Том 53, № 4 (2016)

An idea of B.N. Dostovalov’s to represent a mass of frozen soil, prior to its failure, as an elastic brittle body is considered. An analytical estimate is provided of the temperature field and thermoelastic stresses occurring in the near-surface layer as a result of sudden atmospheric cooling. The principal parameters of primary frost cracks are calculated. An analysis is presented of their dependence on mechanical and thermophysical soil properties and baseline data.

The contact problem is examined of the effect of torque on an annular plate lying on an elastic layer. The practical analog of this problem is the problem of determining the tilt of a high-rise structure resulting from wind load. The problem is solved using the Ritts and orthogonal polynomial methods. Results are presented of calculations of annular plate rotation angles in response to torque.

Determination of the bearing capacity of bed soil using the finite-element method is often undertaken by seeking a critical load value under the assumption that the solution to a system of equations converges. This approach does not always provide a satisfactory result when studying the spatial interaction between sliding soil and retaining structure piles. The proposed criterion for assessing the limit slide load on a pile under the assumption that soil is kept from passing between piles or flowing around individually standing piles is based on an analysis of relaxation stresses in soil when the slide load is dynamically applied.

Results of static pile tests using the static cycling quick-load test (SCQLT) and Osterberg (O-Cell) methods are presented.

A procedure and results are examined for experimentally studying the seismic stability of sandy soil in the bed of a developed high-rise building in Kazan’ city. It is shown that the studied soil are not susceptible to fluidification in response to expected seismic events, although in certain of these, development of large additional deformations is predicted, which should be taken into account in design.

Based on Biot’s theory of saturated porous media, the propagation of Rayleigh waves in nonhomogeneous saturated porous media is studied. The frequency equation of Rayleigh waves in inhomogeneous saturated porous media is derived in which the variation of shear modulus is taken into account, and the existence conditions are also given. It is pointed out that the shear modulus of the material parameters is a function of depth via a theoretical derivation, and the final expression of the solid skeleton and fluid displacement in the medium is obtained.

A process aspect of installing bored situ-cast piles-the cleaning of widened borehole sections and its impact on the pile bearing capacity in slightly moist clay soil-is examined. Results are presented of field static tests on bored situ-cast piles fabricated using both the manufacturing process and installed in boreholes after they have been completely cleaned of drilling waste. A significant divergence is established between design and experimental values of soil resistance R under the pile, which suggests a need to update SP 24.1330.2011.

Prefabricated vertical drains with vacuum preloading is widely used in accelerating consolidation of dredger fill. Based on the property of ultra-soft soil and engineering demands, this paper proposes a 3D drainage system comprising a new-type drainage. First, the structural features, working principle, and construction technology of the 3D drainage are explained, and field test at dredger fill treatment project is used to verify the feasibility of the method. It is found in the field test that in contrast to the traditional plastic sheet drains, the 3D drainage system reduces the duration of vacuum preloading by 50% and increases the soil vane shear strength by 30%, producing good test results.