编号 9 (2025)

In the context of the active development of the metro system, special attention is given to ensuring the safety of existing buildings and structures located in the construction impact zone. The construction of new tunnels near operational metro facilities may lead to undesirable deformations, including the subsidence of structures or rail threads. The aim of this study is to identify the key factors influencing the subsidence of the shallow station structure of the Moscow Metro during the construction of a tunnel using a tunneling boring machine (TBM) directly beneath it. The initial data are based on results from geotechnical monitoring, compared with the technological parameters of tunneling – the average ground support pressure at the face (p), the volume of ground output for installing one ring (v_g), the volume of injected grout into annular void (v_i) – as well as geometric characteristics (plan distance (r) and height (h) to the observation point) and the physical-mechanical properties of the soils. It was found that the most significant influence on the subsidence magnitude comes from the following parameters (in descending order of importance): r, v_g, p, v_i. Based on the identified factors, a subsidence forecasting model was constructed, explaining 90,9% of the sample variance and having a mean squared error (MSE) of 0,1353 mm², which confirms its high predictive accuracy and its adequacy for practical application.

The main data on piezostatic soil sensing (“Piezocone Penetration Testing — CPTU”), which allows, in addition to the soil resistance to probing, to determine the pore pressure in the soil adjacent to the probe, are considered. Focus is done on the pore pressure measured between the cone and the friction coupling u₂. The normalized probing parameters (q_t, Q_t, B_q, F_r) implicitly account the pore pressure u₂ are given, Foreign experts often use these parameters when drawing up map-diagrams to identify soil varieties (“q_t–B_q”, “q_t–F_r”, “Q_t–F_r”, “Q_t–B_q”, “Q_t(1–B_q)–F_r”, etc.). Recently, many of the foreign map-diagrams, starts to be used in Russian geotechnical practice, including compiling computer programs for processing sensing data without conducting comparative studies. The article presents the experimental results to verify possibility of using foreign “q_t–R_f” and “q_t–B_q” card schemes proposed by P.K. Robertson et. al. The comparative experimental studies shown impossibility to use these foreign maps-schemes for soil varieties identification and determination on the territory of Russia during engineering and geological surveys due to their unreliability.

In some cases, when drilling piles are installed in permafrost soils, mixtures are made with chemical additives to ensure concrete hardening. During such piles installation heat and mass transfer between the concrete mixture and the soil occurs, which lead to artificial base salinization. Presently the regulator does not recommend to use such piles in the cryolithozone due to insufficient knowledge and lack of reliable calculation methods. The purpose of the work described in this article was to refine the methodology for the bearing capacity of drilling piles in artificially salted permafrost soils determining. Comparative analysis has shown the insufficient accuracy of the standard method for shear strenth determining. Proposals to refine the methodology for the determining bearing capacity of piles by introducing an operating conditions coefficient γ_sh,sal assumed to be equal to the ratio of the calculated frozen soil shear strenth in artificially salted and unsalted conditions are made. The maximum long-term artificially salted soil shear strenth is proposed to determine depending on the salinity degree, and the pore solution concentration to determine by calculation using a known model. The methodology was tested using data from static tests of full-scale piles by calculating a set of coefficient values for sandy soil and a concrete mixture including sodium methanoate as an antifreeze component and a multifunctional modifier. It is shown that the improved methodology makes it possible to increase the calculation reliability.

This paper discusses issues related to the design of deep excavations. During the writing of the article, the experience of deep excavation designing was summarized and the main aspects of current approaches to solving this issue were highlighted. An analysis of the most popular software used in geotechnical practice was also carried out. The main features were highlighted. During the analysis and comparison of the most common geotechnical software systems with calculation programs from other fields, a promising direction for the development and improvement of the current capabilities of foreign and local software systems was identified. A solution based on probabilistic analysis was proposed. It makes possible to increase not only the reliability of design solutions, but also the economic efficiency of deep excavation design in case of dense urban development. The direction of automation of the design process is very relevant today and allows you to significantly reduce costs not only for the labor costs of the design companies, but also for the final implementation of construction. The automated approach will not only reduce the probability of making the mistakes during calculations but also provide a better understanding of geotechnical design. The combination of approaches based on probabilistic analysis and the idea of automation opens up wide horizons for future research.

The article is devoted to an in-depth study of modeling patterns of wind flow distribution over a geometrically complex curved surface covering a unique large-span building based on a comparison of two options for performing aerodynamic calculations. The first method consists in conducting a computer experiment on a digital model of the projected object in computational fluid dynamics software systems. The second one is based on the implementation of simplified calculation procedures according to the methods set out in the regulatory documents adopted in the construction industry. When performing a computer experiment, the characteristic features of modeling in the ANSYS CFX software and computing complex are highlighted, such as the construction of a computational model, the formation of a computational grid of finite elements, and the setting of a height-varying wind profile in three of the most relevant directions. Special attention is paid to the correct setting of boundary conditions, which is critical for obtaining reliable results. According to two calculation options, adapted patterns of wind pressure distribution over the curved surface of the building are presented and a comparative analysis of the results is performed, reflecting an excess of wind loads calculated according to regulatory documents by about 1.5–2 times in relation to the data obtained during computer modeling.

In the part 3 of the article about methods of urban heritage regeneration by means of integrated landscaping, topical issues, tasks and methods of engineering networks integrated reconstruction in the historical neighborhoods regeneration and reconstruction context are considered. In order to preserve the historical and cultural protected areas and ensure the preservation of the heritage of the quarters, it is proposed to include in the improvement programs planning and technical measures to improve drainage, comprehensive engineering networks reconstruction, special measures to protect against geoecological processes affecting historical buildings physical preservation. To ensure the preservation of the heritage, an interdisciplinary and interdisciplinary methodology and methodology for the reconstruction and modernization of engineering networks in the improvement of residential areas under the programs of the national project “Infrastructure for Life” and the Integrated development of territories are proposed. It is shown that carrently there are new prospects for historical neighborhoods engineering reconstruction and landscaping by improving, modernizing networks and geotechnical protection of facilities and territories by means of geosynthetic materials,drainage PVC pipes, trenchless laying or reconstruction usage.