| Karst landform is a general name for the morphology of the earth's surface and underground, which formed in the process of soluble rock dissolved by the running water. Karst landform distributes in the whole world with the total area of about 22 million square kilometers, and influences one billion people's life. For China, the area is about 1.3 million square kilometers, and it mainly centralized in the Southwest area.In the karst area, the ecological environment is very weak, which requires management and maintenance with patience. However, in order to keep the balance of development between the regions, many large foundation engineering are constructing in the karst area. The tunnel will be the new path for the underground water, and the hydrogeology will be seriously affected. Therefore, the traditional concept, which mainly depends on the drainage method, should be changed during the tunnel construction.Throughout the history of tunnel development, the construction trend is longer, larger, and deeper. During this process, conventional technology for the tunnel has a considerable progress. However, when facing geological disasters, such as water inrush, rock burst, and collapse, human still suffered the bitter lessons. Among all the disasters, water inrush is the worst one, because of its destructive effects and frequent occurrences. Water inrush can destroy the equipments, submerge the tunnel, delay the construction period, scrap the whole project, and even cost great loss of the national economy. In order to decrease the destructive force of water inrush and guide the treatment, numerical computation was studied in this paper under different driving forces in the tunnel with the FLOW-3D.For this dissertation, the research is based on three tunnels, one is Longtan tunnel, the other one is Qiyueshan tunnel in the Hurong west, the last one is auxiliary tunnel for the Jinping second hydropower station. Disasters of water and mud inrush have occurred many times during the construction of Longtan tunnel. The construction period is five months and five years which is twice of the predicted one. For the last 5 meters of the left line, it cost five months to pass, from which we can know the severity of the disasters. The Qiyueshan tunnel passes through the source of Qingjiang, which is full of conduits, cavities, and even underground rivers. The geological condition is so complex that water inrush has occurred many times during the construction process. Especially when it was raining outside, water was running in the tunnel. The outlets for the reverse slope construction have also been submerged several times. The engineering's process has been severely delayed. The buried depth of the auxiliary tunnel is more than two thousand meters, and the karst morphology is mainly fractures with good interconnectivity. Under the high pressure, water will inrush into the tunnel in an extremely high speed, and the destructive force would be ghastly.With the development of the modern grouting technology, emergence of the new grouts and improvement of the grouting equipments, grouting has become the main way to treat the water inrush geological disaster in the karst tunnel. However, as a science, the theory of grouting and its systematicness still need to be well established. For the grouting theory research, the model of injected medium and the rheological property of the grouts have to be studied. Starting from the unique features in the karst zone, by studying the injected medium, the conclusions obtained in the dissertation are that the grouts diffusion in karst zone isn't controlled by the seepage theory, but by the mass and momentum conservation. Because the viscosity changes with time has to be considered, based on the feasibility of the solution and the rationality of the theory, Newton fluid model with changing viscosity upon time has been selected. The mass and momentum conservation equations have derived from thess theory, and the closed equations in the velocity and pressure have been acquired.The control equations about the mass and momentum conservation are complicated partial difference ones, it is impossible to solve them using the mathematics and fluid mechanics for now, so numerical solution based on the modern computer technology has to be selected. In this dissertation, based upon the finite volume method which are widely used in the fluid dynamics, several discretizations schemes such as HQUICK, Central Difference, Crank-Nicolson, Adams-Bashforth, have been applied to discrete the diffusion and convection term in the time and spatial domain. Based on the discrete form of the equation, the velocity and pressure have been solved by the Pressure Poisson Equation Method by applying the non-staggered and non-structural grid. Now, the numerical solution has been theoretically calculated.Based on the advanced programming software Matlab(?), the discrete form of equations has been programmed, and the GSK (Grouting Simulation in Karst zone) software package has been developed. GSK software package includes four parts, which are grid construction, preferences, analysis, and post-processing. By using non-structural gird, the model with arbitrary shape can be established, so the complexity requirement of the injected medium in the karst zone can be satisfied. Preferences part includes the initial and boundary condition, grouts properties and computational parameters. Run and restart are the two functions of the analysis parts. The pressure and velocity can be plotted by the contour map, vector map, cloud map, and in the animation form. It can plot the curves, which indicate the grouting volume, grouting pressure, diffusion radius changes with respect to time as well.Triune control system of the karst water has been proposed, it can be revealed as the comprehensive advanced predictions, early warning and treatment. Water inrush controlling is a systematic engineering in the karst zone. If only depending on the grouting technology itself, the effects might not be good enough, or it even doesn't work. But when combining with the comprehensive advanced predictions, the exact condition of the injected medium could be well understood, and the grouting work will be more efficient. In order to reduce the catastrophic damage caused by the water inrush in the karst zone, the advanced early warning system and device must be adopted. At last, the control system of the karst water inrsush is successfully applied to the field test, and the simulation of the grout loss phenomenon has been verified by the GSK package.
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