| Slope, volcano and earthquake are global terra disasters. But the happening of slope is more than the other two disasters in frequency and extent. There are too many premium factors for slope, but reservoir place a premium on slope more often. Slope mostly happen in early days of sluice. The fluid field change which is aroused by sluice has important effect on the stability of slope. In fact,it is not only a problem rock affecting water or water affecting rock but a problem of the coupling of the two when disaster happen. The mechanics theory like rock theory and flow theory can not settle the complicated problem, even more difficult to guide engineering. So the reasonable hydraulic model is very important. To estimate the stability of slope, we should know about the change of fluid field at first. We can analyze the stability of slope according to the change. We are able to offer stability foundation for stability estimation and fathering engineering.The normal storage level is 175 m in the Three Gorges Reservoir. During the process of water storing, the rising of reservoir water level will cause the change of the seepage flow field within the slope. I have scattered the distortion equation crack seepage equation of rock mass and come out concrete expression. Ihave worked out a suit of three dimension solid fluid coupling procedure of block rock mass. I have put forward the numerical solution. The basic seeking answer strategy is: that regard solid stress field and seepage field as independent subsystem, coupling change to work out the answer and that use difference on time and use FEM in room. On the basis, I have worked out corresponding computer fountain procedure.So the author set up reasonable seepage model which simulates the change of the seepage flow field within the slope when the water level is up to 175m. The seepage model of block -fracture slope is studied. In order to make the model more reasonable and more effective in application, the author create the seepage model of double porosity media including discrete media and equivalent continuum. Based on the relationship of fracture and engineering mass. 1-2 grade fracture net is considered. .According to the equivalent of pressure of two kinds of media, three dimension seepage model is created by using modern fracture theory and FEM solution is given. After calculating, we can see that main cracks is better than simulated media as seepage media The water press simulated media lag behind main cracks at the first, but they will be the same as time goes on. The part which is easier to change decide the form and magnitude of deformation. The judgement is important because that the deformation can show the slope deform and become unstability. The displacement of the upper is contrary to the one of the underneath and the boundary is along the first main crack. The safe parameter which is based on the first maincrack has deduced 11.7 percent when water level rises,not considering physics and chemistry action. The safe parameter which is based on the second main crack has changed from, 3.74 to 3.82(the fifth month after water level rise ),then down to 3.56.The reason for the increase at first is that the water load increase the cut strength of the crack. But the safe parameter decrease as seepage goes on.The author think that we should make up reasonable model according to the law of crack distribution at different level after proving. It is important for the stability of block slope of rock. I try to settle the bottle neck which does harm to the credibility of calculation result.
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