某病险水库主坝在除险加固过程中发生了滑坡，通过对主坝工程地质条件、施工方法、施工过程及建设管理等方面的深入分析，获得滑坡产生的原因：①坝体质量较差；②防渗墙施工方法不当；③发现险情后，未及时采取措施；④水位骤降过大，孔隙水压力未消散。结合工程实际情况，提出了应急处理措施及除险加固方案，经后续加固，水库运行状况良好。本案例总结的经验和教训，也可为其它类似工程提供经验和参考。

The main dam landslide of certain dangerous reservoir occurred in the course of reinforcement process. Through the analysis of engineering geological conditions, construction method, construction process and construction management, the causes of landslide are acquired. The causes of the landslide are concluded as follows： 1. The construction quality of the dam body was bad. 2. The construction method of the cut-off wall was not appropriate. 3. Adopting emergent measures were not in time after the dangerous status appearance. 4. Pore water pressure inside the dam slope did not vanish when the water level of the reservoir declined suddenly. In combination with the actual situation in the project, contingent measures and reinforcement program were put forward. By following reinforcement , the reservoir is running in good condition. The experience and lessons summed up can be used as a reference for other similar projects.