| Pumped-storage power station is a special form of hydropower station.Its upper reservoir basin is usually formed by excavation and filling.There are seepage problems and slope stability problems in different degrees.Taking Tongde pumped-storage power station as the research object,its seepage problem is systematically studied by using the seepage theory,theoretical calculation and numerical simulation,and the stability of the slope around the reservoir is analyzed based on the strength reduction method,and relevant conclusions are drawn.The main research work of this paper is as follows:(1)Based on the field survey of the upper reservoir engineering area of Tongde pumped-storage power station,the engineering geological conditions and hydrogeological conditions of the proposed power station are analyzed by combining the data of drilling,adit and field test.The results show that after excavation of the upper reservoir basin of Tongde pumped-storage power station,the exposed lithology is mainly Tertiary conglomerate and Triassic sandstone and slate,and the permeability is from slight to medium,generally belongs to weak permeability layer.(2)This paper discusses the principle of using finite element method to calculate the seepage quantity,sets up two dimensional and three dimensional models respectively,and makes a comprehensive study to determine the permeability parameters of engineering area according to the results of field water pressure test and the general conversion relationship between Lu value and permeability coefficient.(3)By means of analytical method and numerical simulation method,the seepage quantity under natural condition and seepage control condition of upper reservoir of Tongde pumped-storage power station is calculated,which provides a basis for the anti-seepage design of reservoir basin.The calculation results show that no matter which method is adopted,the calculated seepage is greater than the minimum seepage in the case of no seepage control stipulated in the 《Code for Design of Pumped Storage Power Stations》,so the corresponding anti-seepage measures should be taken.(4)Based on RS2 and Midas GTS NX software,the strength reduction method is used to analyze the stability of the perimeter slope.It is obtained that the minimum stability coefficient of the perimeter slope is 1.37 under the conditions of natural,rainfall,earthquake,normal water level and sudden drop of the reservoir water level,indicating that the slope is in a stable state under various working conditions. |
