新干航电枢纽工程右岸浸没评价与控制

Immersion assessment and control of the right bank of Xingan Navigation and Power Junction

为预测赣江新干航电枢纽工程库区浸没范围和程度,以库区右岸为例,建立新干航电枢纽工程右岸浸没评价的地下水三维非稳定流有限元渗流模型,模拟预测在多年平均水文条件下,库区蓄水后浸没程度及范围,并对比布设防渗墙和防渗墙与减压井联合布设对计算区的浸没控制效果。结果表明:无防渗措施工况下坝址下游发生渗漏型浸没,坝址上游发生顶托型浸没,在坝址处形成浸没程度过渡带;防渗墙能够延缓浸没发生,但在275 d后仍然发生严重浸没现象,不能满足设计要求,故采用防渗墙和减压井相联合的工程措施,能够有效控制计算区浸没范围达到控制浸没要求,且防渗墙能够大幅度减小减压井排水量。

In order to predicate the immersion range and degree of the Xingan Navigation and Power Junction on the Xingan section of Ganjiang River,taking the right bank of reservoir as an example,a numerical model of threedimensional transient flow based on the finite element method was established for the predication and assessment of immersion range and degree of the right bank of Xingan reservoir. Furthermore,based on the simulation model,a comparison was made for the effectiveness of immersion control with two operation conditions including the impervious wall and relief well combined with the impervious wall.When there is no operating conditions,the results indicate that the leakage immersion occurred at the downstream of dam site,the backwater immersion occurred at the upstream,and the immersed transition zone is formed at the dam site. Although the impervious wall can retard the immersion process,serious phenomenon of groundwater immersion will emerge after 275 days. The assessmentresults showed that the measure combining impervious wall and relief well can effectively control the immersion range,and the impervious wall can greatly reduce the displacement of the relief well. The findings can provide scientific basis for the immersion evaluation and controlling of the Xingan Navigation and Power Junction.