NUMERICAL MODELLING OF POWERHOUSE STRUCTURE STRESS-STRAIN STATE CAUSED BY UNEQUAL SETTLEMENT AND DURING ITS LEVELLING OPERATIONS

Abstract

Reinforced concrete elements of the Zagorsk-2 pumped storage station structure had got into unexpected stress-strain state after unequal settlement and bending of the structure crosswise of the flow as a result. Cracks emerged in the load bearing reinforced concrete elements and the reinforcement crossing the cracks suffered significant tensile stresses. Important to mention, that the main reinforcement is arranged along the flow. There was a cofferdam designed and constructed across the reverse channel, which allowed to decreasethe water level and remove water from the channel to provide stabilized position of the powerhouse. After stabilization of the powerhouse, it was planned to level the powerhouse by the compensation grouting method.Based on the finite element soil-structure model of the powerhouse, the stress-strain state of reinforced concrete elements subject to unequal settlement and during the levelling operations was determined.The results of the stress-strain state analysis were compared with the actual in-situ stress data obtained by the “reinforcement de-stressing” method. According to the results of the analysis, it is necessary to strengthen the RC load bearing structures of the Zagorsk-2 powerhouse.In the article, the main design proposals for strengthening the RC load bearing structures of the Zagorsk-2 powerhouseby the external carbon fibre reinforcement are given and justified.

Keywords

• здание станционного узла
• неравномерная осадка
• несущие железобетонные конструкции
• напряженно-деформированное состояние
• трещины
• напряжения в арматуре
• внешнее армирование
• управляемое компенсационное нагнетание