Salnikova I. Justification of the repair-and-renewal operations deadlines on the reinforced concrete girders of bridges

Subject of inquiry is the processes implementation of repair-and-renewal operations on the reinforced concrete girders. The aim of the dissertation is development of theoretical concepts and methods of rational justification regarding deadlines of repair-and-renewal operations on the reinforced concrete girders in conditions of resource constraints with the influence of organizational and technological factors. Research methods: analysis and synthesis of national and international experience, regulations, methodological approaches to organizing and managing the maintenance of artificial structures and implementation of repair-and-renewal operations on the reinforced concrete girders; methods of system analysis, formalization; methods of probability theory and mathematical statistics, Delphi method, correlation and regression analyzes; organizational and technological modeling. Theoretical and practical results: developed an algorithm and software for calculation of rational timing of repair-and-renewal operations on the reinforced concrete girders of railway bridges and creation of the ranked list of defective structures for further implementation in repair-and-renewal works, based on the degree of impact damage, by using program Borland Delphi. Novelty of the research: first established the regularities of organizational and technological factors (factor length of the object, the factor of technical facility, adaptability factor, factor congestion) in the projected time frame repair-and-renewal operations on the reinforced concrete girders of railway bridges; improved methodical approach to determine the effect of the degree of the reinforced concrete girders's damages on their technical condition with further formation of the ranked list of objects concerning priority of repair-and-renewal works; received further development method of justification the deadlines for repair-and-renewal operations on the reinforced concrete girders in the development of organizational and technological solutions, the implementation of which can achieve more reliable values of temporal parameters under resource constraints; received further development method justification deadlines for repair work on concrete bridge spans in the development of organizational and technological solutions, the realization of which allows to achieve more reliable values of time parameters. Implementation extent: used Hidromontazhspetsbud Ltd. (Dnepropetrovsk) in the preparation of tender documents and drafting implementation of the repair-and-renewal works on the line Volnovaha - Krivoy Rog, bridges PK 85+708 m, PK 140+128 м, PK 155+130 m. Implementation of the rational justification deadlines of repair-and-renewal operations on the reinforced concrete girders on the predesign phase models made it possible to reduce the timing of repair-and-renewal works by 5-7%. Range of application: implementation of repair-and-renewal operations on the reinforced concrete girders of bridges.