Seismic safety of high earth-rock dams during earthquakes coupling with rapid drawdown of reservoirs
CEN Wei-jun1, WANG Jian1, WANG Shuai2, XIONG Kun3
1. College of Water Conservancy & Hydropower Engineering, Hohai University, Nanjing 210098, China; 2. Guangdong Hydropower Planning & Design Institute, Guangzhou 510635, China; 3. Chang Jiang Survey Planning Design and Research LLC, Wuhan 430010, China
Abstract：Rapid drawdown of reservoir has a great influence on the seepage, deformation and stability of an earth-rock dam. Under earthquakes, it may pose a new threat to the dam safety. Combined with a 300 m-super high core wall earth-rock dam to be constructed, the unsteady and saturated-unsaturated seepage analysis of the dam under the rapid drawdown of reservoir is carried out and the pore water pressure is acquired. Based on the seepage and static stress field, the seismic response of the dam is analyzed to get the basic dynamic response. Meanwhile, the evaluation of seismic stability and permanent deformation of dam slope are also conducted to evaluate its seismic safety. The results show that rapid drawdown of reservoir mainly affects the distribution of pore water pressure of the core and upstream dam body, causes the large change of static average effective stress field of the upstream region of the dam for the high core wall rockfill dams with good barrier performance core and upstream filter protection. The occasional earthquake will significantly affect the dynamic response and the seismic performance of upstream dam slope, and more attention should be paid to it. The change of water level does not affect the distribution of seepage field of the downstream dam body obviously. Therefore, the rapid drawdown of reservoir has little influence on the seismic safety of downstream dam body.
岑威钧, 王建, 王帅, 熊堃. 水库骤降期偶遇地震作用时高土石坝抗震安全性分析[J]. 岩土工程学报, 2013, 35(zk2): 308-313.
CEN Wei-jun, WANG Jian, WANG Shuai, XIONG Kun. Seismic safety of high earth-rock dams during earthquakes coupling with rapid drawdown of reservoirs. Chinese J. Geot. Eng., 2013, 35(zk2): 308-313.
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