Page - 725 - in Book of Full Papers - Symposium Hydro Engineering

to observations, vibrations can be felt on the mountainside area near the county town downstream on the right bank, the vibration was magnified obviously in this region in the propagation process. Geological exploration results from the downstream area showed that the surface and foundation of that area consisted of sand layers and mudstones, respectively. An ancient channel with an average width of about 200 m was identified situated near the right-hand side of the mountain in the main urban area downstream; the maximum thickness of the covering layer over the ancient channel was 80 m. In comparison, the covering layer besides the ancient channel area covering layer of the other urban area had a significantly thinner thickness. The locations of the different regions are shown in Fig. 3. Fig. 3 Schematic diagram of each region in the hydropower station dam area and the downstream area 4. THE ESTABLISHMENT AND IMPROVEMENT OF HYDROELASTIC MODEL 4.1. THE ESTABLISHMENT OF HYDROELASTIC MODEL Before making the hydroelastic model, the foundation plain fill was excavated and replaced, reinforcement treatment was undertaken using a C50 concrete foundation (7 m long × 7 m wide × 1.5 m deep); and a vibration isolation channel (0.1 m wide × 1.5 m deep) was created to reduce the influence of background vibration and vibrations caused by the water pump. In addition, in order to prevent background vibrations generated at the convergence between the upstream and downstream sections of the hydroelastic model from being transmitted to the transmission path, the upstream or downstream sections were connected using a rubber belt to form a flexible connection, thereby reducing the influence of external Ancient channel area Non-ancient channel area Dam area T9 725