| Since rubber dam was born in1957, the rubber dam has been more andmore used in various areas, because of its advantages of lowcost, shortconstruction period. Rubber dam built in the urban river can store water,beautify the urban water landscape, recharge urban groundwater, improve thesmall regional climate.But with the number of rubber dam built over the river which through thecity. It’s storage capacity increases, when the rubber dam collapse release floodwaters, if improper scheduling, may cause the "artificial peak"phenomenon, resulting in a serious threat to the safety of downstream areaduring the rainy season. Based on this problem, we should study the damcollapse of rubber dam on flow discharge, master the flow rule, developa reasonable and safety program of the collapse of the dam. The mainresearch contents and results are as follows:(1)Using the basic formula of weir flow calculate the collapse of thedam leakage of rubber dam. The parameters of the formula in the design to bedetermined by hydraulics, the collapse of the dam use gradual timeinterval algorithm. using VB language programming to calculate. The calculation results analysis show that, With the collapse of the rubberdam dam leakage flow rate increases first and then decreases. The influencingfactors of rubber dam discharge have fall time, height of water retaining andwater storage capacity, channel slope, etc. Shorter dam collapse time, higherdam (water storage capacity), the greater the maximum discharge of rubber dam,the greater the reached the maximum and the sooner.(2)Adopt the method of reverse step by step upward dam collapse torealize collapse of the dam of rubber dam, water balance method to calculate thecollapse dam discharge of cascade rubber dam. procedure programmed with VBlanguage to calculate multiple sets of scheme respectively, and analyzes itscalculation result, find out the patterns of the collapse dam discharge of cascaderubber dam. The flow line of downstream rubber dam is a multi peak curve, andthe flow line of upstream rubber dam is a single peak curve. At the sametime, when the collapse of the dam, the rubber dam of the downstream has themaximum maximum discharge value. The longer the lag time of rubberdam, the less effects of the next level rubber dam discharge. When rubber damcollapse time lag in the same in the different scheme, the collapse of the dam atdifferent times, At all levels of the rubber dam collapse of the dam itself moretime (in speed) scheme, the maximum discharge at all levels of the rubberdam is smaller.And vice versa.(3) Establish the model to optimize collapse of the dam scheme of cascaderubber dam, Take rubber dam collapse time and the time interval between adjacent rubber dam collapse as the control variable, take total collapseof the dam at least as the objective function, and it’s constraint conditionsinclude time constraint condition and the flow constraint conditions. To get theoptimal scheme by solving the model.(4) The rubber dam of Fenhe a project as an example, Make groupsof collapsed dam scheme to calculate dam collapse leakage of the4rubberdam. Establish the optimization model for the project to solve the model to findthe optimal solution. |
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