Research Of Dam Foundation In Yan'erhe Reservior From The City Of MianYang

This paper studys if the overlay can be used to be the base or to be part of the base of the reservoir dam and what measures we can take when use it.The subject is from Mianyang Yan'erhe reservoir dam.The Yan'erhe reservoir is one of the sixth period of the Dujianyan Renmingqu reservoirs.The principal function of the reservoir is irrigation for agriculture ,and ,as a reservoir it also can be anticipated to be one of a water resource for town and to be a place for tourism.The Yan'erhe reservoir contains the following projects: the dam ,the tunnel spillway for guiding the flow, the tunnel spillway for irrigation,the conduit for town and the spillway.the dam is constructed of sand and gravel with a cutoff wall. The upstream reservoir normal level is 496.00m, chech level is 496.56m, the top of dam is 497.50m, the maximum height of the dam is 49.5m, the containance of the reservoir is 20.7 million m~3.The geological section indicates that the overlay of the dam base is too thick, In order to avoid extra excavation and to save expendituer, question of whether the overlay could be used as dam base becomes significant.Based on geological and hydrological investigation data ,through physical and mechanical performance research of the overlay ,The following plans are proposed: use part of the overlay ,use majority part of the overlay ,not to use the overlay to be the base of the dam. and ,corresponding the former plans are outlined above ,Three different sections are assumed, by seepage analysis and stability calculation,The optimization section of the dam is drew. For plan 3(using majority part of the overlay to be the dam base),Finite element to analysis the movement of the dam and the foundation is used as the force altering, and draw the conclusion whether the plan is feasible.The calculation and analysis of the three plans are drew from《Lizheng analyzing and calculating for seepage》designed by Beijing Lizheng software research and design institute.The stability of the dam slope is demonstrated by Sweden Arc Method and Bi Xiao Pu Method, and checked by Mogen-Pulaisi Method that can meet the balance of the force and moment. By using the computer, the stability of the darn is checked by《prograrns of the sand and gravel dam slope stable analyze》designed by China institute of water resource and hydropower research.The stress and displacement of the dam body and foundation is calculated to third plan by finite element method.Through the two-dimension finite elernent calculation, analyze rule of the dam body and foundation under many forced conditions.and evaluate the safety of the dam.Comparing the three plans technically and economically,the most reasonable plan to be adopted is picked up and give my advice on how to build the dam.