Page - 717 - in Book of Full Papers - Symposium Hydro Engineering

Table 2 Emergency monitoring items for flood overtopping Number Monitoring item Grade Ⅰ Ⅱ Ⅲ Ⅳ 1 Inspection ● ● ● ● 2 Water level ● ● ● ● 3 Rainfalls ● ● ● ● 4 Inflow and outflow discharge ● ● ● ● 5 Superficial deformation ● ● ● ○ 6 Seepage pressure ● ● ● ○ 7 Seepage discharge ● ● ● ○ 8 Discharge flood pulverization ○ ○ ○ ○ Notes：● mandatory item, ○ optional item 2.3.2. ABNORMAL SEEPAGE AND STRUCTURAL INSTABILITY Abnormal seepage and deformation may occur in dam. Variation of tendency should be more concerned during inspection and monitoring. Monitoring items for corresponding items are shown in table 3. Monitoring data should be analyzed in time. Table 3 Emergency monitoring items for abnormal seepage and structural instability Number Monitoring item Grade Ⅰ Ⅱ Ⅲ Ⅳ 1 Inspection ● ● ● ● 2 Water level ● ● ● ● 3 Rainfalls ● ● ● ● 4 Seepage pressure ● ● ● ● 5 Seepage discharge ● ● ● ● 6 Surface deformation ● ● ● ● 7 Cracks ● ● ● ● 8 Underground water level ● ● ○ ○ Notes：● mandatory item, ○ optional item 2.3.3. EARTHQUAKE The damages caused by earthquake are related with earthquake magnitude and distance from epicenter. ICOLD bulletin “Inspection of dam following earthquake guidelines” notes that dams around 25km, 50km, 80km, 125km and 200km from earthquake epicenter should be monitored for corresponding earthquake magnitude of 4.0, 5.0, 6.0, 7.0 and 8.0. Little dams are damaged below 4.0. Dams will be damaged seriously if magnitude in more than 7.0. Crack, leakage, structural 717