Aiming at the coupling influence from the uncertain factors of inflow, discharge, etc. on the cofferdam under the environment of the construction of cascade hydropower project and targeting at the overflow risk from the project, the uncertain inflows during the construction periods of all the cascades are estimated with Monte-Carlo simulation sampling technique according to the proportion of the watershed area of project, and then a model for calculating the overflow risk from earth-rock cofferdam under the cascade condition is developed in accordance with two different flood discharging modes, i.e. safety of project construction and failure of cofferdam during flood period;moreover, actual case analysis is made with the model as well. The result shows that the safety of the upstream project during flood period can effectively lower the overflow risk of the downstream project under the environment of the construction of cascade hydropower project, while the hydraulic parameters related to flood discharge have no larger influences on the overflow risk of project, but the main factor of the influence on the safety of project during flood period is just the hydrological risk. When the failure of the cofferdam of the upstream project occurs, the flood combination in front of the downstream project is to be changed, which is to significantly increase the probability of its failure. The study result can reasonably predict the overflow risk of project under the environment of the construction of cascade hydropower project, thus can provide an important decision-making support for the design of earth-rock cofferdam and its safety of construction during flood period.
Water Resources and Hydropower Engineering
safety of construction during flood period
cascade hydropower development in watershed
陈玉玺(1994—),男,硕士研究生,主要从事水利水电工程研究。E-mail: firstname.lastname@example.org;通信作者:卢晓春( 1983—),男,副教授,硕士研究生导师,博士,主要从事水利水电工程方面的教学与研究工作。E-mail: luxiaochunl014@163. com.