库水位下降条件下码头岸坡稳定性分析

以重庆市纳溪沟改扩建工程岸坡为依托，对接岸结构与码头结构无直接相互作用的情况，采用PLAXIS有限元分析软件分析了库区水位下降条件下码头岸坡稳定性影响因素、重力式挡墙受力变形规律及潜在滑坡失稳破坏机理。结果表明，码头岸坡安全系数随库水位下降呈先减小后增大的变化趋势，不同库水位下降速率会引起不同的码头岸坡最不利水位；岸坡内潜水位下降速率的滞后将产生指向坡外的渗透水压力，码头岸坡安全系数随库水位下降速率的增大而不断减小；库水位下降时重力式挡土墙可能发生绕基座底部朝向岸坡临空面方向的失稳倾覆，墙后回填岩土层可能发生拉裂解体，并沿危险滑面滑移失稳。

Stability Analysis of Wharf Slope under Drawdown of Reservoir Water Level

Relying on the reconstruction and extension wharf project of Naxigou in Chongqing City, taking a bank-linking structure under no interaction of bank-linking type and front wharf in the three gorges reservoir area for an example, the PLAXIS finite element analysis software is used to analyze the influencing factors of the bank slope stability, deformation law of gravity retaining walls and potential landslide failure mechanism under the drawdown of the reservoir water level. The results demonstrate that safety factor of bank slope not only with the drawdown of the reservoir water level firstly decreases and then increases, but also it is decreasing with the dropped rate of water level increasing; different dropped rate will cause the different worst water level; because of the dropped rate of phreatic water lagged, seepage pressure will point to the bank slope outside, resulting in lower overall stability of bank slope; the gravity retaining wall will instable and overturn around the bottom of the base towards the direction of the free face under the drawdown of the reservoir water level; at the same time the backfill rock-soil layer after the wall will happen tension damage and slip instability along the dangerous sliding surface.