| Since 1957, rubber dam with its simple structure, low cost, easy installation, convenient operation, low maintenance cost, good environmental compatibility, and many other advantages, in the water, power and urban river landscape construction play a significant economic and social benefits. Flood comes, the rubber dam should collapse dam discharge, unreasonable the fall discharge process of collapsed dam is likely to cause flooding overlay, endanger the safety of the project and downstream channel. Therefore, research of the rubber dam discharge characteristics and master of the rubber dam discharge laws, for scientific scheduling and operation of the rubber dam, and the rubber dam safety in the flood season has important significance. At present, less research on discharge characteristics of the rubber dam, and largely focuses on the study of the design height working condition of rubber dam. According to the rubber dam on the Fenhe River in Taiyuan City has been built and will be built, through physical model test method, with the water filied rubber dam using double line anchoring as the research object, for it in design height and different height of dam collapse of the discharge characteristic were studied. The main research contents and results are as follows:(1) The development situation and current situation of rubber dam technology at home and abroad are reviewed. At the same time, the existing research achievements and existing problems of the hydraulic characteristics of rubber dam are introduced.(2) Design and manufacture of the model and determination of the test plan. Flow capacity test of rubber dam for it in design height and different height of dam collapse. A total of 31 groups of high dam test, each test 5~6 flow, a total of 184 groups of test. Measure the upstream water level, the dam height and the dam bag pressure head of each flow.(3) Physical model verification of the design height working condition of six types. The results show that the model is reasonable and reliable.(4) Observation the water surface line feature and flow pattern characteristic of the rubber dam. Results show that, in the process of dam collapse, the dam bag shape is formed by the practical weir to the broad crest weir.(5) The rubber dam is a kind of thin-walled flexible hydraulic structure, high dam and dam bag section shape changes along with the change of upstream and downstream water level. The test found that with the increase of the height of the collapse of the dam, dam height variation more and more big, the dam bag shape is more unstable, the dam deformation is increased.(6) Through the model test and theoretical analysis, study on variation of pressure head of dam bag of the water filied rubber dam using double line anchoring at the free flow appearance. The calculation formula of the dam bag pressure head h is , its average relative error is 5.04%.(7) Combined with the weir flow theory and experimental data. It is concluded that the calculation formula of discharge coefficient m at the free flow appearance of the water filied rubber dam using double line anchoring is , its average relative error is 1.17 %. |
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