Research Of Simulation For Penetration Clogging Effect On The Permeability And Seepage Of Zhuo Yu Reservoir Dam

Duration of sunshine is longer in southwest China, with less annual rainfall, andlarge amount of evaporation, water retaining structure is inevitable to build on thedeep loose dam foundation in order to supply the local people with daily water andagricultural irrigation. For loose foundation the distribution regularity is poor, withplenty of interstices, good connectivity, great permeability and thick cover layer, theconstruction quality of commonly used anti vertical seepage measures is different tocontrol, anti-seepage effect is not often ideal, so it is extremely urgent to search forseepage control measures with high capability price ratio. Based on the investigationand survey on Tibet reservoir for many years, leakage is more serious during theinitial operation. After a few years, the leakage reduced rapidly, and some of thesereservoirs even reached the normal storage level. Research shows that thephenomenon is due to the existence of clogging, internal pores can be blocked and thepermeability of dam foundation can be reduced through clogging effect. So theprinciple of clogging can be used to achieve auxiliary seepage and controlpermeability reducing.Based on a reservoir of Tibet, combined with early preliminary study on the region, the outdoor siltation research and indoor siltation research are conducted andthe results are remarkable. The first attempt is made to summarize clogging effect oninfluence rule of dam foundation seepage, the mathematical model is derived to agreewith dynamic permeability coefficient, and the feasibility and accuracy of the modelare verified. From the perspective of seepage control theory, the features of differentseepage control measures are described. Based on the Seep/W module of GeoStudio,different seepage control schemes of dam foundation seepage are simulated. Optimumanti-seepage scheme is recommended by carrying on the contrast analysis for seepageflow of the dam foundation, flow velocity, the foundation head, seepage flow andseepage gradient of different seepage control program. In this paper, the researchresults are as following:(1)Based on a lot of indoor simulation test and data analysis, we have inductedand summarized that coefficient of permeability variation of clogging effect occurs inthe process, the mathematical equations of the reservoir permeability coefficient arededuced, and the feasibility and accuracy of this type are verified.(2)On the basis of seepage control theory, the different seepage preventionmeasures and effect of engineering application of the deep overburden layer aredescribed, providing reference for special foundation soil impervious of the southwest region.(3)The local complex geological conditions are reasonably simplified, andtheoretical calculation and software simulation results is very close, whichillustrated that this method is feasible.(4) The Seep/W module of GeoStudio is used to simulate the different seepagecontrol scheme of dam foundation seepage, flow velocity, the foundation head,seepage flow and seepage gradient, and the different effect of seepage controlprogram was compared and analyzed.(5)According to different types of seepage control effect, optimum anti-seepageis recommended and the next phase of research issues are put forward, providingguidance and advice for seepage control and seepage control scheme selection.