圖書典藏及影音數位平台

阿公店水庫（以下簡稱本水庫）位於高雄市燕巢區境內，係匯集阿公店溪上游支流旺萊溪及濁水溪之水量而成。本水庫自民國42年興建完成迄今已營運六十餘年，為解決本水庫日趨嚴重之淤積、供水及滯洪空間不足等問題，並繼續維持本水庫防洪、灌溉、公共給水等多目標功能，因此本水庫自民國86年起進行更新改善計畫，至民國94年完工，為台灣舊水庫再造的最佳案例。本水庫原為一防洪為主要目標之水庫，為確保水庫蓄水及營運期間壩體之安全及穩定，以提供水庫下游民眾生命財產之安全保證，因此利用大壩埋設及鄰近之監測儀器，於水庫營運期間持續辦理監測，並對大壩進行定期或不定期安全檢查，以維本水庫營運期間之壩體安全性。

In 2018, safety inspection and monitoring of Agongdian reservoir was entrusted by Southern Region Water Resources Office, WRA, MOEA(WRASB), and it was executed by Liming Engineering Consultants. The purpose of this project is by using the monitoring instrument to continuous monitoring during the operation of the reservoir and carry out the regular or irregular inspections of reservoir to maintain the safety of reservoir during the operation. The work content and summary of key content are the following: a.The overview and the work content The Agongdian reservoir is the reservoir which is built for preventing flood and solve the issues of sediment accumulation, irrigation, domestic water supply, and inadequate freeboard. At the same time, it can achieve the target functions of Flood control, irrigation and public water supply. The updated improvement project started from 1997 and finished in 2006, which is the best case of old reservoirs re-building in Taiwan. In order to ensure the residents living downstream of the dam are safe and secure. During the project progress, doing safety inspection and monitoring analysis with the related equipment. This project include the following works: 1. Dam safety monitoring analysis. 2. Dam safety inspection. 3. Trans basin waterway safety inspection. 4. Dam behavior and safety evaluation. 5. Review of the operation and maintenance of safety monitoring devices. 6. Automatic water level real-time transport system at downstream seepage area of dam. 7. Work Briefing, report writing and printing. b.Facility basic information and annual overview The main civil structures at Agongdian reservoir are include the main dam, spillway, intake works, and the interbasin transfer spillway. The monitors at Agongdian reservoir are spread across five sections: 0k+280m、0k+425m、0k+700m、1k+100m、1k+500m. The dam safety and stability can be long-time tracking by the five section’s monitoring value. The monitoring content includes 1. The water pressure inside the dam (piezometers). 2. The water level inside the dam and downstream (groundwater gauges). 3. The dam seepage (seepage weir). 4. The lateral displacement of dam(inclinometer). 5 The dam settlement (settlement observation point). 6. The dam seismic intensity (seismograph). In 2019, the dam water level was between EL. 28.14m~ EL. 36.84m, the annual accumulated rainfall is 1,511.9mm. The maximum daily rainfall is 126.4mm on Jun-11rd. The seismograph recorded 15 earthquakes, the maximum PGA value is 12.038 gal, which was recorded on ED02. Overall, the highest water level is 0.24m higher than last year. The annual accumulated rainfall is 740.7mm less than last year. The maximum daily rainfall is 191.9mm less than last year. c.Project result According to the various monitoring instrument and inspection, the result is the following: 1.Dam The change in the total head which in the dam body and dam foundation is regular and stable. All +0the monitors at the dam sections are both below the warning value. Therefore, the dam seepage is considered as reasonable. During previous year, the maximum settlement increments at upstream is 7.9mm, and the maximum settlement increments at downstream is 2.4mm. Neither of the settlement on upstream and downstream exceed the allowable value. (The vertical settlement in dam stabilization period should less than 10mm/year.) The vertical settlement demonstrates a stable tendency. The dam structure, upstream slope and downstream slope are overall good. There are no wide range sliding, leakage, settlement and damage. 2.Trans basin waterway The abnormal conditions of spalling tunnel lining, exposed deformed bar, crack, seepage and efflorescence already exist form the past. There is no significant difference from last year’s results. The heaving inverted lining at sta.7k+475m is affected by the shear zone. The exposed deformed bar at sta.2k+467, 6k+725, 6k+890, 8k+940 are the relatively severe area, but there are no signs of being affected by external forces on lining. It might be caused by the aging of the material (Neutralization of concrete). 3.Review of the operation and maintenance of safety monitoring devices Currently, there are 8 sets of pore water pressure cell, 10 sets of self-recording groundwater gauges, 8 sets of groundwater gauges, 3 sets of seismograph, 11 sets of inclinometer, 26 sets of settlement observation point, 1 set of seepage weirs and 5 sets of data recording devices, and it is enough to judge the dam safety. 4.Automatic water level real-time transport system at downstream seepage area of dam. The automatic water level real-time transport system at water well CL-02~CL-04 was finished in this year. The onsite water level data can be transport to the monitoring room in real-time and show up the water level data on the monitor screen. The related monitoring and analysis results are presented at Chapter 6. The other water wells which haven’t been automated are recommend to continue the achievement of this project. Considering the result of this report, unautomated water level wells are proposed to be upgraded.