The Numerical Analysis Under Excavation Unloading Of The Slope Stability Of The Three Gorges Shiplock

The effect of excavation unloading has been studied on the ground of the Three Gorges Shiplock Project in this thesis.The simulation experiment on the granite rock of the shiplock has been carried out with computer, and then regard the media of the rock as elasto-plastic material and in the stress space,the general constitutive relation is described.In this thesis,the unloading region of a typical cross section of shiplock slope of TCP is given, that is 15570 according toin-situ test and geological survey.Considering the effects of excavation unloading, numerical analysis for shiplock slope is made by FEM and FLAG.Using the theory and software described in this thesis,the excavation analog and the stability analysis of the typical cross section of the Three Gorges shiplock high slope has been carried out. And the conclusion can be obtained thatrAfter excavation,the horizontal deformation increased continuedly with the depth of excavation .while the whole deformation takes on a tendency of nearly horizon and slightly downward.The middle part of the shiplocks maintains the state of unloading feedback during the excavation,when the excavation is finished ,it expands toward two sides. After excavation,there are concentration phenomenon of stress at the corner or the shiplock room,and the tension zone lies in half of the middle part as well as the part of the two slopes to the lower part of the upright wall.Finally the analysis results are compared with site monitoring data in period of construction as well as the feedback reports, the result of all comes to meet with each other very well.After excavation,the slope is stable on the whole,because there are not distributions of the plastic zone inside the slope,the slide on a large scale will not take place because of the damage in the deep earth.The results obtained from the analysis have been applied to the slope designs.