Controlling Theory And Applying Study For Anti-Seepage Reinforcing Effect Of The Dike

Among all the accidents of the dams, those of earth - rock dams made up the biggest share, accounting for 70.5 percent of the total. Seepage is a common problem of earth - rock dams and is harmful to the safety of the dam when the seepage is serious. At present, the research about the effects of the seepage reinforcement is limited, so it is essential to study the seepage reinforcing, safe monitoring and evaluating problems of the earth - rock dams.In this paper, based on model tests, calculation of the finite element and analysis of the prototype observed data of the anti-seepage reinforcement project of the reservoir dyke, each factor which affects seepage of the earth - rock dam is analyzed,impervious effect of the project is studied systematically. Safe monitoring and evaluating system on seepage is developed.Based on the 2-D saturated and unsaturated basic seepage equation, a FEM (Finite Element Method) governing equation for seepage problem is presented by applying Galerkin Method. Various factors which affect seepage are analyzed by using the FEM software SEEP/W to the earth - rock dam reinforced by the underground diaphragm wall. The results indicate that the construction quality of the wall is the most significant factor for impervious effect of the dyke.Through model tests of different cross-sections with different cutoff walls which have different permeability coefficients, comparison between the testing results and calculating results is made. The results indicate that the seepage velocity reduces obviously, seepage quantity declines 26.9～71.6 percent, the total water head as well as the saturation line decreases, and seepage gradient declines 29～75 percent after reinforced. The capacity of seepage resistance of the dyke has a remarkableimprovement. Through correlation analysis of the prototype observed data, overall reinforcing effect is verified to be better. From above, the numerical analysis can simulate the reinforcement project more perfectly, and the result calculated can be the reference of design and construction.According to the vibrating experiment of the model, the capacity of earthquake-induced liquefaction under many working conditions is analyzed. The experimental results indicate that when the dyke directly contacts clay it has stronger liquefaction resistance, and when the dyke directly contacts silt or sand soil it has weaker liquefaction resistance. The dyke shows liquefaction resistance better in the case of earthquake after reinforced.The relation between the factors which affect seepage of the dyke and the equivalent factors which can be directly measured is studied, and the seepage-monitoring model also be established. F and T inspections show that correlation is better. Based on ACCESS 2003 and VB6.0, the dyke seepagemonitoring and multi-fuzzy evaluating system which is a scientific practical andintellectual system is developed. It can play an effective role in monitoring, predicting and safe evaluating for behaviors of the dyke.