The results of an experimental study of the strength of reinforced concrete beams with rigid reinforcement are considered. The nature of the stressed state and fracture along oblique sections is established. Stresses in the wall of the steel profile reached the yield point. The stresses in the lower flexible armature did not reach the limit values. The joint work of concrete and rigid reinforcement was observed up to the exhaustion of the bearing capacity of the beams. The stratification of structures on the contact of concrete and the steel profile was not observed. The appearance of critical inclined cracks was observed at a load of about 80% of the fracture. The method of transferring the external load and the varying span of the cut did not affect the character of the cracking and fracture of the samples. The destruction of the prototypes of the beam elements occurred along oblique cross sections under the 45 ° hole. The recomendations for determining the pushing forces are given.

A mathematical model of a dynamic process in a loaded beam on an elastic Winkler foundation with the sudden formation of a defect in the form of a change in the boundary conditions is constructed. The solution of the static problem of bending of the beam clamped at the ends serves as the initial condition for the process of forced vibrations of the cantilever beam initiated by a sudden break in the links that impede the movement of one of the end sections of the beam. The effects caused by the sudden transformation of the calculated scheme of the loaded «beam-foundation» system for various combinations of mechanical and the geometric characteristics of the beam and the foundation are investigated.

It is proposed the program and methodology of experimental studies of reinforced concrete structures under the action torsion with bending. The main purpose is to check the calculation premises and to determine experimentally design parameters of the proposed calculation method. The program of experimental studies includes testing composite structures of beam and plate types. It was created a pilot installation for the experiment was specially at the Department of Unique Buildings and Structures of the South-Western State University. It allows to create a torque on the investigated sections of the transverse bend and it is able to extinguish it on the support in combination with static test circuits (without requiring special expensive devices). Particular attention is paid to the determination of the angles of rotation and deflections of the calculated cross-sections; schemes for the crack formation, crack development and opening of crack; for the deformation of concrete in difficult stressed areas of reinforced concrete structures under the action torsion with bending.

In the article the analysis of results of calculation of reinforce-concrete beam is presented on second group of the maximum states on home norms and Eurocode 2. Experimental data over are brought on bending of reinforce-concrete beam and width of opening of normal cracks. Experimental samples are presented - beams of rectangular cross section with dimensions of 10cm x 20cm and length of 220cm.Their comparative analysis is produced with the results of calculations on home norms and Eurocode 2. The curvature of the reinforced concrete element without cracks in Eurocode 2 is determined. Under operational loads, satisfactory convergence of the calculated values of the opening width of normal cracks is observed. The deviation is within 5%. Experimental values of the width of the opening of normal cracks on the entire range of stresses in the reinforcement are 1.2 ... 1.4 times lower than those calculated by domestic and foreign standards.

The purpose of this article is to present an approach for calculating exact critical buckling load of axially loaded column with generally defined semi-rigid end restraints (translational and rotational) with regard to convenient programming. The formulation of general boundary conditions to the buckling differential equation is explained and the corresponding matrix for finding eigenvalues (critical loads) is provided. A technique to account for absolutely rigid connections without the need to compute additional parameters and consider several end connection types, and as a result several matrices to include in programming, is demonstrated. The program composed in MATLAB environment was tested on five different cases with varying parameters of column length, flexural rigidity and values of translational and rotational stiffness of end restraints. The results of program computation (critical loads and K-factors) were contraposed to the results from FEM analysis, reference data and results from another scientific article. The results of comparison of computer program results, FEM analysis results and reference data showed relatively small deviation and none was observed for one available theoretical value from another article.

Complex studies of semi-real models of interaction of single and group of stepped piles in sandy and clay soils. The determination of the degree of compaction of the soil half-space around the surface broadening in the form of steps, followed by the development of an effective methodology for their calculation. Determination of the dependencies of the stepped piles deformation-strength characteristics. Experimental researches of single and group of stepped piles on static vertical loading and researches of interaction of piles with various types of soils were carried out. Results. In the course of experimental studies, dependencies of the deformation-strength parameters of the deep foundation work consisting of stepped piles were established. For stepped piles, the bearing capacity is increased as a result of the formation of a soil jacket around it, so that the maximum movement of the stepped piles is obtained when they are static loaded in wet loam, and in water-saturated sands the sediment of the stepped structures is 30-60% less at different stages of static loading than in wet loam; the sediment is 8 times smaller than the usual prismatic and 3-4 times smaller than the prismatic ones with surface widening from the prefabricated wedges.

The new estimation method of the seismic isolation of the whole nuclear power plant building and the vibration isolation method of structures will be introduced. This method has been developed by Professor E. Kurbatskiy. The method is based on the properties of Fourier transforms finite functions and gives opportunities to estimate effectiveness of different means of seismic protection. At present time the new production power-generating units of nuclear plant are under consideration in Russian Federation. One of the tasks of this problem is to create the structures that can be used in the high seismic activity regions. In many industrial areas there appears a significant problem of isolation from vibration caused by trains and different equipment. An inexpensive way of vibroisolation by placing granular rubber or polymer -soil mixtures around foundations can be of great benefit to the infrastructure protection. In recent years, the disposal of scrap tires has become a significant environmental problem. Utilizing rubber tires in earthquake hazard mitigation can be a viable approach of resolving the chronic problems associated with waste tire disposal and costly provisions for the earthquake and vibration protection of the infrastructure. Applications of artificial granular medium to vibration and seismic isolation are offered.

It is not always possible to establish unambiguous reasons for the appearance of damages in the construction structures of objects in operation. The consequence of this is the difficulty in formulating specific recommendations for the elimination of damages, conclusions about the possibility of further operation of the building. Often the causes of damage are not obvious, they are a consequence of the simultaneous impact of several, sometimes implicit, factors. To identify possible causes of cracks, mathematical modeling of the load-bearing structures of the underground reinforced concrete reservoir under load was carried out using the LIRA PC, and the stress-strain state of the walls of a monolithic reinforced concrete reservoir was studied. The possible causes of cracks and water filtration in the walls of the reservoir are considered and explained as a consequence of the combination of several factors: the nature of the load on the walls of the underground reservoir; violation of the technology of erection of monolithic reinforced concrete structures of an underground reservoir; corrosion of concrete and reinforcement of reservoir walls due to pressure filtration through them of ground (thawed) waters.

The article presents the results of investigations of the stress-strain state of a bent element in the anchoring zone of reinforcement on free end supports. Procedures for determining the length of anchoring of reinforcement for the inner edge of the support are outlined in accordance with domestic and foreign norms. Absolute anchoring lengths for d10-28 rods are calculated using concrete classes B10, B20 and B30 and reinforcement bars A400 and A500. The dependency curves of the required anchoring length are plotted against the types of materials used. Based on the results of the numerical experiment, recommendations are given on the refinement of design standards in determining the anchoring length of the reinforcement for the inner edge of the free extreme support. A simplified formula is proposed for calculating the length of a straight anchoring. The results presented in the paper can be used in the further development and editing of norms.

This article provides a comparative analysis of two different normative documents on earthquake engineering, one of which operates in our country and the other in Europe. For the calculation example and the comparative analysis of estimated 10-storey buildings on the seismic resistance of Russian and European normative documents. Based on the calculation results obtained and the associated strength and deformation characteristics, and the associated criteria for evaluation of seismic resistance. It is established that the European normative document imposes more stringent requirements on the seismic resistance of the building than the Russian. This follows from the calculation results of the considered building. Move along X and Y axes in the case of the European rules make it almost 4.5 times higher. The variation of the deflection of the slab above in 2 times in comparison with calculation in accordance with Russian standards. And the percentage of reinforcement of columns in the calculation according to European norms turned out to be 3.5 times higher than calculated according to Russian norms, and 1.5 times higher than the maximum permissible value.

The adopted dynamic load in the form of an instantaneous pulse, which is a design model of a high intensity load. Destruction of the concrete of the compressed zone leads to the appearance in the lower and upper armature of the longitudinal tensile force H and the design beam scheme becomes the cable system, in the case of ensuring the strength of the butt joints and sufficient anchoring of the reinforcement bars. Equations of motion of the guy with a constant longitudinal tensile force H are obtained and a corresponding dependence is adopted to move the cable. A method is proposed for evaluating beam structures when taking into account work in the elastic, plastic and in the deformation stage of reinforcement as a cable system. For the dynamic calculation of reinforced concrete structures for explosive and shock loads, methods are used in which dependences are given for determining the parameters of dynamic loads arising from explosions of various substances. Limit moments are determined with dynamic resistances of reinforcement and concrete.

Analytical relationships, which allow to determine the additional dynamic stressesin reinforcement of a reinforced concrete composite element at crack formation and abrupt structural alteration caused by abrupt failure of an element, subjected action of shear forces along the seam of the contact, are obtained. It is established that coefficient of additional dynamic stresses in the effective reinforcement for the two-component reinforced concrete structural element at abrupt structural alteration of the structural system depends on the percentage of reinforcing, prestress level and topology of the structure. It is necessary to take into account the dynamic additional coefficient for the secondary computational model (model, which appears after destruction of the load-bearing element of the system) at designing the protection of reinforced concrete structures against progressive destruction.

The process of creating the system architecture and town planning of space throughout the history of all eras, a daunting task of architects. When the detailed study of all architectural objects can be exploded into elementary components. But that doesn't mean that on the basis of practical knowledge, you can generate spatial Wednesday, an object with predefined quality settings. In addition to knowledge of the structure of the elements of the system of residential space, account must be taken of an important feature of the behavior of the system, namely the principles on which all too often, even dissimilar items may acquire quality integrity inherent in almost all biological and social systems. As a result of the conducted analysis, identified a number of common system for architectural and urban principles, in our view the most important of which are the principles of compactness, defining characteristics, the structure invariance. The set does not exhaust all applied to the field of architecture and town planning of general principles such as the principle of integrity, as well as the hierarchical structure of the feedback. Today, more and more, it becomes clear that in theory and practice of architecture-CCA Benno in urban planning as a strategic-level activity, Wednesday-there is a need for improving individual methods and methodological the concept of decision-making in General. This, in turn, moves to establish a methodological and basic human capacities, develop a system of ontological and mathematical models studied and designed facilities, training, informally know the methods optimization with the use of modern information and communication technologies and computing. Researched and proposed principles that apply to a specific task of the living Wednesday, will develop the system methods and models for the study of architecture and town planning objects.

In this paper, strength of adhesion between steel, glass-composite, basalt-composite rebar and foam concrete were studied by pulling the rods from the concrete samples. It is determined that the best joint work of rebar with concrete is coursed by application of the glass-composite rebar. The strength of adhesion between the glass-composite rebar and foam concrete В7,5 (D1400), В10 (D1600) is more on 20-45% than that between the steel, basalt-composite rebar and foam concrete for all combinations of strength classes and rebar diameters (Æ 6,8,10 мм). The strength of adhesion between rebar and foam concrete will increase, if the strength classes of foam concrete increases too. At the same time, the strength of adhesion changes the different way for steel, glass-composite and basalt-composite rebar with varying their diameters.

Recent tendencies in precast concrete industry include application of innovative materials like self-compacting concrete, fibre reinforced concrete, textile reinforced concrete, carbon concrete composite and strain hardening cementitious materials. By the application of non-metallic reinforcement, such as carbon meshes and carbon bars, there is no corrosion risk for the reinforcement resulting in an essentially lower concrete cover and depth of structural members. However, the use of carbon reinforcement requires new design concepts and new construction methods. By solving these problems there is a big chance for precast concrete industry to enhance their market share.