Evolution of scientific approaches to the multifunctional public complexes’ development

. This research aims to analyze the socio-economic conditions and urban planning features influence on scientific approach and multifunctional complexes hypotheses throughout history. A retrospective analysis of scientific theory, socio-economic and political conditions, and territorial planning city trends helped to identify the specifics of the cultural and social service sector and multifunctional complexes, as the most effective form of public construction development. The idea of multifunctionality as a scientific hypothesis evolved from the objective tasks to revive national economy in the early twenty century and was initially implemented by residential complexes with a developed system of public functions to balance work, leisure, and rest for workers. The planning aspect is revealed through the linear city concepts and new system of resettlement. Later, the function diversity principle was implemented within the development of the citywide center system. The efficacy of multifunctional public construction has been proven over the years; however, modern social, economic, and ecological conditions require different scientific approaches to consider the multifunctional public buildings as an urban planning subsystem requiring interrelated development within the model of territorial spatial environments. The novelty of the research lies in defining modern scientific approaches to the urban planning subsystem of the multifunctional public complexes.


Introduction
Intense interest in the planning of multifunctional public complexes has arisen against the backdrop of the growing problems of development in the modern largest city. The negative characteristics of the environmental conditions are primarily due to the high rates of urbanization, including densification of the building environment, reduction in natural recreational areas, and high traffic congestion resulting from daily pendulum population migration for work and cultural and household purposes. The second factor is the need for effective use of the established residential and public construction areas to resolve historically formed problems of low availability of cultural and domestic services for the population.
The object of the research is a system of multifunctional public complexes, interpreted as a planning structure of a settlement, formed by components and types of territorial-spatial objects. The subject of research is the changes in scientific approaches to the development of multifunctional public complexes under the influence of political, socio-economic conditions, and the city planning features.
A multifunctional public complex is a local urban planning structure that includes one or several buildings and the territory they occupy, forming a public space with social and administrative functions. It has a fairly regular daily and monthly visitor load, as well as convenient pedestrian and transport accessibility.
Interest in multifunctional buildings has existed for a long time. However, this research focuses on the time interval from the beginning of the 20th century to the present. At the beginning of the described period, attempts to create multifunctional buildings were implemented in the form of unique commercial, religious and other objects located in the central zone of the city, as well as in the formation of workers' settlements (residential complexes provided with primary cultural and consumer services) at large industrial enterprises.
Later, in the second half of the 20th century, with an improvement in the standard of living of the population and an increase in consumer demand for commerce, consumer services, public catering, culture, sports, etc., the principle of combining functions in one complex began to be considered as an opportunity to bring a wide range of services closer to a potential consumer as much as possible.
Further, at the turn of the 21st century, characterized by the territorial resources of the city in established developed areas being exhausted, multifunctional complexes played a unique role in the improvement of social facilities, including all levels of service (daily, periodic, and episodic).
The concept of a multifunctional public complex is closely related to the concept of a public center. Let's turn to the definition of the city public center: communicative territories with the maximum density of public functions, including vital hubs of the settlement forming its framework. Consequently, the multifunctional public complex is a structural part of the public city center. In this regard, to understand the principles of the complexes' location, it is necessary to consider the system of public centers, including the evolutionary stages of its formation, patterns and features of the functional planning structure.
Over the past 100 years, the principles of functional zoning of urban areas and the formation of public center systems have been deeply studied by the urban planning science.

Material and Methods
The goal of the study is to analyze the evolution of scientific approaches to the development of multifunctional complexes. The research objectives are to characterize the evolutionary stages of scientific approaches to the formation of scientific problems and hypotheses of the public complexes evolvement, planning their development as a planning structure; determine the features of modern stage scientific research; to formulate a theoretical platform for the further development of the public complexes' system.
Statistical data, results of the system, typological, functional, and structural analysis were used. Data from official municipal and regional sources were used.

Results
The evolution of scientific approaches to the development of multifunctional public complexes (MPC) is determined by the socio-economic conditions and planning characteristics of the city territory development. Each new step in the science evolution is conditioned by the exacerbation of the contradiction between the increasingly complex conditions of city functioning and the inefficiency of existing scientific and practical tools to solve current tasks of urban infrastructure planning.
The formulation of the scientific problem and hypotheses relates to the consideration of objective peculiarities and specificity of processes and phenomena characteristic of the current city development stage. At the same time, a few social, demographic, and planning tasks are being solved, such as improving cultural and consumer services for the population, developing architectural and construction solutions for new types of public complexes that meet the social demand for new services and workplaces, effective use of the city's territory and natural complex, and others.
The aim of the research is to study the evolution of scientific approaches in two directions: -from the creation of separate MPC to the formation of a planning system, built with consideration for the diversity and hierarchy of human needs, determined by the frequency of demand for services, pedestrian or transport-pedestrian accessibility, size and functional composition of buildings, and their architectural and construction solutions; -from non-systematic placement of separate MPCs to planning the development of urban structures of public complexes, considering a systemic analysis of the conditions of placement and interrelation of the life environment components.
Moscow case study reveals the theory and practice evolution process of forming MPCs in the period from early 20th century to the present day. At the beginning of the mentioned period, MPCs were unique buildings constructed in the Moscow downtown and funded by private entrepreneurs, state, and charitable organizations.
The buildings in question are the GUM (1880), TSUM (1897), and the Christ the Savior Cathedral (1881, rebuilt in 1999). The core function of both the TSUM and GUM complexes, acting as the "generators," is the implementation of non-food and food-based commercial activities, supplemented in TSUM by public catering service and consumer services (figure 1a). The underground spaces were utilized for the entrance of transport and delivery of goods. The functional composition of GUM was enriched by wholesale trade, a financial institution (bank), a communication facility (telegraph), and an exhibition hall. The unique multifunctional complex that aimed to enrich the cultural and spiritual life of individuals was the Christ the Savior Cathedral. The core functional purpose of this ecclesiastical complex was complemented by functions serving as a place of cultural significance, including a concert hall, a library, and a venue for official celebrations (figure 1b).
The evolution of scientific approaches to the formation of MPCs is examined using the example of four historical periods in urban planning theory: 1920-50s, 1960-80s, 1990-2020s, and 2010-present, each with unique socio-economic and planning features that have affected the specificity of project activities and scientific research. The period from 1920 to 1950 occurred in the context of the recovery and consolidation of industrial economy after the Great October Revolution and Great Patriotic War. During the first half of this prolonged period, the cultural and consumer services sector, represented by a very limited range of services and facilities, played a supportive role that was related to overcoming depopulation of the country, ensuring population growth, and developing skilled labor resources. These measures were aimed at creating conditions for the country's industrialization. The primary goals were to provide for collective welfare, minimize temporary expenditures on domestic issues, involve women in the production process, and so forth. The first multi-functional residential complexes (communes-houses and worker settlements) were created, and public complexes were constructed to provide unique services to residents and visitors of Moscow. (Figure 2a Theoretical research during this period was focused on solving scientific problems related to a strict functional zoning of settlement territory with the goal of reducing time and economic costs for necessary transportation movements [1,2]. Public service functions, represented by preschool and school institutions, physical culture schools, were located alongside residential buildings. Trade, public catering, and household services were adjacent to industrial areas where the population was employed (Figure 3).
A concept is proposed for the linear spatial development of two capitals, Moscow and Leningrad, that envisages their sustainable economic, social-demographic, and planning interaction. The functional zoning of Moscow is justified in the form of a parabolic planning structure with the location of public and administrative functions along the main northwest axis, towards Leningrad [3].
The role of planning and design standards for settlements was fulfilled by the general development plan of Moscow in 1935. The document established the volumes of construction for educational, healthcare, sports, and cultural institutions for the next 10 years. During this period, scientific problems and hypotheses were not related to finding ways to improve the system of cultural and community services, effective functional-planning approaches to the formation of public complexes due to lack of economic resources and the absence of planning restrictions for the development of the city's territory. The period between 1960 and 1980 was characterized by favorable socio-economic conditions: population growth in Moscow, planned economy, and budget financing of construction. The level of per capita income led to a shift in demand from industrial goods to cultural and community services. The priority became the formation of a comprehensive system of services for the population.
Among the planning features of Moscow were the expansion of its territory, especially in the north and south directions. The mass housing construction led to an increase in population density. The 1971 General Plan of Moscow defined its new planning structure with seven planning zones.
The practice of building multifunctional complexes developed in two directions: the formation of daily service within residential neighborhoods, and the provision of selective services to residents and guests of Moscow in areas with high transport accessibility.
Urban planning theory focused on cultural and community services for the population, emphasizing sustainable socio-economic development. The law of "continual growth of needs" reflected the influence of the development of productive forces and social relations (К. Marx, F. Engels, writings, v. 23, p.182), and necessitated diversity and richness in social communication forms. This resulted in the constant development and improvement of public consumption resources.
Settlement planning and design theory considered three evolutionary schemes of organizational methods for public services: step-by-step organization, "focusing" system, and linear-temporal system with centers of "standard" and "non-standard" services [4,5] ( figure 4). The progressive transformation of these schemes was associated with abandoning the strict planning attachment of daily and regular service objects to residential areas. It is suggested to locate service focuses on convenient transport access intersections. As the system became more sophisticated, this scheme took on a linear character, and "focuses" -service centers -gave way to public functions zones location (standard and non-standard services).
Important steps have been taken in understanding the pulsating nature of the settlement's community center system growth. The concepts of the core and subcenters of the city level center are introduced [6] (figure 5). Scientific progress has led to apprehension of the significance of the multifunctional complex as part of a larger whole, rather than an isolated element of settlement surroundings. The complex represents a continuation of the environment, a creation of the settlement, and its complex external conditions affect its functional and spatial characteristics. A theoretical model of the functional and spatial organization of settlements and the location of multifunctional complexes has been developed. The model provides a spatial interpretation of modern settlement centers, their integration with each other and the surrounding structures on a planning scale. The concept of a "generator" of multifunctional complexes or a "function carrier," which represents the dominant function of public service based on which the complex is formed, has been introduced [7]. Cultural institutions, administration, hotels, and transit hubs serve as "generators" (figure 6a).
Research is being conducted, opening fundamentally new trends in science related to more efficient use of urban space. The concept of multi-level territorial and spatial formations has been suggested, with the patterns of formation and development of exploitable flat roofs being revealed as an important territorial and natural recreational resource for settlements [8]. The role of the exploitable flat roof has been defined as an "intermediatory space," where the functional roles and "artificial land" -the territory built with various technical methodsintersect. The use of such resources brings an opportunity to combine a greater number of various functions within the framework of a public complex (figure 6b). The standard construction regulatory document SN 41-58 is characterized by excessive and detailed standardization of cultural and household service facilities (about 90 objects) but does not provide for differentiated consideration of the planning specifics of the territory and the needs of various population groups.
The scientific problem is limited by the perception of cultural and community services for the population as a set of facilities with all kinds of services. There is a lack of apprehension of the service sector's key role as a basic component of settlement activity requiring constant improvement in line with the changing level of social development.
The scientific hypothesis is based on the necessity of planning the comprehensive development of the cultural and household service system (all types and levels of services included) based on an objective assessment of the social functions development. MPCs are a priority type of territorial-spatial formations for settlements, ensuring the efficiency increase in their space use [9].
The period from 1990-2000 was marked by unstable domestic political, economic, and social conditions, steep differentiation of income levels, and the emergence of private property in real estate. This stage resulted in the formation of a steady imbalance in the structure of the cultural and household service facilities' network.
MPCs development leads to a positive industry outcome such as the emergence of a commercial buildings network (Auchan, Metro, Leroy Merlin, and others). However, their location in Moscow and the Moscow region is not reasonable. These complexes functioning leads to traffic congestion, environmental problems, and unreasonable transportation time waste for Moscow residents.
The characteristic feature of this period is the built-up area densification without necessary layout rationale. As a result, the natural complex of the land object was used inefficiently, and significant volumes of free land within the object were misused.
The current period (2010-present) is characterized by manifestations of the service and banking-information economy with a key role of social facilities as a tool to create a modern, comfortable living environment, and increase human capital quality. Scientific research confirms that social sphere prevails over the economy [10]. Socio-demographic conditions find expression in the increasing life expectancy, the rising average age of Muscovites, and the differentiation of consumer demand for different groups of residents, as well as the acceleration of modern life, which increases people's consumer demands. The adverse ecological situation is manifested in the critical degree of air pollution, visual and audio discomfort.
Hence, the hypothesis is suggested that urban planning for the development and location of a system of multi-functional public complexes can become a priority tool in improving the city's social facilities, providing increased volume and diversity of services, bringing them closer to the population.
It is necessary to consider the urban planning subsystem MPC as a complex hierarchical structure differentiated by planning, functional, volumetric-spatial characteristics. The successful implementation of this approach is ensured by progressive scientific experience: the basic principles of the general systems theory and the model of territorial-spatial of formation of settlements' objects.

Conclusion
A scientific approach to planning social facilities as a planning metasystem, functioning in the interdependence of four territorial-spatial objects, will ensure integrity of the MPC formation in newly developed territories and improve its characteristics in existing development. A new prospective for the social facilities development ensuring the increase in volume and diversity of services, bringing them closer to the population against the background of territory shortage, is the creation of an MPC planning system.
The priority content of this system should be its social orientation, allowing for the formulation of problematic issues justifying scientific problems and hypotheses, the characteristics, and specifics of which are related to the provision of sports facilities, cultural institutions, supplementary education establishments, and social protection for the population on established territories.