АО «Научно-исследовательский институт энергетических сооружений»Строительный проезд, д. 7А, Москва, Россия, 125362 2 ООО «Инженерный центр сооружений, конструкций и технологий в энергетике» ул. Свободы, д. 35, Москва, Россия, 125362 3 ПАО «РусГидро» ул. Малая Дмитровка, д. 7, Москва, Россия, 127006 В целях усиления железобетонных конструкций общестроительного назначения широко применяются композиционные материалы из углеродного волокна. Для обоснования решений по усилению железобетонных конструкций гидротехнических сооружений внешним армиро-ванием из углеродного волокна потребовалась разработка методики расчета прочности уси-ленных конструкций. Были учтены характерные особенности массивных железобетонных конструкций гидросооружений и действующих на них нагрузок, в том числе противодавление воды в трещинах и раскрывшихся строительных швах. Разработаны зависимости для расчета прочности в нормальных сечениях изгибаемых железобетонных конструкций гидросооруже-ний, усиленных внешним армированием из углеродного волокна.Ключевые слова: гидротехнические сооружения, массивные железобетонные конструкции, внешнее армирование, композиционные материалы, нормальные сечения, изгибающий мо-мент, прочность, строительные швы, противодавление воды В настоящее время широкое применение находят композиционные материа-лы при усилении железобетонных конструкций общестроительного назначения [1][2][3][4].При этом в гидротехническом строительстве отмечаются лишь отдельные слу-чаи применения систем внешнего армирования (СВА) в качестве элементов уси-ления железобетонных конструкций. Следует отметить, что вышесказанное в большей степени относится к зарубежной практике [5][6][7].При проектировании усиления железобетонных конструкций гидросооруже-ний (ГТС) необходимо проводить расчетное обоснование проектных решений. В связи с этим возникает необходимость в разработке методики расчета проч-ности железобетонных конструкций ГТС, усиленных СВА на основе углеродных материалов.При этом необходимо учитывать характерные особенности массивных желе-зобетонных конструкций ГТС, а также особенности характера действия нагрузок.

Relevance. Hydroelectric facilities include reinforced concrete retaining walls. They are intended to protect the main structures from the collapse and sliding of soil massifs. Retaining walls are characterized by significant size, relatively low content of reinforcement, the presence of horizontal interblock seams, which considerably affects the features of the work and the state of retaining walls. The normative documents that were in force during the design and construction of most retaining walls (the second half of the last century) did not fully take into account the features of the retaining walls, as a result of which long-term operation revealed deviations from the design premises, including excessive displacement of the top of the walls, the disclosure of horizontal interblock joints, which exceeded the design values. In a number of cases, reinforced concrete structures of retaining walls were reinforced in areas of interblock joints. The aim of the work is to conduct experimental studies of reinforced concrete retaining walls, including taking into account their reinforcement by inclined reinforcing bars. Methods. The technique of experimental studies of hydraulic engineering reinforced concrete structures was applied in accordance with regulatory documents and the developed program of experimental studies of reinforced concrete retaining walls. The results obtained showed the opening of horizontal interblock joints, the formation of inclined cracks emerging from the joints. An increase in the strength of reinforced concrete structures of retaining walls and a decrease in their deformability due to reinforcement by inclined rods in the area of the interblock weld were recorded.

Introduction. In connection with the long-term operation of hydraulic structures (HPP), the installation of significant temporary loads, the presence of alternating effects on individual structural elements, it is possible to reduce the carrying capacity and strength of reinforced concrete structures. One of the most crucial elements is the reinforced concrete overlap of the machine hall, the work presents field and design studies, a proposal to strengthen the structures with external reinforcement. Materials and methods. The scientific and technical documentation was analyzed, instrumental studies and visual inspections of the state of the structures were carried out, and a 3D mathematical model was developed based on the finite element method. Multivariate non-linear computational studies of the actual stress-strain state of structures have been carried out. Results. Conducted visual and instrumental examination showed the presence of cracking on the lower edge of the reinforced concrete floor of the machine room. The simulation of the actual state of the structures has been carried out; according to the results of calculations, a schematic diagram of the gain of structures has been proposed. Conclusions. As a result of computational studies of stress-strain state, the occurrence of cracks on the lower edge of reinforced concrete floor of the machine hall was confirmed. When applying temporary technological loads to overlap, it is possible to achieve the yield strength of the reinforcement in certain zones. In order to ensure further safe operation of the structures, a conceptual amplification scheme based on the results of stress-strain state calculations has been proposed.

Operating experience and results of on-slte observations of the work of reinforcedconcrete hydraulic structures (such as locks, retaining walls, abutments) show deviations in behavior from the calculated assumptions, expressed in more intense cracking and increased deformation, which ultimately indicates a decrease of bearing capacity [6,7]. Examples are the wall of the No. 2 lock of the Moscow Canal [7], retaining walls of the Plyavinyas hydroelectric station, the results of'testing a large-scale model of the lock of the Votklnsk hydroelectric station at the testing station of the B. E. Vedeneev All-Unlon Sclentific-Research Institute of Hydraulic Engineering (VNIIG) [9], and abutment of the Khantalka hydroelectric station. In a number of cases costly repair works to strengthen the structures were required.The cause is the inaccurate prediction of external effects and resistance to them of the reinforced-concrete structure experlenclng the combined effect of the bending moment and transverse forces [8].

Introduction. Floorings of the turbine hall and installation sites of the HPP (PSS) are one of the most important reinforced concrete structures, as during operation they are subjected to significant process duties, including those not provided for by the project. Thus, during the testing of crane equipment on the floor surface of the installation site of the Alluriquin HPP under construction, the cargo weighing 22 tons fell, under the influence of which the floor slab was punched, which required a comprehensive study of the condition of the reinforced concrete structure of the floor and the surrounding area of the failure of structures, as well as the development of measures to strengthen the damaged structure. Materials and Methods. Visual and instrumental studies of the stress and strain state (SSS) of the reinforced concrete structure of the turbine hall slab and surrounding structures were carried out with the use of optical devices (MPB-3 reading microscope), Schmidt hammer to determine the strength of concrete structures, as well as the “reinforcement load removal” method to determine the actual stresses in the reinforcement of structures. Results. The punching of the reinforced concrete floor of the installation site with vertical displacements of the edges of through cracks up to 12 mm, as well as the system of cracks formed during the fall of cargo was revealed. The actual stresses in the reinforcement are determined by the “reinforcement load removal” method. On the basis of finite element modeling the actual condition of structures during the period of cargo fall and after the removal of the load is obtained. On the basis of the analysis of results of field and design studies the schematic diagram of strengthening of structures by carbon composite materials is developed. Conclusions. The actual SSS of the reinforced concrete floor of the installation site and its support structures during the period of the cargo fall and after the termination of the impulse load is established. The vertical displacement of the edges of the crack of the floor punching was 17.5 mm during the period of the fall of the load and 12 mm after the removal of the impulse load. Crack opening width in reinforced concrete structures in the cargo drop area reached 2 mm. At the moment when the cargo fell on the floor slab, the values of stresses in the reinforcement cage reached 200 MPa; after the impact — 76.2 MPa. With a view of the subsequent safe operation of the reinforced concrete floor and surrounding structures the basic schemes of their strengthening by external reinforcement on the basis of carbon fiber have been developed, which have been proved by calculation.