The Justification of Technical Feasibility of Using Existing Urban Industrial Objects at the Reprofiling of their Appointment

Establishment of the valid technical condition, research of relationship of cause and effect and hierarchy of the factors influencing use reliability of load-carrying structures of town-planning objects of industrial function at their reconstruction and reprofiling is the main objective of safe and reliable operation. By method of the atomic and emission spectral analysis it is established that separate elements of farms are made of the “boiling” steel that does not conform to requirements of existing rules. Values of movements, efforts on combinations of loads by snow load and ranges of distribution of potential energy of deformation on farm elements are received. The analysis of intense state of strain of roof frames of covering of the inspected industrial buildings has shown that their bearing capacity in zone of possible formation of snow “bag” from height difference and extension to workshop of higher flight is not sufficient. By results of the conducted researches recommendations for safe further operation of roof frames of covering and valid conclusion about degree of their suitability for the planned conversion and modernization of industrial buildings are formulated.


Introduction
Practically in each large city it is possible to meet now the industrial enterprise which for one reason or another does not perform the initial function any more. Nevertheless, this object has the essential potential for further development of urban areas. In this case will be reasonable to carry out building reprofiling, to give it new, civilized lines, applying the innovation technologies and minimizing damage caused to the environment. Therefore today there is task: having reconstructed these townplanning objects, to leave them significant for the city, to make functional, eco-friendly, selforganizing. At the same time, industrial building that will be subjected to reprofiling can become unique, not having analogs on the structure and the organization of space. The available building constructions of the building which has lost the initial functionality (farms, cranes, columns, big flights, load bearing walls of considerable thickness, light lamps, etc.), allow the architect to find it space-planning decision at which there will be new forms of space interpretation, dynamism of structure of the building.
At reconstruction of industrial building under object of town-planning of public assignment it can be added with interesting designs from different modern composite materials that will give the International science and technology conference "FarEastCon-2019" IOP Conf. Series: Materials Science and Engineering 753 (2020) 032073 IOP Publishing doi: 10.1088/1757-899X/753/3/032073 2 necessary character and unique plastics to facade, will make the building easily recognizable, and in certain cases such building can even become certain dominant of the area or city. At the same time, the scale of such reconstruction will depend on in what degree parameters of technical condition of the building and its designs conform to modern requirements, including safety requirements and reliability.
Among loads of building constructions, the most changeable are snow. During the winter the snow load on covering of the building accepts values unknown in advance, i.e. is random variable. In addition, the variability in time is characteristic of snow loads. Unfortunately, the available cases of collapse of coverings of public buildings because of snow load lead to the fact that the problem of rationing of snow loads on coverings of constructions becomes very relevant [17][18][19][20][21].
In this work assessment of degree of suitability of load-carrying structures of covering at action of the additional snow loads arising in connection with the planned reprofiling and extension of higher flights to the production body of the former car repair plant in Voronezh is provided.

General information about the existing process building of workshop
The workshop building is one-storey, consists of two flights on 18.0 m integrated by insert 4.5 m wide. Flights of workshop are equipped with bridge basic cranes of average operating mode. The general dimensions of the building in the plan -41.14х106.53 m. In one end face of workshop the two-storied block of administrative accommodation spaces is built-in, to other end face the threestoried block of accommodation spaces with sizes in respect of 9.64х43.88 m is attached. The period of construction of object -the end of the second half of the 50th years of the last century.
The considered flight of workshop is structurally executed with the brick longitudinal load bearing walls strengthened in places of supporting of crane girders by pilasters with a section of 0.  Check of distances between connecting levels (crackers) ensuring team work of two corners has shown shortage on one level for two drag struts. Besides, for number of compressed rods of upper belt, racks and drag struts of some farms only about one level, instead of recommended by norms not less than two is established.  According to the given types of loadings and types of loads in design model the following combinations of loadings (table 1) have been considered.         In case of extension to workshop of higher parallel flight, bearing capacity of farms of covering will not be provided. The extreme element of the lower belt does not meet requirements for durability ( figure 16). Besides, at the adjoining elements margin of safety is insufficient.

Conclusion
On the basis of the conducted examination, tests and the executed calculations of roof frames of covering of the production body, it is possible to conclude the following: 1. Grades of the "boiling" steel St3kp and St4kp from which drag struts and bottom flanges of farms are executed do not conform to requirements of SP 16.13330.2012, table B.1. This steel is inclined to fragile destruction at low temperatures, is characterized by the small resistance to fragile destruction and applied in the least responsible designs. Taking it into account, further operation of rafter roof structures at reprofiling of this town-planning object of industrial function in public is admissible only on condition of the organization of systematic control of their state and operating conditions [15,16]. 2.
Bearing capacity of farms of covering is sufficient for perception of the loadings existing at the time of inspection, except for extreme in step from end face of workshop of the farm which is in zone of possible formation of snow "bag" from height difference with the existing building of the household body. 3.
In case of extension to workshop of higher parallel flight with the planned height difference of 4.5 m, bearing capacity of roof frames in zone of possible formation of snow "bag" will not be provided. Therefore, the planned extension without work on strengthening or replacement of loadcarrying structures of covering in workshop is impossible.