The Karst Leakage Of Reservoir Study On Shanxi Zhenan Pumped-storage Power Station

Along with the high speed developing of the Chinese economy in recent years, the construction and development of the pumped-storage power stations are also growing rapidly, which achieved great successes during this time.The pumped-storage power station is that kind of hydropower station which can pump water and generate electricity.It has two reservoirs, using redundant power pumping water from the lower one to the upper one, and keep as potential energy that can generate electricity once needed.It contributes a lot to hydroelectric power to China.And it is thought highly on feasibility and safety evaluation in karst region particularly in complex geological environmental conditions.ZhenAn pumped-storage power station in shanxi located in about 47km northwest from ZhenAnXian, About 40km north from NingShanXian.The first-stage reservoir located on the right bank of lateralchannel in moon river-JinPen ditch, its storage capac is 1000×104m~3, its Normal water level is 1390m, the total installed capacity is 2400MW.Due to the complicated geological conditions in karst region, belonging to defective geological bodies, it is necessary to ZhenAn pumped-storage power station builting on karst reservoir project reservoir security and stability conditions were studied.The second-stage reservoir and the lower reservoir locate in Intrusive rocks zone, have better geological conditions.Therefore, this paper pay attention to karst seepage analysis on security and stability condition of the first-stage reservoir.This paper Survey on the groundwater system of karst area hydro geological conditions and hydrodynamic characteristic on the basis of geological environmental conditions.Finding out the development degree and scale of the surface and underground in karst zone, summarizing the main distribution, evaluating the permeability exhibition features of karst medium space.Research different parts of the leakage appearing in reservoir area, then use modflow software tu simulate, then compute the risk and water leakage of the possible leaks parts, giving further evaluation the influence of reservoir leakage.The main research content and result are as follows:(1) This article has carried on the diagnosis to geographic and geomorphic conditions, formation lithology, geologic structure, regional techonic stability and Karst hydrogeology conditions.And also do research on the engineering geology and hydrology geology conditions.(2) On the basis of the analysis of its scale, development and distribution, this article has done research on the mechanism and dissolution regularity of distribution combining indoor experiment results.And focus on the underground karst medium corrosion situation and hydrological geology characteristics, giving clarification of the possibility of karst seepage channels.(3) This paper analyzes the penetration ability of the karst medium through the water pressure test data and permeability tensor calculation, and summarizes the upward and vertical permeability of spatial distribution characteristics of dissolvable rock in reservoir region, which provides the basis for the model that can be generalized.(4) On the basis of leakage passage and water dynamic conditions in the area, this paper gives emphasis to position of the leakage especially the submerged in the thin underground watershed ridge and the dam along with its abutment which corrode seriously.(5) This paper USES 3-d numerical analysis method to analog the seepage of groundwater under 3 different conditions: before water storage, impoundment and add anti-seepage curtain.The main leak-points are: the leakage of dam foundation is 713.63m~3/d, the leakage of left the abutment is 115.79m~3/d, the leakage of feeble ridge a is 131.46m~3/d, and the total leakage of the reservoir is 1140.37m~3/d.(6) Due to the different simulation results of karst developmental characteristics, rock permeability propertiesand and reservoir seepage field, it is thought that the degree of karst development is relatively low in the reservoir and dam region of ZhenAn pumped-storage power station.This paper puts forward reasonable seepage control measures and suggestions to ensure safe operation of the pumped-storage power station.