Author(s): Moogui Mohsen; Abolghasemi Mahdi; Khaghani Milani Zeinab
Linked Author(s):
Keywords: Risk analysis; Diversion system; RCC1 dam; Hydraulic calculations
Abstract: In the last few years, the standard and design practices used for hydraulic structures (such as dams) have been adjusted to prevent these structures from being damaged by natural disasters. There are several methods for assessing dam risk. These methods which are complementary and are used together cover all aspects of a risk study: analysis, assessment, management and risk minimization. When applied together, they become a reliable decision-making tool for the dam management team when regarding intervention on structures. Consideration of technical, economical and risk criteria in large dam projects attach great importance to selection of flood return period for diversion system. Therefore, the various alternatives of diversion system should be taken into consideration based on hydraulic and economical studies and eventually by imposing risk analysis criteria, the alternative which has the lowest cost of risk must be selected as the final alternative. This study shows that how can reach to optimum solution in huge dam projects by hydraulic, economical and risk studies in dam and related structures with respect to the total risk and construction cost. This methodology can be used in every dam project with considering of governed conditions in it and the optimum combination of diversion system will be selected based on the results. This presentation will demonstrate a study on risk analysis by overtopping of diversion works of Rudbar Lorestan Dam and Hydropower in Iran that was carried out to examine the overtopping event during the flood seasons at the dam site. In this study, hydraulic calculations of diversion system which consist of upstream cofferdam and diversion tunnel are used for risk analysis study. The risk analysis was made considering the hydraulic structures data and the final construction programme, to establish a performance function that combines the risk of original deterministic analysis with a probabilistic analysis made in the first study. The study also focuses on practical construction stage of dam and related structures, like access tunnels, river diversion, dam, bottom outlet, spillway and power intake. The work here is presented as a case study and will demonstrate how risk analysis leads to a technically practical solution that significantly reduces the total risk and construction cost of diversion system.
Year: 2007