Problems And Countermeasures Of Small And Medium-sized Dangerous Reservoirs In Dandong

The main reservoirs in Dandong area were earth-rock dams,However,many dangerous reservoirs with various degrees of damage have appeared because of the small and medium-sized reservoirs built in the early times with a long of history,poor quality,inadequate pre-research and insufficient design.We can gain the main factors affecting the safety of earth-rock dam through the risk analysis,which can play an important role in strengthening and ensuring the safety of the dangerous reservoirs.According to the complexity and uncertainty of the risk factors of the earth-rock dam,the network analysis method is introduced into the analysis of the risk factors and the network analysis basing on triangle fuzzy was also applied to the practical engineering,which can illustrate the idea of model.The main research was as follows.(1)There were many water systems in Dandong area of Liaoning Province,among which the small and medium-sized reservoirs with serious problems were representative.In this paper,the data of 13 small and medium-sized dangerous reservoirs would be analyzed in terms of the age of reservoir construction,the emergence of dangerous problems and their causes and the risk factors for the establishment of dangerous reservoirs.(2)Based on AHP(Analytic Hierarchy Process),a triangular fuzzy number was introduced to improve the index system and network chart of risk factors of earth rockfill dam.Besides,according to the calculation and analysis of the index weight,the significant degree of influential factors of dangerous reservoirs can be drawn.And the conclusion can accord with the actual reservoirs situation.(3)According to the significant degree of the influential factors obtained by the network analysis combined with the specific situation of Dandong area,the main problems of the dangerous reservoirs in Dandong area were summarized,including 6main problems such as flood control safety,seepage safety,structure safety,engineering quality,mental structure and operations management.(4)The corresponding countermeasures should be put forward in view of the above six problems.So many measures can be taken,such as raising the flood control standard of the dam;adopting irrigation and impermeable measures;setting up concrete impermeable walls;adding skin drainage equipment;clearing loose soil on both sides of the crack and around the crater;reconstructing the gate chamber and pedestrian bridge on the pier;adding a crane room;implement the responsibility system for dam safety;carrying out the work of demarcating and confirming rights inaccordance with the law;defining the scope of management protection;improving reservoir management facilities;ensuring the maintenance fund.(5)Taking small dangerous reservoirs as an example,we will select Tai Ping Reservoir in Kuandian country,which has obvious problems.The design of anti-danger reinforcement project was referential and reproducible.Analyzing and calculating of the hydraulic characteristics of the buildings,we can put forward scientific and reasonable solutions to the insufficient condition.In addition,the hydraulic calculation of the water tunnel is done to designed the reinforcement project,aiming at the problems of the insufficient overcurrent capacity in the original water tunnel and the poverty of the energy dissipation effect of the downstream dissipating pool.Then we will do a study on the above problems.The results of the governance of Tai Ping Reservoir can verify the scientific nature and rationality of the study and provide references for the management of the dangerous reservoirs in the future.