Study On Technical Parameters Of Curtain Grouting In Deep Holes

The control of groundwater in mining area is the key point and the difficulty to exploited the deep-buried mineral resources. Compared to the traditional drainage and dewatering from surface, the curtain grouting technology can both protect the groundwater resource and water environment and reduce the project cost greatly, which can reach the target of safe, economic and environmental friendly exploitation. So, with the accelerating paces of exploitaton of mining resources in our country, the application of curtain grouting technology in water-intercepting and anti-seepage in deep mines becomes more and more popular.The technical parameters are not only the core of curtain grouting, but also are the key points whether the curtain can intercept water successfully or not. The perfect curtain grouting parameters are the ones that can anti-seepage successfully and reduce the project cost and protect the groundwater resource and water environment. Therefore, from the view of quality and safety and economy of project, it has very important practical significance to determine proper and reasonable curtain grouting technical parameters for the water-intercepting and anti-seepage project of deep mines, and it also has extremely important theoretical value to study the way of determining, verificating, and optimizing the technical parameters for deep-hole curtain grouting technology.Taking the Under-construction curtain grouting project of Zhongguan Iron Mine as the case, which is the NO.1 curtain in Asia, this paper makes a deep study and analysis on the way of determination, verification and optimization of the two main control parameters (grouting pressure and diffusion radius) by the four ways of curtain grouting tests, theoretical calculation, empirical calculation and numerical simulation.First of all, It reviews the development and the present situation of the cutain grouting technology, and also summarizes the research status and the deficiency of the grouting parameters in the aspects of theory, test and numerical simulation. Therefore, it puts forward the "One and Three Synthesis Method" for the first time to determine the optimal curtain grouting parameters of deep holes, and then it plans to make a deep and detailed analysis and study on the composition, calculation and selection of the grouting pressure by the four ways of grouting tests, theoretical calculation, empirical calculation and numerical simulation. Then, it makes a detailed analysis and discussion on the composition, calculation, selection and determination of the grouting pressure, and makes a deep analysis and study on the determining standard of the diffusion radius and the Theoretical formula and Empirical formula, and gets the Extended-Lombardi formula. By taking the two curtain grouting tests of Zhongguan Iron Mine as the main research subject, it studies the grouting effects and the testing results of the two main control parameters. Based on the analysis of the grouting effects, the paper mainly studies the empirical pressure, control pressure, designed pressure and practical pressure of curtain grouting tests in Zhongguan Iron Mine, and obtains the way of determining the grouting pressure in deep holes; Due to the very satisfactory results of the grouting effects, it gets a conclusion that the the grouting hole distances lean to a conservative results. Finally, by using the Extended-Lombardi formula and Empirical formula, it verificates the accuracy of the grouting pressure and diffusion radius of the two tests, and it comes to a conclusion that the diffusion radius in grouting tests are conservative. hereby, the optimized diffusion radius and grouting hole distance are recommended by synthesizing and analyzing the testing and verificating values. The results of numerical simulation of curtain grouting give a supplementary verification to the grouting pressure and diffusion radius, and also simulate the process of curtain grouting.The paper achieves the two vested goals:the first one, recommending the optimized grouting pressures and diffusion radiuses for the curtain grouting project of Zhongguan Iron Mine, and the other one, proving the feasibility of using "One and Three Synthesis Method" to determine, verificate, and optimize the grouting pressure and diffusion radius of curtain grouting projects.