Development Of Emergency Situations Research Articles

Special features of using neuronetwork technolo-ies to control the work processes of bulldozers with a gnss-intensifier

Abstract. Problem. The specificity of modern road construction works requires evaluation of the situation; forecast of the machine's normal operation and the development of emergency situations; synthesis and evaluation of possible actions of the operator and selection of the best ones. That is, there is a problem of effective support of the road car, whose solution is transferred to the intelligence of the car itself. A distinctive feature of intelligent systems is the ability to plan behaviour, adapt and learn. An intelligent system automatically changes the algorithms of its functioning and the structure in order to preserve or achieve an optimal state when external conditions change. The integration of algorithmic methods of controlling complex objects and methods of artificial intelligence is aimed at solving the tasks with uncertainty of the source information. The implementation of intelligent systems shows their prospects in the field of road construction works. Thus, optimization of road machine work processes, increasing the efficiency of road-construction machines (RCM) due to an intelligent control system is an urgent task. Studying the structure of the intelligent system of the road machine is relevant as well as developing a mathematical model of intelligent optimization of work processes based on the complex of readings of integrated GNSS sensors. Goal. The purpose of the research is to increase the efficiency of construction machines through their intellectualization, development of scientific algorithms for creating mathematical models of the working bodies of the RCM with SNS-intensifier of work processes of interaction with the soil environment. Methodology. In the paper the scientific methods of system analysis and decision-making theory for the structuring and synthesis of intelligent control systems are used; mathematical modeling methods for building and researching hydraulic and dynamic models of road vehicles; theories of automatic control under conditions of uncertainty; methods of object-oriented programming for simulation modeling of a road machine work process during operations. Results. For the first time, the methods of solving the problem of controlling the hydraulic drive of a road machine were offered, which, unlike traditional ones, take into account the execution of digging operations in conditions of a short decision-making time, which ensures the movement of the working body along an arbitrary trajectory in a short time with high accuracy. Originality. This paper is one of the first in Ukraine in which the scientific problem of increasing the efficiency of RCM at the interaction of working bodies with the soil environment in conditions of limited time for decision-making was formulated and solved. Practical value. Time of work is cut due to the reduced number of passes during soil development and increasing the productivity of RCM, which will have a positive effect on financial and labour costs, ensuring the possibility of continuous operation, which increases the productivity of RCM.

"Human factor" in emergency situations development at Nuclear Power Plants in the conditions of war

Since the beginning of Ukraine's full-scale war with the russian federation, the personnel of two Ukrainian Nuclear Power Plants (NPP) (Chornobyl and Zaporizhzhya) have been held hostage by the russian occupiers and subjected to intimidation and abuse. An additional strong stress factor can significantly affect the decision-making of NPP control panel operators, increases the probability of erroneous actions in the event of emergency situations, and can even become their cause. The purpose of our study was to determine the possible influence of the "human factor" on the development of emergency situations, as well as additional parameters for monitoring the health and psychological state of NPP operators working as hostages. Fourteen expert psychologists with at least 10 years of experience in the field of extreme psychology were involved in the study. After the introductory seminar, they were offered a questionnaire to determine the range of professionally important qualities that have the greatest impact on the effectiveness of professional activity. The results of the expert evaluation became a hypothesis for the next stage of research on the possible influence of the temperament of operators on resistance to the stress of captivity. The technique of professiograms and psychograms separation, methods of scaling and balancing, methods of mathematical statistics and system analysis were used for the research. One hundred and twenty-four anonymous psychological examination cards and occupational profiles of NPP control panel operators who received a license for professional activity in Ukraine or improved their qualifications within the period of 2017‒2020 were analyzed. The predominant types of psychological reactions according to subjective-objective indicators in response to significant stressful situations were studied, and the types of temperaments were determined. The ability to perform professional functions at high and medium levels was recorded in 79 sanguine operators (63.2% of the total number of examined), in 16 choleric operators (12.8%), and was not recorded in melancholic operators. Also, high and medium levels of neuropsychological stability of operators were recorded in 74 sanguine operators (59.2% of the total number of examined), in 6 choleric operators (4.8%), and was not recorded in melancholic operators. To assess the psychological state of NPP control panel operators, it is proposed to use a retrospective analysis of interrelated parameters necessary for the performance of professional functions and indicators of neuropsychological stability. The study of additional parameters of the psychological state will allow to reduce the influence of the "human factor" on the risks of creating or untimely correction of emergency situations. Keywords: professionally important qualities, nuclear terrorism, hostages, performance of professional functions, neuropsychological stability, NPP control panel operators.

АНАЛИЗ СООТВЕТСТВИЯ НОРМАТИВНО-ПРАВОВЫМ АКТАМ РФ ПОРЯДКА ОБЕСПЕЧЕНИЯ ПОСТОЯННОЙ ГОТОВНОСТИ СИЛ И СРЕДСТВ К ЛОКАЛИЗАЦИИ И ЛИКВИДАЦИИ ПОСЛЕДСТВИЙ АВАРИЙ НА УСТАНОВКЕ ПРОИЗВОДСТВА СЕРЫ

Uncontrolled development of emergency situations at hazardous production facilities can lead to significant damage and loss of life. To reduce possible human and material losses, the Angarsk Petrochemical Company has established a special procedure for ensuring the constant readiness of forces and means to localize and eliminate the consequences of accidents. The work is devoted to assessing the compliance of this procedure with the regulatory legal acts of the Russian Federation

Стохастическое моделирование каскадных сценариев возникновения и развития чрезвычайных ситуаций

Introduction. The development of methods for modeling the flows of events in the occurrence and development of emergency and critical states, designed to solve the problems of supporting the management of rapid response to incidents in conditions of incomplete information, as well as the generation of preventive algorithms for rapid response in emergency situations, seems to be a promising direction for improving information and analytical support of management in security systems. The purpose of the research is to create mathematical tools for predicting emergency and critical conditions in local incidents based on discrete-event modeling of the dynamics of emergency situations. Methods of stochastic modeling are based on the representation of a cascade scenario of the dynamics of the development of accidents and catastrophes by a Markov process using a three-parameter Weibull distribution to set the intensities of transitions between emergency and critical states of adjacent levels. Results and discussion. A general stochastic model is constructed that describes the dynamics of the occurrence and development of accidents and catastrophes of technogenic and natural origin initiated by local incidents according to a cascade scenario with a branching structure with a set of possible elementary states represented in the form of a stratified graph. The main stages of the emergence and development of emergency situations are considered within the framework of the proposed representation of the cascade model by a Markov process with discrete states and continuous time. The expediency of local modeling of individual stages is substantiated based on the description of transitions between states of adjacent levels. Local systems of differential equations corresponding to some of the most probable scenarios for the development of events in the event of incidents are given. Non-stationary solutions of differential equations of Kolmogorov-Chapman are obtained, with assignment of intensities of transitions by three-parameter Weibull distributions. Conclusions. The proposed stochastic model makes it possible to predict the dynamics of the development of emergency and critical states according to a cascade scenario, and also reflects the probability characteristics of the timeliness and effectiveness of possible impacts in a prompt response to incidents. Keywords: stochastic modeling of technogenic accidents, cascade development of accidents and catastrophes, Weibull distribution.

Analysis of regulatory and legal support in the sphere of population protection under military state

The article analyzes the regulatory framework of Ukraine to ensure the protection of the population under martial law. The main attention is focused on the Constitution of Ukraine, as well as the Code of Civil Protection of Ukraine, defining its advantages. The conclusion is made about the duplication of the Laws of Ukraine "On the Civil Defense of Ukraine" and "On the Legal Basis for Civil Protection" in terms of terminology. An attempt was made to divide the formation of civil protection of Ukraine into three stages. An important step in the development of the system of protection of the population in emergency situations was the Law of Ukraine "On the Protection of the Population and Territories from Emergencies of a Man-made and Natural Character", which fixed the organizational and legal foundations for the protection of citizens of Ukraine, foreigners, stateless persons located on the territory of Ukraine. protection of industrial and socаial facilities of the environment, from man-made and natural emergencies It is proved that in today's conditions in Ukraine, the regulatory and legal mechanism in the field of civil protection, in particular, regarding the risks of occurrence and development of emergency situations, needs to be improved. Within the framework of the current regulatory and legal mechanism for protecting the population during emergencies, there are no clear approved instructions for the implementation of the provisions of legislative and subordinate regulations to prevent the risks of occurrence and development of emergencies, and there is also no effective mechanism for monitoring the prevention of emergencies.

The Risk Factors for Development of Emergency Conditions in Tender-Age Infants in Acute Intestinal Infections of Different Etiologies

Among the leading risk factors for the development of emergency conditions in acute intestinal infections, especially in infants, some authors point to rickets, anemia, and abnormal antenatal pathology. The aim is to determine the frequency of occurrence of various risk factors for the development of emergency situations in tender-age infants. Materials and methods: 338 tender-age infants with urgent conditions were under observation. The study involved clinical-anamnestic, bacteriological, and serological methods. The aggravating factors were as follows: diseases of parents in 16 (6.2%), related marriages - 20 (7.7%) pregnancy pathology-137 (52.9%), prematurity-16 (6.2%), artificial feeding - 127 (49.0%), early diseases (acute respiratory viral infections, pneumonia, encephalopathy, intestinal infections). Results: According to the results of the study, the central nervous system damage was most often observed in children from 1 month to 6 months (80.2%), anemia was more detected in children of 1-3 years - 56.4%, rickets was more diagnosed in children aged 6-12 months -38.2%.

Analysis of the existing legal, regulatory and technical support for the prevention of environmental emergencies at gas pipeline facilities in Uzbekistan

Operation of new and existing pipeline systems is carried out in accordance with the relevant instructions, with technical inspections, diagnostics and control carried out, if necessary. In accordance with the pipeline safety concept being developed, the possibility of operational diagnostics of the occurrence and development of emergency situations should be provided. Analysis of data for the last years of gas pipeline operation indicates the occurrence of various environmental emergency situations. Therefore, the task of this study is to classify the factors of accidents and damage to gas pipelines with the determination of the main share of the most significant. The proportion of emergencies due to mechanical damage to pipes by machines and mechanisms during excavation has maximum values. This indicates that during this period of time, many violations of technological regulations were registered. With regard to emergencies due to corrosion damage, there is some stability. As can be evidenced in this research paper, mainly accidents, repairs and leaks occur in summer - winter periods.

Надзвичайна ситуація: визначення, проблеми та рішення

Надзвичайні ситуації постійно супроводжують людство, призводячи до великих матеріальних втрат і людських жертв. Обговорювалися визначення та загальні закономірності розвитку надзвичайних ситуацій, їх роль у розвитку аварій та катастроф. Стверджується, що на сьогодні немає єдиного поняття надзвичайної ситуації. На підставі проведеного аналізу наданий механізм розвитку надзвичайної ситуації, сформульоване її визначення: надзвичайна ситуація — це стан природної та антропогенної активності в зовнішньому середовищі та соціумі. Обґрунтована необхідність зміни нормативного визначення поняття «надзвичайна ситуація».

The degree of survivability of building structures under dynamic loading

The relevance of the work is due to the increasing possibility of impact on the critical building structures of industrial buildings of short-term dynamic loads in abnormal emergencies. These situations lead to significant damage of the constructions of buildings. There is a high possibility of human victims and significant damage of expensive technological equipment when the structures collapse. Therefore, in order to ensure further functioning of the structure, it is necessary to design building structures as well as the object on the whole with the properties of survivability under non-stationary impact. Such properties should be analyzed when constructing scenarios of origination and development of emergency situations as well as analyzing risks. In the course of the research the strain gauge methods were used to measure deflections, accelerations and loads on the samples. The work proposes a method for assessing the degree of survivability of a critical building structure under short-term dynamic loading based on the analysis of the energy parameter. Using the example of a specific test of a bending reinforced concrete element for short-term dynamic load the values of the specified coefficient were obtained.

Information support for decision-making in emergency situations

In this article, the technology of information support for decision-making in the event of natural and technogenic emergencies is considered. Its implementation was carried out using the created information system (IS) for predicting the consequences of emergency situations, which is based on a single information space of the territory of the subject of the Russian Federation. The paper proposes an approach to creating an IS based on a distributed, peer-to-peer architecture when information resources (in relation to the considered IS) are not only presented as data, but also as various applications of basic ISs. A geographical information system is used as a basic one for solving problems of forecasting development and consequences of emergency situations. The decision support subsystem meets the following requirements: provides forecasts of occurrence and development of emergency situations in the form of predictive bulletins for review and approval of the management; provides paperwork for submission to rapid response services. Calculation of consequences of emergency situations is based on the following methods: assessment of consequences of accidents at explosive and fire-hazardous objects; forecasting and assessment of medical consequences of accidents at explosive and fire-hazardous objects; predicting the extent of contamination with highly toxic substances in accidents (destruction) at hazardous chemical facilities and transport; predicting possible accidents, catastrophes, and natural disasters; assessing damage from man-made, natural and terrorist emergencies, as well as classifying and recording them.

Нейросетевое моделирование эффективности реагирования на чрезвычайные ситуации в многоуровневой системе управления

Introduction. It is important to have models that adequately describe the relationship between the integral indicators of the functioning of the system with the particular indicators of the lower levels of management in complex control systems, in particular in RSChS. Traditional approaches based on normative models often turn out to be untenable due to the impossibility of covering all aspects of the functioning of such systems, as well as due to the high variability of the environment and the values of the set of target indicators. Recently, adaptive machine-learning models have proven to be productive, allowing build stable and adequate models, one of the variants of which is artificial neural networks (ANN), based on the solution of inverse problems using expert estimates. The relevance of the study lies in the development of compact models that allow assessing the effectiveness of the functioning of complex multi-level control systems (RSChS) in emergency situations, developing according to complex scenarios, in which emergencies of various types can occur simultaneously. Goals and objectives. The purpose of the article is to build and test the technology for creating compact models that are adequate to the system of indicators of the functioning of hierarchically organized control systems. This goal gives rise to the task of choosing tools for constructing the necessary models and sources of initial data. Methods. The research tools include methods for analyzing hierarchical systems, mathematical statistics, machine learning methods of ANN, simulation modeling, expert assessment methods, software systems for processing statistical data. The research is based on materials from domestic and foreign publications. Results and discussion. The proposed technology for constructing a neural network model of the effectiveness of the functioning of complex hierarchical systems provides a basis for constructing dynamic models of this type, which make it possible to distribute limited financial and other resources during the operation of the system according to a complex scenario of emergency response. Conclusion. The paper presents the results of solving the problem of constructing an ANN and its corresponding nonlinear function, reflecting the relationship between the performance indicators of the lower levels of the hierarchical control system (RSChS) with the upper level. The neural network model constructed in this way can be used in the decision support system for resource management in the context of complex scenarios for the development of emergency situations. The use of expert assessments as an information basis makes it possible to take into account numerous target indicators, which are extremely difficult to take into account in other ways. Keywords: emergency situations, hierarchical control system, efficiency, artificial neural network, expert assessments

Prompt forecasting of heat flows under fire conditions in a vertical steel tank having an ANFIS protective wall

Introduction. Tanks and tank farms are widespread in many constituent entities of the Russian Federation and are among the most important elements of the model for the production, treatment, transportation and processing of oil and oil products. It is relevant both at the Russian and global levels to ensure that fire safety is arranged for tank farms to reduce highest risk levels according to the risk-based safety model. In the context of information and communication technology (ICT) developments and introduction of ICT into the operation and management of various facilities, over the past decades advanced methods have emerged for predicting the occurrence and development of emergency situations at facilities and enhancing management decisions on containment and elimination of emergency situations including fires.Goals and objectives. In this paper, the authors present a model that they developed to promptly forecast heat flows using artificial neural networks. The forecast model will improve the safety of fire brigade personnel responsible for extinguishing fires inside ground-based vertical steel tanks having protective walls. In the research, the authors place special emphasis on identifying dependence between the heat flow and the wind load. Methods. To achieve this goal, the authors arranged and conducted a series of experiments, collected experimental data on heat flows, and created training and test samples.Results. Dependences between heat flows and environmental factors were identified by constructing adaptive neuro-fuzzy inference systems or adaptive network-based fuzzy inference systems (ANFIS). Various types of membership functions, optimisation and system generation methods were compared and it was found out that for ANFISs, prediction of heat flows with regard to and disregarding wind loads were optimal, if subcluster and hybrid optimisation methods were used, as they had lowest error values for samples.Discussion. The analysis shows that wind speed and tank location can rise temperatures of the air, tank wall and petrol. Therefore, despite the complexity of the analysis, the regard for all these factors makes it possible to identify a safe distance between a burning tank and firefighters.Conclusions. The research made it possible to develop a model for prompt heat flow forecasting with the help of artificial intelligence elements (ANFIS). The results obtained in the course of the work make it possible to increase the efficiency of prompt forecasting of the dynamic behaviour of fire inside tanks and tank farms and optimize managerial decision-making by responsible persons.

Специфическая структурно-логическая модель управления чрезвычайной ситуацией


 
 
 
 
 
 
 
 161
 
 
 
 
 
 
 
 
 Работа посвящена решению одного из специфических аспектов управления чрезвычайными ситуациями террористического характера – актуальной научной проблемы современности. Для достижения поставленной цели в работе первоначально дается анализ этапов развития чрезвычайных ситуаций. Показано, что чрезвычайные ситуации это объективные (существующие независимо от отношения к ним) пространственно-временные процессы, каждый из которых условно разделяется на пять этапов, а именно: повседневного накопления негативных факторов; экстремального развития негативного фактора; катастрофического события; ликвидация последствий этого события и их отдаленных последствий. Они происходят на транспортных средствах, техногенных и природных объектах, участках территории, водных бассейнах и горах, городах и административных регионах. Вид каждой чрезвычайной ситуации привязан к определенному катастрофическому событию, которое может произойти, происходит или уже произошло. Затем рассматривается прототип – типовая структурно – логическая модель управления чрезвычайной ситуацией, которая состоит из шести блоков. Это мониторинг ситуации (сбор повседневных факторов), выявление риска (обнаружение экстремального фактора), анализ риска (прогноз и моделирование чрезвычайной ситуации), подготовка вариантов управленческих решений, принятие решения и доведение его исполнителям. Последующее воздействие на ситуацию (объект управления), через структуру исполнителей, замыкает контур управления, обеспечивая непрерывный процесс управления в интересах недопущения катастрофических событий. На основе прототипа разработана специфическая структурно-логическая модель управления чрезвычайной ситуацией террористического характера, вызванная обнаружением малогабаритного взрывного устройства. Она состоит из тринадцати блоков. Это мониторинг ситуации, выявление риска, оповещение и эвакуация людей, поиск и идентификация взрывного устройства, взрывное устройство, муляж, безопасный предмет, принятие решения на использование специального купола, подготовительные мероприятия, обезвреживание взрывного устройства, локализация последствий обезвреживания, принятие решения на возобновление и режима работы объекта, воздействие на ситуацию. Расположение блоков на десяти иерархических уровнях, соединенных логическими связями, обеспечивают сбор информации о состоянии объекта массового скопления людей через элементы системы мониторинга и воздействие на объект через систему исполнителей, обеспечивая непрерывный процесс управления в интересах минимизации последствий террористических событий.

Природные условия развития чрезвычайных ситуаций на территории Сибирского федерального округа

Природные условия развития чрезвычайных ситуаций на территории Сибирского федерального округа

Progressive damage to structural elements of pipeline systems and efficiency assessment of protection measures

The Aim of this paper is to evaluate the effect of transportation node protection on the resilience of pipeline systems to the development of damage by the mechanism of progressive blocking of nodes as well as the efficiency analysis of the employed protection measures. Damage to a point element of a system due to simultaneous transition into the down state of all the pipelines converging into it is called blocking. The process of progressive blocking of a transportation system’s nodes in a random order is considered to be progressive damage of a network structure. Progressive damage is a hazardous emergency development scenario that is associated with the disconnection of first some, then all end product consumers from the source. A system’s ability to resist progressive damage is estimated by the resilience indicator, the average share of the damaged nodes whose blocking in a random order causes the disconnection of all end product consumers from the source. Methods of research. A system’s indicator of resilience to progressive blocking of nodes was defined using computer simulation. The resilience indicator can only be used in comparative analysis of network structure properties if the analyzed systems are comparable. The condition of comparability of systems with protected point elements is the presence of equal numbers of disconnectable consumer nodes and damageable nodes. If the analyzed systems include protective peripheral clusters that represent interconnected sets of point elements, the following must be equal to enable the comparability of such systems: – number of peripheral clusters with two and more consumer nodes on condition of equal number of such nodes within each system; – most probable order of disconnection from the source of both individual consumers and peripheral clusters with equal numbers of end product consumers.Results. A system’s resilience to progressive blocking can be improved by means of managerial and technical measures of transportation node protection. It has been established that the highest efficiency of protection of individual point elements is achieved in case of protection of a consumer node located at the shortest possible distance from the source of the end product. It is demonstrated that the peripheral cluster for protection of a transportation system should be synthesized by including consumers situated at the minimal possible distance from the source node.Conclusions. The development of emergency situations by the mechanism of progressive blocking of nodes is a hazardous scenario of pipeline system damage. The resilience of a network structure to damage can be improved by means of measures of transportation system nodes protection. The highest efficiency of protection of individual point elements is achieved in case of protection of a consumer node located at the shortest possible distance from the source of the end product. The peripheral cluster for protection of a transportation system from progressive damage should be synthesized by including consumers situated at the minimal possible distance from the source node.

Progressive damage to structural elements of pipeline systems and efficiency assessment of protection measures

The Aim of this paper is to evaluate the effect of transportation node protection on the resilience of pipeline systems to the development of damage by the mechanism of progressive blocking of nodes as well as the efficiency analysis of the employed protection measures. Damage to a point element of a system due to simultaneous transition into the down state of all the pipelines converging into it is called blocking. The process of progressive blocking of a transportation system’s nodes in a random order is considered to be progressive damage of a network structure. Progressive damage is a hazardous emergency development scenario that is associated with the disconnection of first some, then all end product consumers from the source. A system’s ability to resist progressive damage is estimated by the resilience indicator, the average share of the damaged nodes whose blocking in a random order causes the disconnection of all end product consumers from the source. Methods of research. A system’s indicator of resilience to progressive blocking of nodes was defined using computer simulation. The resilience indicator can only be used in comparative analysis of network structure properties if the analyzed systems are comparable. The condition of comparability of systems with protected point elements is the presence of equal numbers of disconnectable consumer nodes and damageable nodes. If the analyzed systems include protective peripheral clusters that represent interconnected sets of point elements, the following must be equal to enable the comparability of such systems: – number of peripheral clusters with two and more consumer nodes on condition of equal number of such nodes within each system; – most probable order of disconnection from the source of both individual consumers and peripheral clusters with equal numbers of end product consumers.Results. A system’s resilience to progressive blocking can be improved by means of managerial and technical measures of transportation node protection. It has been established that the highest efficiency of protection of individual point elements is achieved in case of protection of a consumer node located at the shortest possible distance from the source of the end product. It is demonstrated that the peripheral cluster for protection of a transportation system should be synthesized by including consumers situated at the minimal possible distance from the source node.Conclusions. The development of emergency situations by the mechanism of progressive blocking of nodes is a hazardous scenario of pipeline system damage. The resilience of a network structure to damage can be improved by means of measures of transportation system nodes protection. The highest efficiency of protection of individual point elements is achieved in case of protection of a consumer node located at the shortest possible distance from the source of the end product. The peripheral cluster for protection of a transportation system from progressive damage should be synthesized by including consumers situated at the minimal possible distance from the source node.

Safety Improving of Cooling Unit of is Open Tane - Isoprene Charge Stock for Production of Isoprene Rubber

The main hazards of the isopentane-isoprene charge cooling unit of isoprene rubber production are analyzed. The conditions for the emergence and development of emergency situations were studied, and existing measures to ensure safety at work were considered. The main initiating event in case of emergency situation in the shop is depressurization of equipment accompanied by the release of significant amount of hazardous substance with subsequent negative development of the accident.Activities aimed at reducing the risk of an accident at the facility are: reducing the probability of depressurization of equipment; minimizing the quantity of hazardous substances entering the accident site; localization of the accident site; limiting the time spent in hazardous areas. It is proposed to equip pipelines at the site boundaries with high-speed shut-off valves with a response time of 12 seconds. This measure allows minimizing the quantity of hazardous substances entering the accident sitethat leads to a significant reduction of environmental and economic damage because of accident.

Повышение стойкости трубопроводных систем к повреждениям транспортных узлов при развитии аварийных ситуаций

Повышение стойкости трубопроводных систем к повреждениям транспортных узлов при развитии аварийных ситуаций

Features of design, construction and operation of underground tunnels and tunnel structures in dense urban areas

The development of a modern city and the increase of its transport infrastructure, in particular metro facilities, has a significant impact on the urban environment and requires the development and implementation of a set of special protective measures. Moreover, if the construction of metro station complexes is carried out, as a rule, in relatively free areas with minimal impact on the surrounding buildings, then during the construction of tunnels and tunnel structures, engineering communications, buildings and structures located on the earth’s surface, including transport facilities, architectural monuments and cultural heritage objects fall into the zone of their influence. The effectiveness of design solutions for the protection of objects that are in the zone of influence of the construction of underground structures is largely determined by the degree of reliability of the assessment of geotechnical conditions and the results of the survey of the technical condition of building structures. Analysis of the causes of the formation and development of emergency situations and incidents arising in the construction and operation of underground structures shows that they are mainly the result of the use of unreliable initial engineering-geological and hydrogeological conditions, significantly changing due to intensive urban development. The resulting barrage effect, changes in groundwater levels and directions that are not taken into account at the design stage, can be accompanied by significant deterioration of soil properties and the General stress-strain state at the base of existing buildings and structures. This suggests the need for careful study of the properties of soils at significant depths, the development of forecasts of possible changes of the state of the soil massif and hydrogeological conditions, the implementation of a comprehensive survey of the bases of closely spaced buildings and structures, and significantly larger volume of engineering-geological surveys compared to the current regulations.

The effect of the structural composition on the resilience of pipeline systems to node damage

TheAimof this paper is to study the effect of the structural features of pipeline systems on the development of emergency situations by the mechanism of progressive blocking of transportation nodes. The blocking of an individual point element of a system is considered as the result of simultaneous failure of all the pipelines converging into the node. The process of progressive blocking of a certain set of nodes of a pipeline system in random order is called a progressive blocking. The development of progressive blocking is associated with the disconnection of the consumers from the source of end product and is a dangerous scenario of emergency development. The system’s resilience against progressive blocking is estimated by the resilience indicator F„, the average share of the system’s nodes whose blocking in a random order causes the disconnection of all consumers from the source of the end product.Methods of research.The values of 0 <F„< 1 were identified by means of computer simulation. After each fact of damage associated with a random blocking of an individual node, the connection between the source and consumers of the end product was established. The statistical characteristics of the process of progressive blocking were evaluated according to the results of repeated simulation of the procedure of damage of the analyzed network structure. In general, the structure of a pipeline system is characterized by a graph that describes the connections between point elements. The valence of an individual graph node is the number of edges that converge into it. Similarly, the valence of the respective network node is the number of converging linear elements (pipelines). Furthermore, an important characteristic of an individual node is the composition of the converging linear elements. Thus, the set of a system’s linear elements includes the following varieties that ensure the connection between: the source and the consumer (subset G1), two consumers (subset G2), a consumer and a hub (subset G3), two hubs (subset G4), the source and a hub (subset G5).Results.The author analyzed and examined the effect of the structural characteristics on the ability of pipeline systems to resist the development of emergency situations through the mechanism of progressive blocking of nodes. It was established that with regard to structural optimization the most pronounces positive effect associated with the increase of the values F^ is observed as the valence of the source node grows and additional linear elements of subset G1 are included in the system.Conclusions.The process of progressive blocking of pipeline transportation system nodes is a hazardous development scenario of an emergency situation. The most efficient method of improving pipeline system resilience against progressive blocking consists in increasing the valence of the source node and inclusion of additional linear elements of subset G1 in the system. Structural optimization of pipeline systems should be achieved by defining the values F^ for each of the alternatives with subsequent adoption of a substantiated design solution.