Page - 730 - in Book of Full Papers - Symposium Hydro Engineering

surface holes, followed by ground vibrations generated when discharge occurred from the mid-level outlets; an obvious adverse operating range can be identified. The strength of the vibrations generated with discharge from both the surface holes and mid-level outlets was significantly less than normal operating conditions with the same rate of discharge. 6. RESULTS AND DISCUSSION The source of vibrations induced by flood discharge from the high dam and the factors affecting vibration intensity were examined based on the combination of a hydroelastic model and prototype observation data. The research findings from our study are: (1) Before establishing the model, the foundation plain soil at the bottom of the model was reinforced by excavating it and replacing it with concrete, and a vibration isolation channel was set around the foundation. The convergence section between the hydroelastic model and the upstream/downstream sections were connected using a soft rubber belt to form a flexible connection. This adaptation effectively reduced the influence of external vibration sources on the hydroelastic model. Simulated discharge condition results inversed from the experimental model had the same change rule with actual measured ground vibrations, having a high correlation. The prediction results therefore accurately reflected ground vibrations. (2) The orifice open and upstream and downstream water levels were the major influences on ground vibration intensity, thus controlling these factors and regulating the discharge modes, especially avoiding unfavorable operation ranges for the surface holes and mid-level outlets is beneficial in minimizing ground vibrations. ACKNOWLEDGEMENTS This work was supported by the Foundation for the National Natural Science Foundation of China (Grant No. 51709280) and the State Key Laboratory of Simulation and Regulation of Water Cycle in River Basin of China. 730