Journal of Geotechnical and Geoenvironmental Engineering

Damage to piles supporting structures, bridge abutments, and utilities can occur as a result of the construction of nearby embankments. This is because the lateral displacements resulting from these construction activities can induce forces and moments in the piles. The resulting stresses can be significant particularly when soft soil deposits are present and the lateral soil displacements are large. This paper describes a simplified numerical procedure based on the finite-element method for analyzing the response of single piles to lateral soil movements. The flexural bending of the pile is modeled by beam elements. The complex phenomenon of the pile-soil interaction is modeled by hyperbolic soil springs. A framework for determining the soil parameters for use in the analysis is summarized here. Comparisons are made between the observed behavior of full-scale tests and centrifuge model tests and those computed by the proposed numerical method. Based on parametric studies, empirical design solutions for pile foundation systems at the base of a sloped embankment are presented.

This paper presents a theoretical procedure for analyzing the lateral response of vertical piles subjected to lateral soil movements. The lateral pile response is computed via a simplified boundary-element analysis, using a specified free-field soil movement profile. For pile groups, the group effect may need to be preassessed via a finite-element analysis. Based on an appropriate assessment of the lateral soil movement, soil Young's modulus and limiting pile-soil contact pressure, the present method can generally give a satisfactory prediction of the pile response, as demonstrated via a study of some model tests and published case histories. For practical convenience, some elastic solutions have been generated using the present boundary-element program and are presented in chart form. These design charts tend to give an upper-bound estimation of the maximum pile bending moment and pile head deflection, although a close estimation may be obtained for small soil movements.

This paper deals with slope stability in a oddly behaved, expansive, overconsolidated, stiff Tertiary clay of S$ão$ Paulo, Brazil. The properties were not fully recognized until a recent major failure occurred during excavation on a 26-m-high, 250-m-wide slope constructed for the new Carvalho Pinto Motorway. A comprehensive site investigation was carried out and involved laboratory and in situ tests and successfully employed the Marchetti dilatometer. Back analyses of failures showed two different mechanisms, one leading to shallow failure in tertiary clays owing to expansion, followed by surface degradation or slaking. The other mechanism was lack of shear strength in the clay to resist stresses imposed by a high and steep slope. This paper gives site investigation data, discusses the causes, and back analyses of failures, and presents the final slope design.

The technique of reinforcing soil for foundation improvement is well established. This paper addresses the aspect of settlement of reinforced sand foundations, where the major part of the existing work deals with the aspect of bearing capacity. A detailed analysis is made paying individual attention to soil, reinforcement, and the interface between the two. A three-dimensional, nonlinear finite-element analysis is presented that uses a three-dimensional, nonlinear soil-reinforcement interface friction element, along with other three-dimensional elements to model the system. The results of the analysis are compared with those from tests conducted in the laboratory and are found to be in good agreement. The studies lead to a better understanding of the behavior of the system at different stages of loading.

Extreme-value statistics for the maximum depth of soil freezing are developed based on model-derived soil freezing estimates for the northeastern United States. The model used is shown to be quite accurate at estimating the annual maximum depth of soil freezing using only daily air temperature, snow depth, and precipitation data. These data are available from a relatively dense network of climatological observing stations, permitting the development of a regional climatology of extreme soil freezing levels. The performance of a suite of theoretical probability distributions for representing the resulting distributions of extreme soil freezing depths is also investigated, and the Gumbel distribution is chosen to provide the best regional representation of soil freezing extremes. The results suggest that maximum soil freezing levels within the northeastern United States are found across eastern Maine and north-central Pennsylvania. South of these areas, freezing levels decrease because of warmer temperatures, while to the north decreases in the depth of maximum soil freezing can be attributed to deeper and more persistent snow cover. The results provide physically based information for establishing building codes that rely on soil freezing information.

A series of dilatometer test profiles were carried out in a calibration chamber on Toyoura sand using a standard blade and a special research dilatometer. Pluviated sand samples were prepared using various combinations of boundary conditions, relative density, and stress history. The research dilatometer probe consists of a standard blade modified internally to allow monitoring of the complete pressure-displacement soil response during a test. Precise performance of small unload-reload cycles can also be performed to evaluate elastic deformation properties. The pressure-displacement response during the expansion tests clearly shows the influence of stress history and density. The stiffness of the Toyoura sand from both dilatometers were also compared to that measured in laboratory monotonic shear tests and to various empirical relationships. The results suggest that the moduli measured from the unload-reload cycles during the research dilatometer tests reflect the elastic properties of the soil and can be correlated to results from resonant column tests and monotonic torsional shear tests. Modulus values measured with the standard dilatometer are more representative of an elasto-plastic response.

Test foundation walls were constructed in an area of planned subsidence. These crawl space-sized block bearing walls were located in the tension zone of a longwall panel. The test walls were 12.2 m (40 ft) long and were vertically loaded on top with soil bins to simulate the weight of a house. As the longwall proceeded past these test foundations, subsidence movements damaged the test structures. These damaged foundations were then structurally and aesthetically repaired by using a steel strap retrofit and applying a cementitious surface coating. The repaired test foundations underwent significant subsequent subsidence as an adjacent longwall was mined beneath. The response of the repaired foundation is summarized in this paper. The steel straps were also used to relevel another set of the test foundations after they were tilted and damaged by subsidence. First, the straps were applied to the block bearing walls, and then wall jacks were used to lift the upper portion of the walls to a level position. This releveling procedure is outlined with the results.

Retaining walls that do not move are customarily designed based on the assumption of at-rest conditions, with no consideration of vertical shear loads applied by the backfill. However, field and laboratory measurements have shown that vertical shear loads do act on nonmoving walls. A simple theory for calculating the magnitude of vertical shear loads on nonmoving walls is presented in this paper, and typical results from the theory are discussed. A companion paper presents the results of finite-element calculations, case history data, and recommendations for retaining wall design.

Massive concrete walls constructed on rock foundations, as well as other nonmoving retaining walls, are customarily designed for at-rest earth pressures. Vertical shear loads applied by the backfill are usually not considered in design of nonmoving walls, even though many field and laboratory measurements have shown that such loads exist. Vertical shear loads can be very beneficial for stability of retaining walls, because they provide restoring moments to counteract overturning moments from lateral earth loads. In this paper, model test results and case history data are reviewed, the results of finite-element calculations are presented, and a simple design procedure is developed. It is shown that significant economies can result from consideration of vertical shear forces in design of nonmoving retaining walls.

This paper presents measurements and results of three centrifuge experiments that model the uplift loading of a constrained footing by the frost heaving of a layer of freezing, saturated silt. The experiments were performed at different scales to investigate the validity of scale factors predicted for small-scale frost heave modeling. The working hypothesis was that the developing frost heave forces measured in the different models should, using the predicted scale factors, scale to the same full-scale response. Results from the tests support this hypothesis and provide an indication that the centrifuge modeling technique is applicable to frost heave loading of structures.