Study of Consolidation Works Application on Bridge Pier Protection

• Main Authors: Yu-Te Chen, 陳裕德
• Other Authors: Chuan-Yi Wang
• Format: Others
• Language: zh-TW
• Published: 2009
• Online Access: http://ndltd.ncl.edu.tw/handle/04667280827827762254

碩士 === 逢甲大學 === 水利工程與資源保育研究所 === 97 === The main purpose of this study is to discover the protection effects of pier foundation before and after the installations of the traditional and box caisson consolidation works for the straight channel by hydraulic experiments. This study is to increase our understanding of the mechanism of scour and deposition under different arrangement conditions including the type, slope, interval and elevation of consolidation works. The variation of riverbed and the retardation rate of riverbed scour are indexes used to determine the stability of river. It can be served as a reference of design for relevant engineers in future. The results showed that certain degree of protection were obtained after any type of consolidation works were set downstream of the pier through the indices of river variation, retardation rate of riverbed scour, and riverbed transverse stability, especially for a slope of 1/30. For the scour depth in front of pier and retardation rate of riverbed, the scour of box caisson consolidation work is better than the traditional consolidation work for a slope of 1/50, and the types of consolidation works have no difference while the slope is 1/30. In terms of interval between pier with consolidation work, the better retardation rate of riverbed scour was observed for consolidation work installed immediately downstream of the pier under the slope 1/50, and the types of consolidation works have no difference while the slope is 1/30. The scour volume for all kinds of consolidation works decrease with an increase of rows of consolidation works in any slope. In addition, better protection effect was observed while bigger stuffing stones were used for the box caisson consolidation work under the condition of 1/50, and the stuffing stone size of box caisson consolidation work has no effect for the slope of 1/30. In general, the best protection effect was obtained for box caisson consolidation works with an interval of pier width downstream of the pier, stuffing original riverbed sediment. The resulting retardation rate of riverbed scour is about 90%. Therefore, box caisson consolidation work gives good protection effects for pier foundation.