地震作用下库水位变化坝坡稳定性数值模拟

NUMERICAL SIMULATION OF DAM SLOPE STABILITY WITH RESERVOIR WATER LEVEL VARIATION UNDER EARTHQUAKE

为探究地震作用下库水位变化下坝坡渗透稳定性变化规律,利用Geostudio软件对三峡库区某边坡进行了数值模拟,得到了安全系数及Newmark位移变化曲线,计算结果表明,库水位水平越高,边坡安全系数越低,Newmark位移越大,最小安全系数的出现相对与地震的峰值加速度时刻有较大的滞后性;库水位骤降下,边坡安全系数随着库水位水平的逐渐下降,呈现先增大后减小的规律,库水位下降速率越大,边坡在库水位骤降与地震耦合情况下的最小稳定系数越小,最大Newmark位移也越大;边坡安全系数随着库水位水平的逐渐上升,呈现先减小后增大的规律,边坡在地震下的最大Newmark位移在库水位高程下降至157m之前呈现不断上升趋势。

In order to investigate the variation law of seepage stability of dam slope with reservoir water level variation under earthquake action, a slope in the three Gorges reservoir area is simulated with Geostudio software, and the safety factor and Newmark displacement curve are obtained. The results show that the higher the level of reservoir water level, the lower the slope safety factor, the larger the Newmark displacement, and the greater the lag between the occurrence of minimum safety factor and the peak acceleration of earthquake. Under the sudden drop of reservoir water level, the slope safety factor gradually decreases with the level of reservoir water level, which increases first and then decreases. The greater the rate of decline of the reservoir water level, the smaller the minimum stability coefficient of the slope in the reservoir water level dip and seismic coupling,and the greater the maximum Newmark displacement is. The slope safety factor gradually increases with the level of reservoir water level, which decreases first and then increases. The maximum Newmark displacement of slope under earthquake shows a rising trend before the height of reservoir water level drops to 157m.