CAJ | 학술논문

阶梯-深潭系统是山区河流广泛分布的重要河床结构，其破坏机理对于认识山区河流稳定性及河床演变具有重要意义。针对单个阶梯-深潭，以关键石块为研究对象，综合考虑上游来水条件、下游冲刷和泥沙环境，建立单个阶梯稳定性的理论模型。基于理论模型，分析弱输沙条件下阶梯破坏的临界条件和失稳机制。结果表明：（1）河道比降、关键石块粒径、来流流量、下游冲刷和互锁作用是弱输沙条件下影响单个阶梯-深潭稳定性的关键因素。（2）来流恒定时阶梯下游冲刷降低阶梯稳定性。阶梯失稳临界流量随冲刷增强而减小，因此水流破坏作用表现为阶梯下游坡脚冲刷降低失稳临界流量，同时来流增加超过临界流量导致破坏。（3）互锁作用可有效提升阶梯稳定性，并在阶梯坡脚冲刷程度较大时明显提升失稳临界流量，这是阶梯在一般洪水中维持稳定的方式。
계제-심담계통시산구하류엄범분포적중요하상결구，기파배궤리대우인식산구하류은정성급하상연변구유중요의의。침대단개계제-심담，이관건석괴위연구대상，종합고필상유래수조건、하유충쇄화니사배경，건립단개계제은정성적이론모형。기우이론모형，분석약수사조건하계제파배적림계조건화실은궤제。결과표명：（1）하도비강、관건석괴립경、래류류량、하유충쇄화호쇄작용시약수사조건하영향단개계제-심담은정성적관건인소。（2）래류항정시계제하유충쇄강저계제은정성。계제실은림계류량수충쇄증강이감소，인차수류파배작용표현위계제하유파각충쇄강저실은림계류량，동시래류증가초과림계류량도치파배。（3）호쇄작용가유효제승계제은정성，병재계제파각충쇄정도교대시명현제승실은림계류량，저시계제재일반홍수중유지은정적방식。
Step-pool system is one of the most important and widespread bed forms in mountain rivers. The failure mechanism of step-pools, although poorly understood, plays a significant role on the stability and fluvial process of mountain river bed. Combined with effects of water discharge, downstream scour of the step and sediment environment,the forces of the keystone in step-pool formation are schemed and ana?lyzed so as to advance a new theoretical model for individual step-pool stability. The model illustrates that channel gradient, keystone diameter, discharge, downstream scour angle and interlocking effect are the key factors that influence the stability. Downstream scour reduces step-pool stability if the discharge remains constant and bed load transport remains low. With stronger scour, critical discharge for failure becomes smaller. Therefore, strong flow breaches the step because the discharge surpasses the critical discharge low?ered by downstream scour. Step-pool stability can be largely strengthened by interlocking effect, especially if downstream scour angle is large,which is a self-protection mechanism for step-pool system.