圖書典藏及影音數位平台

花蓮溪原名紅巖溪，流域位於台灣東部花蓮縣內，北接吉安溪，南界秀姑巒溪流域。本溪幹流全長57.28公里，流域面積1,507.09平方公里，主要支流有五條均在西側，由南往北依序為光復溪、馬鞍溪、萬里溪、壽豐溪及木瓜溪。本溪支流坡陡流急，崩山處處，每遇颱洪挾帶巨量砂石而下，數小時內即由橫谷進入縱谷平原。河床比降在谷口由急陡驟變為百分之一左右坡度，使砂礫淤積於下淤平原段，威脅溪旁兩岸人民生命財產安全，故防洪構造物之安全性影響甚大。花蓮溪堤防多屬老舊堤防，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花蓮溪堤防之安全，以利後續維護管理。本計畫主要目的為暸解花蓮溪堤防內容結構現況，採用非破壞檢測方式，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含水狀況等情形，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。

Hualien Creek mostly old dike along the river. The existing structures of flood wall of the creek system were found partially collapsed, hollowed out, and material deterioration due to long years of weathering effect and struck by typhoon and heavy rains. In order to look for effective maintenance and reinforcement programs to ensure the safety of lives and property of the people on both sides, there is a need to perform the safety assessment program, whereby the stream carried Hualien Creek System comprehensive review of the safety of the dike, in order to reach the subsequent maintenance and management.The scope of project consists of dikes in the Mugua River and Shoufong River such as Chuying NO.2, Chuying NO.1, Hualung Bulkhead, Jrshiue, Vinland Bulkhead, Vinland Bulkhead(upsterm), Fengtian NO.2, Fengtian NO.1, Sikou, Sikou(upsterm), Pinglin, Linzung, Silin, Silin Bulkhead, Silin NO.1 Bulkhead, Silin NO.1 Bulkhead(upsterm) in the total length of 34,326 meters.The project consists of four parts: dike inspection, dike structures strength investigation, non-destructive inspection and data collection and analysis and dike safety asswssment.The dike inspection includes: In three on-site visits, 82 damaged parts were identified. After visual inspection on damages, 82 sites need to be improved by this project. Damage types are mainly caused by cracks, about 19 sites, followed by three pothole damages. Additionally, the non-destructive testing is conducted on erosion with the ground-penetrating radar to complete the measurement length of 26,566 meters. It was found that 318.5m of dike was slightly cleaned out, 3.5m of dike was intermediately cleaned out, and no dike was seriously cleaned out. Furthermore, through the cross-examination of radar testing, Infrared thermal imaging testing, Shock testing, impact-echo method, rebound hammer method, and core testing, similar empirical proofs were identified. Thus, this project utilized ground-penetrating radar to inspect dike structures to fully understand the current state of them.This project adopts six indicators for evaluation: visual inspection result, non-destructive testing result, historical information of dikes, dikes preserved, evaluation of dike structures, environmental factors, and hydraulic analysis evaluation. Every 500-meter dike was marked as one section for evaluation; 33 sections were found normal while 41 were required to be improved by the project. The 41 sections that need to be improved by the project shall be listed for regular inspection and monitoring. Additionally, for the total of 82 damage sites, please refer to Chapter 5-5 for repairing evaluation and analysis. The amount for maintenance and repairing totals 3.65 million.