圖書典藏及影音數位平台

近年來彰化縣沿海地區因大量抽取地下水造成地層下陷情形相當嚴重，需防止沿海地區地盤下陷持續惡化及淹水風險增加。對於海邊之構造物而言，除土壤鹽化影響，而導致當地水工結構物易產生腐蝕情形外，再加上海浪衝擊所產生滲流情形，亦會造成海堤底部沖刷，進而發生掏空現象。如此易影響整體海域及當地民眾生命財產安全。 本計畫主要為暸解彰化縣海堤內容結構現況，採用非破壞檢測方式，檢查海堤構造物之使用狀況與內部損壞狀態，至少包含結構體內部裂縫，含水狀況以及管路情形，以便未來整體規劃時設計利用

In recent years, quite serious stratum sinking situation was found at the coastal area in Changhua County due to a large amount groundwater was pumped out. In order to prevent the coastal area from causing dike destroying and sea water flooding, the safety assessment project would be conducted to look over the clear security of the coastal dikes for facilitating the subsequent maintenance management. This project is mainly used to understand the present situation of dike structure in Changhua County. The visual inspection of the dike was carried on by the personnel first. According to the preliminary inspection result, the suspicious cleaned out dike sections were identified for analysis. The ground penetrating radar was adopted by the non-destructive testing to detect the using state and inside damage of dike structure, including internal crack, moisture state and pipeline situation, so as to facilitate the design and utilization at the time of future overall planning. Two times of site inspection were conducted in this project. There are 138 damaged places, in which 138 places should be planned for improvement. The fund should be prepared as soon as possible, in order to avoid destroying and continuing expansion. It is also worth noting that found two new damage at The end of November in Wanggong Reclaimed Land dike,And the Fourth River Management Office has carried out emergency response measures. This project has finished 19 dike sections by the non-destructive testing. The longitudinal length is 41,714m and the horizontal length is 1,111m. The total length is 42,825m. From the NDT.I index of every dike section, No. 14 North Dacheng Dike Section (0K+000~1K+250), No. 13 Yentsuo Dike Section (1K+850~2K+480) and No. 12 Yentsuo Dike Section (0K+697~1K+530) have the highest 3 indexes. This project adopts the visual inspection result, non-destructive testing result, historical information of sea dike, dike body structure assessment and marine environmental factor assessment as the assessment index. The assessment area is divided into 144 sections for 43 dikes. Every group of dike sections was assessed in accordance with every assessment index. The assessment result of 144 sections revealed that 88 sections were classified as the normal sections, 56 sections were classified as the planned improvement sections, and there was no noticed improvement section and immediate improvement dike section. There were 138 damaged places in scope of project. It was judged that the preliminary repair fee is about NT$ 6,686,000 calculated by every dike section. The visual inspection and assessment was conducted for 37 bridges in scope of this project, including 4 proposed forbidden pass or reconstructed bridges. They are Haipu No. 32 Watergate Bridge, Urgang No. 37 Watergate Bridge, Hanbao No. 49 Watergate Bridge and Hanbao West 8 Bridge. The preliminary estimate repair fee is NT$ 61,280,000. Two proposed reinforcement bridges were Hsinjei 13 Bridge and Dacheng North 83 Watergate Bridge, and the estimate fee is NT$ 1,000,000. The information collected by this project includes the geological change and overview of coastal area, domestic (foreign) dike body inspection method, literature survey for factors influencing the structural safety, current facility state of project scope and improvement proposal, repair and reinforcement alternative, dike inquiry system, multimedia briefing and fold paper, and handle flood prevention, volunteer protection worker education and training.