none

• Main Authors: You-cian Wu, 吳侑謙
• Other Authors: 周憲德
• Format: Others
• Language: zh-TW
• Published: 2015
• Online Access: http://ndltd.ncl.edu.tw/handle/53847672769052176289

碩士 === 國立中央大學 === 土木工程學系 === 103 === Under the impact of global climate change, the slope-land disasters such as landslides and flash floods caused by highly intensive rainfalls occur more frequently. Alluvial fans at foothills in Taiwan often accommodate villages and infrastructures, and are high-risk areas for the landslides and debris flows. In this study, the formation for alluvial fans is explored by using experimental study. A small-scale flume-basin model was setup with silo, laser lights and camera to investigate the fan forming processes. By changing the sediment concentration (i.e., the ratio of sediment discharge(Qs)to water discharge (QW)) and the base-level water depths, the longitudinal profiles, cross profiles, fan shapes, angles of topset and foreset angle have been analyzed. The size of the silo opening and particle size control the particle discharge. The longitudinal profiles of the fans depict a concave shape, while the lateral profiles are convex. The angles of topset slope decrease with decreasing sediment concentration, while the foreset slopes with tail water are close to the friction angle of the sediment.