Performance and design of geosynthetic-reinforced soil slopes subjected to rainfall: considering regional hydrological conditions
| Autor: | I-Hsin Lee, 李奕新 |
|---|---|
| Rok vydání: | 2018 |
| Druh dokumentu: | 學位論文 ; thesis |
| Popis: | 106 A series of numerical analyses based on the framework of transient seepage and unsaturated soil mechanics was performed to investigate the impact of rainfall on the design of geosynthetic-reinforced soil (GRS) slopes. To consider the regional hydrology, the antecedent and major rainfall were input using the rainfall intensity-duration-frequency (I-D-F) curves from Taipei as an example. The numerical simulations consider backfill fine contents (i.e., 0, 6, 19, 30 and 60%), soil initial matric suctions (i.e., as compacted, after plum rain, and after typhoon), and major rainfall conditions (i.e., 7-day extremely heavy rainfall and 1-day torrential rainfall). The hydraulic responses and stability of the GRS slopes including porewater pressure development, factor of safety (FS), and required reinforcement strength (Treq) are evaluated and compared. The numerical results reveal that under the combined effects of plume rainfall and 7-day extremely heavy rainfall the GRS slopes with high backfill fine contents (≥ 19%) could develop high porewater pressure which consequently leads to the slope failure. To satisfy FS ≥ 1.1 under the prescribed rainfall conditions, the Treq values in the GRS slopes with backfill fine contents of 30% and 60% should be increased by 2.65 and 2.06 times, respectively, of the original design values in which the effect of rainfall is not included: the corresponding FS values are 1.48 and 1.64, respectively, when the increased Treq values are used in the original design. The rainfall thresholds for the GRS slopes with various backfill fine contents and antecedent rainfall conditions were established. The calculated rainfall thresholds as well as those determined from failure cases of GRS structures were compared with the regional rainfall I-D-F curves to facilitate the assessment of selecting backfill type for the GRS structure in the region of interest. |
| Databáze: | Networked Digital Library of Theses & Dissertations |
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