Hydrodynamic Monitoring and Analysis during the Closing of the Closure Gap of Qingcaosha Reservoir

When the large width closure gap need to be completed under the condition of rapid flow and limited construction period, gap closure work becomes one of the most difficult construction part of all the whole Qingcaosha reservoir dike project. Considering the huge engineering quantity and complex hydrology of such engineering during construction phase, the real-time monitor, analysis and prediction of the hydrology are implemented. With numerical analysis of the closure gap under the design tide process, the model results show that the rising flow of the closure gap is more rapid than the ebb flow, and the maximum current speed caused by water level difference between the internal and external is mostly located at top slope corners of the gap protection layer. From the result of observation and calculation, the local maximum current speed was about 4.0m/s and experienced a short time due to small tidal range, which is suitable for construction. To sum up, it is feasible and helpful to combine the real-time observation with numerical analysis to ensure the safety in construction during the closing of the closure gap. Keywords: Closure gap, Tide range,Water level, Current speed