(1. Department of Applied Mechanics and Engineering，Sun Yat-sen University，Guangzhou，Guangdong 510275，China； 2. Guangdong Research Institute of Water Resources and Hydropower，Guangzhou，Guangdong 510610，China；3. State Key Laboratory of Subtropical Building Science，South China University of Technology，Guangzhou，Guangdong 510641，China)
Abstract：Because the foundation of Shijiao segment of North River Levee is made up of the strong permeable layers, the dangers happened many times during historical flood periods. In order to raising the ability of preventing flood，many reinforcement measures are adopted，including constructing the high pressure-injected cut off walls，counterweight filling，building filtration and drainage structure，relief wells，etc. After the construction，the Shijiao segment stands the tests of floods many times. But the parts of effect of the measurements are arguable. The article is just right about the evaluation of these measurds by analyzing the data of field observations and simulating the seepage field，and a conclusion is drawn that the counterweight filling engineering is effective for this segment. The safety of preventing seepage is appraised. The conclusion is worthy of reference for the designers and managers.
