Research Of Moshan Reservoir Cutoff Wall

Seepage problems have occurred because of inadequate seepage control measures or poor preparation of the foundations and abutments. Seepage can lead to soil piping and embankment sloughing or sliding, both of which can lead to dam failure. Therefore, to maintain dam integrity and safety, there is a great need to develop new technology to control seepage problem.In this study, the rehabilitations of Moshan Reservior Dam, which is located in Shandong Province, are investigated as case studies. Out of several potential failure modes identified, the seepage failure of dam foundation is considered the possibility for leakage of the reservior. The acknowledgement of the potential mechanism, diagnosis of the developing mechanism, and the permanent construction remedy devised to avert the seepage failure is described in this dissertation.First, the reasons resulting in seepage of earth and rock fill-dam is discussed. The general and recent development of anti-seepage technology is reviewed and summarized.Second, three strengthening methods involving vertical seepage barrier, horizontal seepage barrier and downstream drainage are compared. With the choice of cutoff location and wall material, the plastic concrete cutoff wall is employed to rehabilitate Moshan Reservior Dam, which is the best method in the name of economy, technique, construction and management.Third, based on the characteristics of seepage through earth and rock fill-dam, the interaction between seepage and stress in the dam is analyzed, the mathematical model for coupled seepage and stress fields is proposed, and the relationship between the incline of cutoff wall and seepage capacity is established. The incline of the slot due to construction deficiency has little influence both on the steady state of seepage and stability of the slot wall, but affects the stress of the cutoff wall. To assure the safety of dam, the incline of the slot must be taken into consideration in the design of the cutoff wall, which is also significant to the successful design of similar projects.