dry sand tested in such an apparatus at different strain levels, vertical pressures, void ratios, and number of stress cycles. From this study, the size of specimens that would provide cyclic properties that are independent of size were determined.

A comprehensive experimental study has been completed to study the effect of specimen size on the cyclic properties of dry sand: namely, the shear modulus and damping in a large‐scale simple shear apparatus. The tests were performed on three different specimen diameters, 3, 6, and 12 in., while the specimen height varied from 0.25–4 in. to have diameter to height ratios of 12, 9, 6, and 3 for each diameter. In this paper, an ideal size of soil specimen in cyclic simple shear testing that produces results independent of the specimen size is presented. Formulas relating the cyclic properties and the specimen size were developed. In addition, formulas and charts for correction factors were developed to correct the properties obtained from simple shear testing of specimens having sizes other than the proposed ideal size.

The strength of a marine sand is investigated by means of cone penetration tests and plate load tests, and by measurement of the resistance against penetration by the steel skirts underneath a gravity platform. Several methods are used to interpret the test results and to evaluate the angle of internal friction, $\varphi \prime \text{.}$ Probability methods are used to analyze the uncertainty about $\varphi \prime$ due to spatial variation in the data and model errors in the equations used for interpretation. It is found that different methods of interpretation give different values of the internal friction. The correct value of $\varphi \prime$ cannot be determined with certainty because the errors in the interpretive models are not well known. Hence, subjective opinion is introduced as a means of exercising the engineer's judgment. Bayesian updating is used to combine the results obtained by the different tests. The methods illustrate how the various uncertainties may be combined to arrive at the most likely value of the angle of internal friction and the uncertainties about that value.

The “ideal sampling approach” (ISA) for elucidating, formulating, and predicting minimum disturbance effects in deep tube samples of saturated clays is proposed. The ISA relies on approximate solutions based on the strain path method to incorporate tube penetration disturbances. Laboratory test results on normally consolidated Boston blue clay indicate that the ISA provides more realistic predictions than the existing perfect sampling approach and that tube penetration disturbances are significant in “undisturbed” tube samples of soft clays obtained by means of existing thin‐walled sampling techniques.

Loads applied at the ground surface may have a significant effect on culverts and buried pipelines. A semi‐analytic procedure is developed to estimate the response of buried tubes to surface loads. The procedure can be used to predict distributions of hoop force and bending moment in the buried structure, as well as radial and circumferential deflection. The solution makes use of one geometrical approximation to simplify the analysis. The validity of the approximation is established through comparisons with elastic finite element solutions. Techniques for analyzing tubes buried in embankments and trenches are considered.

Monotonic and cyclic torsion shear and cubical triaxial tests were performed to study the influence of rotation of principal stress directions on the behavior of $K_0$‐consolidated clay. The stress‐strain and pore‐pressure relations were clearly affected by stress rotation. Strength and pore‐pressure developments occurred faster in monotonic tests without stress rotation, but the effective friction angle was not affected by initial $K_0$‐consolidation or stress rotation. In cyclic tests, two‐way stress rotation produced more rapid degradation, higher pore pressures, and larger strains than in tests with one‐way stress rotation and tests without stress rotation. Monotonic tests after cyclic loading showed that the effective stress failure condition was not influenced, but the stress‐strain behavior was affected by hardening due to cyclic loading.