长江堤防防渗墙对堤内地下水位的影响分析

Influence of cut-off wall in Changjiang dike on ground water level at its inside aera

为了解防渗墙对堤内地下水位的影响,对长江重要堤防隐蔽工程近3年的安全监测资料进行了综合分析,分析结果表明:悬挂式防渗墙对堤内地下水位没有造成明显的影响,不会造成或加剧堤内的滞害。半封闭式、全封闭式防渗墙对堤内200m范围内的地下水位的影响明显,主要表现为,在汛期,布置防渗墙部位堤内的地下水位明显低于没有布置防渗墙部位堤内地下水位,有利于防治和减轻滞害;枯水季节,这一情况与之相反。布置半封闭式防渗墙部位堤内地下水位的变化较外江水位的变化滞后7～15d。防渗墙两端100～200m部位存在比较明显的绕渗现象。

For understanding the influence of cut?off wall on ground water level of dike inside, a synthetic analysis about safety monitoring information from key dyke stretch in recent 3 years is performed. The results are represented as follows: The hanging cut?off wall would not cause obvious effect on ground water level and delayed disaster inside the dike, but the semi?clsoed and closed cut?off walls would create distinct influence on ground water level in the extent of 200 m of dike inside; In flood season, the ground water level of dike inside with cut?off wall is obviously lower than that without it, and it would be benifit to decrease delayed disaster; In dry season, the state is opposite to that in flood season. The changes of ground water level inside a cut?off wall would be delayed 7～15 days than that of river level, and there exists obvious circumfluene phenomenon in the domain of 100～200 m off both ends of a cut?off wall.