Fluid-Solid Coupling Analysis On Splitting Grouting In Earh Dam

Splitting grouting, firstly invented in our country, is a new techonology that can control the deform&seepage stability of dangerous dam economically and effectively. It has been widely used in more twenty provinces in china since 1980's, which contibutes to development of construction technology and theoretical study, as well as economical and social effectiveness. But, its history is so short that many techanical problems should be solved.Based on a great number of studies performed by former researchers, the work finished in this paper focuses on several aspects of the following:1.Some kinds of recent grouting curtanin shapes are pointed out, the problems of earth-dam grouting engineering are discussed. Beginnig the stress field around the grouting hole, the first splitting situation around the hole is introduced. Then, some problems shoud be paid attention to reasonable grouting technology.2.Mechanism of splitting in the plain equal-stress field is discussed. We can deduce splitting pressure formulation and splitting factors by the theory of cavity expansion, plastic mechanics and large deformation. Menwhile, the splitting pressure is calculated during the course of cracking.3.The curve of the first splitting situation vs.the stress field around the hole is analyzed by using FEM software-ANSYS. At the same time, the relationship between grouting pressure and splitting length is obtained after the hole cracking.4.Applying the fluid-solid coupling theory of a single fracture, numerical analysis is carried out between grouting seepage field and soil fracture stress field. Mechanism of splitting grouting is discussed, as well as the forms and area of splitting grouting. Meanwhile, the curve of fracture wide vs.splitting length is gained, and the principal of pressure-control is introduced.5.Using the theory of fluid-solid coupling calculating, stability analysis is discussed between the seepage field and the stress field after grouting curtain being built. So we can get the reinforcement range of the dam and the principal of grouting holes diposal. The conclusions of analysis are satisfied with the observations.In recent years, with the development of splitting grouting technology in earth dam, many high dams are reinforced , many cases are beyond the theories and specifications of current grouting. It is not reasonable to use the earth dam grouting specification of SD266-88 continuely. In order to deveolop the grouting technology, it is necessary to strengthen the theoretical study. The research of splitting grouting in the essay can contribte to provide reasonable technology and guidance for construction and design, as well as it will promote the theoretic development. Consequently, splitting groutng will play a more important role in anti-seepage reinforcement of dangerous dam in the future.