Numerical Analysis of the Mechanism of Debris Flow Initiation
| Autor: | Jui-Chang Huang, 黃瑞昌 |
|---|---|
| Rok vydání: | 2003 |
| Druh dokumentu: | 學位論文 ; thesis |
| Popis: | 91 A two-dimensional (2-D) finite element deformation analysis incorporated with transient seepage analysis was adopted to simulate the initiation of debris flow. Two limit equilibrium methods “Spencer” and “Bishop” were applied to determine the factor of safety of soil mass during precipitation. Firstly, several sets of flume experiments are examined by numerical tools to verify the appropriateness of numerical model and the validity of numerical procedures. The numerical predictions of the pore water pressure response are reasonable in agreement with the laboratory measurements for flume experiments. Subsequently, the numerical analysis was shifted to debris flow field sites in Tung-Men and Feng-Chiou for a full-scale simulation of debris flow initiation. For numerical results in Tung-Men and Feng-Chiou Debris Flows, it can be seen that the rainfall might raise the groundwater table and in turn generate the pore water pressure. Eventually the displacement increment increases abruptly and the corresponding factor of safety dropped immediately at the moment of pore water pressure rising. This study establishes the critical rainfall line for different groundwater table conditions in Tung-Men and Feng-Chiou areas. The critical rainfall line for groundwater table at z=1.5m appears reasonably close to the regression analysis in Tung-Men area and at z=2m agrees with the regression analysis in Feng-Chiou area. |
| Databáze: | Networked Digital Library of Theses & Dissertations |
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