圖書典藏及影音數位平台

本計畫旨在針對雙溪水庫工址蒐集鄰近可能震源，檢視是否有新事證須加入地震危害度分析，並蒐集與選用適切之地動預估式評估鄰近地震模型對壩址可能造成之影響，再進一步檢討壩體設計耐震強度之合宜性。另洽台電公司取得近年完成之核四鄰近海域線形判釋資料，研析該海域中之線形構造，了解是否有可能延伸進入陸域鄰近水庫工址，同時亦評估這些線形構造可能對壩址影響之地震動強度，以利進行第二階段環境影響評估審查作業。 一、以定值法評估鄰近海域可能震源對場址之地震動影響 依目前蒐集海域線型資料推估，以定值法評估東北海域之結果，海域線型對雙溪壩址可能造成的PGA值保守估計為0.18g，低於目前場址之設計值0.49g。 二、機率式地震危害度綜合評估 本計畫評估分析係以PGA考慮強地動1個標準差(σlny)為主，其中10,000年再現周期之最大可能地震(MCE)的水平向尖峰地表加速度值為0.41g，而950年再現周期之設計基準地震(DBE)和475年再現周期之運轉基準地震(OBE)的水平向尖峰地表加速度值為0.29g和0.25g。根據雙溪水庫之水利建造物之大小，雙溪水庫最大設計地震(MDE)應採用MCE之地動水準，即0.41g，仍低於目前場址之設計值0.49g。 三、震源參數拆解 綜合機率式地震危害度曲線及參數解構之成果，彙整各迴歸期推估之最適規模與最適距離及其可能震源，貢獻震源比例由多至少排序依序為 區域震源(S04、S14B)、北宜蘭構造、隱沒帶內部型震源(NP2~NP4)。

The project aims to collect nearby potential sources for the site of the Shuangxi Reservoir, examine whether new evidence is required to be included in the seismic hazard analysis, and collect and select appropriate ground motion prediction equations to assess the possible impact of the seismic source model on the dam site. Further review the suitability of the seismic strength of the dam design. In addition, contact the Taipower Company to obtain the linear interpretation data of the sea area completed in recent years, and analyze the linear structure in the sea area to understand whether it is possible to extend into the inland area to the reservoir site, and also evaluate the impact of these linear structures on the dam site. 1. Evaluating the influence of linear interpretation data of the sea area to the Shuangxi dam site using Deterministic method Based on the current data collected from the sea area, the results of the northeastern seas are assessed using the Deterministic method. The conservative estimate of the PGA value for the Shuangxi dam site is 0.18g, which is lower than the current design value of 0.49g. 2. Comprehensive assessment of probabilistic seismic hazard analysis The evaluation and analysis of this project is considering 1 standard deviation (σlny), where the PGA of the 10,000-year return period (MCE) is 0.41 g. The horizontal peak acceleration values of the design basis seismic (DBE) and the operational basis earthquake (OBE) are 0.29 g and 0.25 g. According to the size of the water conservancy structure of the Shuangxi Reservoir, the maximum design earthquake (MDE) of the Shuangxi Reservoir should use the ground motion level of MCE, which is 0.41g, which is still lower than the design value of the current site of 0.49g. 3.De-aggregation The hazard curve and the results of de-aggregation, the optimal scale and the optimal distance for the possible source of each return period are estimated, and the proportion of the contribution source is sorted in order to be the Area source (S04, S14B), Northern Ilan structure, and Subduction intraslab source (NP2~NP4).