Influence of Shear Banding on the Slope of Nanhua Reservoir

• Main Authors: CHEN, YEN-CHUN, 陳彥駿
• Other Authors: HSU, TSE-SHAN
• Format: Others
• Language: zh-TW
• Published: 2017
• Online Access: http://ndltd.ncl.edu.tw/handle/u843y4

碩士 === 逢甲大學 === 土木工程學系 === 105 === In the past, domestic and international reservoir safety assessment has ignored the primary effect of tectonic earthquakes and has instead considered the secondary effect of tectonic earthquakes as the primary effect. As a result, many dams were damaged, as we were unable to assess the impact of cumulative amount of shear bandings on the safety of dams. In view of this, the authors studied shear bands at Nanhua Reservoir site and the north slope, and the associated slip failure mechanism. Results show that there are in fact some shear bands in the Nanhua Reservoir site and the north slope, and shear banding does occur in the event of felt earthquakes or during the construction of desilting tunnels, which affects the stability of the dam and the north slope. However, since the dam safety assessment did not take shear banding into consideration, the selected slip failure mechanism and shear strength parameters are not in agreement with the actual conditions. Therefore, the extent of damage caused by the construction of desilting tunnels to the dam and the north slope cannot be assessed. In the future, the situation may be similar to Gouhou Dam in China where many shear bands were found at the dam site and in the embankments after the dam failed. It is recommended that relevant regulations on reservoir safety assessment should include the primary effect of tectonic earthquakes and place strict requirements on the monitoring, testing, and analysis of shear banding. It is only through these measures that the key factors in reservoir safety and the level of risks can be clearly vivid so that the safety of reservoirs can be ensured.