№ 4 on 2024:

COMBINED NUMERICAL SIMULATION OF THE OPERATION OF SAND-GRAVEL MIXTURES

Retunskiy A.A., Goryachev M.G.

Abstract:
The study of the behavior of granular environments under the influence of transport load makes it possible to substantiate the scope of their effective application, changes in composition occurring during the operation of the granular environment, as well as its design characteristics for the design of road pavements. To the study of sand-gravel mixtures is paid insufficient attention. Based on the computational experiment matrix developed by the authors, based on the selected mathematical models and modeling parameters, a numerical assessment of the probable values of the strength properties of sand-gravel mixtures was performed. The results obtained indicate the need to differentiate the modulus of deformation and elasticity of the sand-gravel mixture from the type of sand in the range up to 35% gravel, and when exceeding 35% gravel, the strength properties depend on its proportion in the mixture.

Keywords:
finite element method, modulus of deformation, modulus of elasticity, sand-gravel mixtures.

PREPARATION OF ASPHALT-GRANULOCRETE MIXTURES IN MIXING PLANTS

Al-Karaguli M.M., Lupanov A.P., Silkin V.V., Rudakova V.V., Silkin A.V.

Abstract:
The article is devoted to processing of asphalt granulate in a mixing plant by regulating the granulometric composition. It has been established that by introducing cement with a plasticizing additive, asphalt granulocrete can be obtained that exceeds the strength characteristics of asphalt concrete from hot asphalt concrete mixtures. At the same time, the selection of the optimal composition of the mixture and the addition of an aqueous plasticizer solution makes it possible to obtain the strength of asphalt granulocrete almost 1.5 times greater than in compositions without plasticizers.

Keywords:
asphalt granuloconcrete mixtures, asphalt granulate, economic efficiency, cement, cold milling, mixing plant, properties of granuloasphalt concrete

ENSURING THE DURABILITY OF THE BASE OF HIGHWAYS WHEN USING COLD RECYCLING TECHNOLOGY

Nikishin V.E., Melnikov M.I.

Abstract:
The technology of cold recycling has been revealed, which ensures effective repair of highways. The Saratov region has accumulated significant experience in the application of this technology at various facilities in a variety of conditions. During the repair of foundations on the Ershov street and road network using the stabilizing additive Ecopell, results were achieved confirming the effectiveness of this approach. But for the successful implementation of cold recycling technology in our country, further refinement of recommendations on its application is required.

Keywords:
asphalt-granulocrete mixture, cement composition selection, cold recycling, increased durability

THE BEARING CAPACITY OF THE PILE, WHICH DEPENDS ON ITS PARAMETERS AND THE CONDITION OF THE SOIL

THE BEARING CAPACITY OF THE PILE, WHICH DEPENDS ON ITS PARAMETERS AND THE CONDITION OF THE SOILHtet Aung

Abstract:
This article presents the results of calculations of the bearing capacity of steel H-shaped and tubular piles in the engineering and geological conditions of Myanmar. Due to the complexity and secrecy of the geotechnical characteristics, the reliability of the pile foundation has been studied to a lesser extent compared to the strength of the building structures themselves. The length of the pile, depending on the type and properties of the soil at its base, also directly affects its bearing capacity. In this article, the length of the pile and the soil parameters are left unchanged, while the diameter and perimeter of the pile undergo changes, thereby ensuring an increase in the load-bearing capacity with the growth of these indicators.

Keywords:
bearing capacity, perimeter, pile, reliability, stability

ASSESSMENT OF THE STRESS-STRAIN STATE OF THE ‘SOIL MASS – TUNNEL – REINFORCEMENT ZONE’ SYSTEM IN THE ENGINEERING-GEOLOGICAL CONDITIONS OF HANOI (VIETNAM)

Kravchenko V.V., Ma Van Lok

Abstract:
The paper deals with the improvement of the bearing capacity of the soil foundation during the construction of road transport tunnels in difficult engineering and geological conditions of Hanoi (Vietnam), where soils have low bearing capacity, high porosity and full water saturation. The prospects of application of the technology of reinforced concrete pile array arrangement as a base under the tunnel through slab to reduce the deformations of structures have been investigated. To estimate the stress-strain state of the system ‘soil massif - tunnel - reinforcement zone’ during the construction of an underground structure, the model of reinforcing soil on the basis of the software complex ‘Plaxis 3D’ has been considered. Numerical calculations are carried out on the basis of field data obtained during the construction of the Thanh Xuan motorway tunnel (Hanoi). The results of calculations of vertical deformations of the tunnel and the day surface, as well as changes in the stress-strain state of the system ‘soil mass - tunnel - reinforcement zone’ without reinforcement of the base under the flume slab and with reinforcement of the base with reinforced concrete piles are shown. It is revealed that when the tunnel base is reinforced with pile field, the maximum vertical deformations of the day surface and the tunnel are reduced. The effectiveness of using reinforced concrete piles as a means of strengthening the underlying soils of the base of road transport tunnels in the engineering-geological conditions of Hanoi has been noted.

Keywords:
deformations, engineering-geological conditions, Plaxis 3D, reinforced concrete piles, road transport tunnel, soil mass, stress-strain state

REQUIREMENTS FOR THE TEXTURE OF THE MACRO-ROUGHNESS OF STRUCTURAL ELEMENTS OF BRIDGE STRUCTURES

Martinson V.L., Martinson A.V., Kochetkov A.V., Kochnev V.I., Bolyachevets I.A.

Abstract:
The article proposes new geometric parameters of the roughness of steel-reinforced concrete and metal orthotropic slabs of a bridge structure, taking into account the statistical distribution of the depths of depressions and active protrusions to ensure the quality of three-layer waterproofing.

Keywords:
bridges, highways, humidity, materials, soils, temperature, thermal conductivity, thermophysical properties

DYNAMIC TESTING OF RAILWAY BRIDGES

Khazanov M.L.

Abstract:
The processing of the results of dynamic tests of railroad bridges should take into account that the load in the form of a locomotive has a length comparable to the length of the bridge span, and the recorded vibrations of the span may have nothing to do with any form of free vibrations. The paper presents a method of processing the obtained data to avoid erroneous conclusions.

Keywords:
dynamic coefficient, influence line, oscillation period

ROAD SURVEYING AND DESIGNING IN SEISMIC AREAS WITH RISK DETERMINATION

Abduzhabarov A.H., Mekhmonov M.Kh.

Abstract:
The research results presented in the article make it possible to accelerate the work on the survey of roads designed in earthquake-prone areas and to determine the risks of the options being developed. The results of scientific research were obtained on the basis of model and field experiments in earthquake conditions.

Keywords:
degree of risk, groundwater level, seismic forces, slope, soils, structures for strengthening the roadbed

APPLICATION OF IR SPECTROMETRY FOR TESTING OF BITUMEN BINDERS

Menkina U.O., Vasiliev Yu.E.

Abstract:
This article discusses the prospects of using chemometric methods for accelerated determination of the properties of petroleum bitumen, which is an urgent task in road construction. This approach can be considered as an express method that not only speeds up the analysis process, but also increases its objectivity. The use of chemometric methods allows for multidimensional analysis, which makes it possible to identify hidden patterns in the data and predict the properties of materials based on their chemical composition. For example, using multidimensional regression analysis methods, it is possible to quickly determine the viscosity, softening temperature and other key characteristics of bitumen, which is especially important for their further use in construction.

Keywords:
accelerated methods, bitumen, chemometrics, IR spectrometry, road construction tests

INFORMATION MODELLING TECHNOLOGIES IN TUNNELLING: CHINESE CONCEPT

Konyukhov D.S.

LIST OF ARTICLES PUBLISHED IN THE MAGAZINE IN 2024