Research On Diseases And Reinforcement Measures Of Concrete Spillway Dam Of Fengman Hydraulic Power Plant

Those diseases including water leakage, cracks, freeze-thaw often exist in mass concrete, such as Fengman concrete spillway dam. The damages created by cracks and freeze-thaw are greatest.In the stage of construction and operation of concrete dam, cracks have been paid enough attention because some serious cracks may reduce the dams' safety. The cracks may occur and expand in the period of both construction and operation. In this paper, the causes of cracks and freeze-thaw are analyzed according to the observation data of water temperature of the Fengman upstream reservoir, the observation data of air temperature and construction information. It is indicated that the concrete temperature rise created by heat of hydraction, the change of environmental temperature and construction quality may have crucial action to the cracks and freeze-thaw.According to the several years' operation of Fengman concrete dam, the wash-off destroy of spillway dam in 1986 are analyzed here. Because of a great lot of seepage, the concrete at the downstream side are in the state of seepage saturation which prick up the freeze-thaw destroy of the concrete at the downstream and induce the large-area wash-off accident. For purpose of destroyed spillway dam's safe operation before next flood season, a series of effective schemes and technologies have been taken in the reinforcement of the spillway dam. After several years' flood discharging, it shows us those measures are useful and obvious social and economical benefits have been gained. Those effective measures are concluded in this paper in order to give reference to the reinforcement of other dams in severe cold zone and improve the existent reinforcement technology.