Anti ice build-up method on small railway culverts

One of the most important problems with the small railway culverts operation is the ice build-up on the inlets of these structures. This problem is universal in occurrence, but the northern regions are the main danger zone. The objective of this paper is to determine the phenomenon causes and factors that directly affect it, as well as to find a way to solve the problem. A small culvert is considered as a subsystem of the «Road/Railroad» system, which allows us to execute complete analysis and description of the technical and special production processes accounting related to design, construction, maintenance, scheduled, overhaul, as well as reconstruction, and solution of some problems, during the culverts operation. Consistently considered reliability issues during structural engineering: functional, structural, and informational. described Regulations that allow determining the nature of the ice build-up problem on pipes. In the analysis process of the existing methods for solving the problem, it was found that each method has its particularities, but in the end, is ineffective. According to the methodology presented by the authors, under Professor’s Yu.L. Scheviev supervision, has been developed a completely new approach, that provides effective financial resources use, in relation to the work result during the entire object’s life cycle, in form of a long structure operation period with the elimination of the ice build-up problem possibility. Technique application leads to a sharp decrease in the technical work frequency at small culverts. The paper analyzes a detailed algorithm for using the technique based on the calculation of a small culvert with a circular cross-section.

Free vibrations of a thin-walled curvilinear section of an oil-trunk pipeline during ground laying

In this article authors obtained solutions to determine the ground curved sections free vibrations of thin-walled large-diameter pipelines with a liquid flow, based on a geometrically nonlinear version of the semi-momentless toroidal shells medium bending theory by V.Z. Vlasov and V.V. Novozhilov. The pipeline is a toroidal shell, the design scheme is presented in the form of a half torus. Angle β = 1800. The shell is laid on an elastic foundation and makes contact with the ground along a narrow strip. The problem of the soil pressure influence on the shell along a narrow strip is solved as a contact problem, using Fourier's series and an impulse function. The shell is exposed to the cooperative effect of the internal operating pressure, the liquid flowing pressure, the elastic soil foundation, and changes in the geometric characteristics. Motion equations of the middle shell surface are obtained taking into account the geometric and mechanical characteristics, and all the components of the shell material inertial forces. The hinged fastening of the shell ends is taken as the limiting condition. Using the semi-momentless shell theory assumptions, displacements in the longitudinal and circumferential directions are obtained. The solution to the problem of determining the free vibrations comes down to solving the problem of determining AB matrix values. The solutions obtained make it possible to determine the free vibrations frequencies at various wavenumbers values in the longitudinal and circumferential directions, and also make it possible to determine the internal operating pressure contribution, the soil bed coefficient, and geometric characteristics to the pipeline free vibrations frequencies.

Interaction peculiarities of a single unit bored pile with the surrounding rock mass under the horizontal load effect

Interaction peculiarities of a single unit bored pile with the surrounding rock mass under the horizontal load effect, as well as loss mechanism of piles bearing capacity, are considered. The article presents the numerical modeling results and a method developed on their basis for calculating piles in rocky soils under the horizontal load effect under the spatial elastic-plastic problem conditions, with the account of the contact behavior between the pile and the rock mass. The study of the single unit bored pile interaction and the surrounding rock mass under the horizontal and moment loads effect was carried out based on the numerical models’ analysis of the piles and the surrounding rock mass in a spatial setting using the finite element method. The use of regression analysis methods made it possible, to obtain parametric equations, based on the numerical modeling obtained results, that connected the studied response functions (bearing capacity and horizontal displacement of the pile) from preselected independent factors reflecting the geomechanical properties of the body and the design piles peculiarities. The developed calculation method allows at the preliminary design stage to estimate the horizontal pile displacement value, as well as its bearing capacity. Also, using the proposed technique, it is possible to make a piles load test schedule, which can be used in the field observation preparation at the design stage. The relevance of the topic is due to the fact that in modern construction practice, bored piles are used to transfer to the foundation significant loads, on the rock foundation from structures for various purposes, including transport (bridges and overpasses piers’ foundations, etc.).

Design peculiarities of pipeline support on landslide slopes

The pipeline construction in complex engineering-geological conditions requires a thorough initial data analysis, as well as complex slope modeling using modern software systems. The article discusses the features of the foundation construction for stand-alone supports for power lines and pipelines on landslide slopes composed of clay soils. Relevant Russian regulations documents administer above-ground pipelining, which significantly complicates the design process. However, above-ground pipelining allows monitoring the slope condition (formation road edge breakaway), foundations (deviation from the design location), as well as the pipeline (displacement of the route axis, the state of welds). Timely detected deviations allow avoiding an emergency situation. The author considers possible options for constructive solutions for support foundations, as well as protective structures exemplified by a real Krasnodar Krai object. The pipeline construction in active landslide displacements conditions, as well as the presence of seismic effects, requires not only ensuring the construction's economic feasibility, but also the work safety. In the developing process of optimal design solutions, slope computer modeling was executed both in two-dimensional and three-dimensional formulations based on the finite element method using the Plaxis 2D and Plaxis 3D programs. The considered design situations made it possible to take into account the worst load combinations possible during pipeline operation. According to the calculation results and a comprehensive engineering and geological conditions study at the site, as well as the construction organization peculiarities, a block diagram has been developed that makes it possible to determine the optimal design solutions for protective structures in relation to any landslide construction site.

Experimental studies of the energy dissipation processes at the tops of fatigue cracks in the elements of bridge structures

In the article, the authors investigated the possibility of using the thermal control method for diagnosing fatigue cracks in the metal superstructure, determined the necessary parameters for that control method. The studies were conducted during cantilevered steel samples fatigue tests simulating the superstructure beam wall operation, reinforced with stiffening ribs. To carry out the experiments were developed a test setup and a loading procedure at the various intensity of exposure. An electric motor with eccentrics is used as a loading device. The sample surface heating was recorded by thermal imagers with 0.03 K and 0.05 K temperature sensitivities and 60 frames/s and 9 frames/s shooting speed, respectively. Was confirmed the possibility of determining crack presence before its emergence to the surface namely at the stage of its initiation, and also were determined the self-heating zone dimensions at the tip of a crack. The conducting a laboratory experiment technique on the dissipative processes study in the metal superstructure elements is described.

Heat setting system development of bridge floor surface using low temperature geothermal energy

Multilevel transport interchanges play a decisive role in the road infrastructure both throughout the world and in Russia. Significant problems of the safe operation of multi-level highways in the general metropolitan traffic system and the country territory, in general, are associated with the need to thoroughly clear them of snow and ice during winter and off-season periods. The simplest, most obvious, and historically proven non-mechanical ice control method is using the chemical reagents mixtures. Despite the fact that the quality of the original anti-ice chemical products is constantly being improved, the reagents composition is updating, the target operation remains unchanged — a decrease in the ice and snow melting temperature point. Unfortunately, in the process of melting with heavy snowfall, the concentration and, accordingly, the brine viscosity increases, leading to «oiling» of the asphalt pavement, thereby worsening the already difficult situation on the road. One of the attractive ways to keep the roadway in proper condition is to heat it to get rid of ice. Direct heating methods such as central heating or electric heating are too costly and economically unfeasible. It seems promising to use low-temperature geothermal energy, which will significantly reduce energy costs and increase the transport projects’ economic attractiveness. This work is devoted to the study of the practical applicability of the bridge floor surface heat setting technology using low-temperature geothermal energy as part of the «Best available technologies» concept implementation in accordance with GOST R 56828.15-2016 in terms of infrastructure facilities energy efficiency. Based on the work results, the authors provide the study results and numerical modeling, as well as their comparison. The results presented in this article are a part of the dissertation research «New technological solutions development for the bridge floor surface at transport interchanges» Kostenko S.А.

Structured asphalt binder is a new binder type in asphalt concrete mixtures

The data presented in the article are part of disserta-tion research on the formula development and pro-duction principle of composite material for road con-struction with phosphogypsum and secondary poly-ethyleneterephthalate use. The article provides an assessment of the existing most successful and effec-tive technologies for creating asphalt concrete pave-ments with high technical performance characteris-tics, and the key role in formula is an asphalt binder on the binary system mineral powder/oil road bitu-men basement, their main advantages and disad-vantages are described. A new technological method for the asphalt concrete mixtures production is de-scribed - pelletization by rolling, which was proposed by the authors. The paper presents the study's results to determine the structured asphalt binder technical and operational properties obtained by the method of pelletization by rolling. A brief theoretical substantia-tion of the physicochemical nature of improving a number of developed composition technical and op-erational characteristics of a structured asphalt binder is presented. The dynamics of over time changes in the main structured asphalt binder indicators, from 2005 to 2019, are given. It has been theoretically proven that in a structured asphalt binder obtained by the method of pelletization by rolling, bitumen is in a film state, and the bitumen interlayers thickness be-tween the mineral powder particles is of the order of 100 nm, which makes it possible to classify the prod-uct as a nanomaterial and determines its special properties set. The data of independent and our own experimental studies are also presented, indicating the previously obtained theoretical justification correct-ness for increasing the strength indicators, improving the water saturation indicators, and the water re-sistance coefficient. The absence of negative changes in the main technical and operational properties dy-namics for 14 years confirms the possibility of storing the mixture in a cold form outside a sealed package in an unheated room, which makes it possible to assert the possibility of preparing material for future use and transporting it over unlimited distances

Structured asphalt binder is a new binder type in asphalt concrete mixtures

The data presented in the article are part of disserta-tion research on the formula development and pro-duction principle of composite material for road con-struction with phosphogypsum and secondary poly-ethyleneterephthalate use. The article provides an assessment of the existing most successful and effec-tive technologies for creating asphalt concrete pave-ments with high technical performance characteris-tics, and the key role in formula is an asphalt binder on the binary system mineral powder/oil road bitu-men basement, their main advantages and disad-vantages are described. A new technological method for the asphalt concrete mixtures production is de-scribed - pelletization by rolling, which was proposed by the authors. The paper presents the study's results to determine the structured asphalt binder technical and operational properties obtained by the method of pelletization by rolling. A brief theoretical substantia-tion of the physicochemical nature of improving a number of developed composition technical and op-erational characteristics of a structured asphalt binder is presented. The dynamics of over time changes in the main structured asphalt binder indicators, from 2005 to 2019, are given. It has been theoretically proven that in a structured asphalt binder obtained by the method of pelletization by rolling, bitumen is in a film state, and the bitumen interlayers thickness be-tween the mineral powder particles is of the order of 100 nm, which makes it possible to classify the prod-uct as a nanomaterial and determines its special properties set. The data of independent and our own experimental studies are also presented, indicating the previously obtained theoretical justification correct-ness for increasing the strength indicators, improving the water saturation indicators, and the water re-sistance coefficient. The absence of negative changes in the main technical and operational properties dy-namics for 14 years confirms the possibility of storing the mixture in a cold form outside a sealed package in an unheated room, which makes it possible to assert the possibility of preparing material for future use and transporting it over unlimited distances.

Resource planning of the railway facilities construction technological process with the use of an artificial neural network

The article is dedicated to theoretical and practical research in the resource planning field for the railway facilities’ construction technological process using artificial neural networks. The study is a part of the subsystem in the development of railway construction engineering and technical maintenance — engineering and technical maintenance of railway facilities construction technological process. The subsystem is based on the effective automated systems use with elements of artificial intelligence. This is caused by deviations occurrence from the target requirements during the technological process implementation, due to the railway construction stochasticity, and the need for a prompt revision of the already made decisions. The existing methods allow us to correct the construction work organization, however, the technology remains unchanged, which is dictated by the design documentation and the work safety requirements. To give technological process flexibility in order to adapt to work changing conditions, it is necessary to provide an operational solution to the resource planning problem. The existing resource planning methods peculiarities, the current problem dimension, and the need to take into account a number of restrictions allow us to use artificial intelligence tools. In this regard, a methodology and a railway facilities construction technological process resource planning (labor, technical) computational-logical model with the artificial neural network use were developed. This approach is based on the lack of precise algorithmic actions or rules that can provide the desired result without formal complications. Also, the author has developed a special software module, prepared a data sample, an artificial neural network topological structure, and implemented an algorithm for its training, configuration, and testing. Based on the theoretical research and software module application results, the article presents the practical aspects of resource planning for the railway roadbed flooded embankment erection technological process.

Effect of the anchors' free length that made of tubular screw rods on the forces distribution in pile-anchor retaining structures on highways

Pile-supported retaining structures are widely used to protect road sections from landslide processes. The article describes the design and calculation peculiarities of pile-supported retaining structures reinforced with a drill and inject anchors from tubular screw rods. The authors considered two options for this type of anchors setup: without free length and with a pre-set free length. In the software geotechnical complex Plaxis, on the finite element method basis, mathematical modeling and calculation of a pile-supported anchor retaining structure with different free anchors lengths from tubular screw rods for various soils types have been performed. Numerical relationships have been obtained between the anchors' free length and the resulting forces in the retaining structure. The performed calculations series of the test scheme showed that with an increase in the free anchors' length in the retaining structure, there is a decrease in the applied load in its load-bearing elements due to the horizontal displacements growth. The article presents the survey results of a real road section, on which a landslide displacement is being prepared, and considers a design solution for a pile-supported anchor retaining structure to ensure its safe operation. Performed a series of calculations for various landslide process development stages in this area showed that the effect of the anchors' free length also largely depends on the state of the adjacent soil mass. Obtained results clearly show that the design of a free length section for anchors made of tubular screw rods makes it possible to design more cost-effective pile-supported anchor holding structures without reducing their reliability.