The effect on seepage is small when the opening of cutoff wall crack is less than 0.3cm,themaximum relative water head at the bottom of lower core wall is only 2.02%.

• 防渗墙出现裂缝开度小于0.；3cm时；对渗流场的影响不大；防渗墙下游心墙底部最大相对水头值仅为2