Study On The Bank Protection Mechanism Of Spur-dike Group And Permeable Pile Dike

In our country, sediment-laden river represented by the Yellow River, due to carryingmore suspended sediment, scouring and silting in riverbed change drastically, formed unstablewandering river characteristics in the long evolution process, so that poses a great threat tothe economic development and the living of the people along the river. In order to mitigate thethreat to the river banks by the wandering rivers change frequently, adopts the effectiveengineering measures for river regulation, control and stabilize river regime, is very importantfor reducing the pressure of flood control and ensuring the economic development along theriver.Spur dikes as the most common type of river regulation structures widely used in theriver regulation project, especially in the alluvial plain, which river regime is scattered andriverbed stability is poorer. To protect the beach and control river regime, often use the planelayout of spur dikes as engineering planning and design to protect the beach and control riverregime. Although the traditional spur dikes has played a good role in the regulation of thewide and shallow wandering river, the local of spur dikes often destroyed by the flood, whichwill affect the protective effect. Given the sediment carrying capacity of sediment laden flowis proportional to the high order of flow velocity, if a small change of the flow velocity, thedecrease of the sediment carrying capacity is considerable, which will urges the riverbed fromscoured to not scoured even deposition. In recent years, the permeable technology measuresof river bank protection that based on the basic principle of river dynamics embody manyadvantages on protect the beach and control river regime. The protection technology of riverbank that combination permeable with entity, rigid with flexible is one of the maindevelopment direction of river regulation technology in the future.In order to provide basic theoretical basis for the development of the composite technologyresearch that combination permeable with entity. Combined with a river regulation project,through movable bed model tests, the law of the local scour when the design parameters ofthe non-submerged spur-dike group are changed is analyzed and studied herein, in which theimpacts from the various azimuthal angles of axes, spaces and lengths of the spur-dikes aswell as their desilting locations are summarized, and then the method for analysis and calculation of the local scouring depths at the heads of all the spur-dikes are put forward inaccordance with the experimental and measured data concerned; Then through generalizedmodel test, combining theoretical analysis, the functions of control and guide flow with theeffects of deposition falling with tranquil flow for the permeable spur dike with reinforcedconcrete well-pile, permeable pile dike for short, used widely in the Xinjiang region havebeen studied. Research shows that the permeable pile dike has a remarkable effect ondeposition falling with tranquil flow under certain seepage rate and azimuthal angles of axes.Finally, the mechanism of the interaction that the above two kinds of spur dike with flow inthe actual operation is studied through the numerical simulation method. The simulated resultsare consistent with the law of model test. The results from all these can provide references forthe planning and design of the relevant river regulation project, and provide a convenient andpractical analysis method for research and development of the composite technology for riverbank protection.