On the example of the room in the large-pane building the nature of distribution of temperatures indoors from local sources of the fire is analyzed. With the Fire Dynamics Simulator (FDS) program are constructed isosurfaces of temperatures that allowed tracking the movement of heated air indoors. It is considered the influence of high temperatures on pliability of connection in vertical joints of external panels taking into account uneven distribution of temperature on is considered. It was revealed that the high-temperature effect up to 980С in the considered period of time 120 minutes leads to an increase in the pliability of the butt connectors by (82-84) %. The received results allow estimating extent of influence of the lowered strength characteristics of concrete, in a consequence of high-temperature influence, on pliability of discrete communications.

The paper studies the effect of variability in the structural parameters of the joints of columns of frame buildings using tub welding on the reliability of the connection. The main design positions are given and the parameters that determine the bearing capacity and reliability of the joint are identified. We obtained the coefficients of ponderability parameters in the calculation of reliability. An assessment of the reliability of the joint with the correction of the values of the construction parameters specified by the characteristics of the normal distribution was carried out. To analyze the ponderability of the parameters, one of the probabilistic calculation methods was used - the linearization method of the original function. The main objective of the study is to identify the most significant structural parameters of the joints for managing reliability, assessing the impact on reliability of changes in the values of the probabilistic characteristics of the calculated strength and geometric parameters of the junction of columns. The study found that not all parameters of the joints equally affect the probability of structural failure and, ultimately, the reliability of the entire structure. The greatest weight of all the construction parameters in determining the reliability of the joint has the strength of the concrete monolithing. The calculation of the reliability of the joint on the design values of the probability characteristics of parameters without taking into account the load variability showed that the reliability index exceeded the recommended standard value. During the assessment of the impact of the correction of the probability characteristics of the construction parameters, it was found that the reduction in the probabilistic mean of the column cross section parameters has a significant effect on the reliability of the joint, which requires strict consideration when assessing the technical condition of the frame building.

In this article, we study the dynamic support reactions that occur in a two-span bridge farm, due to the impact on the superstructure of the moving load. The most interesting is the study of horizontal support reaction. Both the span and the moving structure are deformable elastic systems. The interaction forces between the rolling stock and the span structure are obtained by solving a contact problem. For numerical modeling, the method and the corresponding computer program developed at the Department of Structural Mechanics were used. The method of solving the equations of motion is based on an explicit integration scheme with extrapolation according to Adams. When obtaining the results of the solution, the internal friction forces in the material were taken into account using the generalized Prandtl model. The results obtained allow us to conclude that, under vertical action, the horizontal support reaction reaches very significant values.

Given a new constructive solution of precast-monolithic platform butt joint panel stand-frame and the disk overlap panel buildings, Otley significant feature of which is the presence of a special centering device to improve the accuracy of installation of the panels-frames. Given the estimated model of the design of the junction and the analysis of the stress-deformirovannogo status of this design at various levels of loading with nonlinear deformarea-tion and cracking. A special method of "jointing" of plane-stressed finite elements along the boundaries of these elements was used to model cracks. The analysis of deformation, crack formation and destruction of the considered structure of the platform joint is carried out. It is shown that the proposed version of the computational model with the task of explicit cracks-cracks "jointing" allows to predict the scheme of the platform joint development.

The article provides a comparison of the values of the reduced geometric rigidity of elliptic sections with free torsion of a rod, obtained using exact and approximate solutions. The exact solution is presented depending on the geometric argument - the form coefficient, and the approximate solution - in the form of a linear relationship, which approximates the known exact solutions using the geometric argument - the ratio of conformal radii (internal to external). The results of the comparison showed that an approximate solution gives an error not exceeding one percent in the range of ratios a / b <6 (a and b are ellipse semiaxes). The possibility of presenting the desired solutions in the form of dependencies on geometric arguments allows us to extend the prospects of using the interpolation method both in terms of the shape factor and the ratio of conformal radii.

This paper consider in depth the size effect and its influence on the shear resistance of beam elements without transverse reinforcement, as well as the approaches to take into account the size effect, based on the provisions of the fracture mechanics. The results of comparison of shear resistance models against the background of experimental data and verification of the influence of the size effect are presented. Based on the verification of the resistance models, this paper presents recommendations on the account of the size effect and the impact on the target value of the reliability index of structural elements.

The advantages of building a tunnel from lower sections through the Nevelskoy Strait are considered. The problem of increasing the impact of the rolling stock on the tunnel design when critical speeds are achieved is described. t is noted that in weak soils the critical speed is determined by the speed of propagation of Rayleigh surface waves. In the course of the work, it was noted that when critical speeds are reached, a significant increase in the dynamic impacts on the soil foundation is possible. A technique for calculating the tunnel for determining the critical velocities using the Fourier transform and the theory of residues is presented. An example of determining the critical speeds of the load movement using the presented methodology is considered. It is concluded that, at present, the critical speeds of the movement of the load are achievable

Analytical dependencies for determining of the parameters of the static-dynamic deformation diagram of RC elements of structural systems due to crack formation are given in the article. The moment-curvature dependence is assumed to be bilinear for bending non-tensioned and prestressed, as well as eccentrically loaded structures. Nonlinear deformation sections are assumed to be parallel for non-tensioned and prestressed structures. An algorithm for determining of the dynamic curvature in RC elements for the considered loading condition with the use of the dependencies is given. The results of the numerical analysis of the parameters of the static-dynamic deformation diagram are given using of a two-span three-story frame the beam of which are reinforced with two-way prestressed reinforcement.

The issues of industrial waste disposal are one of the priorities of the environmental policy of the regional authorities, in the territory of which enterprises produce fabricated raw materials. In addition, the reduction in the reserves of traditional raw materials makes us look for new ways to replace it with various types of waste. The construction materials industry, unlike other industries, has unlimited possibilities of using waste, which is explained by the large scale of the construction complex, its materiality and the range of different products. In the present work investigated the possibilities for using the tonnage of waste: waste of energy ─ slag material and nanotehnologija carbonate sludge in the production of ceramic bricks based on rare ─ beidellite clay. The resulting ceramic bricks had high physical and mechanical properties. For the production of bricks as a binder and burning additives used ash-slag material Togliatti TPP. The presence of fine carbonate sludge in the raw material makes it less sensitive to drying, i.e. reduces the cracking of bricks. The presence of nanoscale particles in the system increases the volume of adsorption and chemisorption bound water and reduces the volume of capillary-bound and free water, which leads to an increase in the plasticity of the ceramic mass and a reduction in the clay binder in the compositions of ceramic masses. Developed innovative proposals for the use of multi-tonnage waste in the production of ceramic bricks, the novelty of which is confirmed by a patent of the Russian Federation.

The article covers various aspects of the use of materials with a changing phase state in the envelope building structures for energy and resource saving. Such materials are used to control the microclimate in buildings (in cooling or heating systems) and in the building structures since they are able to absorb excess energy and subsequently release it in the event of energy shortage. The building envelope structures using materials with a phase transition accumulate the solar radiation energy during peak temperatures in the daytime and consume it at lower temperatures, which reduces energy consumption and improves a thermal comfort by smoothing temperature fluctuations in the room, reducing and/or shifting peak loads. The article treats the classification and properties of materials with a phase transition, methods and results of their integration into the building materials and structures based on a detailed review of scientific publications abroad. It was found that the climatic operating conditions significantly affect the efficiency of materials with a phase transition in the envelope structures, while their operation at predominantly negative temperatures for walls has virtually not been studied and is of interest for further research. The article shows the temperature and energy values of phase transitions for more than 300 brands of commercial materials with a changing phase state.

Flask is a strong porous siliceous sedimentary rock. Recently, it is increasingly used as a sorbent and as an additive to building materials. An important technological process for obtaining the product is crushing, sowing, calcination and so on. All of them are accompanied by the release of dust. This dust can be a pollutant of the air environment, waste, etc. The article presents the results of experimental and field studies of aerodynamic and physico-chemical characteristics (sedimentation rate) of dust flask Volgograd field. A scheme of the process of dedusting sorbent production in the field of water supply and sanitation and additives from flask in construction is proposed. The experiment was conducted, the installation and the method of data processing were described. Built the cumulative distribution function of the mass of the dust particles of the flask at the dia-meters of the probability-logarithmic coordinate system for the entire ensemble of particles and for particles of different speeds of deposition.

In the buildings, where reinforced concrete floor slabs are subjected to the action of aggressive liquid environment due to the technological process, reinforced concrete structures have small remaining life and technical condition of them is close to inadmissible one, that causes necessity of repair works or reconstruction. Instrumental inspections of the precast reinforced concrete flat floor slabs under the action of lactic acids show, that slabs have numerous defects and damages: deep corrosion of rebars and concrete, failure of support ends of the slabs. The main elements of floor slabs are in bounded functional condition or inadmissible condition at the parts The constructive solutions on reconstruction of the floor slabs by construction of a new slab are suggested. These solutions consider technological loading on the floor, stability of columns, rigidity of a building frame during the construction, change of a floor level.