Mechanical Characteristics Of Soil Research Articles

CONTACT INTERACTION OF AN UNDERGROUND PIPELINE WITH SOIL UNDER DYNAMIC IMPACTS

The interaction between a semi-infinite underground pipeline and the surrounding soil during longitudinal seismic wave propagation is examined in the article. The wave travels through the soil with its front perpendicular to the pipeline's axis, and the nonlinear laws of interaction (friction) on the surface of their contact, including the Amonton-Coulomb law, are used to solve related wave problems for the pipeline and soil. The method of characteristics and the finite difference method are sequentially used to solve these problems numerically. The implementation of the law of interaction (friction) processes is shown, depending on the parameters of the wave in soil and the mechanical characteristics of soil. It was determined that a wave in soil that involves the pipeline generates a powerful wave in the pipeline. The amplitude of this wave is many times greater than the amplitude of the wave in soil, and it propagates through the pipeline without attenuation. The dependences of the amplitude of this wave on the parameters of the law of friction, waves in soil, and the mechanical characteristics of soil are determined.

Assessment of different agricultural soil compaction levels using shallow seismic geophysical methods

A well-developed soil structure is crucial for a fertile soil and rules its influence on the ecosystem. Slight variations in the way soil components are organized and connected can greatly impact the soil mechanical and hydraulic characteristics. However, these features are challenging to measure at a scale that is relevant for agricultural management. In this study, we assess the capability of two seismic geophysical methods, i.e. Seismic Refraction Tomography and Multichannel Analysis of Surface Waves, to monitor the effects of compaction on agricultural bare soil. The purpose is to highlight the different mechanical response caused both by soil plastic deformation and soil water distribution due to increasing compaction. Results demonstrate that both geophysical techniques provide sufficient information to capture the effects of soil compaction and distinguish its significance, while traditional direct measurements, being punctual, lack sufficient spatial coverage. P-wave velocities carry a strong imprint of soil compaction, provided by seismic refraction, incorporating the information given by the multiphase medium in its entirety. On the other hand, S-wave velocity derived from Surface Waves discriminates the effect of solid matrix structure. This work, moreover, aims to pave the way for seismic methods to spatially characterize compaction at field scale, illustrating its potential and suggesting possible developments.

Evaluating vehicle trafficability on soft ground using wheel force information

In the areas of aerospace and military industry, wheeled vehicles are expected to have the ability of passing various ground surfaces, including lunar soil, sand, marsh, mud flat, etc. This makes vehicle trafficability on soft ground become a very hot research topic. There are very a few difficulties in the present research of vehicle trafficability on soft ground, such as obtaining wheel-ground interaction information, inaccurate identification of soil mechanical characteristics parameters, and single evaluation index. In this paper, a novel approach of evaluating the vehicle trafficability on soft ground using wheel force information is proposed. As parts of the proposed approach, the methods of obtaining wheel force information, identification of soil mechanical characteristics parameters and integated method of trafficability evaluation, are discussed in detail. The proposed approach was validated through a practical test.

Prediction of constrained modulus for granular soil using 3D discrete element method and convolutional neural networks

To efficiently predict the mechanical parameters of granular soil based on its random micro-structure, this study proposed a novel approach combining numerical simulation and machine learning algorithms. Initially, 3500 simulations of one-dimensional compression tests on coarse-grained sand using the three-dimensional (3D) discrete element method (DEM) were conducted to construct a database. In this process, the positions of the particles were randomly altered, and the particle assemblages changed. Interestingly, besides confirming the influence of particle size distribution parameters, the stress-strain curves differed despite an identical gradation size statistic when the particle position varied. Subsequently, the obtained data were partitioned into training, validation, and testing datasets at a 7:2:1 ratio. To convert the DEM model into a multi-dimensional matrix that computers can recognize, the 3D DEM models were first sliced to extract multi-layer two-dimensional (2D) cross-sectional data. Redundant information was then eliminated via gray processing, and the data were stacked to form a new 3D matrix representing the granular soil's fabric. Subsequently, utilizing the Python language and Pytorch framework, a 3D convolutional neural networks (CNNs) model was developed to establish the relationship between the constrained modulus obtained from DEM simulations and the soil's fabric. The mean squared error (MSE) function was utilized to assess the loss value during the training process. When the learning rate (LR) fell within the range of 10-5–10-1, and the batch sizes (BSs) were 4, 8, 16, 32, and 64, the loss value stabilized after 100 training epochs in the training and validation dataset. For BS = 32 and LR = 10-3, the loss reached a minimum. In the testing set, a comparative evaluation of the predicted constrained modulus from the 3D CNNs versus the simulated modulus obtained via DEM reveals a minimum mean absolute percentage error (MAPE) of 4.43% under the optimized condition, demonstrating the accuracy of this approach. Thus, by combining DEM and CNNs, the variation of soil's mechanical characteristics related to its random fabric would be efficiently evaluated by directly tracking the particle assemblages.

ЕКОНОМІЧНА ЕФЕКТИВНІСТЬ ВИКОРИСТАННЯ ОРГАНІЧНИХ ДОБРИВ З ПОСТІЙНО ВІДНОВЛЮВАЛЬНИХ ДЖЕРЕЛ ПОБІЧНОЇ ПРОДУКЦІЇ ТВАРИННОГО ПОХОДЖЕННЯ

This article is related to the study of the economic efficiency of using organic fertilizers from constantly renewable resources of animal by-products (chicken manure), taking into account the latest innovative technologies that reduce the cost of agricultural production while improving the results of economic activity of enterprises. It is proved that the utilization of animal by-products (chicken manure) through the production of organic fertilizers is one of the most valuable sources of nutrients. The ecological and economic benefits and prospects of using organic fertilizers, the main raw material component of which is chicken manure have been analyzed. The effectiveness of the usage of such organic fertilizers in intensive technologies of growing corn, sunflower and sugar beet has been tested and confirmed by scientifically based experimental studies. It is summarized that the production of organic fertilizers from chicken manure is a promisingly expedient, cost-effective resource for meeting the needs of the agricultural industry of our country in terms of nutrients. During the period of martial law, the most important current economic problem of our country is to overcome the decline in production by finding effective and optimal solutions for the reproduction of all its links. Today's dynamically changing conditions of the agricultural market require a mobilizing combination of efforts by the legislative and executive branches of government together with business owners to find and implement anti-crisis measures to ensure stable cooperation, improve the financial and economic performance of enterprises, and preserve and enhance soil fertility in the process of exploitation. Conservation, rational use of soils, and improvement of their fertility are a steadfast component of the sustainable constant of Ukraine's food, economic, social, environmental, and energy security. Being a key component of the sustainability of Ukraine's economy, including agriculture, organic fertilizers significantly contribute to increasing crop yields and improving their biological quality. An additional advantage is that they improve the agrochemical, biological, physical and mechanical characteristics of soils, positively affect soil fertility, and are much more costeffective for farmers.

Effect of leachate and used motor oil on the geotechnical and mechanical characteristics of soils with different mineralogy under different moisture conditions

ABSTRACT In order to evaluate the geotechnical characteristics of four types of fine-grained clayey soil, including clay with low plasticity (CL), calcium bentonite (CB), sodium bentonite (SB), and a mixture of 50% CL and 50% SB (CL-SB) from the effect of water, leachate and used motor oil (UMO) was used. Unconfined compressive strength (UCS), indirect tensile strength (ITS), standard compaction, Atterberg limit, and free swelling tests are performed. This results showed that the PI of SB, CB, CL, and CL-SB soils with leachate is 43, 25, 10, and 33% higher than water, respectively. The PI of SB, CB, CL, and CL-SB soils with UMO is 72, 66, 12, and 43% lower than water due to the low dielectric constant. Adding leachate compared to water caused a decrease in maximum dry density (MDD) for CL, CL-SB, SB, and CB by 2.6%, 4%, 6%, and 4.5%, respectively. Also, adding leachate and UMO reduces UCS and ITS of all soils. Due to SB soil’s high cation exchange capacity, the changes in its mechanical and geotechnical characteristics were higher than in other soils. Finally, the increase in soil moisture during the sample construction decreased the soil strength due to the addition of leachate and UMO.

Infiltration and shear strength characteristics of gully heads soil of typical vegetation on the gullied Loess Plateau, Northwest China.

Gully head is the main active part of gully erosion, which seriously affects the occurrence of gully headcut erosion. To investigate root distribution and soil physical and mechanical characteristics of typical vegetation gully head, we analyzed the infiltration, root distribution, physical and mechanical properties of soil-root complex of soil in different layers (0-1 m) in natural restoration gully head and artificial restoration gully head. The results showed that the variability of soil bulk and total porosity among different vegetation gully heads was low, with bulk density ranging from 1.10 to 1.37 g·cm-3 and total porosity ranging from 48.3% to 58.4%. Infiltration index of different vegetation gully heads generally decreased with increasing soil depth. The infiltration rate of different soil layers in natural restoration gully head tended to stabilize in 20-30 min, while that of artificial restoration gully head tended to stabilize in 40 min. The infiltration capacity and average infiltration rate of artificial restoration gully head were generally higher than those of natural restoration gully head in all soil layers. Root length density, root surface area density, and average diameter all tended to decrease with increasing soil depth. Except for the 20-40 cm soil layer, root length density, root surface area density and average diameter of natural restoration gully head were all lower than those of artificial restoration gully head. Root system of both vegetation gully heads mainly consisted of 0-0.5 mm roots, accounting for 84.2%-93.6% of the total root length. In the vertical depth, with the increases of water content, the cohesion force decreased linearly with the deepening of soil layer, ranging from 0.42 to 22.67 kPa. The average cohesion force of artificial restoration gully head was higher than natural restoration gully head at each level of water content. The study revealed the effects of vegetation on the gully head cut erosion, which could provide scientific basis for the effective prevention and control of soil erosion in the region.

Soil Reinforcement Model Test Using Timber Pile at Liquefaction Area

Indonesia is a tropical country threatened by many disasters, such as earthquakes and other collateral hazards (liquefaction). Utilization of micro pile on the liquefaction prone areas is quite popular to increase the soil bearing capacity. In this research, Eucalyptus Pellita Timber was used as micro-piles alternatives. This study aims to determine the effect of timber pile addition on soil settlement and the increase in bearing capacity. Some laboratory investigations were conducted, such as timber and soil physical and mechanical characteristics, preloading tests, and seismic load tests by using small-scale shaking table test. The preloading tests were carried out for 40 days, and the settlements were recorded every 24 hours. Subsequently, seismic load tests were conducted on sandy soil with Dr = 40%. The seismic duration was 37 seconds, with PGA = 0.3 g and f = 0.78 Hz. The preloading test results show that Eucalyptus pellita timber piles are able to reduce the settlement by 18%. and from seismic load testing results are able to reduce the settlement by 68% due to earthquake loads with PGA = 0.3g and a frequency of 0.78 Hz on sandy soil with the potential for liquefaction. This is due to the resistance at the tip of the pile and the skin friction on the timber pile. So, from the results of the model test, it shows that the use of Eucalyptus Pelita timber piles can be used as an alternative to handling sandy soils in areas where liquefaction has the potential to occur. Doi: 10.28991/CEJ-2023-09-06-016 Full Text: PDF

Effects of Acidic/Alkaline Contamination on the Physical and Mechanical Properties of Silty Clay

Contaminated soil management and renovation is one of the major environmental geotechnical issues in China. Due to their special strength and stiffness properties, contaminated soil has attracted extensive attention in foundation and slope stability design. For the differentiated influence of acidic/alkaline contamination on the geotechnical physical and mechanical characteristics of soil, this study mainly introduced a remodeled silty clay sample contaminated by acidic and alkaline solutions in the laboratory and conducted research into its basic physical properties, compressive properties, shear strength, and microstructure. It was shown that when the hydrochloric acid concentration increased from 1% to 7%, the density and specific gravity decreased by 7.07% and 3.11%, respectively. The void ratio showed a descending trend with increasing concentration of acid. The acidic solution concentration was negatively correlated with the cohesion of the soil, but the internal friction angle remained constant with a concentration of 1–5%. Alternatively, when the sodium hydroxide concentration increased from 1% to 7%, the density and specific gravity increased by 1.88% and 2.67%, respectively. The void ratio decreased linearly with the increase in consolidation pressure. Alkaline concentration could affect the internal friction angle and cohesion in a positive correlation. Through the observation of microstructure, the surface of acidified soil particles was smooth and flat, while the surface of alkalized soil particles was rough and uneven. The results can provide reference for the evaluation of the mechanical properties of soil contaminated by acid and alkali.

Prediction of principal stresses from external loads in sandy soils and ash-slag mixtures

Introduction. Earlier studies indicate that a change in the structure of any material triggers a change in its stress state development pattern. It is obvious that when the type of soil, humidity and density of the massif change, its mechanical characteristics and the stress state change respectively. Therefore, to study the influence of genesis on the stress state, the authors analyzed dependences, proposed for predicting maximum principal stresses arising in soil massifs subjected to external loading by a round plate. The analysis shows that taking into account the features of the stress state development in the proposed models is connected with mechanical characteristics of soils. However, previous studies show that these dependencies are not universal.
 Materials and methods. To verify the adequacy of the solutions, experimental studies were conducted to determine pressures arising in sandy soils, ash-slag mixtures subjected to external loading. Physical and mechanical characteristics of the materials in the state under study were determined (such as the angle of internal friction, specific adhesion, modulus of deformation (elasticity)).
 Results. The experiments show that the pressure attenuation intensity increases with depth along with the increasing density of massifs, regardless of the genesis, and attenuation is more intense in ash-slag mixtures. The authors have found that the development of stresses in soils of various genesis can be described by applying solutions based on the mechanics of the granular medium (Kandaurov’s solution) and continuum mechanics (this solution was proposed by Frohlich).
 Conclusions. The results of the work demonstrate the need to employ different approaches to predicting the stress state in soils of various genesis. Correlations between mechanical characteristics of soils (such as the friction angle and the modulus of elasticity) and parameters of the distributing medium indicate the need to study clay and other types of man-made soils.

Condition Monitoring of the Unfinished Frame Building's Load-Bearing Structures in the Railway Zone

The current technical condition of the load-bearing structures of an unfinished frame building after downtime and under the influence of dynamic loading in the railway zone is considered. The construction under investigation was designed as a railway administrative building. The results of monitoring the technical condition of the elements of building structures of a frame building Real physical and mechanical characteristics of soils were studied on prototypes. The results of a visual survey and field measurements of foundations in control holes, surveys of foundation structures and characteristics of the soil base are presented. Calculations of the strength of concrete foundations and columns were done. Recommendations for the repair of foundations, taking into account the substantiated category of their technical condition have been developed.

Study results of a stress-strain state of a pylon station construction from monolithic reinforced concrete in the engineering and geological conditions of St. Petersburg

In recent years, structures made from monolithic reinforced concrete have been increasingly developed in the field of underground construction. This has been made possible by the development of modern tunneling technologies such as NATM and ADECO&RS, which have proven themselves abroad. Being low-sedimentation methods of underground structures construction, they have found wide application not only in mountain transport tunneling but also in construction in an urban environment, where precipitation and negative impact on the surrounding infrastructure has a decisive role in the choice of one or another technology. Foreign experience of construction in the same physical and mechanical characteristics of soils gives reason to assert the possibility of using new technologies in our country. However, this task requires a comprehensive approach to its solution. This article presents an experimental and theoretical substantiation of a pylon station lining made from monolithic reinforced concrete in the engineering and geological conditions of St. Petersburg on the example of the planned St. Petersburg Metro station “Chernigovskaya” of the “Krasnoselsko-Kalininskaya” line being built from “Obvodniy Kanal-2” station to “Yugo-Zapadnaya” station.

Prediction of the Radon Situation in Buildings Constructed Under the Renovation Program

The paper is devoted to the study of the regularities of the radon situation formation in modern multi-storey buildings at the design stage. Calculation schemes for radon entry into the premises of the lower and upper floors are constructed, a method for determination of radon concentration in the building after its erection is proposed. It is based on a joint analysis of the soil base physical and mechanical characteristics of and the design features of the underground shell of the building. According to the calculations results, a significant role of air exchange in the formation of a favorable radon situation in the building was noted.

One−Dimensional Seepage of Unsaturated Soil Based on Soil−Water Characteristic Curve

The uneven pore water distribution in unsaturated soil will cause water movement, change the hydraulic and mechanical characteristics of soil, and then cause soil damage. Therefore, it is important to study the hydraulic characteristics of unsaturated soil. In this paper, the law of conservation of mass and Darcy’s law were used to analyze the unit soil after seepage to obtain a continuous equation. Combined with the soil-water characteristic curve (SWCC), the effect of matric suction and permeability coefficient of unsaturated soil on infiltration rate is substituted into the equation. Through the analysis of pore water stress of the unit soil, the function of the unsaturated permeability coefficient with the effective saturation degree is obtained, and the theoretical formula of the one-dimensional infiltration rate of unsaturated soil is derived. Compared with other models, this formula has fewer parameters and is easy to use.

Study of the reliability and efficiency of using reinforced soil models within the framework of the finite element method

Within the framework of the finite element method, the influence of the dimensions of the calculation model on the values of subsidence when using different soil models was studied.
 Numerical calculations of the soil environment based on FEM differ from analytical ones in that a necessary condition for their application is the choice of a soil model, which is characterized by a different theoretical basis, which, with the help of equations of different complexity and input parameters of a different number, describe the behaviour of the simulated soil massif.
 Given that the numerical solution of problems based on FEM involves the modeling of objects as a finite limited area, the question of choosing the lower limit of the calculation model in the study of subsidence is acute.
 The stiffness of soils in their natural state increases with the depth of their occurrence. In simple soil models, such as the Mohr-Coulomb model, soil stiffness is a constant value. This circumstance leads to the fact that during numerical calculations, the deformations of subsidence increase linearly when the dimensions of the calculation model increase vertically.
 Advanced models, such as Hardening Soil, can take into account the soil strengthening when the stress level increases, however they require a wide range of soil characteristics, which are determined by experimental methods, using special equipment, and the determination of a number of parameters is not regulated by regulatory documents.
 It is shown that the use of the reinforced soil model proposed by the authors, which, on the one hand, complies with state building regulations, and on the other hand, does not require the involvement of additional physical and mechanical characteristics of soils, allows obtaining more accurate values of the parameters of the stress-strain state of the foundation.

Soil micro-penetration resistance as an index of its infiltration processes during rainfall

Rainfall infiltration is one of the most important driving factors of geological hazards, ecological environment problems, and engineering accidents. Understanding the principle of soil wetting during rainfall infiltration and its influence on soil mechanical properties is crucial for preventing geological hazards. In this study, micro-penetration tests coupled with moisture monitoring were performed to investigate the infiltration process during wetting through the measured change in mechanical characteristics. Results show that penetration resistance increases in the deep layer gradually. With increasing infiltration time, the wetting front keeps moving downward, and its range becomes wider. A slight increase of the penetration resistance in the shallow layer ( d ≤ 17.5 mm) is observed. However, the penetration resistance in the middle layer (22.5 mm ≤ d ≤ 32.5 mm) decreases firstly before a slight increase. In the deep layer ( d ≥ 37.5 mm), the penetration resistance decreases continuously during infiltration. Based on the measured water content profile during infiltration, it is found that the evolution of soil mechanical characteristics is fully responsible by the infiltration-induced re-distribution of water content along depth. Generally, the penetration resistance decreases exponentially with increasing water content in the soil. When the water content is low, wetting can weaken soil strength significantly, whereas this effect diminishes when the moisture surpasses a certain threshold. The results highlight that the penetration curves and water content profile show close inter-dependency and consistency, which verifies the feasibility of using micro-penetration to investigate rainfall infiltration and wetting process in surface soil layer or laboratory small-scale soil samples. This method enables fast, versatile and high-resolution measurements of infiltration process and moisture distribution in soil. • Micro-penetration was proposed to study rainfall infiltration in surface soil. • Relationship between soil penetration resistance and water content was established. • Moisture infiltration behavior is different at different depths. • Penetration curve and water content profile show close inter-dependency. • Micro-penetration provides refined investigation of soil hydro-mechanical behavior.

Identificación de tipos de deslizamientos en la zona de acantilados entre Ancón y Anconcito, Santa Elena, Ecuador

On the Ecuadorian coasts, landslides are frequent that occur on cliffs that correspond to an instability maintained by the mechanical characteristics of soils and rocks in which there are discontinuities, fault planes that are activated by precipitation or coastal erosion; for this reason, this research was focused on identifying the different types of landslides found in the coastal cliff areas of Ancón and Anconcito in the province of Santa Elena, this study was carried out by photogrammetric flights with UAV technology, carried out by three flights in the study area. It was found that the study sector corresponds to an inclined rocky coast, where mass landslides (soils) and rockslides were found, such as: rotational, earth flows, erosion gullies, falling blocks, sinkholes, planar breaks, and wedge breaks. The results identified in the studied areas highlight the importance of knowing how susceptible they are to different types of movements due to high coastal erosion due to wave incidence and other factors, on the other hand, research should be carried out to show how much the coastal retreat is (m/year) produced by landslides in these areas.

Transfer Factor of Heavy Metals due to Mining Activities in Plateau State, Nigeria (Health Implications on the Inhabitants)

Accumulation of heavy metals in agricultural soils is instigated by industrial and other human activities such as mining, smelting, cement-pollution, energy and fuel production, power transmission, traffic activities, intensive agriculture, sludge dumping and melting operations. Plants received heavy metals from soils through ionic exchange, redox reactions, precipitation-dissolution, and so on. Which implies that the solubility of trace elements based on factors like minerals in the soil (carbonates, oxide, hydroxide etc.), soil organic matter (humic acids, fulvic acids, polysaccharides and organic acids), soil pH, redox potential, content, nutrient balance, other trace elements concentration in soil, physical and mechanical characteristics of soil, soil temperature and humidity, and so on. In this study, the soil-edible plant and soil-water Transfer Factor (TF) for various metals showed that the TF values differed slightly between the locations. On soil-edible plant transfer, the mean TF for different heavy metals in soil-edible plants decreased in the following order: As (0.6) mg/kg > Cd (0.1) mg/kg > Cr (0.06) mg/kg > Pb (0.003) mg/kg > Ni (0.001) mg/kg. The total TF for different location decreases in the following order: Barkin Ladi (1.0) mg/kg > Jos South and Jos East (0.7) mg/kg > Bassa and Mangu (0.6) mg/kg. On soil-water transfer, the mean TF for different heavy metals in soil-edible plants decreased in the following order: Cd (0.001) mg/l > As (0.0007) mg/l > Cr (0.0005) mg/l > Pb (0.0001) mg/l and Ni (0.0001) mg/l. The total TF for different location decreases in the following order: Jos South (0.003) mg/kg > Barkin Ladi, Bassa, Jos East and Mangu (0.002) mg/kg. Based on the findings of this study, it can be concluded that the water and edible plants in the study area are good for public consumption, even though, regular checking of heavy metals in the study area is recommended.

A UNIVERSAL METHOD FOR ASSESSING THE BEARING CAPACITY OF THE BASE OF A PRESSED PILE BASED ON THE SOLUTION A PARTICULAR PROBLEM OF SOIL MECHANICS ABOUT ITS STABILITY AND THE USE OF PHYSICAL AND MECHANICAL PROPERTIES OF SOILS

The article presents a universal method for assessing the ultimate resistance of base foundations to the pressing of piles of all types (ready-made, stuffed), according to the classification of TKP 45-5.01-254-2012, according to the physical and mechanical characteristics of soils, taking into account their design parameters, technological aspects of manufacture and device. The method is developed on the basis of the proposed analytical solution of a particular problem of the theory of the ultimate equilibrium of soils in relation to the stability and bearing capacity of the base of a single pile loaded with vertical indentation/pulling force in a flat formulation. The calculation of the characteristic (bearing capacity) and design limit resistance of the foundation to the pressing of piles is carried out using partial coefficients that take into account the possibility of deviations of the structural, technological parameters of piles, soil properties from their representative values and the uncertainty of the soil model compared with the actual behavior of the loaded soil. The deviation of the calculation results according to the proposed method from the experimental data on the results of testing piles with a static indentation load is within the error of the test method.

Оценка технического состояния оснований, фундаментов и железобетонных колонн каркасного здания

The paper presents the results of assessing the technical condition of foundations, foundations and reinforced concrete columns, which are elements of building structures of a multi-storey frame public building. The results of the survey of foundation structures and the characteristics of the soil base are given. The physical and mechanical characteristics of soils were determined using samples taken from the pits during the survey. The results of visual examination and field measurements of foundations in control pits are given. The results of calculating the strength of concrete foundations and columns are given. The construction and correction of the calibration dependence of the indirect non-destructive testing method was carried out on the object using the method of separation with shearing. The results of verification calculations of foundations are considered. Defects and damages of foundations were revealed. The category of technical condition of bases and foundations is substantiated. Recommendations for the repair of foundations have been developed. The design and reinforcement of columns are considered. Identified defects and damage to the columns. the results of verification calculations of columns are given. The category of the technical condition of the columns is determined. Recommendations for the repair of columns have been developed. Defects and damages of reinforced concrete columns recorded in the list of defects and damages are investigated. The main conclusions are made based on the results of a survey of foundations and reinforced concrete columns of a multi-storey frame building.