三峡工程蓄水运用以来荆江河段河岸稳定性初步研究

根据实测资料分析了三峡工程蓄水运用以来荆江河段水沙输移变化,河道冲淤变化以及典型险工段近岸坡度变化等,并在此基础上对其河岸稳定性进行了初步研究,结果表明,三峡水库蓄水运用以来,坝下游河段来沙量大幅度减少,荆江河段普遍发生冲刷,部分地段近岸河床的水下岸坡冲刷变陡,河岸稳定出现了不同程度的隐患,局部河段甚至发生了崩岸险情,已影响防洪安全与河势稳定等;建议加强荆江险工段的监测,对已发生的崩岸险情进行及时治理,对以往护岸工程的薄弱地段或可能发生崩岸险情的地段需及时加固守护;建议加强三峡工程运用后荆江河道演变与治理方面的研究.

Preliminary study on bank stability in Jingjiang reach since operation of the Three Gorges Project

According to observed data,this paper analyzed the change of flow and sediment condition,the change of river erosion and deposition,the change of bank slope at some typical control works,and the riverbank stability after operation of the Three Gorges Project(TGP).The results show that:(1) The incoming sediment load in lower reach of the dam decreased drastically after storage of the TGP,and this leads to prevalent scouring in Jingjiang reach;(2) The slope of underwater bank at some sections became steeper which may cause problem to the stability of the existing bank.In reality,the bank collapse in some places has happened and already affected flood control safety and river regime stability.To alleviate current situation,the following suggestions were put forward:(1) The monitoring to control works in Jingjiang reach should be enhanced,the happened bank collapse should be treated,and the weak parts of bank protection works should be reinforced in time;(2) More attention to the effect of operation of the TGP on the riverbank stability in Jingjiang reach and the study of corresponding treatment countermeasures is needed.