bluuebunny/crossref_metadata_2025_split huggingface dataset:
Influence of possible water saturation of loess soil on the stress-strain state of the foundations of a multi-storey building
Authors: Zhuk Veronika , Pavlenko Iryna 
Published: December 2022

The consequence of human activity in the field of construction is an increase in the density of buildings. As a result, areas that were previously considered risky from the point of view of the quality of soil conditions or increased saturation of the soil stratum with underground communications are allocated for development. All these factors are of direct importance when it comes to the use of loess soils as a basis for the design, erection and operation of new construction facilities.
Loess soils cover about 80% of the territory of Ukraine. These soils have a negative feature - the ability to reduce their mechanical properties when in contact with water and give additional collapse deformations. Therefore, a significant part of the buildings is erected in such soil conditions. That's why, the foundation structures of these buildings and structures must be designed taking into account the possibility of uneven deformations. For this reason, the relevance of taking into account the joint work of the "collapsible base - foundation - above-ground structures" system does not decrease, but even increases.
Loess soils in a dry state have good physical and mechanical characteristics due to structural bonds. However, with increasing humidity, the soil porosity undergoes a sharp change, the compressive strength decreases rapidly, structural bonds are destroyed and collapse deformations occur.
The search for a reliable and economical option for foundation structures is an urgent issue in the design of buildings and structures at the modern level. This is especially relevant in the conditions of construction on soils capable of collapsing with possible water saturation.
The work presents a variant design of the foundations of the building. At the same time, the impact of possible water saturation of the loess soils of the base on the stress-strain state of the foundations was considered. Different schemes of possible soaking of loess soils were considered. Different sizes and locations of water saturation zones within the building plan were considered. An analysis of the results of the numerical simulation of the joint work of the elements of the "base - foundation - above-ground structures" system was performed. The choice of the most reliable foundation option is substantiated. It has been confirmed that the size and location of loess soil water saturation zones influence the redistribution of stresses in foundation structures. It is shown that the use of variable design of foundations allows choosing an economical and reliable foundation option, if we consider different options for their parameters and take into account the negative factors of the soil conditions of the construction site and emergency situations that may occur during the operation of the building.
Determination of the impact of pile modeling methods on the distribution of forces in the pile foundation
Authors: Bondareva Liudmyla , Nechiporenko Dmytro 
Published: December 2022

The effect of the pile and the soil environment modeling method on the distribution of forces in the pile foundation and its deformation was studied and analyzed.
Based on the obtained results, the difference in the distribution of forces in piles and the difference in the settlement of the pile foundation was demonstrated. A comparison is drawn between the models, in which elements of the scheme such as "base" and "foundation" were made using different methods. The zones where the peak forces are the largest and the smallest were marked.
The structural scheme and geological conditions are based on the existing project, as well as engineering and geological investigations.
The finite element model of the building consists of a base, underground, and above-ground structures. A linear-elastic model with the following soil parameters was used to simulate the work of the base: E – modulus of elasticity; V – Poisson's ratio; as well as the elastoplastic Mohr-Coulomb model, in which the soil is defined by the following parameters: E – modulus of elasticity; V– Poisson's ratio; c – cohesion; φ is the friction angle. The calculation was performed with the help of the LIRA-SAPR 2017 software complex.
In order to improve the accuracy of the calculation of the results, the identification of the parameters of the base was carried out, where the results of in-situ test piles for static indentation were used as the initial data. The soil parameters, which were obtained in the result of identification, were applied to the model of the soil environment in the calculation scheme. As a result, it is possible to assess the influence of the identification parameters on the change in the stress-strained state (SSS) of the foundation structures as well as compare the forces values in piles and the deformation of the foundation before and after the identification.
With the development of technologies and software complexes, the number and variability of calculation methods were increasing, as well as the variety of calculation models. Each calculation model is unique and created with a certain goal – to make the calculation results closer to the real work of foundation structures. It is necessary to make the most effective and rational modeling method to achieve the goals set, as well as to obtain a quick and accurate result.
The influence of the rigidity of the joints of the panel house on the stress-deformed state of the foundation structures
Authors: Nosenko Viktor , Kashoida Ostap 
Published: December 2022

The work compares the stress-deformed states of the pile foundations of the house depending on the method of modeling the joints of the wall panels.
The use of wall panels is due to the fact that their installation is a relatively fast technological process, but the disadvantage of such buildings is, among other things, the lack of free spatial planning [1]. During the creation of a numerical model, questions arise: what method (type of connection of panel elements to each other) should be used to model the joints of prefabricated reinforced concrete structures and how does this affect the stress-strain state in above-ground structures and foundations?
This paper presents the influence of the adopted decision (chosen method of joint modeling) on the stress-strain state of pile foundations.
A comparison was made of the stress-strain state of the pile foundation (piles and grid), which were obtained using the following joint modeling options:
1) reinforced concrete elements: monolithic floor, monolithic staircase-elevator shaft and prefabricated wall panels are rigidly connected to each other.
2) the joints between reinforced concrete elements are made using the principle of "combination of movements", i.e., the nodes of the finite elements of the structures are stitched and interact with each other on the basis of certain parameters: horizontal joints - only vertical movements are taken into account (combination movements in the HSC along the Z axis); vertical – take into account movement only in the horizontal plane (along the X and Y axes, in GCS);
3) joints between reinforced concrete elements are made using the functionality of PC "Sapphire". Horizontal joints take into account filling with solution (the so-called platform joint), the behavior of which is described by the elastic law of deformation. Vertical joints take into account embedded details, with the help of which elements are connected to each other in the corresponding places foreseen by the project.
It is shown that the choice of modeling option for the joint of reinforced concrete structures affects the VAT not only of the foundation structures, but also of the vertical load-bearing elements of the building (wall panels and monolithic structures of the stair-elevator shaft). When using various joint modeling options, it is possible to obtain quantitative differences in forces from 2 to 20%, and the type of joint practically does not affect the deformation of foundation structures.
Assessing the impact of the process of constructing foundation pit enclosure structures on surrounding building
Authors: Bondareva Liudmyla , Khoronzhevskyi Maksym 
Published: December 2022

An important issue in the calculations of retaining structures of pits and their interaction with the foundation and existing structures is taking into account the features of their installation technology. Quite often, during calculations, this factor is ignored or taken into account by introducing correction factors, which are somehow based on the statistical processing of observation data during the construction of similar objects.
The development of numerical methods has enabled designers to use detailed finite-element models in calculations to more accurately predict the behavior of bases and structures, without spending excessive amounts of time.
In this work, numerical modeling methods are used to reproduce the process of installation of the pit enclosure structures using the trench method "wall in soil" to determine its impact on existing buildings. For this, a numerical model of a 9-floor building with a soil massif was created. Modeling of the foundation pit and enclosure structures, which is installed next to the building, was done. At the same time, the use of a three-dimensional formulation of the problem made it possible to take into account the length of the wall panel and the technological sequence of the construction.
The existing methods of trench excavation modeling were analyzed and one of them was implemented in the calculation scheme.
The impact of various factors on the formation of additional deformations of the existing building was investigated, such as: L - distance from the foundation pit to the building; Нст - the depth of laying the sole "wall in the ground"; Lзхв - the length of the wall panel; ρг.р - is the density of the clay slurry.
Within each task, the settlement of the foundation of the building is determined with different input parameters: L={1,2; 3; 5; 10m}, Нст={12; 18; 24m}, Lзхв={3; 4; 5m}, ρг.р={1.05; 1.10; 1.30t/m3}. The results are presented in the form of graphs.
The results of the research show that the most determining factors affecting the «technological settlements» of the slab foundation of the building are the distance from the pit to the building and the depth of laying the sole of the "wall in the soil". With different combinations of these parameters, the values of calculated vertical deformations of the building can differ up to several times.
Assessment of fire exposure on the load bearing capacity of basement storey walls
Authors: Nosenko Viktor , Fesenko Oleg , Donets Taras 
Published: December 2022

This paper presents the numerical modelling of the fire exposure on structural element and its static analysis taking account of the material properties reduction due to elevated temperature.
The reinforced concrete wall of basement storey was subjected to one side fire exposure.
Advanced calculation methods were used to assess the fire exposure on the structural element as most reliable and approximate to fire test results. Thermal analysis was performed with LIRA-CAD software by the simulating of three main heat-transfer ways: thermal conductivity, convection and radiation. As a result of the thermal analysis, temperature distribution in the concrete and reinforcement parts of the structural element cross-section was obtained. The thermal analysis of the wall structural element was performed for 120 minutes in standard fire exposure. Reduction factors for the strength of concrete and reinforcement steel were determined based on the temperature distribution in the wall structural element cross-section. The cross-section is divided into a number of parallel zones of equal thickness where the mean temperature and the corresponding mean compressive strength is assessed according to the Zone method procedure. The fire damaged zone of thickness az at the fire exposed sides and reduced cross-section were obtained.
Static analysis of the wall load-bearing capa-city was performed using the procedure applicable for normal temperature design. The Deformation method for normal temperature design taking to account concrete deformation was used. The Deformation method for normal design taken to account concrete deformation at every step of iteration was used. The reduced load-bearing capacity of the fire damaged wall taking into account residual concrete strength was calculated and relevant load-bearing capacity diagrams were determined.
Assessment of the stress-strain state of pile foundations of a multi-story building with possible water saturation of loess soil
Authors: Zhuk Veronika , Pavlenko Iryna 
Published: December 2022

The increase in the density of buildings leads to the need to set aside for development areas that were previously considered unfavorable from the point of view of the quality of the geological conditions. Deposits of loess rocks cover almost 80% of the territory of Ukraine. Such soils are characterized by a negative feature - the ability to rapidly reduce their mechanical properties in contact with liquid and to cause additional subsidence deformations. Based on this, a significant part of buildings and structures is erected in conditions of the possible occurrence of uneven deformations due to water saturation of subsidence soils. Therefore, the foundation structures of these structures must be designed with taking into account the occurrence of subsidence of loess soils.
In their natural state, loess soils have sufficiently high mechanical characteristics due to structural connections. However, as the moisture content increases, the resistance to compression rapidly decreases, structural bonds are destroyed, and soil subsidence is observed.
The modern level of foundation structures design involves the search for a reliable and cost-effective foundation option. This is especially relevant in the conditions of construction on soils that have the property of settling with possible increase in moisture content.
The paper presents the results of a comparison of foundation options, taking into account the influence of possible water saturation of loess soils on the stress-strain state of foundation structures. Different schemes of possible water saturation of loess soils were considered depending on their size and location.
This publication is a continuation of the previously published work [4]. It was about the results of the research, which was devoted to the variant design of foundations using numerical simulation of the joint work of the elements of the "soil base - foundation - above-ground structures" system. According to the results of the study, the choice of a rational option of foundations was substantiated, based on its indicators of reliability and economic efficiency. The conducted research confirms that the size and location of the soaking zones of the subsiding soil affect the nature of the stress distribution in the foundation structures. It is shown that the variant design of foundations, taking into account the negative factors related to the soil conditions of the construction site, as well as man-made situations that may arise during the operation of the building, make it possible to design a reliable and at the same time cost-effective option of the foundations.
The effect of changing the structural scheme of reinforcing strip foundations with short piles
Authors: Maevska Irina , Blashchuk Natalya , Horodnik Liliya 
Published: December 2022

In the work, mathematical modeling of the reinforcement of the strip foundation of shallow laying with short piles is performed in two variants: reinforcement at the level of the sole of the existing foundation, reinforcement from the soil surface. For comparison, short piles of different lengths are considered in both versions. In order to verify the possibility of determining the bearing capacity of the reinforced foundation as a conditional foundation of shallow laying, mathematical modeling of the conditional foundation was performed for both variants of the design solution. In mathematical modeling, not only the length varies, but also the pitch of the reinforcement piles, as well as soil conditions. The obtained results were analyzed with a comparison of all options.
The results of the calculations showed that when using short piles, it is effective to switch to the reinforcement option, when there is no need to dig trenches to the level of the sole of the existing foundation, with the placement of the riser of the newly created foundation at the level of the paving or floor. This option excludes time-consuming work of manual digging of trenches, and also allows you to perform reinforcement work not with small grabs, but in an arbitrary manner. In general, this makes it possible to significantly reduce costs of labor, time and money.
Research has established that increasing the pitch of the piles leads to a decrease in the bearing capacity of the reinforced foundation for both short and long piles, and the consideration of the foundations as conditional arrays is most consistent with the option with a pile pitch of 3d (600 mm).
The results of the calculations also showed that the bearing capacity of the reinforced foundation, obtained by modeling in Plaxis, exceeds the bearing capacity calculated according to the recommendations of the standards. Therefore, the implementation of the load-bearing capacity of the piles and grillage of the newly created pile foundation during reinforcement improves the joint operation of its elements.
Trends in modern construction
Authors: Saviovskyi V. 
Published: December 2022

The article highlights the results of analysis and systematization of certain trends in the development of modern construction in Europe and Ukraine. It is indicated on the main directions of increasing the efficiency of investments in construction due to the improvement of structural and organizational and technological solutions.
It was established that one of the priority areas in construction is construction processes aimed at improving the thermal protective properties of buildings, namely, the device for heat insulation of external enclosing structures of walls, roofs, windows, and external doors. This area is key in domestic and European construction. According to statistics, more than 75% of existing civil buildings in Europe and more than 90% in Ukraine do not meet modern standards for energy conservation.
The next direction of development of construction technologies indicates the introduction of prefabricated and prefabricated monolithic structures. The direction in construction, which was recently dominant in our country and over time partially neglected, is reviving again at a rapid pace, both in Europe and in Ukraine. Full-assembly and prefabricated monolithic structures and technologies make it possible to carry out relatively simple technological processes of erecting buildings on a construction site with structures of high factory readiness. This reduces the labor intensity of construction processes, improves the quality of work and does not require a high level of qualification of individual construction professions, such as an installer.
One of the important areas of modern construction is the reconstruction of existing buildings and territories. The reconstruction of civilian buildings is aimed at restoring the operational properties of existing buildings with a possible superstructure, extension, reconstruction and their mandatory thermal modernization. These processes include disassembly of the roofs of low-rise buildings with their subsequent superstructure, extension of balconies, improvement of adjacent areas. These activities are aimed at extending the time frame and improving the conditions for the further operation of buildings. Also, the scope of work on the reconstruction of industrial buildings and territories for objects for civil, socio-cultural purposes, that is, their revitalization, is constantly expanding.
Methodology of imputed rent: rethinking of the own housing costs
Authors: Shcherbyna A. 
Published: December 2022

International comparisons of household expenditures on housing and communal services, despite a significant increase in tariffs, indicate an unreasonably low absolute and relative level of these expenditures in Ukraine. Analyzing this problem, the article considers the concept of conditional (imputed) rent (rent), which in recent years has been used as macroeconomic statistics and statistics on income and living conditions. The need to reliably determine the conditional rent is due to the differences in the formation of annual expenditures and incomes of households living in their own homes and those who rent housing.
The aim of the article is, however, to compare the statistical expenditures of households on housing and communal services, in particular on housing maintenance services in cases where households are homeowners or tenants and national statistical observations differ in the methods of determining conditional rent or no such definition at all.
The research methodology in this article deals with the definition of conditional rent in Ukraine in scientific publications on housing economics. Such publications are intended to clarify the idea of the full cost of homeowners necessary for its normal reproduction. Therefore, it is important how perfect the methodology for determining the conditional rent abroad is and how domestic statistics determine (or do not determine at all) the conditional rent.
The results of the study indicate the general problems of determining the conditional rent, related to the incompleteness of the information base required for calculations. At the same time, in domestic practice there is a methodological gap in the reflection of conditional rent in macroeconomic statistics of final consumption expenditures of households and the lack of a corresponding indicator in sample surveys of income and expenditure (living conditions). It is concluded that correct comparisons in domestic surveys, further improvement of housing statistics and adjustment of absolute and relative indicators of household expenditures using their own housing, and thus an overall increase in the share of expenditures on housing services.