都會區既有跨河橋梁改建工程施工階段風險分析之研究

• Main Authors: Ishang Jan, 詹益祥
• Other Authors: 謝定亞
• Format: Others
• Language: zh-TW
• Published: 1999
• Online Access: http://ndltd.ncl.edu.tw/handle/38389755137280807585

碩士 === 國立中央大學 === 土木工程研究所 === 87 === As Taiwan is fast approaching the living standard enjoyed by industrialized countries, many of its river crossing bridges are to be upgraded for improved safety and serviceability. In-situ upgrading a river crossing bridge involves technology and considerations which are unique to traditional bridge design and construction. Quite understandably, its design has to incorporate the behavior of both the old and newly built structures, while during the construction stage the traffic flow should not be interfered by construction activities under various weather and daylight conditions. During typhoon seasons, its substructure under construction also has to withstand the force caused by the high water. The purpose of this study is to investigate the critical risk factors which make bridge upgrading a uniquely difficult task. With this finding, it is then possible to contemplate means of containing or avoiding the risks. The study conducts a thorough interview on two groups of expert at issue, one of which represents the employer, the other the contractor. It then employs Eigen Vector method to test the consistency of expert opinions. The result of the analysis shows a clear agreement within each group and an interesting contrast of both groups. It finally proposes ways of controlling the critical risk factors. The main conclusion of this study is that the critical risk factors affecting in-situ bridge upgrading projects include design errors, lack of constructability consideration, existing structures or underground utility lines in vicinity, insufficient construction planning, deficient construction experience and the torrential rain during the typhoon season.