Seepage failure of a triangular dyke:Throughflow hydrograph and surface topography measurements

• Main Authors: Shu-Yuan Yang, 楊淑媛
• Other Authors: Herve Capart
• Format: Others
• Language: en_US
• Published: 2008
• Online Access: http://ndltd.ncl.edu.tw/handle/32001341294861907669

碩士 === 國立臺灣大學 === 土木工程學研究所 === 96 === The failure of a dyke due to groundwater seepage followed by breach incision and widening is examined in this research. To investigate the flow pattern through the dyke and the downstream surface failure, wide triangular dams are studied in laboratory experiments. The materials used are sand and kaolinite. The mixing ratio between the two materials, the water quantity and angle of the dyke constituted are determined on the basis of preliminary experiments. The water flow through the dyke and the state of the downstream dyke face are monitored throughout the failure process. For this purpose, a throughflow hydrograph is measured using a combination of mechanical and imaging methods. Using laser scanning, the surface topography during the failure process is also characterized in detail. Some of the failure patterns appeared in laboratory experiments are similar to what have been discovered and interpreted through field investigation, including main scarp, minor scarp, mud wave, zone of bulging, and alluvial fan. Although the above failure pattern all occurred in each experiment, their development proceeds differently, as reflected by the evolution of the height of failure and width of breach.