This article presents the results of the experimental study of how the loading rate effects the strength characteristics of soft soils. As such characteristics, the shear strength of soil was used being equal to the magnitude of tangential stresses when the limiting state was reached. The magnitude of the shear strength is considerably dependent on the strain rate. The experimental determination of this dependence was performed using the method of dynamic penetration of an axisymmetric body into the soil. Along with that, a direct measurement of stresses acting tangential to the surface of the body during its penetration into the soil was effected. Experimental studies were carried out for the body being penetrated with the range of rates from 2 to 100 m/s. It has been found that within the range of rates from 2 to 10 m/s the magnitude of the shear strength of soil increases as the loading rate grows. Further, its magnitude starts decreasing and at the rate of over 95 m/s becomes negligible. This gives grounds to construe soft soils subjected to dynamic loading as a compressible liquid.

Keywords: limiting soil state, shear strength, soil strain diagram, strain rate, method of dynamic penetration, compressible liquid

The article deals with the specifics of the work to strengthen the foundation. Examples of the use of synthetic materials in the construction industry are given. The sediment of the embankment at construction sites with a different index of the modulus of deformation of the synthetic material was analyzed. On the basis of the above method of production, the possibility of forecasting an algorithm for the production of a construction site under the condition of various types of soils is manifested in the purchase of operating enterprises, organizations of new enterprises, redistribution of investments in the interests of organizing and developing new products in existing production areas.

Keywords: constructive solution, strengthening of soils, base, synthetic material, polymeric material, geotextile, mound sediment, deformation module, erection, ground

In the article there are results of modeling of the work of steel concrete screw and drilling piles interacting with the soil massif . For the purpose of modeling the mathematical apparatus of finite element method was used in realization of the license certified program complex Lira- soft v.10.6. The process of modeling of the subsidence is described. There is a presentation of three options of interaction of soil and piles. Draft magnitudes of single piles from external load and from negative friction forces are found.

Keywords: Steel concrete screw pile, drilling pile, soil massif, subsidence, Lira-soft, draft, deformations, movements, tensions

The paper presents the results of mathematical modeling of the behavior of a single conical bore injecting pile from the action of static compressive loads, as well as the effect of physical and mechanical characteristics of soils on its draft. The study was carried out by the finite element method in a nonlinear setting, taking into account the slippage of the soil along the contact surface of the pile. Comparative assessments are given on the example of the calculation of a single conical drilling-injection pile, and quantitative dependences of the effect of the characteristics of clay soils on its bearing capacity are shown.

Keywords: Conical bore injector pile, sludge, bearing capacity, clayey soils, nonlinear FEM model

Improvement of Method of Design and Limit Calculation by the 1st Limit Stability Case. Proposing Metod of Calculation for Ultimate Limit Stability and Deep Limit Calculation of Pit. Graphical building the Chart of Statically limited stressing field inside triangular with vertical edge, Jet Grouting Coloumn Body , wich were generated with help(using) Modified Preliminary Method of Assuming from V.V. Sokolovskii, in case assuming Limit Stabilities wedqe with internal friction and cohesion and wedqe with internal friction without cohesion. As resalt of this sume there is Limit Stability of wedqe with low Strength(Stability) characteristics. Receiving Solution is the basement for Calculation of Possible Deep of Pit.

Keywords: gruntiest, jet grouting, strength characteristics, stress-strain state of the Foundation soil allowable stress field, the stability of the fence of the pit, plane strain, ultimate load, external load, approximate method

The methods of calculation of tense and deformed state of loessial collapsing soil grounds subsiding loess soils under the influence of long-active compactive loads at their incomplete water saturation as elastoviscoplastic environments. The determining equations are based on hereditary type current theory taking into account the bulk, shear plastic deformation, dilatancy phenomenon, different values of form making creep cores and all-round compression. The soil is isotropic environment. The increments of stresses are composed of viscoelastic and visco-plastic components. The algorithm is performed using solutions of iterative techniques and finite element method and includes solutions of linear-elastic, elastoplastic and elastoviscoplastic tasks in the definite sequence. Physical and mechanical properties, dependences of the stress and strain on the time at different values of humidity and soil compaction pressures are determined in the laboratory. Use of the reliable mathematical models of the base, taking into account the creep deformation at the design on the loess subsiding soils under conditions of incomplete water saturation contributes to reliability of the erected construction projects.

Keywords: loessial collapsing soils, creep, elastoviscoplastic environments, calculation methods, hereditary type current theory, rheological models, calculation methods, finite element method, iteration process, soil tests

The article presents the project design to strengthen the foundation reinforcement to soils through the gaps arranged at the discharge cementogenesis solutions. Also describes development work at the construction site, which allowed to adjust the project and reduce the cost of consolidation.

Keywords: Reinforcement, soil, comentaron, cementation, directional hydraulic fracturing, drilling, well, development work

In this article the territory of the city of Rostov-on-Don is considered and engineering-geological conditions for the purpose of construction of buildings and constructions on a monolithic base plate of small laying are analysed. The schedule of dependence of the limit module of deformation on pressure under a base sole is constructed. The analysis of engineering-geological conditions in the city of Rostov-on-Don is made, and also the map and the chart of distribution of the average module of deformation in his territory are made.

Keywords: the average module of deformation, extreme draft of a subfoundation, pressure under a base sole, a monolithic base plate

To preserve the historical integrity of the city it is necessary to use individual approach to reconstruction in strict accordance with the rules of land use and development. Analysis of the housing stock the Central part of the city of Rostov-on-don was produced using data from the monitoring of its technical condition and showed that the Central part of Rostov-on-don residential buildings of old buildings, low rise and an unsatisfactory technical condition, proves the need for a comprehensive reconstruction. Over the past five years in the Central part of the city the construction of high-rise buildings in area of historic buildings, leading to disruption of its historic appearance.

Keywords: reconstruction of the urban environment, the construction of high-rise buildings, the violation of the historic appearance, information-analytical system utilities, GIS database, land use and development

The soil reinforcement via the directed gaps arranged at the discharge cementogenesis solutions, widely used in construction on subsiding soils. During the development of the project strengthening of soil foundations, using the method of directional hydraulic fracturing can be applied in various constructive schemes of reinforcement of foundation depending on the foundation type, ground conditions and tasks. The article describes the method of quality control of cement soil and also shows its application in the production of works to consolidate the base of the building.

Keywords: Reinforcement, soil, cement soil, cement grouting, quality control, directional hydraulic fracturing, drilling, well

The paper discusses the influence of geometrical parameters of tapered CFA piles in their settlement. The results of calculations of single CFA piles by finite element method under static compressive loads in clay soils . A comparative assessment of the effect of the length and angle of the side surface of the conical faces CFA piles on her draft. The example shows the effect of the angle of inclination and length of piles on their draft, as well as compares with precipitation cylindrical piles of similar material intensity.

Keywords: CFA conical pile, bearing capacity, settlement, finite element method

Features of a site of construction of constructions of seaport of Taman are considered. The settlement scheme of influence of new construction of point of loading on an existing complex of tanks is proved. The final and element model of a coastal zone with an arrangement of underground designs of existing and port constructions under construction is constructed. Results of calculation intense the deformed condition of the soil massif and construction designs are given.

Keywords: the pile bases, the soil basis, modeling, a deposit, intense the deformed condition.

The article describes the experience of the device of pile foundations under the multi-storey building in difficult engineering-geological conditions in Rostov-on-don

Keywords: Drilling piles, test, conductor pipe, sandconcrete, foundation

 A significant part of Rostov region and North Caucasus regions of the built-over territories according to its settlement consists of I and II type loess soil.
     The author develops a method for optimal parameters determination of the stabilized loess bases under the influence of different factors (loads, emergency steeping, ground waters level alteration etc.). Selection of optimality criteria depends on the applicable method of technical melioration. Determinative limitation is the calculation upon the II group of limit states. Application of non-linear mechanical and mathematical models for calculation of structural and unstable soils upon deformations is recommended.
     Silicification stabilizing of loess soils is almost impossible at the filtration coefficient of K<0.1 m/day.
     Characteristics of the fixed massive depend on soil moisture level, injection mode, density of sodium silicate solution, time of injection and volume of solution.
     Determinative conditions for the possibility of soils injection stabilizing with cement or other solutions are the following: geometric criterion (cement particles size and soil pores size, determined by the active openness), solution viscosity in relation to density, injection pressure, water-cement ratio, filtration coefficient. The most common pores in loess soils are active pores of 20 micron diameter, quantity of which comprises 20-50% of total soil openness. Solution-conductive (active openness) are the pores of more than 0.01 mm at size.
     Selection of stabilizing method depends on the form of the stabilized area.
     The author, basing on variation principles of mechanics of constructive and non-linear systems and theory of adaptive evolution of mechanical systems, developed determination method of rational form of the stabilized basal complex. Specific feature of the developed model is increasing of bearing capacity, stability and location of stabilizing area with more specific accuracy level within soil. To detect stress-deformed state in bases of buildings and constructions there are elaborated programs in APDL languages in the ANSYS software environment.  

Keywords: loess soil; method for optimal parameters determimation; form of the stabilized area;theory of adaptive evolution of mechanical systems; ANSYS software environment

We consider two different manufacturing techniques developed screw piles ACSYS. The order of devices of this type of piles. Describes the advantages of the pile ACSYS in comparison to other existing precast, vibrodent and rammed piles. Marked features of work in a structurally unstable soils.

Keywords: screw pile, AXIS, subsiding soils, screw, load capacity, screw skvazhinoobrazovatel, besklinkernom binder, vent soil liner

The questions of definition of subsidence by different methods. Points out the defects in the regulations and the factors that must be considered when determining the subsidence in the laboratory. The results determine the subsidence of its own weight of soil, obtained by different methods.

Keywords: subsidence, flooding, filtering, warping, base

Consider the problem the interaction of conical punch with soil base. A scheme of partition the study area into finite elements, The formulation problem, boundary conditions, allowing the equation. Presents some results the calculations.

Keywords: conical punch, foundation, base, axisymmetric problem, stress, displacement.

The article investigates the deformation characteristics and screw piles. Presented the procedure of production models piles and preparation of test rig. Results are given trough experiments performed in the laboratory. 
Keywords: screw pile, pile drilling, soil, foundation bearing capacity, settlement, testbench.

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