Gersevanov Research Institute of Bases and Underground Structures

Based on the known experimental data the physics of soil freezing is discussed. A model for predicting coupled stress-strain behaviour and heat-mass transfer of freezing soils is proposed in accordance with the general thermodynamic approach.

Introduction . The present article considers a research into the spatial structures of buildings with load-bearing precast reinforced concrete elements manufactured using the technology of flexible mould processing (FMP). Aim . To develop the fundamentals of the regulatory framework for the design of buildings with FMP elements. Materials and methods . Computational and theoretical studies of design concepts for domed and vaulted buildings using precast FMP elements are carried out. Data on the stress-strain state of various-size building structures under various loading conditions are obtained. Results . The results of computational and theoretical studies are analyzed to develop recommendations for the design and reinforcement of elements and units. Proposals for standardizing the parameters of building structural elements are developed for inclusion in regulatory documentation. Proposals are made to introduce a new section on the spatial building structures made of precast FMP elements into SP 387.1325800.2018. Conclusions . The developed recommendations are aimed at increasing the efficiency of spatial design concepts for building structures.

Introduction . Highly intensive work on the construction of pile foundations requires a well-established system of testing and quality control. The main non-destructive methods of technical geophysics used to monitor the integrity of concrete and depth of piles is sufficiently well studied from both a scientific and practical point of view. The transition to a parametric standardization system established a number of provisions for the application of these methods in national standards. Low strain impact testing methods and crosshole sonic logging received their own State Standard R 71039 and State Standard R 72171 standards; thermal integrity profiling was included in broad-scope State Standard R 71733. The simultaneous release of several regulatory documents will expand the field of geophysical activity due to the ability of performing complex work. Aim . To inform test engineers, designers, and employees of supervisory organizations about the current state of regulatory framework on non-destructive testing of pile foundations. Materials and methods. The paper describes a set of geophysical methods used to monitor the integrity and length of pile foundations. The methods developed sufficiently for including in regulatory documents are indicated. Results . The performed work systematizes the information on the current state of regulatory framework on the use of geophysical methods for non-destructive testing of piles. The content of standards for low strain impact, crosshole sonic logging, and thermal integrity profiling testing is used to demonstrate possible directions for regulating methods of technical geophysics. Conclusions . The main geophysical methods used in non-destructive testing of pile foundations have now received the necessary regulation in national standards. The possibility of accumulating information on the capabilities and limitations of auxiliary examination methods is provided. The prospects for developing regulatory frameworks lie in the further harmonization of standards with current codes and State Standards, including the analysis of empirical data to correct documents during future revisions.

Introduction. This paper presents the results of experimental and theoretical studies of reinforced concrete cylindrical elements in a triaxially stressed state. Aim. The main objective of this work was to analyze experimental data on the influence of various structural and force factors on the stress-strain state of prestressed reinforced concrete elements in a triaxially stressed state at all stages of their operation, as well as to develop a methodology for their calculation. Materials and methods. The materials of previously performed experimental studies on prestressed reinforced concrete samples of cylindrical shape with stressed wire reinforcement wound along the side surface were used. The calculations were performed by the finite element method in a physically nonlinear formulation using the ATENA software package. Results. The analysis of experimental data on the effect on the bearing capacity of cylindrical samples of the ratio of their geometric dimensions, concrete strength, degree of lateral compression. The features of the nature of deformation under load of samples in the cage, their behavior during repeated loading are considered. Computational finite element modeling of the operation of triaxially loaded cylindrical slabs at all stages up to destruction is performed, the results obtained and comparison with experimental data are presented. Conclusions. Recommended values of geometric and force parameters have been determined, providing the most rational design solutions for thick slabs operating in a triaxially stressed state. A method for calculating such structures has been developed.

Purpose To enhance the efficiency of personnel assignment in layout operations, this study employs 0–1 integer programming optimization theory, integrated with practical layout operations in steel structure construction, to assign manpower under known constraints to find the optimal personnel assignment and minimal cost and to provide management decision-makers with an effective way to control operational costs. Design/methodology/approach The research considers constraints such as personnel availability and part types, constructing a mathematical model with one objective function and 11 constraints. By applying this model to a real-world project for constructing a technology factory and using LINGO 18.0 software, the study demonstrates that optimizing personnel assignment can reduce total costs by 12.82% and manual assignment time by 99%. Findings The findings also elucidate the following: (1) Sensitivity analysis indicates that decreasing the number of working days slightly increases total operational costs, whereas extending the duration to 30–40 days results in cost reductions. Furthermore, reducing high-efficiency and high-salary personnel has a minor impact on overall costs, while cutting low-efficiency and low-salary personnel leads to a substantial cost increase of approximately 50–52%. (2) Efficient and rapid personnel assignment contributes to achieving minimal operational costs, with a cost reduction of 12.82%, while also facilitating the attainment of project goals in the most effective manner. Originality/value The study developed a mathematical model featuring a single objective function and 11 practical constraints, providing practitioners with the flexibility to adapt it as needed to address empirical engineering challenges related to personnel layout assignments.

Introduction. The article discusses the structure of Russian classifiers for technical, economic, and social information. Proposals for the formation of a structure and approaches to classification are given for use in a construction information classifier. Algorithms for applying the construction information classifier are considered.Aim. To give proposals for the formation of a structure and approaches to classification for use in the construction information classifier.Materials and methods. Russian classifiers, their purpose, structure, and development prospects are analyzed. Principles of algorithms for applying the construction information classifier are proposed based on the performed analysis.Results. The given proposals consider the formation of a structure and approaches to classification for use in the construction information classifier.Conclusions. As a result of the conducted study, we propose to replace the construction information classifier with a construction classification system. This proposal implies coordination of existing industrial and inter-industrial classifiers, thus eliminating the irrational increase in the work time for classifying elements and attributes of information and digital information models. In addition, this proposal falls within the paradigm of applying a unified system for classification and coding of technical, economic, and social information.

Introduction. In modern conditions, the design of reinforced concrete structures requires prompt processing of a large amount of regulatory data presented in text format. The task of automatization of the extraction and analysis of information from regulatory documents is becoming urgent, as it makes it possible to increase the accuracy and efficiency of design work. Aim. Development of the information model integrating algorithms for processing regulatory documents (using the example of SP 63.13330.2018) with design systems. Materials and methods. The Mistral language model, deployed locally through Ollama, is used to process text data. Key entities (material parameters, loads, requirements) were extracted automatically, and their relationships were visualized in a graph database. The integration of the calculation and design systems is carried out using the IFC and XML formats. The formulae are implemented (for example, the calculation of the length of the reinforcement anchoring) in Python, and the automation of reinforcement selection is carried out in the Revit environment. Results. The application of the proposed algorithm has made it possible to automate the extraction of material parameters, design characteristics and design requirements, which significantly reduces the complexity of routine operations. The integration of the calculation model with the design environment (Revit) has provided automatic selection of reinforcement and welded meshes, contributing to increased design accuracy and reducing the likelihood of errors. Discussion. The developed system demonstrates high efficiency in automating the processing of machine-readable regulatory documents, which leads to a reduction in design time and an improvement in the quality of construction work. Further research will be aimed at expanding the algorithm to work with other types of documents and adapting the model to specific engineering analysis tasks. Conclusions. Machine-readable documentation formats and LLM models increase the accuracy and speed of processing of the regulatory data. Integration of the calculation and design systems via IFC/XML reduces labor costs and errors. Automation of reinforcement selection demonstrates the potential for scaling to other design stages.

Loading due to railway traffic on bridges has developed over time to suit the evolution of the rolling stock operating on a network and the understanding of dynamic effects. For the London Underground (LU) network, the development of loading was achieved through research work undertaken by the London Transport Executive in the 1960s and 1970s. The resulting load models were designated as RL (Railways London) loading, which were included in the former British Standard BS 5400-2:2006 and its predecessor BS 5400-2:1978. These standards also included load models for bridges on the GB mainline railway. The current loading standard for mainline rail traffic is Eurocode 1 for traffic loads on bridges (BS EN 1991-2:2003). However, the load models in the Eurocode are only representative of the rail traffic operating on the GB mainline railway and are not appropriate for rail traffic operating on the LU network, where mainline traffic is not permitted to run. The inclusion of RL loading in the Eurocode was addressed through an amendment of the complementary UK National Annex to BS EN 1991-2:2003. The background to the development of standards for railway bridge loading in general, but specifically for the RL load model, is explained in this paper.

Introduction. The ongoing climate changes in the permafrost zone associated with global warming significantly impact the temperature regime and the depth of seasonal thawing of permafrost soils. In current design practices, a constant calculated value for the depth of seasonal thawing is adopted; however, in reality, it varies and may exceed the design values. Existing regulatory requirements for design neglect this variation, which underscores the relevance of the study.Aim. To develop a methodology for forecasting changes in the thickness of the seasonal thaw layer based on climate parameters altering with warming.Materials and methods. The methodology of the study involved an analysis of contemporary scientific and technical literature, regulatory documents, methodological literature, and archival data from meteorological stations across Russia; determination of the relationship between changes in the depth of seasonal thawing over time; development of a forecasting methodology for changes in the thickness of the seasonal thaw layer based on climate parameters affected by warming; recommendations for utilizing the results in the development of regulatory and technical documents.Results. The depth of seasonal thawing significantly affects the cost and scope of foundation construction and land planning works. The existing calculation methodology fails to account for climate change trends. The permafrost zone of Russia displays an increase in the temperature of soils and the depth of seasonal thawing. The highest convergence of calculated results with field observations was achieved using the Borey 3D heat engineering program while considering climate change.Conclusions. The depth of thawing is to be determined using a heat engineering program that accounts for climate change. Determination of the foundation bottom depth, as well as strength and deformation calculations, are to consider changes in thaw depth during operation and the impact of global warming.