Research On Foundation Treatment Of Chongqing Aikou Reservoir's Asphalt Concrete Core Rockfill Dam

There is a large quantity of karst in the foundation of Chongqing Aikou Reservoir rock fill dam with asphalt concrete core wall which is under construction, and part of the karst rate reaches as high as 21%. Besides the generally-worried problem of lekage, there are problems of core wall cleft which may be caused by the uneven deformation and the destruction of the base rock. In this thesis, the elastic plastic finite method is adopted to simulate the geological structure of the foundation and the filling and constructing process of the dam body and to analyze the stress, deformation and safety form of the foundation before and after the karst being treated. In the thesis, the treatment schemes of the karst foundation is also put forward whose research results have already been put in practice as the design plan.1,Beginning from the development of the treatment method for the foundation of rock fill dam, the status of present research and existing problems of treatment method about karst foundation are introduced briefly home and abroad. And based on the actual foundation conditions of the Aikou Reservoir rock fill dam, the importance and key research contents of karst rate treatment method for high karst rate foundation are put forward.2, In accordance with the characteristics of Aikou Reservoir high karst rate as well as the simulation of the foundation geological condition and karst structure, stress, displacement, stability of the foundation under various kinds of operations are studied. Therefore, the working condition of the karst foundation is mastered and the degree of hidden danger is recognized.3, Various kinds of karst distributing rates and their influence on the stress and stability of the foundation are studied. Thus facts that to a certain degree the change of the karst distributing has greater influence on the foundation stability and that the karst cavern's existence in some parts has greater impact on part of the base rock are realized.4, In view of the actual condition of Aikou Reservoir and the technical level of the karst methods adopted home and abroad, we bring forward the method for the foundation and decide to adopt the scheme of improving the base rock bearing capacity by using different distance among grout holes to grout progressively in different depth . Through the comparison and analysis of the foundation stress and stability before and after its being treated, the rationality and feasibility of the treatment scheme are proved. The application of treatment scheme to the project design provides reference to the research and design of similar project in the future.5, After the three-dimentional finite element calculation of the foundation stress and stability before and after the karst being treated with ansys software and the comparison with the result of the two-dimentional calculation, the calculation result conforms to the conclusion on the whole.In the end, a summary is given and some problems to be further studied are discussed.