圖書典藏及影音數位平台

秀姑巒溪流域位於台灣東部，地跨花蓮、台東兩縣。其北接花蓮溪流域，南與卑南溪流域相鄰，主流秀姑巒溪發源於中央山脈崙天山南麓，東流入台東縱谷後，受海岸山脈阻擋，乃沿縱谷平原向北流，在匯納兩岸諸水後，於瑞穗鄉舞鶴山前再折轉向東流，並以其巨大侵蝕力橫切海岸山脈，而在豐濱鄉大港口附近流入太平洋。流域行政區域包括台東縣之海端、池上與花蓮縣之富里、卓溪、玉里、瑞穗、萬榮及豐濱等八鄉鎮。本溪流域為台東縱谷平原三大水系之一，流域面積1,790.46平方公里，其在花蓮縣部份，占全縣面積三分之一強，居住人口約十萬人，占縣人口三分之一弱，主流全長81.15公里，為全台21條中央管河川之一。主要支流有五條由南至北依序為：樂樂溪、卓溪、豐坪溪、紅葉溪及富源溪。秀姑巒溪現況防洪構造物多屬老舊堤防，為能尋求有效維修與補強方案，擬藉由安全性評估計畫來全面檢視秀姑巒溪堤防之安全，以利後續維護管理。本計畫主要目的為暸解秀姑巒溪堤防結構現況，先以人員目視進行檢查並提出期初報告，後續採用非破壞檢測方式如透地雷達探測、震波測勘等，檢查堤防構造物之使用狀況與內部損壞狀態，包含結構體內部裂縫及淘空狀況等情形，以便未來做為堤防管理、維護之參考依據，以及尋求有效維修與補強方案，擬委外辦理安全性評估分析及研擬改善方案。

The current flood proof structure of Siouguluan River is old dike. The potential risk caused by the climate change, extreme rainfall incident and flow route changes in recent years is considered. In order to understand the current structure situation of Siouguluan River, the visual inspection of dike surface is carried on by personnel first. Then, the non-destructive ways, such as ground penetrating radar, seismic way, are adopted to inspect the use condition and internal damage status of dike structure, so that the results can be used as the reference basis for future dike management and maintenance. The safety assessment and analysis as well as the improvement measures will be handled to seek for effective maintenance and reinforcement alternatives.In this project, three times of visual inspection were conducted for 19 dikes in 31,681m total: As for the non-destructive inspection, 27,683m was inspected by the ground penetrating radar, and 350m was inspected by the seismic wave; 18 places of river dike were investigated for structural strength, the drilling core test was used mainly, and the cross inspection results of resilient hammer test and impact echo method were used for verification. The safety assessment for current situation of dike was conducted by integrating various inspection outcomes, and the improvement countermeasures were drafted in accordance with the assessment result.There were 106 damaged places from visual inspection, including 54 places at Siouguluan River, 27 places at Lele River, and 25 places at Qingshui River, and the damage level was the planned improvement. The ground penetrating radar was adopted to detect the clean-out of dike in 28,678m of length. It was found that 409m of dike was slightly cleaned out, which accounted for 1.43% of total detection length. Take a broad view of the detection result, most of damage was the void at the bottom of dike. 350m was detected by the seismic wave. It was shown that the speed of wave could be used to represent the dense or loose state of same material. The result of drilling core test was between 105.3 kgf/cm2 ~ 492 kgf/cm2, wherein the concrete strength of Leho Dike was slightly low, and there was above 217 kgf/cm2 for other dikes.The assessment results of current river dikes revealed that the dikes were good roughly. Except there were cracks and slight clean-out of dike at 0K+000 to 0K+300 of Yuelei Dike at Siouguluan River, which had disaster loss record and should be improved, 59 sections of dike must be improved in plan, and 49 sections of dike are normal. During current flood prevention period, the major patrol should be conducted to observe if the damage is aggravating, in order to seize the current situation of dike at plan area. The damage points in the scope of project will be repaired by the surface closed method and local patching method mainly, in order to prevent the exterior water from invading the dike body continuously. It is estimated that the maintenance and repair fee is about NT$ 3,489,000