水利学报
水利學報
수리학보
2014年
6期
649-657
,共9页
非黏性均质%黏性均质%塌岸淤床%交互影响%水槽试验
非黏性均質%黏性均質%塌岸淤床%交互影響%水槽試驗
비점성균질%점성균질%탑안어상%교호영향%수조시험
bank failure%bed deformation%interaction%flume experiment%hydraulic force
河岸崩塌是河道横向变形的重要表现形式，崩塌体作为陡增的泥沙源反作用于河床演变，进一步影响岸坡的二次崩塌。在弯道水槽中展开系列试验，研究水力作用下非黏性及黏性均质岸坡冲刷崩塌力学机理、塌岸淤床交互作用过程及其影响因素。试验表明，水流冲刷过程中岸坡破坏是水流淘刷岸坡坡脚、岸坡崩塌及崩塌体淤积坡脚，并在河床上分解、输移掺混中交互作用的反复循环过程。岸坡崩塌、崩塌体与河床发生掺混最剧烈处位于弯道出口水流顶冲点附近，非黏性岸坡崩塌更容易发生在水面附近较浅的地方，而黏性岸坡崩塌更倾向于在坡脚附近较深的地方发生。近岸流速及河床可动程度越大，岸坡总冲刷坍塌量也越大，对于非黏性土其岸坡崩塌体在河床上的总淤积量也越大。研究成果初步揭示了塌岸与河床冲淤的交互作用模式，为进一步深入的研究奠定了基础。
河岸崩塌是河道橫嚮變形的重要錶現形式，崩塌體作為陡增的泥沙源反作用于河床縯變，進一步影響岸坡的二次崩塌。在彎道水槽中展開繫列試驗，研究水力作用下非黏性及黏性均質岸坡遲刷崩塌力學機理、塌岸淤床交互作用過程及其影響因素。試驗錶明，水流遲刷過程中岸坡破壞是水流淘刷岸坡坡腳、岸坡崩塌及崩塌體淤積坡腳，併在河床上分解、輸移摻混中交互作用的反複循環過程。岸坡崩塌、崩塌體與河床髮生摻混最劇烈處位于彎道齣口水流頂遲點附近，非黏性岸坡崩塌更容易髮生在水麵附近較淺的地方，而黏性岸坡崩塌更傾嚮于在坡腳附近較深的地方髮生。近岸流速及河床可動程度越大，岸坡總遲刷坍塌量也越大，對于非黏性土其岸坡崩塌體在河床上的總淤積量也越大。研究成果初步揭示瞭塌岸與河床遲淤的交互作用模式，為進一步深入的研究奠定瞭基礎。
하안붕탑시하도횡향변형적중요표현형식，붕탑체작위두증적니사원반작용우하상연변，진일보영향안파적이차붕탑。재만도수조중전개계렬시험，연구수력작용하비점성급점성균질안파충쇄붕탑역학궤리、탑안어상교호작용과정급기영향인소。시험표명，수류충쇄과정중안파파배시수류도쇄안파파각、안파붕탑급붕탑체어적파각，병재하상상분해、수이참혼중교호작용적반복순배과정。안파붕탑、붕탑체여하상발생참혼최극렬처위우만도출구수류정충점부근，비점성안파붕탑경용역발생재수면부근교천적지방，이점성안파붕탑경경향우재파각부근교심적지방발생。근안류속급하상가동정도월대，안파총충쇄담탑량야월대，대우비점성토기안파붕탑체재하상상적총어적량야월대。연구성과초보게시료탑안여하상충어적교호작용모식，위진일보심입적연구전정료기출。
The paper presents a study on non-cohesive and cohesive homogenous bank failure processes,in?fluence of bank failure mass on bank re-collapse as well as the interaction between bank failure and bed evolution through a series of experiments carried out in a 180° bend rectangular flume. The results reveal the iteration cycle between bank erosion and bed deformation;basal erosion due to fluvial hydraulic force, bank failure under the influence of gravity, failure block staying at bank toe temporarily or being remobi?lized by the flow,exchange between bank failure mass and bed material,bed-material load being reworked or transported either as bed load or as suspended load, and bed deformation. Same as bank failure, the mixing of bank failure mass and bed material is more serious near the curved flow apex. Moreover,non-co?hesive bank failure tends to occur near the water surface, while cohesive bank failure near the bank toe. For non-cohesive material, the bank erosion amount and residual amount of bank failure mass on the bed increase with the near-bank velocity or bed movability. But for cohesive material, only bank erosion amount obeys the above rule. In addition, the research indicates that the mechanism and patterns of bank collapse and interaction between bank failure and bed evolution, which could provide a theoretical basis for further study.
