Transportation Soil Engineering in Cold Regions, Volume 2

The technology for restoring a damaged road system is critical for reaching victims and reconstructing damaged areas in large-scale natural disasters caused by earthquake and tsunami. Soil reinforcement technology with geocell materials can be useful in the above situation. This technology has been applied to road construction on soft soil ground, and its usefulness has been recognized. However, its reinforcement mechanism has not been investigated adequately. The current design method for geocell mattress under vertical load is based on classical pavement engineering and not on the actual mechanism of geocell reinforcement. Further technical investigation is required to achieve the rational design and construction of geocell mattress. The authors have developed a visualization technique for geocell mattress by using particle image velocimetry (PIV) analysis. The results obtained in the current stage are as follows: (1) mixing of colored sand with laboratory fill material is useful in visualizing the bearing capacity model test with PIV analysis. This paper proposes a method to determine the mixing ratio of two types of sand by conducting basic calibration tests. (2) This method can be used to visualize the behavior of soil confined by the geocell through a laboratory model test. This paper reports the results of the visualization.

The current standards for the effective pore diameter in geotextile materials both in Russia and in other countries have been determined by the techniques using natural sands of certain composition. However, particles that fall into geotextiles from railway ballast differ in form from natural sands. Thus, the existing requirements for the diameter of geotextile filtration passages need to be corrected. The calculation methodology for determining the possibility of colmated layers in sands is described. The requirements for the size of geotextile filtration passages preventing them from colmatage and ensuring the preservation of their filtration properties within the required limits throughout the standard service life are presented. In case of non-compliance with the requirements for sands, colmated layers will occur in them, which will lead in pumping.

This work presents the results of experiments carried out to investigate the potential application of the technology of railway track alignment: “stoneblowing”. In this technology, ballast stones are injected into gaps of the ballast bed beneath sleepers. Despite potential benefits, this technology has a limited application. In order to understand the performance of the ballast aligned by stoneblowing and to develop maintenance procedures, we conducted series of experiments at the Experimental Railway Ring in Shcherbinka, Russia. It was found out that the railway track, aligned by stoneblowing and flat reinforcement geogrid, showed better track stability in vertical plane in comparison to the track aligned only by stoneblowing. Finally, railway tracks aligned by stoneblowing techniques proved to show good results under high loads.

The purpose of the conducted model tests was to study the possibility of using a number of design solutions with geosynthetic materials to increase the bearing capacity and reduce the deformability of the sub-base, as well as to evaluate the effectiveness of their use. Small-scale modeling tests were conducted to investigate the stress–strains behavior of embankment reinforced in the upper part with geosynthetics. A series of model experiments have shown that an increase in the number of geosynthetic layers does not significantly effect on the roadbed bearing capacity. Reinforcement in a single layer is sufficient if the geosynthetic has required strength.

Mechanically stabilized layers have rather good potential for the application in construction of transport structures in cold regions. But determination of mechanical properties, which could be used in practice, remains still quite problem both theoretically and practically. The paper describes a new approach how to solve that problem. Presented method, it is a combination of laboratory experiment and inversion FEM modelling. The approach is called mechanistic-experimental. The experiment should be in scale 1:1 and should provide data of at least two independent parameters so that FEM model could be calibrated by iterative inverse modelling accordingly. Then mechanical properties like deformation modulus, Poisson ratio and minimum initial shear resistance of mechanically stabilized layer (composite like) could be determined. The real laboratory and FEM model are described and discussed. The paper is a continuation of earlier published papers (Rakowski in Procedia Eng 189:166–173, [1]; Horníček and Rakowski in Mechanically stabilized granular layers an effective solution for tunnel project. Springer Nature America Inc., New York, [2]; Rakowski et al. in The applicability of recent mechanically stabilized granular layer concept in ME pavement design. Springer Nature America Inc., New York, [3]).

In accordance with the objectives of the study, the program of works provided for stamp tests of ballast reinforced with geomaterials. The need for stamp tests is primarily due to the lack of reliable data to assess the impact of geomaterials on the stabilized railway ballast deformability. Thus, the main purpose of the stamp tests was to study and evaluate the impact of different geomaterials types on the crushed stone deformation properties in different reinforcement variants in a wide range of operating loads.

Nowadays, the use of the geosynthetics in infrastructural projects is a well-known practice, which has shown its advantages worldwide. Market demands as well as technical challenges have led to the development of a wide range of geosynthetics made of different raw materials, in particular, polymer-based materials. This paper focuses on the properties of geosynthetics, made of polyester-terephthalate (PET), which are relevant to their performance in cold regions. In different researches and publications, it has been concluded that some of the main mechanical properties of polymeric geosynthetics, such as stress-strain behavior, including tendency to creep, change if the same material is exposed to different temperatures. The awareness of the properties alterations at different temperatures is indispensable for designing geosynthetic reinforced structures safely and efficiently. With regard to design procedures which are generally calibrated for areas with moderate climate, it allows to come up with more cost-effective solutions by taking into account the temperature regimes of the geosynthetic reinforced structures. The paper shows the dependency of the properties of PET-geosynthetics to different temperatures and indicates its potential utility.

The paper describes the technology of mechanically stabilized layers in road structures. Special attention is paid to weak soils extreme cold regions Theoretical approach to the application of MSL technology in such conditions supported by practical experience is presented. Special attention is paid to the distribution of load through the mechanically stabilized layer. There are described examples of structures where the influence of parameters and structure of mechanically stabilized layers are demonstrated. By proper selection of the structure, the performance of the road can be essentially influenced. Recommendations for future development and widen application are formulated.

The article presents numerical modeling techniques, calculations, and recommendations for rational roadbed structures in the zone of permafrost and soft soils in the independent railway line construction areas that are in the zone of influence of the constructed reservoir in the Far East Federal District of Russia, taking into account constructional measures that reduce the intensity and uneven deformation of the defrost base. The usage of a geomaterials in the structure allows to lessen considerably the volume of expensive hard mineral volcanic filling of high quality. Numeric modeling of the structure behavior was done using a programming geotechnical complex, an “FEM model.” This allowed to give a quantitative and qualitative assessment of freezing and thawing processes in conditions of annual cycle construction.

One of the most important issues of the foundation design for overpasses of high-speed railways is consideration of soil strata heterogeneity (along the track line) influence on differential foundation soil settlements. The possibility of their limiting is directly related to the degree of conformity of predictable (calculated) and actual (obtained) values of foundation soil settlement. The purpose of the article is to optimality substantiation of using the predetermined soil settlement criterion (deformational calculation method) for the design of foundations for overpasses of high-speed railways, because this method allows decreasing the values of differential soil settlements to minimum. The following research tasks were solved: experimental studies on deformation of soil under the model of a shallow foundation (the model tests); comparison of experimentally measured and calculated soil settlements using the deformational calculation method and the numerical simulation; comparison of experimentally measured and calculated soil settlements using the proposed method and the most common approximate (“engineering”) methods; economic efficiency substantiation of the deformational calculation method. Based on the obtained results, the proposed method can be considered as promising for solving problems associated with the design of foundations for overpasses of high-speed railways.

In this article, we consider the problem of thermal response of the near-surface ice-rich permafrost to the effects of linear infrastructure and current climate change. First, we emphasize the scientific and practical significance of the study and briefly describe permafrost conditions and related hazards in the study area. Then we present a mathematical model which accounts for the actual process of soil thawing and freezing and consists of two nonlinear equations: heat conduction and moisture transfer. Numerical calculations were made to predict temperature and moisture conditions in the railroad embankment, taking into account solar radiation, snow cover, rainfall infiltration, and evaporation from the surface. The numerical results indicate that moisture migration and infiltration play the primary role in the development of frost heaving and thaw settlement. During winter, the frost-heave extent is monotonously increased due to pore moisture migration to the freezing front. Strong volume expansion (dilatation) is observed near the surface of the active layer with the onset of the warm season and meltwater infiltration. Settlement of the upper layers of the soil occurs in the summer months (June–August) when there is intense evaporation due to drying. Autumn rains stop the process of thaw settlement by increasing the soil moisture. The above processes are repeated cyclically every year. A “frozen core” shifts to the shaded side of the embankment under the influence of variations in the solar radiation. Over time, the total moisture content of the frozen core is increased which increases differential heaving and negatively affects the stress–strain state in the embankment. The quantitative and qualitative characteristics of the processes of frost heaving and thaw settlement are obtained in the annual and long-term cycles.

Frost heaving is a challenge for geotechnical engineers who deal with transportation infrastructure in a cold climate. To make a frost heave forecast and access reliability of soil masses engineers apply different numerical soil models calibrated by results of in-situ and numerical simulation tests. The recently developed frozen/unfrozen soil model by PLAXIS bv and NTNU was used for reproduction of laboratory and field tests data. The model describes frost heaving as a function of frost front moving rate and water migration rate from unfrozen zone and has 25 parameters: 7 general ones, 12 parameters that are responsible for solid strains, 3 parameters responsible for suction strains and 3 ones that account for coupling effects between the variation of the solid phase stresses and the cryogenic suction. The results of oedometer tests of silt in the unfrozen and frozen states and frost heave tests, presented in the article, allow us to obtain such parameters as initial segregation threshold value, elastic and elasto-plastic compressibility coefficients, rate of change in Young’s modulus with temperature. But we have to apply backward analysis in order to obtain a best-fit of simulated results with test results. Unfortunately, most parameters is to be obtained by only calibration method. Additionally, to validate the frozen and unfrozen soil model the results of geotechnical monitoring of the cold-storage building are used. The frost heave phenomenon was appeared for 29-years period of its operation. Results of in-situ monitoring and numerical simulation showed good correlation with depth of frost penetration but unsatisfied results of frost heave deformations.

In order to study the influence of shallow phreatic groundwater on the maximum frozen depth of the subgrade in the seasonally frozen region, this paper verified the applicability of the modified Berggren equation predicting the maximum frost depth based on the monitoring geotemperature and air temperature in stratum whether the shallow phreatic groundwater does exist. The shallow phreatic groundwater lowers the mean geotemperature, delays it to the extreme value, and reduces the maximum frozen depth in the cold season. The shallow phreatic groundwater lowers the surface freezing index, which makes the average surface n-factor smaller. The influence of shallow phreatic groundwater on the thermal diffusivity of the stratum is small but has a significant influence on the thermal conductivity. The slope of the modified Berggren equation is almost unaffected by shallow phreatic groundwater, and the applicability of the equation predicting the maximum frozen depth is verified based on the thermal conductivity calculation, no matter the shallow phreatic groundwater does exist.

The paper considers soil–transport structure interaction. Soil deformations, completely defining deformations of a road embankment, require an accurate prediction with a help of effective models of soil behavior, which take into account its non-linear and rheological behavior. There is given a visco-plastic model of behavior of soil of small and medium degree of lithification, which allows predicting development of deformations of transport structures in time. It is demonstrated that settlements of structures are defined not only by deformations of consolidation but also by deformation of form change. The authors implemented the soil model in the software complex FEM models, which is an import-substituting domestic production overtaking capacities of western analogs according to the speed of solution of non-linear and rheological problems. The paper shows the results of verification of the software for meeting the results of monitoring of a renown site of transport construction—the dam for protecting St. Petersburg against floods, which test grounds served for long-term investigations of the process of soil deformation under different draining conditions.

Representations in the field of mechanics of frozen and thawing soils require joint calculations: both thermophysical and stress–strain in a single calculation scheme. One of the criteria for assessing the reliability of the structure is to check the stability, the initial data for which are strength parameters. However, the process of transition from the frozen state to the thaw state entails a significant increase in moisture and, as a consequence, sharp decrease in strength, which gradually increases in the process of consolidation. Thus, in the calculations of transport facilities on thawing soils, it is necessary to take into account unstable strength parameters of soils in time and space. One of the methods of such accounting is the use of the type of behavior of undrained A soil models in PLAXIS software, working with the finite element method. The article describes an example of checking the design scheme when using this type of behavior based on the results of laboratory tests.

The quantity slope stability assessment is an organization based on the engineering, geological, and geophysical investigations’ analysis. The geomechanical slope’s models creation realized along with stability assessment for slopes in natural conditions and in conditions of one estimated geological element soaking and thawing. Morgenstern–Price, Bishop’s method, and Janbu’s method were the main in stability assessment. The estimation analysis allows concluding that there are two main mechanisms of sliding processes on the slope. In the first case, landslide dislocations occur in the embankment’s body. The second mechanism bases on the assumption of one estimated geological element soaking and thawing. In this case, sliding dislocations cover the whole embankment. The embankment’s displacement comes along frozen moistening loams (main straining horizon (MSH)). This main straining horizon is the base for made ground. In addition, displacement may occur because of infiltration of the surface water along well-filtering macadam in warm period. The main sliding factors at the territory are significant relief energy, low strength properties of soils during it soaking and thawing, artificial cooperation. Fine probability sliding process activation predetermines the necessity of design and engineering protection measurements organization.

This article proposes a method of monitoring the buildings stability with free station positioning which includes a geodetic monitoring technique with a free station. Processing and adjustment of data are proposed to be conducted with the search method by a specially designed software program. The sequence of monitoring is as follows. The location of the stations is chosen in such a way that each of them shows as many deformation and support points as possible and at least three points should be determined from any other station. It is preferable to choose stations approximately in the alignment of one pair of support points so that the planes of the marks being defined are perpendicular to the line of sight. Measurements of all horizontal angles, zenith, and slant distances to all visible reference points, and deformation marks are made at each station with an electronic total station. As a result, redundant measurements appear in the measurement scheme, which in turn increase the accuracy of the final result. The coordinates determination of the defining marks is performed by deducing the minimal sum of the measured angles deviations squares and of distances squares calculated from the preliminary coordinates of the marks taking into account the weights of the measurements. It is proposed to search for the objective function minimum with a search method using a specially developed program in the form of a macro in the Microsoft Excel software product which provides special features to accelerate the problem-solving process. The buildings deformation monitoring technique mentioned above was successfully tested at several sites.

Reconstruction of buildings is a complex engineering task, and the climatic conditions of cold regions further complicate and increase the cost of solving this task. Therefore, the delay in construction due to poor-quality design documentation leads to large financial losses. This article provides an analysis of results for four projects, where the main task was clash detection between the designed and existing engineering constructions. Each project used a combination of the technology of terrestrial laser scanning (TLS) and CAD. The article describes two ways to apply this methodology. At one of the projects, a point cloud obtained by terrestrial laser scanning was combined with a design three-dimensional model to identify deviations from design documentation. For other projects, BIM of existing structures and communications were developed based on point cloud. Then, BIM based on point cloud were combined with BIM based on design documentation for clash detection between structures and communications. The detected clashes allowed making changes to the design documentation before the start of installation work at the facility. The results showed the effectiveness of the joint use the TLS and CAD systems and identified the causes that affect the accuracy of the results at each stage of the work carried out.

Modern transport infrastructure is the most difficult and centralized system which influences all spheres of life. It can be divided into two broad categories: external (intercity) and internal (in-city). In this context, the importance of transfer hubs should be emphasized as they assist in redistribution of passenger flows in between different types of transport, thus optimizing the transportation process. It is worth mentioning that the safety of transport infrastructure is critical in preserving the stability of the transportation system as any disturbance to it might cause not only severe economic losses but most importantly deaths of civilians due to terrorist attacks, car crashes or other related accidents. Current paper focuses on description of methods to provide the safety of transport system utilizing technologies related to three-dimensional laser scanning that uses algorithms and artificial intelligence to process data and aid in decision making.

Landsliding is considered as one of the major natural hazards that endanger human life and property, particularly in mountainous regions which have high precipitation rate and are seismically active. This paper identifies landslide-prone areas in Murree, a northern area of Pakistan and presents landslide susceptibility mapping technique using Geographic Information System (GIS) and Remote Sensing. The landslide triggering factors considered in this study are elevation, slope, geology (lithology), land use and land cover, seismotectonic settings and vegetation index. A spatial database using Geographic Information System (GIS) was developed. Slope was derived from topographical datasets; lithology and land use/land cover from geological datasets and vegetation index are from Landsat 8 imagery. Then finally, by using weight of evidence (WoE) method, landslide susceptibility map was developed. The final landslide susceptibility map has five classes from very low to very high landslide susceptibility. The results indicate that though only 8% of the study area falls in very high susceptible zone, it has a high land use percentage. This poses a serious threat to infrastructure and human life. Results of this study would be helpful in disaster risk management, geohazard studies and construction and regional planning.

Sometimes, there are deformations of the points of the geodetic network, which are placed on the construction site, in the process of bridges construction on heaving soils. Moreover, most points of the geodetic network are often removed due to heaving soils that make monitoring of such geodetic network more difficult. This article contains comparing and studying the results of the monitoring of the vertical geodetic control network in constructing the bridge over the Verebushka River, obtained by A. Kostechel method and by leveling relative to the bridge under-truss sites. It is proved that the traditional A. Kostechel method in these conditions does not fit because of false results. Consequently, it is suggested for geodetic network monitoring to fasten additional reference marks on the stable elements of the structure in constructing bridges in similar conditions. Then, it is necessary to level their marks regarding the existing benchmarks. It is also suggested to use the heights of these points as control heights to save the common system of heights during constructing in such conditions when traditional monitoring methods are giving false results.

This article provides a systematization of the main errors affecting the results of determining relative heights by unilateral trigonometric leveling. The zenith distance determination accuracy vs the height of the instrument, the known elevation and the distance between stations has been pre-calculated. Refraction is the main factor preventing the use of the accuracy capabilities of modern electronic tacheometers. The results of daily experimental studies to determine the refraction coefficient are presented, and the results obtained have been analyzed.

The Northern latitudinal way is a set of measures for the reconstruction and strengthening of the existing and the construction of new sections of the railway infrastructure “Obskaya–Salekhard–Nadym.” The construction of the railway is associated with the natural and climatic features of the region: permafrost soils, mainly sandstone and sandy loam unsuitable for the construction, losing bearing capacity during thawing. For a rational design and construction of the transport complex in permafrost conditions, detailed engineering and technical surveys have been carried out. On the basis of the results of exploration work, the area grounds with the most favorable engineering-geological and hydrogeological conditions as well as heaving and snow-dumping sites were identified.

Concerning the need for railway capacity increase, the trains marshaled of innovative cars with 27 t axle load are being tested at the test sites. At one of the sites of Sverdlovsk Railway, 100 km Kachkanar—Smychka, the works have been organized to provide geodetic monitoring of the permanent way and the high embankment formation deformations. The geodetic surveys were carried out for eight months from December 2017 to July 2018 at four test sites. The analysis of the measurements shows an intensive frost heaving of the soils at two test sites in winter period. The permanent deformations of the main site of the formation were observed at these sites in summer period.

One of the features of modern construction is the increase of loads on foundations and basements of buildings. Therefore, high-pressure soil compressibility has become a topical issue. However in production conditions tests have been performed at pressure no more than 0.4 … 05 MPa. The article deals with compression curves extrapolation to high pressures for different genetic types of clay soils. The dependence of coefficient of compression Bk and pressure of void ratio at plasticity limit (pp) on the soil condition was analyzed. Two segments are displayed on compression curve: initial segment and the main segment.

The variations on physical properties and microstructures of soils are essential to explore the freeze-thaw mechanisms. We do some experiments on freeze-thaw test of Qinghai-Tibet silty clay and cryo-scanning electron microscope (cryo-SEM) observing after freeze-thaw test and monitoring the changes of temperature, pore water pressure, and displacement. The results showed that the change of pore water pressure was closely related to soil particles rearrange, particle size redistributing, and then develop a new arranging tendency of soil pores during freeze-thaw cycles. During the period of soil freezing, the pore water pressure decreased gradually, and the particles became more gathering from point to point (P–P) form along with freezing rate decreasing, the relevant microstructures had changed from the matrix structure to gel structure, and pores became more simplex. During soil melting, the pore water pressure rose to stability, and the soil mainly experienced a consolidation process. In our study, we also quantify cryo-SEM images by Image-pro Plus (IPP) software. The results reflect the change of pore water pressure had a certain correlation with structural parameters under freeze-thaw cycles. These findings substantially contribute to understand the freeze-thaw mechanism and assist in upscale the microscale physical characteristic of frozen soil.

Small-strain modulus is an important parameter in engineering constructions such as tunneling employing artificial ground freezing method. Temperature and strain rate are two main factors influencing the small-strain deformation behaviour of frozen soil. Testing conditions and some technical cautions are crucial to the accurate measurement of the small-strain modulus. This paper reports an experimental study on small-deformation behaviour of clay frozen directly under confining pressure after being consolidated to different isotropic effective stresses. The loading probes were then conducted at three different axial strain rates (0.001, 0.01 and 0.1%/min) and three different temperatures (−10, −5 and −2 ℃). The freezing method, calibrating factor of local displacement sensor against temperature and loading approach with load cell outside the freezing chamber, was specially considered. The clay specimen was frozen under confining pressure to fully imitate the in situ freezing process. The adopted local gap sensor functioned well under different temperatures in the refrigerant, and the temperature effect on the calibration factor is negligible. After overcoming the error brought about by the external load cell, it is found that the small-strain modulus of frozen clay appears to be independent of strain rate. The samples frozen from higher effective mean stress state exhibited smaller initial stiffness.

To improve the understanding of the influence of induced anisotropy on the strength and deformation characteristics of loess, a series of directional HCA tests under consolidated-drained condition were conducted. The test results indicated that the remolded loess showed a pronounced anisotropy in stress–strain relationship, strength, and deformation. The maximum difference in shear strength due to directional effect was 25% in the range of major principal stress orientation. Induced anisotropy has a great influence on the stress–strain relationship of soil, which is the essence of soil properties. In some engineering practices, the results of stress–strain analysis of soil have great influences. Approximately, isotropic remolded loess substantially eliminates its inherent anisotropy. The soil studied in this experiment is from the permafrost region of Qinghai. With the increase of engineering constructions, the geotechnical engineering problems here are becoming more and more significant. Therefore, this experiment will provide a good reference for the further study of soil anisotropy under complicated stress paths such as principal stress axis rotation.

The construction of traffic routes in the subsoil is increasingly been carried out by artificial ground freezing. Due to artificial heat removal, a load-bearing frost body arises, which becomes water-impermeable in its closed form. However, frost heave at the ground surface may lead to damage buildings. In fine-grained soils, the frost heave is caused by the 9% volume expansion of the pore water during freezing and, in particular, by the formation of ice lenses. For the formation of ice lenses, water from unfrozen zones is suctioned to the frost line and freezes to continuous ice lenses. Based on horizontal freezing pipes in the subsoil, the decisive heaves at the ground surface result from the frost penetration direction to the ground surface and in the opposite direction. In this case, the ice lenses grow parallel to the ground surface. In order to investigate the frost heave due to ground freezing boundary conditions, a test device was designed to carry out one-dimensional frost heave tests taking into account the upward and downward freezing directions.

The laboratory model test was carried out in the freezing chamber and the size of insulated steel box is 0.9 m(L) × 0.9 m(B) × 0.9 m(H) which simulated actual roadbed structure. Data logger was used to measure the variation of temperature. The variation of heaving pressure with elapsed time for various roadbed conditions was determined through the laboratory model test. The influence of crushed natural aggregate to the freezing of the subgrade soil was studied to verify the function and effectiveness of the anti-freezing layer. The thermal gradient is greatly influenced prior to reach the soil temperature of 0 ℃ or below 0 ℃. The heat transfer rate is greater at the roadbed surface and then slightly decreases with the depth of roadbed. The degree of air temperature and the type of soil layer are also influenced on the freezing temperature (0 ℃) at the roadbed depth. On the other hands, the anti-freezing materials like crushed natural aggregates can reduce the event of frost heaving of subgrade soil at the same condition of soil density, temperature, and moisture content. The loading pressure and deflection for the compacted roadbed materials prior to freezing and after thawing and hence, the modulus of elasticity were determined by the application of the light falling weight deflectometer (LFWD).

In areas where heavy clays predominate (clays with plasticity index of more than 27), engineers always face the problem of replacing soils when constructing a roadbed for railroads and highways. Transportation of suitable construction material, as a rule, is very expensive. Construction of the roadbed of railroads and highways, especially in the cold regions of the Russian Federation, is almost always accompanied by a shortage of soils with good physical and mechanical properties. As a rule, these areas are characterized by clay deposits with unfavorable properties: high degree of swelling, low hydration strength, poor compaction, etc. Such properties are also characteristic of heavy clays which are widespread not only in Russia but also abroad. These features of heavy clays do not allow them to be used in the construction of the roadbed of railroads and highways without taking measures to improve their properties. The same problem has been faced by the engineers involved in the construction of the railroad track on the Taman Peninsula. Heavy swelling clays are common for this area. In the summer of 2017, soil samples were taken from the Taman Peninsula and tested in the laboratories of St. Petersburg State Transport University (PGUPS). Physical and mechanical properties of heavy clays were studied as well as properties of reinforced clays. The research shows that the optimal method for improving physical and mechanical properties of heavy clays (swelling, deformability) is the creation of a composite material consisting of heavy clay with the addition of dust filled sand (10% of the mass) and grade M400 cement (3% of the weight). This technique is applicable to all areas where heavy clays are common.

The object of the research is the load-bearing structures of transport facilities used in cold regions. The subject of the research is the method and means of assessing the technical conditions of load-bearing structures of transport facilities at the extremely low temperatures. The aim of the research is to ensure the recording and retaining the transport facilities state parameters at the temperatures below −40 °C. The analysis of the specific use of transport facilities in cold regions and the systems employed for technical conditions control has been carried out. The results obtained gave the possibility to propose some technical designs for transducers capable of recording both current and maximum/minimum values of the transport facilities state parameters caused by the extremely low temperatures. A method for estimating the parameters of the stress-strain state of the load-bearing structures of transport facilities at the moment of accidents caused by temperature anomalies is proposed. The method can be used even in the conditions of the monitoring systems secondary equipment failure.

The relevance of the problem is due to the formation and storage of multi-tonnage mineral technogenic silicates obtained as a result of the construction and mining industry. The aim of this work is to identify useful research geoecoprotective properties of technogenic silicates, as well as in the development of technological solutions for their application in cold regions. The objects of study selected waste of heavy concrete and chlorine-containing crushed stone. The study used methods to identify geoecoprotective properties and iodometric method for determining microbial numbers. Discovered and investigated the properties of the waste heavy concrete and rubble floristerias determine the possibility of their use in geoecoprotective structures. In this case, such structures as the railway embankment may have geoecoprotective function. The article is aimed at studying the possibility of using mineral technogenic silicates in the body of the railway to reduce the negative impact of pollution of different nature. The article presents technological solutions for the use of heavy concrete and rubble floristerias having geoecoprotective properties. The article gives formulas for calculating the required number of mineral technogenic silicates, to make the structures geoecoprotective properties, and the calculation results. The materials of the article can be used to develop technological solutions for the utilization of mineral technogenic silicates in their useful application in transport construction to protect soils and surface runoff of the railway from pollution of various natures.

Every year, 15–17 million tons mineral wastes are generated in Russia including permafrost regions. A large amount of these wastes contain minerals such as silicates and sulfates. Different industries leading to geosystem pollution by heavy metals, including lead, cadmium, copper, zinc, manganese, and iron compounds. Such pollution must be prevented. The purpose of the work was to study geoecoprotective properties of mineral wastes of silicate and sulfate nature and how they can be used to create geoecoprotective technologies against heavy metal ions pollution in permafrost regions. The silicate and sulfate mineral wastes were selected as objects of study in the form of phosphogypsum, foamed gypsum, calcium sulfate anhydrous, hemihydrate gypsum and calcium sulfate dihydrate, asbestos- and chlorite-containing crushed stone, and talc. A potentiometric method for determination of concentrations in solutions was used to define the absorptive capacity of mineral wastes against heavy metal ions. The detected absorptive capacities of aforementioned mineral wastes for such heavy metals as cadmium, copper, lead, and barium are presented in the article. The dependences of the absorptive capacity of the mineral waste on the initial concentration of heavy metal ions, on the interaction time with the solution and on the fraction size are also given in the article. The experimental results showed that the selected mineral wastes can be used in technological solutions for soil cleanup and surface runoff purification from heavy metal ions.

The research area is construction in cold regions. The paper demonstrates that highly effective chemical activation of the cement-containing composite system with the use of a new generation of nanostructural additive ensures the creation of high-strength concretes having improved strength and deformation characteristics which are most effective for road surfaces. The recommended nanostructural additive has an increased effect of triple action: reaction, catalytic and plasticizing effects. The application of the proposed additive increases the hydration activity of the hardening system having chemical and thermal energy effects on it. The heat impact is due to the use of heat released as a result of enhanced hydration processes. This contributes to the creation of high-strength concrete with a new level of physical and mechanical properties.

The intensive development of highways leads to the natural system pollution by hazardous substances such as heavy metals and oil products. At the same time, wastes are accumulated and stored in the metallurgical industry, which has a negative impact on environment. The purpose of the work is to study the applicability of the metallurgy waste for transport construction to minimize the negative impact of polluted roads on the environment in cold regions. The task of the work is using of the metallurgical wastes properties in geoecoprotective technological solutions in road construction and operation. Blast-furnace metallurgical slag was chosen as the object of study. IR spectrometry, atomic absorption photometry, and PQ analysis methods were used to study the properties of this slag. The article presents data on the degree of road pollution and on geoecoprotective capacity of blast-furnace metallurgical slag against heavy metal ions. The authors have proposed the technological solutions for using of blast-furnace metallurgical slag in transport construction and reconstruction, including the effective life calculation during their operation. There are two geoecological problems being solved for cold regions: utilization of metallurgical wastes and the use these wastes for soil cleanup and treatment of runoff containing heavy metal ions.

Today, the evaluation of the proposed geoecoprotective technologies, including the transport facilities construction at low temperatures conditions, is imperative and timely. The purpose of the work is quality evaluation of geoecoprotective technological solutions in construction and operation of traffic arteries. The task of the work is to study the possibility of the use of the property quality method (PQ) for geoecoprotective technological solution evaluation. The objects of research are technological solutions which can reduce heavy metal ions concentration in geosystems. PQ method was used as evaluation method. The calculation results of the geoecoprotective technologies efficiency, using geosynthetic materials, gabions, and mineral geoantidotes have been presented. Mineral geoantidotes (MGa) are substances that can detoxify heavy metal ions. The geomembrane for waterproofing of railroad body and MGa in the form of crushed silicate brick were used in the first technology. The gabion construction and MGa in the form of clinker as filling were proposed in the second technology. The third technology involves the use of a drainage tray, in which MGa in the form of autoclaved foam concrete waste is used as a drainage material. The authors of the article give the values of PQ indexes for these technologies and compare them with the currently known technologies. The article materials can be used for the development of technological geoecoprotective solutions and their evaluation in transport construction of Russia and other countries including cold regions.

In cold regions, one of the major problems is frozen soils, which periodically thaw unevenly, which negatively affects the stability and integrity of concrete structures. The research area is the construction in cold regions. It is shown in the paper that modified repair solutions based on a modified repair mixture have a double effect: penetration effect and protective one. The penetration effect of the mortar mix ensures an increase in compressive strength by two classes, water resistance by two grades and frost resistance by 100 cycles to the loosen concrete base. Repair compositions used as a protective material have high crack resistance, and they are corrosion-resistant materials relative to carbon dioxide and magnesia corrosion. At the same time, they are characterized by high adhesive strength to the concrete base, creating the integrity of the restored base and protective repair composition. The modified repair mix possesses highly effective protective properties in relation to the concrete basis, due to high indicators of durability, crack resistance and corrosion resistance.

The research area is construction in cold regions. It is shown in the paper that in order to create multifunctional concrete with a new level of physical and mechanical properties it is advisable to use two complex chemical additives on a polycarboxylate basis of a different nature simultaneously. They are modified by nanostructural elements of natural and synthetic origin. These chemical additives have the plasticization and reaction effects on cement-containing concrete mix, and they ensure the formation of new organic mineral chains, micro-reinforcing the structure of concrete from the moment of its manufacture to full hardening. The result of the combined effect of two complex chemical additives is the creation of the densest and the most durable concrete characterized by increased crack resistance, frost resistance and water resistance. It can be recommended for the manufacture of essential structures and for high-rise construction, including construction on problem soils in the regions of permafrost.

It is shown in the paper that the effective chemical activation of cement-containing composite mixture with the help of a new generation of a complex nanostructural additive ensures the creation of high-strength fine and heavy concretes with improved strength and deformation characteristics. The use of the proposed complex additive enormously increases the hydration activity of the hardening system, having the chemical and thermal effects on it resulting from the rational use of heat released in the process of hydration reactions and ensuring the creation of a composite building material with a new level of physical and mechanical properties. During the experiment it was found that the developed complex nanostructured additive has: highly plasticizing effect; increases the compressive strength, but to a greater extent, the tensile strength in bending (by 53–59)%, increases the crack resistance of the material by (16–17)%;—increases by 2 times the frost resistance of concrete and its water resistance by 50%. Nanomodified concrete with achieved physical and mechanical parameters is recommended for the manufacture of responsible structures, including cold regions, when using problem soils.

The area of the research is geosphere protection from heavy metal ion pollutions. Such types of pollution are typical for cold regions. Contaminants are military waste of metallic nature and heavy metal ions because of that. The aim of the work is the development of geoecochemical basis for new geoecoprotective technologies based on mineral geoantidotes (MGA) by calculating concentration values and detoxifying pollutions in certain geoecochemical reactions. The methods of the research were chemical, physical–chemical and mathematical ones. The concentrations of heavy metal ions (HMI) in saturated solutions were calculated and compared with the values of maximum permissible concentration (MPC) for HMI in the soils. The range of MGA effectiveness in HMI detoxification by their nature has been developed, and the formula of the effectiveness evaluation has been presented. The classification of MGA as disperse systems was made, which made it possible to distinguish the features of geoecochemical reactions. Five types of disperse systems of MGA have been identified, which provides four types of geoecochemical reactions: lythoreactions, soling, stone formation reactions. These reactions are the basis of new geoecoprotective technologies: lithosynthesis, soling and safing. These technologies conserve detoxification products inside the stone functioning as a useful element in construction.

The research area is natural geosystem preservation during the geoconstruction operations. The problem is connected with the cold region because of low temperature influence on the quality of the geoconstruction. The aim of the research is: firstly, by improving concrete properties, to improve the quality of concrete articles in geoconstruction, their durability and, therefore, to reduce the consumption of natural substances; secondly, to assess the achieved quality by introducing a new summative assessment called quality index. The methods of the research are physical-mechanical and experimental ones for evaluation of the concrete properties, and rating method of quality assessment which has been developed and presented to testing. The improvement of concrete properties was achieved by using sol adsorption technology. By using quality index, the quality assessment showed 37% increase. The achieved results make it possible to reduce the consumption of natural sand and, consequently, preserve natural geosystems in geoconstruction.

The study deals with the methods of environmental protection from pollutions, in particular, safing technologies. Such kind of technologies is important in cold region because of military waste. The aim of the work was to study the specificities of safing technologies as coatings in mineral systems and as dimensional safing. By using a coating has been studied the depth and the composition of the layer on the surface of concretes of self-stressing cement and expanding cement. As dimensional safing, we considered making a phosphate artificial stone which involves binding of heavy metal ions. The methods of the research were electron microscopical image (EMI), electron probe microanalysis (EPM), and chemical and physical-mechanical methods. It is shown that the coating’s layer is up to 7 mm. Due to dimensional safing, special heavy metal ions are binding and hardening of system takes place at the same time. The study presents the development of safing technologies of geoprotection.

The study belongs to the field of silica sol technology application in geoconstruction of the cold regions. The aim of the research was to study the specificities of processes of various kinds of soling technologies—detoxification, absorption, blocking and strengthening technologies. The methods of the research were thermodynamic, experimental ones, electronic microscope scanning, x-ray analysis, derivatograpic and chemical analysis. The correlation of thermodynamic resolution and formation of calcium-hydrosilicates and heavy metal ions has been found. In the first case, this is the basis for property improvement in absorption and blocking technologies, in the second case—in detoxification technology. In strengthening technology, the nature of the soil should be taken into consideration.

The paper concerns geoecoprotective technologies in transport construction in the cold regions. The aim of the research was to develop criteria for the estimation of geoecoprotective properties in the sphere of transport geoconstruction using geoantidotes as an example. Such methods as physical and chemical, physical and mechanical as well as instrumental ones were applied during the study. Five criteria for green geoecoprotective technologies with the help of mineral geoantidotes have been developed. They are the following: energy of geoecoprotective processes must be based only on the internal energy (without the consumption of any kind of natural fuel); detoxication products must have a very low solubility product (detoxication technology) or must be kept in a stone-like in a safe (safing technology); substances, articles, or structures with useful building properties must be produced as a result of green technology, they being the same as natural ones; mineral geoantidotes must have nature-like any natural substance; there must be the field of the application of such substances after their life cycle in order to avoid waste. The examples of the use of precipitations of sparingly soluble compounds of lead and barium, as well as copper, nickel, and zinc, are given.

The paper concerns geosphere protection in a cold region which can be increased by means of raw material economy, pollution detoxication and antidusting lay creation on a mineral surface and soil strengthening. Silica sol was chosen as the main agent for modification. Concrete, sand, slag, limestone, ash, perlite and other mineral articles were used as mineral surfaces. Such methods as physical, chemical and instrumental ones were applied during the study. The chosen substances were penetrated with silica sol agent as well as the second agent and after certain operations modificated surfaces having improved technical and geoecoprotective properties were produced. Besides, obtained compositions had higher mechanical and absorbtion properties. A composition with modificated mineral surface can be applied in transport geocostruction for waste detoxication, e.g. heavy metal ion detoxication, for antidusting lay and geoecoprotective screen creation. The prospects of modification use are considered in this paper.

The main object of our research is the transport construction in cold regions. It based on many natural resources for making building materials, which must be adapted to low temperature. We pay the main attention to usage of industrial mineral wastes. Comprehensive analysis of waste including the structure of atoms of the main phase allows predicts properties of building materials. Using industrial mineral wastes instead of mineral raw, one can affect various structural properties of materials. 3d-metals in technogenic raw materials increase the strength characteristics. And s-elements increase the heat efficiency which is crucial in cold regions. We carried out a comparison of various wall materials with waste. S-elements improve heat technical characteristics of bricks.

Research area is transport construction in cold regions in compliance with geoecology. The goal of the article is to develop a new binder for the simultaneous performance of two functions—construction and technical, associated with soil reinforcement, and detoxification of heavy metal ions (HMI). Silica sol was chosen as such binder. The research methods are chemical (assessment of the silica sol detoxifying ability), physical (determination of the required concentration of silica dioxide), and physicomechanical (strength tests of samples). It is traced that sandy soil reinforcement is provided by 30% silica sol with detoxification functions. The author proposes transport construction technology in which the use of the new binder allows to achieve higher strength indicators of reinforced structures, as well as to ensure the implementation of the geoecological function.

The purpose of the investigation is to obtain the non-autoclaved foam concrete with increased thermal protection properties for various road structures. It is shown that to achieve this goal, polymers and dolomitized limestone are to be introduced into the foam concrete composition, which results in the decrease of the thermal conductivity coefficient of more than a class of average density. The interrelation of thermal conductivity coefficient of foam concrete with physical–chemical characteristic of its stone interlayer (crystal–amorphous ratio characterizing the amorphism degree of its stone structure) is scientifically proved. New technological solutions for road structures construction are proposed. It is shown that the use of foam concrete based on polymers in road structures allows to provide high frost resistance, which is especially important for construction in cold regions. In such regions, in order to arrange road structures on permafrost and heaving soils, they need increased thermal protection characteristics. The use of materials with a reduced thermal conductivity coefficient in their composition will prevent their destruction. When using foam concrete in railway embankments, the load on weak foundations is reduced. It is established that the solutions with simultaneous application of foam concrete of different classes of average density are the most effective. Fourier transform infrared spectroscopy and derivatographic methods of analysis were used in the study of the material obtained. The calculation of road structures was carried out in accordance with the regulatory documentation and showed a significant margin of frost resistance and the load reduction in a weak base.

Mineral resources conservation has been gaining importance in transport and civil construction, including in cold climates. Numerous experiments have established that conservation of mineral resources is possible when using silicic acid nano-solution at the stage of production of cement-base building systems. Some resource-saving technological decisions are present. The article presents the calculated data on the economy of natural resources using these decisions. Resource consumption coefficient is offered. This coefficient determines natural raw materials efficiency. There is another way to preserve natural resources—geoecoprotective decoration of white cement construction products. This decision involves the use of colored solutions of metals instead of the natural mineral pigment. The calculation of the mineral coloring component consumption per 1 m3 of the concrete product was carried out. The valuation showed that the use of colored solutions when painting the surface of the product significantly reduces the cost of natural mineral raw materials.

The purpose of the investigation is to obtain high strength characteristics of foam concrete during its hardening at sub-zero temperatures and using in road embankment structures. It is scientifically proved that the introduction of the granulated slag and waste molding mixture jointly ground with cement into the binder composition reduces the time of cement hydration in winter without using the modern methods of concrete hardening acceleration. The optimal combination of the complex binder components and the amount of injected polymer for foam stabilization are determined. The kinetics of the calcium release in the process of hydration at the initial phases is shown, and the rate of decrease of the alite component in the samples with the mechano-activated binder and polymer foam stabilizer is estimated. It was found that the introduction of the polymer into the active foam does not slow down the hydration process of silicates when introducing a mechano-activated binder. It is shown that the joint grinding of silicate components violates the crystal lattice of minerals and leads to the change in their surface properties. The method of X-ray phase analysis was used in the study of cement stone hardening processes. The paper proposes constructive solutions of road embankments with the use of non-autoclaved foam concrete on the basis of a mechano-activated binder. The use of non-autoclaved foam concrete based on mechano-activated binder is relevant to the construction in the Northern regions. Receive when you activate the secondary of active sites of hydration helps to reduce the binding time binding.

In this article the possibility of using porous silicate-containing waste when receiving an effective ceramic brick (which is used for erection of a transport infrastructure buildings and constructions at low temperature) is considered. The purpose of study was development of ceramic brick compositions made with using of granulated blast-furnace slag and with using of a ground foam concrete crush, which has a lower thermal conductivity coefficient of a crock, and meets the requirements of state standards for other indicators. Optimum compositions of materials and physical-mechanical characteristics of received materials are given. To study the composition of technogenic raw materials and the structure of synthesized ceramic materials the following methods were used: X-ray phase and differential-thermal methods, IR- Fourier-transform spectroscopy, electron microscopy, mercury porometriya method. The estimation of ecological and economic efficiency of use of porous silicate-containing waste is given. This estimation shows a significant reduction of anthropogenic load on the environment, и reduction of the cost of production of ceramic bricks with improved heat technical characteristics, what is needed for erection of buildings and constructions in cold regions.