Analytic models and field data are used to develop procedures to evaluate the tolerance of brick‐bearing‐wall and small frame structures to the ground displacements that develop during opencutting and tunneling. The role of horizontal and vertical ground displacements are discussed and the effects of grade beams, building orientation and building location relative to excavation are examined. Case studies of structures adjacent to opencuts and tunnels are used to verify procedures for estimating potential for structures adjacent to excavations to sustain damage.

Most of the marine sediments in the continental margin are derived from terrestrial sources, but vast areas of the sea floor are covered with sediments that are unique to the ocean environment. A knowledge of the origin and composition of these sediments is very important for their classification. A new classification system is proposed for marine sediments based on the principles of soil mechanics and geology. The system can be used as an auxiliary to the unified classification system. Marine sediments are divided into three major groups: terrigenous; biogenous; and hydrogenous. Each group is then subdivided into various subgroups. The classification system incorporates new symbols, consistent with those of the unified system, for all marine sediments. A classification chart is provided, and numerous examples are cited to illustrate the application of the system.

Buried high voltage power cables generate heat when a current is passed through the conductor, and failure of the cable may occur if the conductor or insulation temperature exceeds the design limit. Thermal instability, a moisture migration phenomenon causing a decrease in soil thermal conductivity, has caused thermally induced failure of cables and may be a problem in the case of other buried heat sources as well. Thus accurate methods for predicting thermal instability are needed. Until recently, such problems have been mainly in the domain of electrical and mechanical engineers; however, geotechnical engineers are now frequently involved in the study of this problem. The Hartley and Black method, based on the assumption that the ratio of the time to instability to the diameter squared of the heat source is a constant for a given heat input rate, is investigated. Laboratory tests, scaled model tests, and field tests were used to provide a wide range in the diameter of the tubular heaters employed (1.6 to 406 mm). Based on data collected from scaled model tests, thermal instability was accurately predicted for a field test of three simulated cables. The influence of cyclic versus constant thermal loading on the thermal stability of sand was also investigated, and it was found that the time to instability was not a function of the method of loading for cycle times that are short relative to the time to instability.

A perturbation technique, the method of multiple scales, is used to obtain an approximate analytical solution of the nonlinear dynamic response of foundations on soils. The analysis takes into account the nonlinearity of the soil material, radiation, hysteretic and viscous damping, and the effect of embedment. Closed‐form expressions are derived for the response, which show clearly the effects of the various parameters involved in soil dynamics. A closed‐form expression is presented for the constant settlement of the nonlinear soil structure caused by the vibration. In addition to large responses accompanying primary or main resonances (the excitation frequency $\check{\Omega }$ is near the natural frequency of the foundation ${\omega }_0$), the results show that large responses can be caused by subharmonic excitations of order one‐half $\check{\Omega }\approx 2{\omega }_0$ and superharmonic excitations of order two $\check{\Omega }\approx (1/2){\omega }_0\text{.}$ Consequently, the practicing design engineer cannot afford to ignore these resonances.

The capability of filters to retain cohensionless base soils is studied through a combination of a physical model of soil particle transport and statistical analysis of laboratory data. It is found that the ratio DF15/DB85, which is the parameter used in Terzaghi's criterion, is the single most significant predictor of filter performance. A clear physical interpretation of this parameter is given. A second parameter, DB95/DB75, is also found to be significant. This parameter is related to the capability of the base soil to form self‐healing layers. Based on these findings, an improved design criterion is proposed, which takes into account both DF15/DB85 and DB95/DB75.

A series of full‐scale, cyclic, lateral load tests on instrumented piles of varying diameter at a test site in submerged, overconsolidated clay is described. A $p‐y$ model is derived from the tests that defines the effect of pile diameter, relative pile‐soil stiffness, and number of load cycles on the unit load‐deflection relationship for soil of the type encountered at the test site. The model is particularly well‐suited to large‐diameter piles. It reflects observations that there is a threshold deflection below which cyclic soil degradation does not occur and the consequences of the fact that degradation was primarily caused by gap formation, intensified by hydraulic scour. Rest periods between loading events did not result in recovery of soil resistance and in fact appeared to produce further degradation through swelling.

A magnesium montmorilionite and a kaolinite clay are subjected to organic and inorganic permeants to study the changes in permeability caused by the reaction between clays and permeants. The permeants are acetic acid, aniline, methanol, and xylene. Tests are conducted in specially designed and constructed flexible wall permeameters that provide precise measurements of pressures and flows. Increases in clay permeability due to clay‐permeant chemical reactions are measured to be on the order of two to three times the original permeability. This is in contrast to the 100 to 1,000 times increases reported by others. The writers believe that the large increases reported by others is probably due to the use of fixed‐wall permeameters. The writers' results show that methanol doubles the permeability of montmorilionite. Acetic acid reacts with the carbonates in montmorilionite and liberated carbon dioxide. The resulting loss of mass triples the clay's permeability. Aniline and xylene will not flow through saturated montmorilionite but will flow through saturated kaolinite at reduced flow rates. Hydraulic fracturing of the montmorilionite occurred when methanol passed through it under a high gradient and low confining pressure.

The skin friction mobilized along the shaft of driven precast concrete piles in dense calcareous sands was determined by field tests on two piles at one site in Kuwait. The results are compared with data obtained from tests on bored piles in the same soil deposit. Values are recommended for the skin friction of driven piles in dense calcareous sands with low carbonate content. These values are smaller than the corresponding values for clean silica sand.