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Evaluating the liquefaction capacity of saturated loose sandy and clayey soils is an important task to be completed in the course of implementing new construction projects in seismic areas. This article addresses the main characteristics and input parameters of three soil models, including HS small, UBC3D-PLM, and PM4Silt. The behavior of the "soil base–pile foundation–structure" system is examined by using these models to simulate the soil behavior during an earthquake. The results demonstrate the main differences between these models and draw attention to the importance of the choice of a soil model for seismic analysis, particularly when soil liquefaction is considered. [ABSTRACT FROM AUTHOR]

The influence of the geneses of disturbed soils on their mechanical characteristics and their changes with moisture content and compaction degree was studied on the basis of tests of technogenic ash and slag mixtures, sandy soils and clays. It was found that in terms of grain composition, strength and deformation characteristics, ash and slag mixtures occupy an intermediate position between sandy and clay soils but demonstrate several specific features, particularly concerning the influence of the water content on the angle of internal friction. [ABSTRACT FROM AUTHOR]

A series of large scale direct shear tests was performed to obtain the shear strength interface parameters for five different geosynthetic reinforcement materials in marginal clayey sandy soil. The performance of geosynthetic layers was evaluated at soil optimum moisture content (OMC) and high moisture content (OMC+6%) conditions. It was observed that the shear strength interface parameters dramatically decreased at 6% wet of optimum in comparison with optimum moisture content. Moreover, a comparison was made between the performance of different geosynthetic layers in a quantitative manner at target moisture content (i.e., OMC+6%). Based on the analysis of large scale direct shear test results, it was concluded that the geosynthetic layer, provided it has high drainage capability, could effectively increase the interface shear strength parameters at OMC+6% condition. [ABSTRACT FROM AUTHOR]

The standard penetration test (SPT) and Menard's pressuremeter test (PMT) are among the available in-situ techniques. This research has been carried out with the aim to develop correlations among the in-situ parameters obtained by both methods. [ABSTRACT FROM AUTHOR]

A solution is presented for calculation of the total settlement of a strip foundation with allowance for additional stresses, which develop in the region under consideration due to displacement of the loaded section of the boundary, and can be determined by solving the second basic boundary problem of the plane theory of elasticity for a half plane. Expressions for the strain components of the second basic boundary problem are presented in closed form, and formulas are derived for calculation of settlement due to a uniformly distributed load. Settlements of the bed, which is composed of sandy and clayey soils, are calculated. [ABSTRACT FROM AUTHOR]

A resonant method for determination of the absorption coefficient, which characterizes the damping properties of soils, is developed for implementation of computer programs for analysis of dynamic interaction between structures and their beds. A series of experiments with sandy and clayey soils of various moisture content, density, and depth of embedment, which are based on investigation of the forced oscillations of these specimens and continued processing of resonance curves within the framework of notions of the linear theory of viscoelasticity of soils, are conducted. [ABSTRACT FROM AUTHOR]

A method of analyzing the strengthening of foundation beds with crushed-stone piles is discussed. [ABSTRACT FROM AUTHOR]

1. It is expedient to increase the weight of a tamper with given lower-surface dimensions and drop height to a certain limit, the excedence of which may lead to the development of shear strains and, correspondingly, to heaving and loosening of the soil around the tamper without a significant increase in the effect of its compaction outside the bounds of this zone. 2. In many cases, the weights of the single-mass tampers employed at the present time exceed those limiting values for which heaving and loosening of the surface layer of the soil is possible. In cases where dual-mass tampers are employed, the probability of the development of soil heaving and loosening is significantly reduced. The volume of tamped-in soil is 25-30% higher for a dual- than a single-mass tamper. 3. At a drop height of 8-10 m and 6-8 blows, a heavy-duty 10-ton dual-mass tamper may compact saturated sands at a depth of 4.5-5.5 m to a dense composition. [ABSTRACT FROM AUTHOR]

The studies that we conducted indicated that the actual bearing capacities of beds may differ significantly from those computed by traditional methods, which are based on experiments on sands compacted in layers. [ABSTRACT FROM AUTHOR]

1. In compacted dry and slightly moist sands and clays of different gradiation, density, and moisture content, the change in the density of the IR-radiation flux is proportional to the change in the sum of the three principal normal stresses in the specimen. 2. The thermoactivity coefficient of sand depends heavily on its initial density and moisture content, while the difference in the gradation does not affect this coefficient in our investigations. 3. For compacted sands subjected to unloading, hysteresis is virtually absent on the curve denoting the change in the density of the IR-radiation flux versus the change in the indicated invariant of the stress tensor. 4. The method of evaluating the stressed state of soil on the basis of the ΔW level makes it possible to perform noncontact and remote measurements; it can therefore be used to monitor the state of a soil subjected to variable and quasistatic loads. [ABSTRACT FROM AUTHOR]

An equation for calculating the depth of compaction of soils prone to slump-type settlement as a function of basic factors (the impact energy of the tamper and the area of its base) is cited on the basis of analysis of experimental data. [ABSTRACT FROM AUTHOR]